Handloads so good they keyhole!

[STAMarine]

Gents, I don't know if it is possible to unf**k me, but I'm going to see if you all can give it a shot.

I've spent a lot of time over the last year learning the ins and outs of reloading in mostly .223, 9mm, and .45 ACP. I thought I was ready to move up to match ammo reloading, but obviously this isn't the case.

I've spent all summer doing ladder tests and working up a .308 match load. My final load was pretty close to Newberry's recommended load for finding the high node. I was getting good groups around both his low and high node recommendations, but I loaded twenty-five rounds of the hotter one for velocity.

Now, I'm a decent shooter with a good deal of precision shooting in the military and after on my own. I can shoot sub MOA consistently, and like most others, better on my good days. I can't tell you what my rifle is capable of because it shoots better than I do. I have shot sub half minute groups on those rare days when I'm on my game. It is a McMillian tac with a 24" barrel. I don't have my log book with me, but it has a little over 2,200 logged round through it. I have been shooting factory ammo also during the time I have been doing my workups and there has been no drop in accuracy. It's not the shooter or the rifle. That being said, I am not a competition or a bench shooter, and I'm not good enough to be. I'm looking for ammo that is as good or a little better than Federal GMM, cheaper that GMM, and since I have been stockpiling components, more available to me than GMM. I'm not doing neck turning and such to get bench rest accuracy because that's not my intended purpose, and I couldn't utilize that level of accuracy even if I could reload that well.

My load is Sierra 175gr Mk, LC brass once fired through my rifle only, 43gr of 4064, Federal match primers, neck sized, and bullet seated with a Forester Ultra seating die.

I was getting a little less than MOA at three hundred for my first ladder and about the same at four for my second. Not great groups, but when this happens I tend to blame myself as having an off day or out of practice. I picked the best load, and loaded up twenty five rounds for my first trip to my home range for a full shooting session. I shot my first group at 850. Nothing. I thought I had really screwed up my wind call so I shot a second group and again, nothing. I then shot a decent group with factory ammo to test my rifle. When I went to check the last group I notice two holes in the bottom and middle of my target board I hadn't noticed the first two times I checked, both perfect keyholes. Now, I was using a 8x4' political sign as my target backer. This was a three foot group of two keyholes!

No impact no idea on where I should go from here. I've researched, read, asked, and haven't been able to put what I've learned into practice.

All that I can offer is perceived recoil was lighter on my loads than the GMM ammo I used to check my rifle.

Where do I go from here?

[Bimmer]

WAG here... You're shooting longish 175s at 850yds, and the recoil is less than "normal," so... I'm guessing they're spinning too slowly and destabilizing.

What's the twist of your barrel?

[rcoodyar15]

Gents, I don't know if it is possible to unf**k me, but I'm going to see if you all can give it a shot.

I've spent a lot of time over the last year learning the ins and outs of reloading in mostly .223, 9mm, and .45 ACP. I thought I was ready to move up to match ammo reloading, but obviously this isn't the case.

I've spent all summer doing ladder tests and working up a .308 match load. My final load was pretty close to Newberry's recommended load for finding the high node. I was getting good groups around both his low and high node recommendations, but I loaded twenty-five rounds of the hotter one for velocity.

Now, I'm a decent shooter with a good deal of precision shooting in the military and after on my own. I can shoot sub MOA consistently, and like most others, better on my good days. I can't tell you what my rifle is capable of because it shoots better than I do. I have shot sub half minute groups on those rare days when I'm on my game. It is a McMillian tac with a 24" barrel. I don't have my log book with me, but it has a little over 2,200 logged round through it. I have been shooting factory ammo also during the time I have been doing my workups and there has been no drop in accuracy. It's not the shooter or the rifle. That being said, I am not a competition or a bench shooter, and I'm not good enough to be. I'm looking for ammo that is as good or a little better than Federal GMM, cheaper that GMM, and since I have been stockpiling components, more available to me than GMM. I'm not doing neck turning and such to get bench rest accuracy because that's not my intended purpose, and I couldn't utilize that level of accuracy even if I could reload that well.

My load is Sierra 175gr Mk, LC brass once fired through my rifle only, 43gr of 4064, Federal match primers, neck sized, and bullet seated with a Forester Ultra seating die.

I was getting a little less than MOA at three hundred for my first ladder and about the same at four for my second. Not great groups, but when this happens I tend to blame myself as having an off day or out of practice. I picked the best load, and loaded up twenty five rounds for my first trip to my home range for a full shooting session. I shot my first group at 850. Nothing. I thought I had really screwed up my wind call so I shot a second group and again, nothing. I then shot a decent group with factory ammo to test my rifle. When I went to check the last group I notice two holes in the bottom and middle of my target board I hadn't noticed the first two times I checked, both perfect keyholes. Now, I was using a 8x4' political sign as my target backer. This was a three foot group of two keyholes!

No impact no idea on where I should go from here. I've researched, read, asked, and haven't been able to put what I've learned into practice.

All that I can offer is perceived recoil was lighter on my loads than the GMM ammo I used to check my rifle.

Where do I go from here?

What twist is your barrel? 1:11 maybe even 1:10 is really what you need with that bullet and range

Chronograph those loads and plug them into a ballistic calculator. My suspicion is that your velocities are low and your bullets are going subsonic and are not stable.

[texasgunhand]

Edit, sorry didn't see that it wasn't making keyholes at 400 but at 850, I would still drop the grain down to the 160ish range. But thats just my preference. I take it that it wasn't doing it with the factory ammo at 850? Then I would also say its running outa power and destabilizing if your twist rate is good for that heavy a bullet.

[IraqVet1982]

TAC308's are 1:10... I'd pull a bullet and check the charge to confirm you're throwing a consistent charge... Other issue might be that the bullets aren't seating concentrically... Might also want to chamber a round and eject it to make sure nothing funky is happening.

[STAMarine]

I think my twist is 1:10. It was actually a gift from my dad when I graduated sniper school. He's passed away and I know the paperwork used to be in his office but I can't seem to locate it. However, it doesn't have any problem stabalizing Federal 175's.

I thought about the bullet going subsonic, but with that much powder should that be a concern at 850? I know a chronograph would help, but I don't have one.

IraqVet, when I chamber a round and eject, what should I be looking for?

[rcoodyar15]

Edit, sorry didn't see that it wasn't making keyholes at 400 but at 850, I would still drop the grain down to the 160ish range. But thats just my preference. I take it that it wasn't doing it with the factory ammo at 850? Then I would also say its running outa power and destabilizing if your twist rate is good for that heavy a bullet.But

the heavier bullet is the way to go at the longer ranges

the 168 match king is a great performer up to 600 yrs. In fact that it what it was designed for. but it has a reputation for doing exactly what you are seeing at the longer ranges and subsonic velocities

[STAMarine]

I actually started out using the 168's in the Federal loadings. I had better accuracy at shorter distances than the 175's, but I was getting better groups with the 175's at farther ranges. I guess it was just bucking wind better.

Maybe I am going subsonic and need to increase my charge weight to stay supersonic, but that will throw out my data from my ladder tests. I'm not at max load and I'm not showing pressure signs, so I have room for more velocity. So, what's the scientific way to get my true long range load since I have tried the ladder work ups and failed?

[Bimmer]

So, what's the scientific way to get my true long range load since I have tried the ladder work ups and failed?


300 Win Mag?

[IraqVet1982]

I think my twist is 1:10. It was actually a gift from my dad when I graduated sniper school. He's passed away and I know the paperwork used to be in his office but I can't seem to locate it. However, it doesn't have any problem stabalizing Federal 175's.

I thought about the bullet going subsonic, but with that much powder should that be a concern at 850? I know a chronograph would help, but I don't have one.

IraqVet, when I chamber a round and eject, what should I be looking for?
Setback. Measure the OAL before and after, if its the same that can be ruled out.

[STAMarine]

Setback. Measure the OAL before and after, if its the same that can be ruled out.

Good deal. I have a Hornady OAL gauge so I can do that.

[rcoodyar15]

I actually started out using the 168's in the Federal loadings. I had better accuracy at shorter distances than the 175's, but I was getting better groups with the 175's at farther ranges. I guess it was just bucking wind better.

Maybe I am going subsonic and need to increase my charge weight to stay supersonic, but that will throw out my data from my ladder tests. I'm not at max load and I'm not showing pressure signs, so I have room for more velocity. So, what's the scientific way to get my true long range load since I have tried the ladder work ups and failed?


What I am going to say will probably bring out lots of disagreement but this is what I would do.

First look at the load data in the loading manual. I am looking now and max is 42.8 gr 4064 41.7 gr varget 41.5 gr 4895 etc.

now you know that these manuals are conservative. You know what pressure signs are. You need to find your max load and work down from there. If you weren't doing the long range thing but the accuracy thing then my advice would be opposite.

I would pick a couple or three powders and start mid loads and load up to well over max at 0.5 gr increments with each. You can load just one round or three rounds of each powder and powder charge. color the bullet from the olgive to the tip with a sharpy. each load a different color. Use a white sheet of paper with an aiming point on it as a target. use a different target for each powder. shoot them, the further the better, stopping when you start getting pressure signs. You found your max. then gather up your targets and see what colors grouped together. That is the load to work on.

For long range most likely you are going to be using loads at the edge of max. Some people can just lob them in with a normal load but it isn't common.

It would be nice to find someone with a croney. You will need the velocity of your chosen load eventually

[TomMcC]

You might consider a worn throat also. With 2200 rounds down the pipe and longish BT bullets you might be right on the edge of a too worn barrel.

[STAMarine]

What I am going to say will probably bring out lots of disagreement but this is what I would do.

First look at the load data in the loading manual. I am looking now and max is 42.8 gr 4064 41.7 gr varget 41.5 gr 4895 etc.

now you know that these manuals are conservative. You know what pressure signs are. You need to find your max load and work down from there. If you weren't doing the long range thing but the accuracy thing then my advice would be opposite.

I would pick a couple or three powders and start mid loads and load up to well over max at 0.5 gr increments with each. You can load just one round or three rounds of each powder and powder charge. color the bullet from the olgive to the tip with a sharpy. each load a different color. Use a white sheet of paper with an aiming point on it as a target. use a different target for each powder. shoot them, the further the better, stopping when you start getting pressure signs. You found your max. then gather up your targets and see what colors grouped together. That is the load to work on.

For long range most likely you are going to be using loads at the edge of max. Some people can just lob them in with a normal load but it isn't common.

It would be nice to find someone with a croney. You will need the velocity of your chosen load eventually

I need to look it up but you're correct on the Sierra max but I'm below the posted max on IMRs website. I still have a little way to go, especially considering the lack of recoil and zero pressure signs. So have I been going for pure accuracy at short range with the ladder tests and longer range requres pushing max? Will my accuracy still be around MOA at max possibly. I know anything is better than what I have now but minute of man is better than minute of barn.

[STAMarine]

You might consider a worn throat also. With 2200 rounds down the pipe and longish BT bullets you might be right on the edge of a too worn barrel.

Holy crap! I thought .308 was good for like 6,000 to 10,000 rounds and it was something like the 6.5's that burnt out that quick. I sure wish I had headspace numbers from when it was new.

[Leaveammoforme]

Using .496 as the ballistic coefficient on your 175's and generic weather data...

To go trans-sonic at 800 yards your muzzle velocity would have to be 2100 FPS.

Lack of recoil tells us you have a light load, but 2100 FPS light? Who knows. Got to get a chronograph.

[rcoodyar15]

Holy crap! I thought .308 was good for like 6,000 to 10,000 rounds and it was something like the 6.5's that burnt out that quick. I sure wish I had headspace numbers from when it was new.


That barrel still has plenty of life left in it. The beauty of a .308.

Yes if you want to shoot long range you need to find your max. It will be considerably above what is in the book. You are going to have to try different powders too. I like varget and RE-15 but then I don't shoot long range with my .308. It is my hunting rifle and I shoot the berger 168 VLD. For example berger says my max is 42.5 gr varget Hogdon says my max is 46 gr I use 44 gr.

For your 175 gr 4064 hogdon says your max is 45.6 gr

[rcoodyar15]

After you find the powder and charge that your rifle likes then you can start playing with COL's. the target below has five groups with the seating depth changed 0.01 for each group. With bergers it really makes a difference. MK's more forgiving.

34401

[texasgunhand]

As far as cronys,i asked a bit ago becouse I need one also and the compitition electronic seemed to be well liked,midway has it for $99 last time I checked. I have had really good luck with them,ordered a bunch of stuff and never had a problem.

I just looked at some factory .308 ammo (hertures,,,sorry not spelled correctly)my cousin had shot and the primers were flat as could be, his reloads were not. So I wouldn't be scared to increase your charge a bit till your find max. The books are not going to publish data they could get sued over. Just step up a little bit at a time.

Thanks for the info on the 160gr bullets,makes sense, I don't have a place to shoot over 500 yards so I've never tryed.

[texasgunhand]

After you find the powder and charge that your rifle likes then you can start playing with COL's. the target below has five groups with the seating depth changed 0.01 for each group. With bergers it really makes a difference. MK's more forgiving.

34401

Nice,really shows how much COAL can make a difference. Finding that sweet spot really shows.

[sinister]

My load is Sierra 175gr Mk, LC brass once fired through my rifle only, 43gr of 4064, Federal match primers, neck sized, and bullet seated with a Forester Ultra seating die.

Whose neck size die are you using and what does it size your external neck dimension to? Are you trimming your cases to length?

[STAMarine]

After you find the powder and charge that your rifle likes then you can start playing with COL's. the target below has five groups with the seating depth changed 0.01 for each group. With bergers it really makes a difference. MK's more forgiving.

34401
Hopefully I can find a good charge but I'm still aways from adjusting COL. That's why I started with the MK's instead of Bergers because I knew I'd need all the leeway I could get!

[STAMarine]

That barrel still has plenty of life left in it. The beauty of a .308.

Yes if you want to shoot long range you need to find your max. It will be considerably above what is in the book. You are going to have to try different powders too. I like varget and RE-15 but then I don't shoot long range with my .308. It is my hunting rifle and I shoot the berger 168 VLD. For example berger says my max is 42.5 gr varget Hogdon says my max is 46 gr I use 44 gr.

For your 175 gr 4064 hogdon says your max is 45.6 gr
Looks like I'll have to start all over again. Your statement about barrel life calmed me down a little bit. I sure don't want to have to do that yet.

[markm]

That's why I started with the MK's instead of Bergers because I knew I'd need all the leeway I could get!

MKs are ridiculously forgiving. Some of the psuedo match ammo makers get away with like .010" runout, crappy brass, and the rounds fired in long leade barrels with no magnificent problems like this. There's something big going on here.

[STAMarine]

Whose neck size die are you using and what does it size your external neck dimension to? Are you trimming your cases to length?

I'm using a Lee neck sizer. Outside dimenw is .338. I haven't done any trimming on my fire formed brass because length is still below max. Should I trim anyway?

[STAMarine]

MKs are ridiculously forgiving. Some of the psuedo match ammo makers get away with like .010" runout, crappy brass, and the rounds fired in long leade barrels with no magnificent problems like this. There's something big going on here.

This doesn't bode well for my efforts. Your posts are ones that I follow and the words "something big is going on here" isn't something one wants to hear.:shout:

[rcoodyar15]

I'm using a Lee neck sizer. Outside dimenw is .338. I haven't done any trimming on my fire formed brass because length is still below max. Should I trim anyway?

Had to get up at 2AM for a concrete pour this morning. Such is my life
I don't trim brass till it Is long. Short brass suxMon

I did think of something last night. Barrel has over 2000 rounds through it. Have you ever used a copper remover like Sweets or Montana extreme?

[rcoodyar15]

I'm using a Lee neck sizer. Outside dimenw is .338. I haven't done any trimming on my fire formed brass because length is still below max. Should I trim anyway?

Had to get up at 2AM for a concrete pour this morning. Such is my life

I don't trim brass till it Is long. Short brass sux

I did think of something last night. Barrel has over 2000 rounds through it. Have you ever used a copper remover like Sweets or Montana extreme?

Try some Hornady Amax 178. Some guns like different bullets. Mine likes the Amax.

I use the lee collet neck sizer with great success

[rcoodyar15]

This doesn't bode well for my efforts. Your posts are ones that I follow and the words "something big is going on here" isn't something one wants to hear.:shout:


I would not worry. It is something simple. Your shorter range groups are too good for something big to be going on.

[opsoff1]

First off, all the rumblings and musings about COL and trimming brass and copper in the bore is completely irrelevant. None of that is going to produce a destabilized round. Your load of 43.0 is a stout load - that isn't any sleeper. Your perceived recoil difference is a starting point though. FGMM isn't a hot load - so to have a 175 w/ that much 4064 behind it feel less tells me something is wrong in your powder tossing op.
A few questions:
1. How did you throw your charges? Hand weigh each? Uniflow or similar? Chargemaster?
2. Is the scale calibrated w/ known/verified check weights?
3. Powder...how old? Does it smell right (should have an ether type odor to it)
4. Is it a new can you just opened or is it something you have been using with other loads?
5. Measure the diameter of the bullets - they should be .3082 max. If they are under .308, i.e. .306 or .307 - thats a problem... Sierra has pretty good QC, but sometimes an odd batch gets by - rare - but it happens.

The rifle issues, and based on the fact that FGMM shoots fine should be the last of your concerns. 1/10, 1/11 or 1/12 will stabilize the 175. I shoot old long BT SMK180's out of a 1/12 Palma rifle and they fly very straight.
A 308 that is driven hard will give you faithful service past 6K - mild loads and no sustained shooting (read rapid fire stuff) may get you up to 8K or more. Everything here points to an ammunition issue.

I would first start by pulling the bullets on a few of the rounds that are giving you problems - measure the powder. From there I would load another 5 rds using the exact same components and procedures as you have been doing.
Shoot these at a range where they will be on paper consistently. (300 yds maybe?) then with known ammo of good quality (i.e. FGM 168's) - shoot another group at the same yardage with all the same settings & zeros. My guess is you are going to see a measurable difference in elevation. If your 175 hand load is way lower - and you have truly 43 gr of 4064 in there - thats a powder issue.

I'm with MarkM on this - something big going on here and I'm pretty sure it isn't the rifle.
Start with the basics and change one component at a time to isolate the problem.
Standing by to assist.

[STAMarine]

Had to get up at 2AM for a concrete pour this morning. Such is my life
I don't trim brass till it Is long. Short brass suxMon

I did think of something last night. Barrel has over 2000 rounds through it. Have you ever used a copper remover like Sweets or Montana extreme?

I did clean it with Hoppes Elite Copper remover after I thought I was getting a little less accuracy. Accuracy immediately went down but has started to tighten again after about a hundred and fifty rounds. It was the first time I had used a copper cleaner.

[STAMarine]

First off, all the rumblings and musings about COL and trimming brass is completely irrelevant. None of that is going to produce a destabilized round. Your load of 43.0 is a stout load - that isn't any sleeper. Your perceived recoil difference is a starting point though. FGMM isn't a hot load - so to have a 175 w/ that much 4064 behind it feel less tells me something is wrong in your powder tossing op.
A few questions:
1. How did you throw your charges? Hand weigh each? Uniflow or similar? Chargemaster?
2. Is the scale calibrated w/ known/verified check weights?
3. Powder...how old? Does it smell right (should have an ether type odor to it)
4. Is it a new can you just opened or is it something you have been using with other loads?
5. Measure the diameter of the bullets - they should be .3082 max. If they are under .308, i.e. .306 or .307 - thats a problem... SIerra has pretty good QC, but sometimes an odd batch gets by - rare - but it happens.

The rifle issues, and based on the fact that FGMM shoots fine should be the last of your concerns. 1 1/10, 1/11 or 1/12 will stabilize the 175. I shoot old long BT SMK180's out of a 1/12 Palma rifle and they fly very straight.
A 308 that is driven hard will give you faithful service past 6K - mild loads and no sustainned shooting (read rapid fire stuff) may get you up to 8K or more. Everything here points to an ammunition issue.

I would first start by pulling the bullets on a few of the rounds that are giving you problems - measure the powder. From there I would load another 5 rds using the exact same components and procedures as you have been doing.
Shoot these at a range where they will be on paper consistently. (300 maybe) then with known ammo of good quality - shoot another group at the same yardage with all the same settings & zeros. My guess is you are going to see a measurable difference in elevation. If your 175 hand load is way lower - and you have truly 43 gr of 4064 in there - thats a powder issue.

I'm with MarkM on this - something big going on here and I'm pretty sure it isn't the rifle.
Start with the basics and change one component at a time to isolate the problem.
Standing by to assist.

I'm using a Hornady LNL Bench scale. I calibrate before each reloading session and weigh each charge by hand. I'll check the lot date of the powder when I get home from work, but it was only purchased a couple of months ago. I haven't used 4064 for anything else. This rifle is the only .308 I load for.

I'll grab a puller on the way home but it'll be Saturday before I can head to the range. I'll load up a few more in the meantime.

I appreciate you all helping and standing by.

[TomMcC]

I didn't mean to imply that your barrel is toast at 2200 rounds. I have seen barrels stop shooting BT bullets because of a worn throat though. Of course you already know that heavy BT need a bit more stabilization than lighter ones, so any change in the throat might have an effect. You'd need a bore scope to really check this, which most of us don't have. It could just be something as simple as 2 defective bullets. Does your rifle do this regularly? I didn't see that in your posts. When you throw charges, do you inspect each case in the block to make sure all the charges look even? Just some ideas.

[STAMarine]

I didn't mean to imply that your barrel is toast at 2200 rounds. I have seen barrels stop shooting BT bullets because of a worn throat though. Of course you already know that heavy BT need a bit more stabilization than lighter ones, so any change in the throat might have an effect. You'd need a bore scope to really check this, which most of us don't have. It could just be something as simple as 2 defective bullets. Does your rifle do this regularly? I didn't see that in your posts. When you throw charges, do you inspect each case in the block to make sure all the charges look even? Just some ideas.

No sweat, I knew what your meant. I know that accuracy degrades over time in any barrel, and while it's not big deal in say an M-4, precision can drop off to a point that accuracy is no longer acceptable in an otherwise serviceable rifle. I didn't say how many rounds I shot intentionally because to tell you the truth, I knew people would be asking why I kept on shooting expecting a different result. Truthfully, I shot fifteen rounds and low and behold, the result was the same. Only two keyholes were on paper, about three feet apart.

They all looked even in the block. I know it would be hard to tell the difference between a grain or two though. How much things are screwed up with my rounds just boggles the mind. Hell, my massed produced practice rounds that I didn't put near as much care into are better than my match rounds with quality components! By far!

I'm going to take the advice of posters and see if I can get a better result to post back.

[TheBelly]

Lots of things to play with here, and you can get lost trying to chase a bunch of details. The issue of keyholing is troublesome, but I agree that stabilization isn't the issue.

BRASS: cleaned, annealed, sized, trimmed, chamfered, de-burred? When was the last time it has been FL sized, with a slight shoulder bump? Does the brass have consistent weight from piece to piece?

POWDER: IMR (non-enduron) powders have a pretty wide variance in how they act at temperature. I recommend something from Hodgdon's extreme line, maybe Varget.

PRIMERS: What kind? I've seen primers cause velocity spikes that throw things off.

BULLETS: Someone recommended measuring the diameter. That is very good advice. I'd also check the base-to-ogive of the bullet itself. You are more likely to find a variance that matters in the measurement.


As with all handloading (with the goal of accuracy), consistency is the key to the magical kingdom. Eliminate variables wherever possible.

My standard load is LCLR brass, 43.0 gr Varget, Fed 210 primer, 175 SMK loaded to 2.279" base to ogive.

[rcoodyar15]

Lots of things to play with here, and you can get lost trying to chase a bunch of details. The issue of keyholing is troublesome, but I agree that stabilization isn't the issue.

BRASS: cleaned, annealed, sized, trimmed, chamfered, de-burred? When was the last time it has been FL sized, with a slight shoulder bump? Does the brass have consistent weight from piece to piece?

POWDER: IMR (non-enduron) powders have a pretty wide variance in how they act at temperature. I recommend something from Hodgdon's extreme line, maybe Varget.

PRIMERS: What kind? I've seen primers cause velocity spikes that throw things off.

BULLETS: Someone recommended measuring the diameter. That is very good advice. I'd also check the base-to-ogive of the bullet itself. You are more likely to find a variance that matters in the measurement.


As with all handloading (with the goal of accuracy), consistency is the key to the magical kingdom. Eliminate variables wherever possible.

My standard load is LCLR brass, 43.0 gr Varget, Fed 210 primer, 175 SMK loaded to 2.279" base to ogive.


so that is not a mag length round. you are into are very close to the lands

[lysander]

...The issue of keyholing is troublesome, but I agree that stabilization isn't the issue....
Actually, stabilization is the key issue.

The bullets would not be key-holing if they were properly stabilized. Why they are not properly stabilized or what is destabilizing them is the mystery...

Do you have a muzzle device? Have you checked it? Have you checked the rifle for any problems, damage, et cetera?

Do you have (or know somebody that has) another rifle in the same caliber to see if this ammo also exhibits this odd behavior in it?

[T2C]

I went to the IMR website and if I read the recipe correctly you should be pushing about 2,580 fps with your reload. Federal 175g GMM is rated at 2600 fps, so your powder charge should be in the neighborhood. I like to load 175's at 2,550 for my .308 loads.

Something I learned developing 30-06 loads for my Garand is that I have to make sure the case lube is removed from inside the case mouth before dropping a powder charge and seating the bullet. Case lube will affect neck tension. I loaded some 150g rounds for my Garand without wiping the case lube from inside the case mouth and muzzle velocity was reduced. I also noticed that if I don't wipe the case lube out of the inside of the neck and I load 150g and lighter bullets, I would have an occasional hang fire. An old school High Power shooter told me the hang fires were due to reduced neck tension.

I haven't run into your issue with my .308 bolt action 1,000 yard rifle, but I always made certain the inside of the case neck was dry before reloading prepped brass. If nothing else, it has helped me cut down on flyers at ranges beyond 300 yards.

If you pick up a 1/4" piece of dowel rod, 2 paper clamps and a caliper you can measure maximum C.O.L. where the projectile will touch the lands. If you pick up a bullet comparator you can measure C.O.L. at the ogive and back off your C.O.L. 0.010", which is a good starting point.

[opsoff1]

Another issue to check - especially if you can pull some loaded rounds apart is the condition of the bullet itself. I am assuming you are shooting IMR4064 (a very good powder for this BTW). 43.0 is as I said earlier, a fairly stout load. The case / powder charge combo should produce a charge density of above 97%, maybe even above 100% (compressed charge). You didn't list your OAL or where you are loading in relation to the lands - If you have a short throat and are loading to fit that - i.e. .010 or .020 off the lands, you would be pushing that bullet deep into the case. This gets into some tricky territory. Long bullets in short throated barrels can move the boat tail deep into the powder column. The pressure during ignition can and will collapse the boat tail or distort it. Once this happens, all bets are off as far as flying straight or maintaining some semblance of stability. This pressure can invoke a core shift (forward) and once that occurs, all you are doing is burning powder.

At 43.0 of IMR 4064, you should be in the neighborhood of 2600 fps. WIth that bullet, at 850yds - you should be printing easily decernable groups on target - all day long.

What is the OAL of your cartidge?
WHere is the bullet in relation to the lands?

Also - highly doubtful, but check the # on the box of SMK's...should be 2275, not 1975.

[rcoodyar15]

Actually, stabilization is the key issue.

The bullets would not be key-holing if they were properly stabilized. Why they are not properly stabilized or what is destabilizing them is the mystery...

Do you have a muzzle device? Have you checked it? Have you checked the rifle for any problems, damage, et cetera?

Do you have (or know somebody that has) another rifle in the same caliber to see if this ammo also exhibits this odd behavior in it?

yeap

My feeling is the rounds are transonic or subsonic so they lose stability.

I suspect that the charge weight is not what he thinks it is. Need another scale to check the loads with and a crony to check velocities.

same gun shoots well with store bought ammo and at shorter ranges with the same loads

[TheBelly]

so that is not a mag length round. you are into are very close to the lands

My gun is very well used. I use AICS-PATTERNED mags, so mine are loaded out to about 2.86" oal.

[TheBelly]

Actually, stabilization is the key issue.

The bullets would not be key-holing if they were properly stabilized. Why they are not properly stabilized or what is destabilizing them is the mystery...

Do you have a muzzle device? Have you checked it? Have you checked the rifle for any problems, damage, et cetera?

Do you have (or know somebody that has) another rifle in the same caliber to see if this ammo also exhibits this odd behavior in it?


If the bullet wasn't stabilized, it would keyhole at 300 and 400. it's hard to keyhole a sub-MOA group. OP stated that he noticed the keyhole issue at farther distances.

I'm betting that the bullet is hitting trans-sonic about the 830 yard mark and is just having hard time STAYING stabilized.

My recommendation stands: Try a slower powder. I'll add that you should give the powder a chance by loading the bullet out a bit. get back some more room in that case if you can.

[rjacobs]

My feeling is the rounds are transonic or subsonic so they lose stability.


175 SMK's dont do this. They were SPECIFICALLY designed to NOT do this because thats the issue the 168's have. 168's will reach out to whatever you can push them to, thats not the issue with them, its the transonic tumble that kills them. I know a guy that burns 168's out of a 300win mag out to 1500+. He loves em, I think its a barrel burner. Ive shot 175's in 308 out to 1200, where they were FAR below subsonic and all they did was stick in the plywood we shot them at.


To the OP: you sure you are shooting 175's? Not saying you arent loading from a box that says "175g MATCH", but that the bullets are in fact, 175g SMK's and not a factory **** up of 168's?

The other thing to check for as has been mentioned, pull a round and inspect the bullet. Do you chamfer the case mouth at all? If you shave copper you will have accuracy and possibly stability issue. 308 has fairly thick case mouth walls and without a healthy chamfer will shave a noticeable amount of copper from the jacket.

[STAMarine]

Well guys, thanks to suggestions to pull the bullet and see what is going on I have found the problem. I stopped after work and bought a bullet puller and started disassembly as soon as I got home. Weights were consistently off by around TEN FULL GRAINS on each and every round. It's time to get a new scale.

I appreciate all your help guys. Sorry it took so long for such a simple answer, but I wouldn't have even pulled the bullets unless I posted.

[rjacobs]

Well guys, thanks to suggestions to pull the bullet and see what is going on I have found the problem. I stopped after work and bought a bullet puller and started disassembly as soon as I got home. Weights were consistently off by around TEN FULL GRAINS on each and every round. It's time to get a new scale.


WOW yea that will do it. Wonder if you were tumbling in flight(I doubt it) or if those were ricochets after your bullet hit the ground well short of the target.

[rcoodyar15]

Well guys, thanks to suggestions to pull the bullet and see what is going on I have found the problem. I stopped after work and bought a bullet puller and started disassembly as soon as I got home. Weights were consistently off by around TEN FULL GRAINS on each and every round. It's time to get a new scale.

I appreciate all your help guys. Sorry it took so long for such a simple answer, but I wouldn't have even pulled the bullets unless I posted.


Glad you got it worked out. See I told you it was something simple!

that is why I have 2 scales on my bench and I still don't trust either one.

never hurts to have one of those old timey beam scales handy. May not be as accurate as a new digital but it sure wouldn't be 10 grs off

[STAMarine]

WOW yea that will do it. Wonder if you were tumbling in flight(I doubt it) or if those were ricochets after your bullet hit the ground well short of the target.

Who knows? I'm just glad my "range" is my own property so I don't have to worry about ricochets or whatever else happened.

[rjacobs]

im still skeptical of the claim of a 175g SMK tumbling when going transonic/subsonic as they are not known to do that(168g SMK's on the other hand ARE known for doing that). They are known to transition through that range very well. Ive shot out to distance where I knew they were subsonic upon impact and never once saw a tumble. Im shooting out of a 10 twist gun as well.

I would lean more towards an impact well short of the target and them ricochet/skipping into the target.

[opsoff1]

im still skeptical of the claim of a 175g SMK tumbling when going transonic/subsonic as they are not known to do that(168g SMK's on the other hand ARE known for doing that). They are known to transition through that range very well. Ive shot out to distance where I knew they were subsonic upon impact and never once saw a tumble. Im shooting out of a 10 twist gun as well.

I would lean more towards an impact well short of the target and them ricochet/skipping into the target.

rjacobs is dead nuts on. Given the significant reduction in velocity, there is no way that: A) They even made it to the target in the air and B) As he stated - the 175s are not known to tumble, and C) Given the fact that 15 rds were fired and only 2 made it on paper - smart money are rounds impacting well short of the target and having a wee bit of luck in that 2 of them skipped / riccocheted on paper.
I also think that the extrapolation of an aproximate MV of 2025 is being very kind. I would not be surprised if the MV was well short of 2K.

[markm]

Weights were consistently off by around TEN FULL GRAINS on each and every round. It's time to get a new scale.

You ought to be able to look into the case when seating a bullet and notice this.