View Full Version : How to tell if a/your barrel likes certain ammo or not...?
Hey,
Obviously when barrel and ammo are compatible tight groups and extreme accuracy are possible under the right conditions.
On the other side, what happens exactly if your barrel does not like certain ammo? Are there certain characteristics to look out for? Is it something that would even be repeatable on different barrels (to use as/for comparision) or is it just not accurate.
Also what are the odds of having inconsistent ammo from a major brand or are they (barrel and ammo) just not compatible? Poi varying in inches every now and then even when aiming at the same spot. IE: Large variances of POI at 50 yards where it shouldnt be as noticable.
Thanks.
Accuracy is what it means when folks refer to a barrel "liking" a particular kind of ammo/bullet. You really notice the difference at longer ranges like 600+yards. If the barrel doesn't "like" the ammo, it won't perform to the potential of the barrel. Lots of factors come into play like bullet weight, powder charge, primers, seating depth, but most of all consistency in the complete loaded cartridge.
Accuracy is what it means when folks refer to a barrel "liking" a particular kind of ammo/bullet. You really notice the difference at longer ranges like 600+yards. If the barrel doesn't "like" the ammo, it won't perform to the potential of the barrel. Lots of factors come into play like bullet weight, powder charge, primers, seating depth, but most of all consistency in the complete loaded cartridge.
Thanks,
So if grouping is not consistent with a certain complete loaded cartridge then it's not compatible.
You mentioned a lot of things come into play but I do not have a good grasp on why some barrel's amy like ammo X while others will not, etc...
Would you mind going more into detail on this or pointing me in the right direction?
Thanks.
There are lots of variables to a successful load combo. Chamber size, barrel length, twist rate to name a few all play into the equasion. Even 2 of the exact part # of a particular rifle can produce different results as far as load combo. The slightest difference in chambers (which is not uncommon) will change the load combo. That's why it's suggested to develop your own recipie when working up loads. Don't assume your buddy's combo will work for your rifle.
It would seriously benefit you to buy a reloading manual & read about load development.
Accuracy depends on so many factors it's difficult to distill it down to something short and sweet. If you're using a chrome lined or other mass produced non match barrel you may not be able to get your groups down to the size where you can tell the difference between operator and equipment. With a stainless or other match grade barrel it becomes easier to distinguish what's causing the variables.
On my match rifles, I can tell if there is a mechanical issue with my groupings. A rifle that always shoots sub MOA that suddenly starts grouping at 1.5" is usually a mechanical issue. It could be as simple a fouling in the barrel. It could be a loose part, or it could be ammo related. I saw a guy testing a reduced course load for his AR15 and all yo had to do is look at the groups to see what the 'magic' load was. He had five groups ranging in size from about 1.5" to 3\4", and one group that was a clover leaf bug hole.
Just this weekend I found out my barrel dont like a certain ammo, and it was only at 100 yards...4 inch with a couple fliers. Changed ammo and was shooting clover leafs the rest of the day. They were my new handloads and I was trying something new...guess it didnt work :mad:
I'll explain what I am experiencing. This may help you guys understand my question in a clearer light or at least relate to it.
Shot some 75gr BHTP match ammo and achieved a 5 shot group of .7 MOA, followed by 3 shots that would have yielded an even better group then the next two rounds fly left a whole inch. As I went through the box, the trend continued.
Luckily I had another box of ammo, some 60gr V-Max ammo and I was able to maintain groups around 1 MOA.
Then I went back to the 75 gr and got the same results.
Although the 60gr V-Max did not make a better group it was consistent, while the 75gr BHTP had a flash of brilliance it was not consistent at all (almost as if i was mixing ammo).
This is what got me wondering if this is a situation of having a barrel not like a certain type of ammo.
I'll explain what I am experiencing. This may help you guys understand my question in a clearer light or at least relate to it.
Shot some 75gr BHTP match ammo and achieved a 5 shot group of .7 MOA, followed by 3 shots that would have yielded an even better group then the next two rounds fly left a whole inch. As I went through the box, the trend continued.
Luckily I had another box of ammo, some 60gr V-Max ammo and I was able to maintain groups around 1 MOA.
Then I went back to the 75 gr and got the same results.
Although the 60gr V-Max did not make a better group it was consistent, while the 75gr BHTP had a flash of brilliance it was not consistent at all (almost as if i was mixing ammo).
This is what got me wondering if this is a situation of having a barrel not like a certain type of ammo.
Blue or red box ammo? Who made the barrel and what's the twist rate? Irons or optics? Shooting sled or sandbags from the bench? The devil is in the details.
Blue or red box ammo? Who made the barrel and what's the twist rate? Irons or optics? Shooting sled or sandbags from the bench? The devil is in the details.
Both 75gr and 60gr were blue box.
Barrel is a Kreiger from Compass Lake Engineering.
Optics, 6.5-20x50.
Shooting prone with bipod, nothing else.
_____
Will add more info sometime this week.
Trying 77gr SMK red box and added an accushot monopod, everything else will remain the same.
I'll explain what I am experiencing. This may help you guys understand my question in a clearer light or at least relate to it.
Shot some 75gr BHTP match ammo and achieved a 5 shot group of .7 MOA, followed by 3 shots that would have yielded an even better group then the next two rounds fly left a whole inch. As I went through the box, the trend continued.
Luckily I had another box of ammo, some 60gr V-Max ammo and I was able to maintain groups around 1 MOA.
Then I went back to the 75 gr and got the same results.
Although the 60gr V-Max did not make a better group it was consistent, while the 75gr BHTP had a flash of brilliance it was not consistent at all (almost as if i was mixing ammo).
This is what got me wondering if this is a situation of having a barrel not like a certain type of ammo.
this is exactly why groups less than 10 rounds are meaningless.
what might be considered a "flyer" in a 5 round group define the norm if ten are shot. there are very, very few sub-MOA rifles in the world but by the judicious editing we usually can get a few bragging groups to show around.
case in point, I built a .243 varmint rifle for my brother that printed a .146" group with three shots. I knew enough to stop shooting there and move over to the next dot for another group.
the next 5 rounds fired at the next dot on the target printed about 3/4" but had I overlayed those two groups for an 8 round group, it would still have been a 3/4" group. that once-in-a-lifetime group is the one I presented to him to show how awesome the rifle was however... :D
it's not unusual to have 3 round touching or nearly on top of each other in a 7, 8, or 10 round group. those three hero shots, just happened to be the first three and I cut it off there...
Both 75gr and 60gr were blue box.
Barrel is a Kreiger from Compass Lake Engineering.
Optics, 6.5-20x50.
Shooting prone with bipod, nothing else.
_____
Will add more info sometime this week.
Trying 77gr SMK red box and added an accushot monopod, everything else will remain the same.
Ok, we're on track here to dial in on the problem. I shoot a CLE service rifle, so I know that shouldn't be the problem. There is nothing wrong with the barrel either. The Black Hills ammo is good to go as well. Shooting from a bipod can be a but tricky if you aren't used to doing it. The rifle feels stable, but there is still some movement to the sights if you don't approach each shot the same way. It is possible that your natural wobble pattern is 'throwing' some shots to the left. I see it all the time and it's not uncommon. Another factor is as good as Black Hills is, it's a generic match load. It delivers sub 1.5 MOA from just about any rifle it's fired from. I can tell you from personal experience that once you find the 'magic' load for your barrel, a Krieger tube will deliver sub MOA all day, every day. You are clearly on the right track to accuracy nirvana, self improvement is the key.
Edited to say ra2bach is correct on the group size. Three rounds is for zeroing because that's the minimum you can fire and be able to triangulate from. For accuracy testing you need a minimum of five shots per group, for at least two groupings. Ten shots works better because most of your standard deviations will make themselves know in ten consecutive shots.
Disclaimer: It seems the more I shoot, the more I realize I still need a lot of work/experience and skills to become a half decent sht.
I am picking up on certain things I need to improve on. Today I noticed I am not placing my head at the same location every time... among a few other aspects of shooting on which I need to improve. Good thing is there is room for improvement.
Even with everything above in mind, i will say the rifle shoots better with the 77gr SMK, it feels much more consistent and manageable, if this makes any sense. Somehow it just does compared to the 75gr.
I even managed a 5 shot sub .5 MOA group but do not count it as i did not repeat it, could have been luck, etc...
Here is a 10 shot group which is at 1 MOA, which is kind of disappointing, i feel the rifle and ammo combo can do much better... it's confirmed I was the weak link today.
http://www.dragonape.com/AR15/6.jpg
On a good note... I always get complemented on the rifle and everyone thinks it's a .308 for some reason or another. I guess i'll keep faking it till I make it...
http://www.dragonape.com/AR15/7.jpg
that's a good looking stick. maybe the FH is the reason most folks think it's a .308.
anyway, I try to console myself that theoretically at least, any shot within a 1" group, is only ever 1/2" away at most, from what I intended to hit... ;)
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