View Full Version : How many rounds per string, barrel too hot?
Ok guys, let's talk about this. How many rounds do you fire before you say, " the barrel is 8 million degrees and I need to stop".
I always fire five and often go 10 round strings. The 308 gets hot and 300 WM GETS REAL HOT!
I'm talking about precision shooting, not rapid fire. But not playing grab ass between shots either.
Does it trash the barrel? I have not really cared because as soon as my 5R's get smoked, I have a Krieger awaiting. But i would like to hear the general concenses. I'm not trying to kill them, but I bought them to shoot.
I'd like to hear more about this also. I have an H.S. Precision Lightweight, in 300 WSM, and it gets hot quick. The fluted barrel helps to cool, but you always wonder if higher temperature firing increases wear, while also creating other negative issues.
Higher temps do accelerate wear, but that's the cost we pay to shoot. The harder a barrel is used, the faster it wears. A barrel will last longer if babied but then are you are you shooting? Just like a set of tires on a performance car- going to the the track and running it hard wears out the tires but if you baby the tires, why go to the track? If you don't run a performance car hard, why did you buy it?
Don't be afraid to wear out a barrel. Shoot the rifle until accuracy falls off enough that it is no longer acceptable for your purposes. It will likely surprise you how long it'll take before accuracy really drops off and needs a new barrel
In that other thread with the dot drills, I've fired 50rnds out of that barrel back to back without stopping, several times. Still shoots good.
The more important issue here is after how many rounds of successive fire does your POI start to wander?
lengthofpull
05-08-12, 21:23
In that other thread with the dot drills, I've fired 50rnds out of that barrel back to back without stopping, several times. Still shoots good.
The more important issue here is after how many rounds of successive fire does your POI start to wander?
I am just one man, but I have a Browning M-1000 in 300 win mag. When I get it ready for deer season in hot august my groups will drop about 2 inches at 300 yards after about 20 rounds in 12 minutes or so.
That may just be my gun and may not be from barrel droop, but if I let it cool down in the shade with the bolt open its back to its original POI.
YMMV.
ICANHITHIMMAN
05-08-12, 21:36
I have never fired more than 2 rounds in a 10 min peroid out of either of my 30 cal magnums. Heat is not your friend but my rifles are not for that purpose either. I suppose if I was competing in something I would see the need to get them hot but I dont.
The excess heat will speed in errosion or your throat
Working up a batch of 5-6 test handloads (4 rounds per specific powder load) involves some range time. I usually rest a bit between each load level, but then fire each of the 4 rounds within a couple of minutes.
High power shooters shoot 40 rounds rapid fire in the course of a standard 80round match. Some match shooters get 8k out of a .308, some get 1,200 out of a 6mm. The point I'm making is heating the barrel during a string of rapid fire is not what wears it out. It's the throat erosion caused by the burning gunpowder that's the real enemy.
I've learned in the last weeks that I clean my guns more than needed and could shoot more rounds if desired. This is good. :D
Gunna get hot ths weekend.
Thats good. :) Don't take it too far though. If you can't touch your barrel midway down for 5 seconds without getting burned... you are probably eating your barrel.
If that's the gauge then I must be eating mine down to the last morsel.
... or maybe you have girly hands. haha! j/k
It's just kind of a guide that I go by. If the outside of the barrel burns my hand... then the inside is smoldering.
My win mag scorches in 5 rounds. 308 in 10.
FWIW most maintenance schedules in the army for our sniper rifles were "supposed" to be sent to Remington for a rebarrel every ten thousand rds. If you can afford to lose your rifles for over three months time than that is ok however they went above that with fine accuracy for probably double. There was also an m24 we had from a certain unit with its own machinist that threaded its barrel in house. Remington would not touch it because they thought it was a bubba job. It had around twenty before they finally were convinced that it was done by a gifted military machinist or similar at the unit. It was just getting to around moa accuracy and its debatable if that was the barrel anyway. Came back shooting a quarter min though.
When I left the army the guys put roughly 1500 rds through an M110 in a 2 hr span and that wasn't good. They sent the barrel in for repair but I couldn't say that it was exclusively from that. After I left they were quite hard on the rifles.
In school we fired over a hundred rds a day at around one rd/min. The rifles are the school houses and all shoot sub min for years. They don't get rebarreled often and if I had to guess are going good at over twenty thousand still sub min. Long reply but hope it helps.
Nice post. Much appreciated. First hand experience like that is invaluable... and far too infrequent around here.
I have fired 88 rounds in under a hour at 500 yards. We had a f class shoot and a storm coming in so we just let fly. By the end of that string I had to keep dialing up elevation and I was taking about 40 seconds between shots. My rifle has about 2000 ends thru it. She's a 300 wm sendero, only real work is glass bedding and a trigger job. I imagine the barrel will need replaced soon, but it's still a half moa rig with my handloads. The only thing is the barrel seems to foul quicker now.
Whew! Yeah, that'll smoke a barrel for sure. 300WM produces a great deal of heat. It has nearly twice the powder as compared to a 308. I wonder why it fouls quicker now?
I'd expect accuracy to suffer, but I wonder what the science is behind the fouling? You suppose the bullet isn't being grabbed by the rifling as hard, and is maybe "free spinning" a bit, leaving more copper behind?
Just a guess but it would seem like if the barrel is fouling more it would be because the barrel is starting to erode in front of the chamber area. I have a GAP 7wsm that has burned out the barrel about 2 in's past the chamber area in less than 800 rounds. I will be getting this barrel cut back a couple of inches and rechambered. It is much more cost efficient then a new tube for me right now. Once I shoot it out again, I will put a new barrel on it. Hopefully one of the Jense Precision/Proof Research carbon fiber barrels to lighten it up a bit. In the future, I will shoot shorter strings than what I used to. I shoot a 300 RUM also and only put about 5-10rounds down it before picking up something else to shoot so it can cool down. That will be how I shoot the 7wsm also. Sometimes you can use Tubbs final finish loads to smooth the area just after the chamber out. It should decrease the fouling and return some of the accuracy you have lost, if any. On my 308's, I have no worries shooting 20-30 round strings. I generally do not go over this. Not because I have seen POI changes but just because I don't want to take chances on burning up my barrels prematurily.
My guess is throughout erossion as well. I have put a ton of rounds thru this rig. Accuracy is just starting to degrade. It was a .5 moa rig solid with some groups coming in at significantly less. Now it's around .5 with some going bigger. It will be rebarreled soon. Just haven't made my mind up on caliber.
I think that barrels last longer the less heat you put thru em. I have seen 308s go 5000 shot in comp guns with no degradation in accuracy. I have seen em go less. Barrel burners do just that. The main concern is throughout erossion in my mind. It's subject to the most heat and pressure. Just don't get stupid with it. No need for 5 rounds then let it cool for 30 and don't try to burn up a case of lake city for the brass in your precision bolt gun.
Littlelebowski
05-12-12, 06:50
I've learned in the last weeks that I clean my guns more than needed and could shoot more rounds if desired. This is good. :D
Gunna get hot ths weekend.
Awesome.
When I left the army the guys put roughly 1500 rds through an M110 in a 2 hr span and that wasn't good. They sent the barrel in for repair but I couldn't say that it was exclusively from that. After I left they were quite hard on the rifles.
If spaced evenly, that's 12.5 RPM for 2 hours. I'm sure it wasn't spaced evenly and they were shooting 40 or 50 or more RPM then taking breaks. Why would they do that?
For you precision guys---
Where do you draw the line between acceptable and unacceptable accuracy?
Also, to address the main concern of the thread, if you want to be as conservative as possible, induce as little wear onto the barrel as possible, and have POI shift as little as possible, without going extreme and waiting to come back to temperature baseline between every shot, a good rule of thumb is to keep the barrel cool enough so that you can grab it like you're jerkin' your gherkin without getting burned, and by burned I don't mean just a little uncomfortable. If you can keep your hand in place, you're not getting burned...well, unless your skin gets fused with the steel I guess.
I personally heat 'em up as hot as I need or want to, and replace them when they stop shooting.
Also, to address the main concern of the thread, if you want to be as conservative as possible, induce as little wear onto the barrel as possible, and have POI shift as little as possible, without going extreme and waiting to come back to temperature baseline between every shot, a good rule of thumb is to keep the barrel cool enough so that you can grab it like you're jerkin' your gherkin without getting burned, and by burned I don't mean just a little uncomfortable. If you can keep your hand in place, you're not getting burned...well, unless your skin gets fused with the steel I guess.
I personally heat 'em up as hot as I need or want to, and replace them when they stop shooting.
Nailed it on two accords....
As long as I been shooting precision ARs with premium blanks, I've used nothing more than the "hand in place" test....If I can grab the barrel for a 5sec count, I'm nowhere near seeing POI shift of any discernible amount.
Second accord....personally I too run em' hot when and where I feel like it with no worries in regards to premature wear or loss.
$500 Rock 5R = 25 boxes (20ct.) of Federal FGMM 175gr. SMK @ $20 per box = $500
I'll won't cry over barrel costs or try to marry any one special barrel as long as ammo doesn't grow on trees.
As for why I'm in the dumb bolt forum I have no idea...:D
If spaced evenly, that's 12.5 RPM for 2 hours. I'm sure it wasn't spaced evenly and they were shooting 40 or 50 or more RPM then taking breaks. Why would they do that?
Dumbass lt running the range and convinced our shooters that ask the ammo needed to be fired before they Coulter close the range because he was too lazy to count the nice 20rd boxes. I assume he was used to m82 ball and assumed it was delinked in a gaggle because shooting out of sniper rifles. Instead it was m118lr and easily counted. You can't give someone common sense these days and I was already out. If it were me I would of told him he was special and to stay in his lane.
For you precision guys---
Where do you draw the line between acceptable and unacceptable accuracy?
I'll explain it this way, it's all relative to distance. I shoot .223 and in my game a barrel that starts shooting off call at 600 yards is still a good 300 yard barrel. I can use that barrel for reduced course matches for another 3k-4k rounds until it starts having problems at 300 yards. At that point it's trash from my perspective, but an action shooter might another 4k out of it because it's still a 2 MOA barrel, I just need sub MOA for my sport.
308 is a pretty stable round and it's not too hard on barrels. I know one M14 shooter that had 8k+ through his match barrel and it was still hitting on call at 600 yards. If you shoot one of those 6mm rounds, your barrel is toast at 1,200 rounds. If you're any good at what you do, you'll notice shots starting to not hit on call, and it's probably time for a new barrel at that point.
there are two things that can happen to barrels when they get shot out. one, is that they become less accurate, usually this is when you see actual "fliers" (as opposed to the shooter just having a mental meltdown on the 5th round and pulling the shot). The second, which has happened to me several times, is that the barrel just slows down.
e.g. I shot a match at butner during hurricane irene (raining like crazy and very high winds) (this is what the radar looked like during the match) (http://precisionmultigun.com/pics/irene.png). We shot the 240b qual course on the pop up range at E types (with bolt guns). No limit to the round count, but several targets only appear for 15 sec, others for 45 sec. technically UKD but you could kinda guess from the berms, and you really didn't know which targets would appear in what order or at what time. net, shooting about 45 rounds in maybe 3 minutes? and everything covered in water I don't remember exactly (the computer scored me at 92% though, which I didn't think was too bad considering the hurricane winds)
Anyway, immediately after that little episode, my dope went from like 6.4 mils at 1000 to 8 mils using same ammo. Rifle still grouped well under 1 moa though.
I'll explain it this way, it's all relative to distance. I shoot .223 and in my game a barrel that starts shooting off call at 600 yards is still a good 300 yard barrel. I can use that barrel for reduced course matches for another 3k-4k rounds until it starts having problems at 300 yards. At that point it's trash from my perspective, but an action shooter might another 4k out of it because it's still a 2 MOA barrel, I just need sub MOA for my sport.
308 is a pretty stable round and it's not too hard on barrels. I know one M14 shooter that had 8k+ through his match barrel and it was still hitting on call at 600 yards. If you shoot one of those 6mm rounds, your barrel is toast at 1,200 rounds. If you're any good at what you do, you'll notice shots starting to not hit on call, and it's probably time for a new barrel at that point.
Thanks for explaining it that way, it simple to understand. Amazing too. I'd be pretty stoked if i were a regular all around 2 moa shooter with iron sights, to be honest.
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