Can you hurt your AR with too many rounds to fast?

JCL

New member
Took my new son in law prairie dog hunting yesterday and got into a big town full of unshot prairie dogs. I let him shoot about 40 rounds in about 30 minutes with my RRA Predator Pursuit 20 inch heavy barrel and put it away and let it cool. We then shot some with my 22/250. After picking up brass we drove on down the 2 track to the middle of the town and got out and were covered up in dogs. I let him grab my AR and he started shooting dogs. After 40 rounds in about 15 minutes he loaded another mag of what ammo Im not exactly sure what it was, just some odds and ends I was gong to shoot up. Next thing I know my 1/2 MOA rifle is putting bullets everywhere. I took the gun and thought gosh the kid is losing it and I took a shot and my shot (the last in a 10 round mag) was off by several feet. I touched the barrel and it was darn hot. We had run through 90 rounds in about 60 minutes. I put the gun away to cool shot a few more with the 22/250 and called it a day so we would be home in time for dinner. I cleaned the AR last night and plan to shoot it tomorrow and see what it is shooting. What to you think ammo or just to hot? I realize any gun shot enough especially full autos with overheat and get crazy but I didn't think our rate of fire was way out of line.

I guess the prairie dogs that charged were trying to ruin my gun!!!!
 
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Personally, I don't think nothing sounds excessive.
How hot was your barrel? Could you hold your hand on it and keep it on?
Were you shooting reloads? Any signs of high pressure?
At what distance was your shot "off by several feet?
Any cross winds at that time?
 
Barrel was hot enough to get a good burn if you placed your hand on it. The reloads were moderate 55gr. Not sure what was in the last mag may have been some FMJs. I had cleaned up my ammo cabinet and loaded any loose rounds into that 10 round mag. Wind was 5 to 10 not enough to really throw them very far. I guess I will know tomorrow when I check it out.
 
Yeah, if you could get a burn from the barrel, I'm thinking it was pretty hot, perhaps too hot. But not knowing the real temp, it's hard to say if there was any damage done.
Shooting it tomorrow will tell you everything.
Post back and let us know how things are.
Pictures of targets are good too!
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JCL, I have a 16" bull barreled DPMS that I've had for the last ten years and shot several action competitions where the stages involved 30-40 rounds in almost as many seconds, as well as taking it as a back up on Prairie Dog shoots and considering the age and activity, it still is pretty darn accurate...The only difference is that the barrel was allowed to cool down quite a bit between the shooting sessions...and I run a saturated bore snake through it once in awhile until I can clean it at night..

I'm just guessing, but I would guess that your barrel is more dirty than shot out and may have some copper build up in it as well...

If you have, or can find, some foaming bore cleaner, soak the barrel with the upper on an angle so it can drain overnight onto a clean cloth and I think you will find a lot of blue drainage the next morning...Then swab/brush it out thoroughly and patch it until there is almost no stains and oil the barrel with some Kroil, or other penetrating oil...

Then swab it out before going to the range and you may be surprised that the accuracy has returned...
 
I have seen a miraculous amount of copper fouling kill the accuracy in a rifle before. I couldn't even sight it in is was so bad.

A couple treatments of a foaming bore cleaner some JB's Bore paste, and a real through cleaning fixed it pretty good.

It had a previous owner, and apparently the standard cleaning I was giving it with Hopes No.9 was not enough to get the copper out, but the patches would run through it clean.
 
Ran 60 rnds tru mine sat in 20 min or less at 75 yds first 30 or so rounds grouped with in 2" and the last few rounds i just pulled the trigger as fast i could just to how it would rapid fire. The barrel was pretty darn hot [beeep]
I will say that i was shooting surplus ammo 55gr fmj ain't shot no good stuff thew it yet or tried to dail it in tight until i figur out what ammo i want to use to hunt with.

Maybe your scope took a dump on ya or it could have got knocked off during all that fun yall was having

Good luck
 
Quote: I have seen a miraculous amount of copper fouling kill the accuracy in a rifle before.

I'm thinking that's the problem.

Quote:the standard cleaning I was giving it with Hopes No.9 was not enough to get the copper out, but the patches would run through it clean.

The first time I ran copper solvent through my .308 (after cleaning it for years with Hoppes), I got quite a shock. Apparently Hoppes #9 doesn't remove copper, because I had patches that came out solid blue.

I'm fairly sure the rate of fire you're describing won't hurt an AR barrel. Even the pencil-barrel A1's would put out a lot of sustained fire without losing their accuracy.

Touching it isn't a test that's worth anything, you can only hold something that's about 160 degrees for any length of time. Lightly oil the barrel and when you see smoke, give it a rest. Don't touch it, it will burn fingerprints into the barrel and blister your fingers.
They ain't cheese, they're hard to melt.
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That doesn't really sound like that much shooting. I hate to admit but I shot a dog town this summer and was shooting 20rnd mags as fast as my buddy could reload them for me. The barrel got pretty hot but the accuracy seems to still be spot on. Give it a good cleaning and then see what happens.
 
I would guess a dirty barrel/fouling before burn out. Let it cool and clean it nicely before using again. I could be wrong but thats my guess.
 
Do you have a free float hand guard? I don't know the options on the models so I'm not sure, but could it have been the heat mixed with hand guard touching it? Also, you can just lose accuracy from have the barrel real warm, or at least have the point of aim wander.

Also, where you wrapped up with the sling when you shot? With a non-free float barrel it could be the problem or aggravate it.
 
I shot dogs this spring with a RRA coyote 20". Used 20 round mags (as 30 were too long for my bipod). Had bro & bro in law and we ran off 5-600 rounds in 2.5 days (along with shooting our 22-250's also). Times we shot 40-60 rounds in under 15 minutes probably and accuracy was always spot on (so I don't think 90 rounds in 60 minutes seems that much). Never cleaned and by the end of the last day was still shooting well.
Shot 55 v-max over H335 moderate loads.
I'll plus 1 for needing a cleaning but add that to check your scope/mount also. Something could have worked loose on that, if you are off by "feet" - but that might depend on the distance, also.
Might even be whatever ammo he loaded (if you aren't sure what bullets were left you just wanted to shoot up), but I'd still be surprised if that ammo was that far off and shooting "all over".
 
Originally Posted By: JCL After 40 rounds in about 15 minutes he loaded another mag of what ammo Im not exactly sure what it was, just some odds and ends I was gong to shoot up.

I don't think you toasted your barrel...I think the fall off in accuracy was more due to the part I underlined.

90 rounds in an hour? I've put that many through my carbine in a single stage when I was competing, and never had an issue...

Give her a good cleaning and then go back to shooting what you normally shoot...
 
As the guys said, copper fouling. I'd be a lot more concerned with the 22-250, it's much easier to burn/wash the throat out of than the .223.
 
It's rare a change in ammo brings point of impact 6 inches off in my experience. A few feet seems like something else, but still doubting the barrel is toast.

NMLeon is right about the 22-250 being much more likely burn out round.

Have you shot it to check it out yet?
 
Well my accuracy returned. I went to the range and shot a 10 shot group. Here is the picture of the group. I sprayed one my error wasn't ready for the trigger to break.
223_Group.sized.jpg


I was wondering what happened to make it go quite so crazy and have come with a theory. I have a Ruger MKII .223 that I use Hornady 55gr SXSP for coyotes. For some reason it just loves those bullets and they work ok for coyotes. I wonder if while picking up loose rounds I may have put a few of those sxsp in the 10 round mag and if the bullets were coming apart before getting to the dogs. I mean these things were throwing up dust multiple feet from the dogs. My AR has a 1:8 twist and that along with a smoking hot barrel may have caused the bullets to fail. Next trip to the range Im going to try a few to see what happens. I have a bad habit of taking loose rounds out of my pocket after hunting and dumping them on my reloading bench to put away later. With no markings and the bullets looking identical to the 1365 Sierra 55 Gamekings I use in the AR for coyotes its way to easy to get them mixed up. I have a free float handguard but it was getting pretty warm also from the radiant heat. I have shot the head space out of my 22/250 2x times with several thousand rounds over the years and I was treating it with kid gloves breaking in a new barrel. No more than 5 shots and it rested for 10 or 15 minutes. I guess my pass experiences with the 22/250 made me a little nervous. Im just like a kid in candy store when I get in a big town of prairie dogs and have a hard time controling myself let alone others. Guess I need to take more friends with their guns so we can tag team the dogs and keep up a good rate of fire. Its unusual this time of year to find a big dog town that has not been educated. I guessing the second prairie dog town another half mile in the drainage hasn't been shot either and another trip is needed!!! Thanks for the advice.
 
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Well JCL.....looks like your Pursuit rifle is shooting like it should!! Good for you!!!
You may be on to something with your theory as 1 in 8 is too fast for the SX bullet.
I'm glad for you that all is well.
Good group by the way!
 
I don't think that the SPSX's were coming apart. I have shot them out of my AR with a 20" 1 in 8 twist, with real good accuracy. Although, my barrel wasn't hot either. I am no expert, just giving my experience.

kevlars
 
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