Worn out barrel???
- Thread starter jtybt
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My second AR was put together with components. Complete upper receiver as JaPes suggested and lower thru individual parts/kits.
I also shoot the same amount with the second AR...and the same amount with my Shield 9 and SD9VE. I guess you can see why I went to steel. I have about 8000 rds on hand and plan to slow down my shooting regiment, now that I can hit what I'm aiming at...'cept for this M&P Sport.
I also shoot the same amount with the second AR...and the same amount with my Shield 9 and SD9VE. I guess you can see why I went to steel. I have about 8000 rds on hand and plan to slow down my shooting regiment, now that I can hit what I'm aiming at...'cept for this M&P Sport.
Went to the range Fri. One shot showed a keyholed round. Finished off the mag and went to the pistol range.
Got home to replace the barrel and, of course, ran into problems right off. The gas block mount on the new barrel had a dimpled set screw instead of the tapered pins like the MP15 barrel so I had to order another gas block that had the three set screws. That'll take at least a week to get here. I ordered another scope so I can see the bullet holes at the 200 yd range. The 200 yd range should slow my excessive firing rate down...but it's not open every day.
I have another problem I'll post about hexmags.
Got home to replace the barrel and, of course, ran into problems right off. The gas block mount on the new barrel had a dimpled set screw instead of the tapered pins like the MP15 barrel so I had to order another gas block that had the three set screws. That'll take at least a week to get here. I ordered another scope so I can see the bullet holes at the 200 yd range. The 200 yd range should slow my excessive firing rate down...but it's not open every day.
I have another problem I'll post about hexmags.
This thread has made me decide I'm going go add a life goal of "Shoot out a barrel". That will be objective proof that I had fun.
OR
That can be an expensive goal. I had 3 prairie dog guns when I lived in Minneapolis. Thompson-Center Contender(super 14 barrel), S&W 1500 rifle, and Remington 700 with Shilen SS barrel in 25-06. After about 8 years, all 3 barrels keyholed 90° at 50 yards, group size was measured in feet at 100 yards.
I shot 34# of surplus H414 through it 52 grains at a time. Those were the "Golden Days" of prairie dog shooting.
Tula and Wolf ammo does have copper plated steel bullets along with the steel case, wondering if the steel bullet will accelerate the life of the barrel faster than conventional bullets.
Yes, its been proven. However, with the money you save over the life of the barrel, you can easily buy a new barrel, or even a basic full upper.
JaPes
Member
Logic.
Barrel Steel is harder than mild steel or copper.
Shoot a bi-metal jacketed round (copper wash over mild steel) and you will erode the lands faster than a copper jacketed projectile.
I have been shooting ARs in NRA high power competition since about 1998. Yes, fouling could be the source of your key holing, but I really think that you shot out your barrel.
Typically, a 223 match grade barrel has an accuracy life of about 5000 rounds. That is using a jacketed bullet over a lead, not steel, core. Additionally, a match barrel will usually fire 10 rounds in 60 seconds, at the worst. Heat is a problem, but I doubt in this case.
In addition to wearing down the rifling, you probably have a high level of throat erosion which has increased the bullet jump (leade).
It has been suggested that you just get another upper, which is fine, but I would Re-barrel your current upper, it can be a lot less expensive.
Typically, a 223 match grade barrel has an accuracy life of about 5000 rounds. That is using a jacketed bullet over a lead, not steel, core. Additionally, a match barrel will usually fire 10 rounds in 60 seconds, at the worst. Heat is a problem, but I doubt in this case.
In addition to wearing down the rifling, you probably have a high level of throat erosion which has increased the bullet jump (leade).
It has been suggested that you just get another upper, which is fine, but I would Re-barrel your current upper, it can be a lot less expensive.
Biggfoot44
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Ok, what size groups ( at what distance) , with ammo of known accuracy, initially ? Now ? A benchrest or F Class shooter would consider a bbl shot out if went from .5moa to .8moa . For shooting 2 minute of Felon, that would be barely broken in.
I like Hoppes #9 for general light cleaning. But for this periodic removing of copper deposits, you need a copper specific product . Leave it to soak 10min to cpl hours at a time. Repeat until patchs come out clean instead of blue.
I like Hoppes #9 for general light cleaning. But for this periodic removing of copper deposits, you need a copper specific product . Leave it to soak 10min to cpl hours at a time. Repeat until patchs come out clean instead of blue.
Jerry M
Member
I think this is the case also. Steel bullets are hard on barrels.
You should check out that Lucky Gunner write-up on steel vs brass--you'll enjoy it!
Friend of mine makes barrels for the guns he sells.... According to him the life expectancy for a good stainless rifle barrel is somewhere between 2 and 3 minutes. The variance of a minute takes into account muzzle velocity, rate of fire, and cleaning...To arrive at a ''round count'' you must figure out how long a bullet stays in the barrel.. Also known as Dwell Time... Then divide that time into 120 or 180 seconds..ans-- round count..
Frank46
US Veteran
There was a study done on gunboards sometime back. two ar's one shot with brass cased copper jacketed ammo and the other was with steel cased and copper plated steel jacketed ammo. The first rifle finished the tests and was ready for more. The second rifle with the steel cased ammo and copper plated steel jacketed ammo never even came close to finishing. Bore was severly worn especially around the gas port to the point it just looked like a hole in the barrel. Moral of the story if you want long life from your barrel stay away from the steel cased copper plated steel jacketed bullets. Should still be on the gunboards site. Was well done and interesting reading. A standard colt barrel should be good for at least 10K rounds providing it has been cleaned accordingly and no mag dumps. I have seen a few indivduals do the mag dump thing and all that does is waste ammo and burn out barrels.Frank
sgtsandman
US Veteran
Stainless also has a reputation of dropping accuracy like falling off a cliff. Where as more conventional barrels tend to drop off gradually. Each has it's pluses and minuses.
Just got my quick reply shot out to the ozone somewhere.
In short... Ebay SS barrel
223 WYLDE Barrel 16" W/1 in 8 Twist Stainless Steel - 5.56
Item #( 262829268847 )
Other AR is also shooting 5' off the target. Had to shoot the berm to see it. Got the whole upper at SAA(Surplus Ammo). They are looking into the 150,000 rd barrel life claim of the replacement SS barrel for the M&P sport.
In short... Ebay SS barrel
223 WYLDE Barrel 16" W/1 in 8 Twist Stainless Steel - 5.56
Item #( 262829268847 )
Other AR is also shooting 5' off the target. Had to shoot the berm to see it. Got the whole upper at SAA(Surplus Ammo). They are looking into the 150,000 rd barrel life claim of the replacement SS barrel for the M&P sport.
Yes many people like myself will site the Lucky Gunner article as proof that steel ammo accelerators barrel wear. It has been discussed here before.
Last time IIRC there was speculation by cyphertext that it is not just the steel case that might be the cause for the accelerated wear but that the cheap power and primer play a part.
Here is a link to that discussion. http://smith-wessonforum.com/smith-...ided-steel-brass-case-new-m-p15-sport-ii.html
It is an interesting read and as JaPes said in this thread if you have shot 10,000 round of even steel case ammo you can afford a new barrel or even a new complete upper.
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There was a published test of several rifles and differing types of ammo. The el cheapo Tula and Brown Bear ammo wore out barrels faster than comparable US made (American Eagle etc.).
Now then, you mentioned a Sport I. That features a melonite rather than hard chrome lined. A recent note from the former CO of the USAMTU advises that melonite barrels may be more accurate (we probably wouldn't notice-also note the MAY) than chrome lined, but aren't anywhere near as long lived.
Rapid fire speeds barrel wear by both gas and bullet friction erosion. As the temperature of the barrel rises, the erosion increases. While stainless tends to resist erosion better than unlined chrome-moly barrels, it tends to lose accuracy suddenly. No gentle wear and slowly increasing group sizes, just sudden loss of accruacy.
The advantage of hard chrome lining of barrels is that it's about twice as hard as the base metal it's bonded to. It resists both gas and friction erosion much longer than a bare or melonite treated barrel. The bean counters at my former employer (retired) forced plain barrels on us for awhile. In the CQB training segment, we proved you can indeed burn out barrels in semi-auto fire. Back to hard chrome lined.
Given the ammo you've used and the type of shooting and cleaning you've done, I expect your current barrel is toast. That said, thorough cleaning has restored accuracy to a good many barrels. Ultra sonic cleaning can help here. [So can plugging the bore and the gas tube and fill the bore with Hoppes, soak 24 hours.] Somewhere I've got a picture of a sectioned M1 barrel with the rifling gone for about 8 inches forward of the chamber. Despite this (and the firing of about 80,000 rounds-it was used for arsenal ammunition accuracy acceptance testing) it still shot militarily acceptable groups.
Now then, you mentioned a Sport I. That features a melonite rather than hard chrome lined. A recent note from the former CO of the USAMTU advises that melonite barrels may be more accurate (we probably wouldn't notice-also note the MAY) than chrome lined, but aren't anywhere near as long lived.
Rapid fire speeds barrel wear by both gas and bullet friction erosion. As the temperature of the barrel rises, the erosion increases. While stainless tends to resist erosion better than unlined chrome-moly barrels, it tends to lose accuracy suddenly. No gentle wear and slowly increasing group sizes, just sudden loss of accruacy.
The advantage of hard chrome lining of barrels is that it's about twice as hard as the base metal it's bonded to. It resists both gas and friction erosion much longer than a bare or melonite treated barrel. The bean counters at my former employer (retired) forced plain barrels on us for awhile. In the CQB training segment, we proved you can indeed burn out barrels in semi-auto fire. Back to hard chrome lined.
Given the ammo you've used and the type of shooting and cleaning you've done, I expect your current barrel is toast. That said, thorough cleaning has restored accuracy to a good many barrels. Ultra sonic cleaning can help here. [So can plugging the bore and the gas tube and fill the bore with Hoppes, soak 24 hours.] Somewhere I've got a picture of a sectioned M1 barrel with the rifling gone for about 8 inches forward of the chamber. Despite this (and the firing of about 80,000 rounds-it was used for arsenal ammunition accuracy acceptance testing) it still shot militarily acceptable groups.
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Shot 1 rd and pulled the rope thru. shot 10 more and pulled the rope thru.
First rd hit 18" off at 7 o'clock. Slowly brought hit to about 3". Could not adjust any closer. Tried over adjusting but not even getting acceptable groups. Rds were clean(not keyholing).
Brought it home and cleaned and inspected. Bolt seemed loose in carrier. Could that cause inaccuracies? Flash suppressor came loose. That could have caused problems. Going to the range tomorrow(Sunday). for another test.
First rd hit 18" off at 7 o'clock. Slowly brought hit to about 3". Could not adjust any closer. Tried over adjusting but not even getting acceptable groups. Rds were clean(not keyholing).
Brought it home and cleaned and inspected. Bolt seemed loose in carrier. Could that cause inaccuracies? Flash suppressor came loose. That could have caused problems. Going to the range tomorrow(Sunday). for another test.
Got the 18" barrel for AR #2 and replaced old barrel. Got new scope for it, too. SO, had 2 AR's with new SS barrels and scope. M&P got the 4-16X50 scope and #2 AR got the new 6-24X50 scope. Could not adjust either rifle satisfactorily. hits were all over the place. I think it's me. Maybe I can blame it on the scope.
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