Average barrel life?

[Dastook]

I was reading the thread about buffer life and didn't want to hijack it. What are you'll getting out of your barrels? I'm particularly asking about 5.56 semi. auto chrome lined but be interested about other versions as well.

[rubiconjp]

I have read that standard milspec barrel will last around 10k rounds, and a cold hammer forged with chrome plating will last around 30k rounds. Maybe someone with more accurate info can chime in.

[OldNavyGuy]

how is this for "other versions"
2,960 rnds from my LWRC 16", 5.56mm polygonal barrel and it keyholes so bad at 100 yd. that out of 20 rnd. mag. only 6 rnds hit a target on a 24"X36" backing, only one rnd. hit the actual target of 8.5"X11.5" standard copy paper.

[markm]

I have read that standard milspec barrel will last around 10k rounds

You'd have to run a lot of high volume fire to kill a military barrel in 10k.

I have that old article where they ran a Colt AR with a NON-CHROME LINED barrel for 10,000 rounds of almost non stop semi auto fire. Of course they killed that barrel. It really depends on the rate of fire, not the overall round count alone.

I probably have one chrome lined bushy barrel with 7 to 10 thousand on it. It doesn't show any signs of accuracy degradation or throat errosion.

[C4IGrant]

You'd have to run a lot of high volume fire to kill a military barrel in 10k.

I have that old article where they ran a Colt AR with a NON-CHROME LINED barrel for 10,000 rounds of almost non stop semi auto fire. Of course they killed that barrel. It really depends on the rate of fire, not the overall round count alone.

I probably have one chrome lined bushy barrel with 7 to 10 thousand on it. It doesn't show any signs of accuracy degradation or throat errosion.

Agree (as in 10K of FA fire). Even then what is most likely going to erode is the gas port.



C4

[lindertw]

In 1996 Rock Island Arsenal performed a 'fire to destruction test' on M16A2 rifle and M4A1 carbine barrels. The test specimens gave up the ghost in <600 rounds of full auto fire (30-round dumps, mag changes every ~10 seconds; rifle/carbine brand not listed in test). The article can be read here (http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA317929).

[rubiconjp]

Since Rock Island Arsenal is part of the US Army, I'd imagine they'd used gov't issued M16 and M4's.

[Ron S.]

Six HUNDRED? Dang! I do that in a weekend!

[markm]

Six HUNDRED? Dang! I do that in a weekend!

Your barrels are all ruined! :p

We used to fire about that much, sometimes more, rimfire in one session. My buddy and I would each buy a bulk pack 550 round box of 22lr, and shoot the entire box thru are 10/22s and my Ruger Mk I pistol.

[rubiconjp]

Six HUNDRED? Dang! I do that in a weekend!
600 rounds of continuous auto fire though.. ;)

[Magsz]

I read alot about mechanical accuracy etc.

What kind of degradation in performance are we talking about here after 10k rounds?

By "ruined" do you mean the barrel becomes dangerous to shoot or what? Obviously a barrel isnt going to become inoperable at exactly 10k rounds.

Ive read that its a good idea to replace gas tubes every year or so just to guarantee that nothing goes boom where it shouldnt. ;)

[markm]

What kind of degradation in performance are we talking about here after 10k rounds?

By "ruined" do you mean the barrel becomes dangerous to shoot or what? Obviously a barrel isnt going to become inoperable at exactly 10k rounds.

Ive read that its a good idea to replace gas tubes every year or so just to guarantee that nothing goes boom where it shouldnt. ;)

In the test article I referred to above, the barrel was keyholing rounds when they fired it on paper. That's a ruined barrel.

Also, I have an AR uppers that is over 10 years old with 7 to 10 thousand on it (as mentioned above). I've never changed a gas tube on it or any other upper I own for that matter.

S.A.W told me they can be changed every 3 thousand rounds, but their advice was so strange on the other two issues I asked about that I didn't put much stock in that opinion.

[Magsz]

Demigod, sorry for the "noob" question but what does keyholing mean?

[Jerm]

an oblong hole in the target...which shows that the round is tumbling and not stabilizing.

[markm]

an oblong hole in the target...which shows that the round is tumbling and not stabilizing.

Yep. The bullet is not spinning like a football. It's tumbling end over end. That can have an impact on the accuracy of the weapon. :D