Speaking of AR's again

[mike in co]

i asked armalite about the bolt life question....this was the question...

" is there a reccommended round count for bolt replacement.

say a typical cmp/dcm rifle in 200/300/600 yd competition"

here is armalite's answer.......

"The rule of thumb is to change the bolt when you rebarrel your rifle though this isn't a hard and fast rule. You should be fine until then."

i hope this puts to bed this issue.

mike in co

[Triggerhappy]

AMEN! Thanks for checking Mike. I know a lot of folks shooting the 70g pellets out of an AR without any problems, including me. And I know that I have close to 10k rounds thru mine without any adverse wear or issues. Not to say that I won't have, but...

Brian.

[GabbyM]

I would assume if you hot rod your loads up above 60K psi a barrel would wear down just as fast as the BR guns that shoot those pressures. I've burned through a few 243 WIN barrels in way under 2K rounds and that's just typical. My 223 varmint rifle last longer but I don't get 2K rounds from a barrel. With an AR you buy a new barrel with fitted and head spaced bolt and it's ready to go. Takes about fifteen minutes to swap a barrel. Once it's on the bench.
Many shooters will spend lots of money to gain a bit of an edge.

I"ve an SP-1 here that' had many thousands of pills down the pipe. Most were hand loads of 10% or so reduced from book max. 52gr HP at around 3,000 fps. I've done more damge to the barrel with poor cleaning practise than shooting it. But I could destroy it in eight minutes if I wanted.

I have a story: Friend of mine told of a USMC LT whom walked out to the edge of the wagon circle one dark night in NAM up in I corps. Two boxes of those 20 round mags and two privates to hand him clips. NVA had been making noise outside the perimeter. He started firing. Empty one clip grab another from his helpers hand, slam it it and go. LT had a pile of empty mags at his feet when the glow of the barrel started reflecting off the grass. When he'd drop the bolt the rounds would cook off pop pop pop then he'd pull the trigger and empty it. My friend says about the time he saw the barrel glow red past the hand guard the bullets started falling short of the tree line. A few mags latter the barrel actually sagged and bent down. LT threw the CAR down and walked away. No more noise from out their for the rest of the night. Don't know what the round count on that barrel was but it was used up.

[mike in co]

""Typical" use varies so much between shoooters, as well as the round count, cleaning method, etc...that giving an iron clad number/frequency is difficult. My best advisse would be to check for any visible damage/wear anytime you have it out of the upper. The areas you particularly want to look at would be the face (any significant pitting, damaged edges,etc...) and around the cam pin hole (weakest spot on the bolt) for any cracks, advanced wear, etc...) Replace the extractor and ejector and their springs every few thousand rounds (or if you start to have difficulties with either). Same with the gas rings.
You would certainly, at a minimum, chech head space any time you go to use THE BOLT with a NEW/different barrel/barrel extension.
Steve/RRA"


just one more major ar company speaks up with no special warnings for heavy bullets or 1200 round count. they were given the same question as armalite.

mike in co

[jjamna]

Mike I found the problem. A little embarrassed to tell but will anyway. Was not torqueing the handguard / barrel nut enough.

[jjamna]

Now back to the bolt.--------You are saying they will hold up to a 6mm-223?

[mike in co]

not an issue, as long as one observes the pressure limits of 5.56/223 saami/cip.....gives you a little room to try the ragged edge.
6 was shot a while back....about 20 yrs back...but is still seen every now and then.

mike in co