Your MAX-11A1/15 is ready!

[strobro32]

I massaged the left side of the receiver straight enough that the charging rod now slides freely in the slot. The second small bolt just under the picatinny rail (that holds the receivers together) sheared. I'm surprised the aluminum threads did not strip. I'm feeling confident the receiver can be salvaged. I will need a new carrier, bolt and extractor. I'm pretty sure many parts of the bolt and carrier can be reused.

 

[m11stuff@hotmail.com]

Send it in, we’ll take care of it!

 

[strobro32]

Thank you Richard.

 

[Tinman45]

Send it in, we’ll take care of it!

Shit, Man. Every time you make a post like that it’s better than any T.V. commercial I ever saw.

 

[9mmsubgun-m11]

I have said many times before and will say it again Richard is one of the best people I know.

 

[strobro32]

New pics on post #219.

I had a little trouble with the new 18" barrel combo this morning. After tuning the gas setting, it was running really great. On round 75, I had a OBD and blew the bottom of the carrier and an aluminum mag apart. The cartridge head was left on the bolt face and separated from the case body. 90% of the case is still in the barrel. The bolt still rotates in the carrier but the extractor is bent outward. Even thought the bolt lugs were unlocked, the bent extractor made it difficult to separate the bolt from the barrel collar. I had to take the upper apart to get the carrier and bolt out.

I'm taking the new 18" Ballistics Advantage barrel to a gunsmith to look at the chamber. It looks ruff. I want to inspect the neck area of the chamber with a probe. It was really a challenge to remove the case. I had to cast the throat and push the case out.

I think the Cry Havoc QDB is part of the problem. I would not recommend using the system with the Max system until we know more about the problem. I think there may be tolerance stacking issues.

I will send the A1 upper back to The Wizard this week for inspection. The charging handle rod is not sliding easily. The receiver may be bent. I really hope its repairable. I love this thing.

 

[A&S Conversions]

To me, that looks like over pressure. I am guessing that the bullet left the barrel? I would think that the bullet would have gotten past the gas port, as the gas would have ruptured the carrier from the inside. The piston area would not have ruptured from the shell failing. The way I read your description the bolt was locked and the extractor was bent outward. You had to push the extractor inward to rotate the bolt to unlock it from the barrel extension. Did you look at any of the brass from previous rounds fired? I would be willing to bet that there would be some bulging near the base of the shells. Is there a bevel at the beginning of the chamber? How is the headspacing?

It would seem to me, from what I see from the pictures, this round had too much pressure. The over pressure inside the carrier from previous rounds might have work hardened the carrier or that one round had way too much pressure. When the gas over pressured the carrier and caused the failure of the bottom of the carrier, it also caused the failure of the base of the brass case. I don't know as I would call this an out of battery. It seems to me that the mechanism did what it was supposed to do. I think that the mechanism was subjected to more pressure than it was designed for and failed. This is just my opinion.

Scott

 

[strobro32]

To me, that looks like over pressure.

I agree.

I am guessing that the bullet left the barrel?

Yes.

I would think that the bullet would have gotten past the gas port, as the gas would have ruptured the carrier from the inside. The piston area would not have ruptured from the shell failing. The way I read your description the bolt was locked and the extractor was bent outward.


The bolt was unlocked but stuck between the lugs. The extractor was bent outward locking the bolt in the barrel collar.

You had to push the extractor inward to rotate the bolt to unlock it from the barrel extension.

I removed the bolt and carrier from the barrel collar by knocking them backward with a punch and hammer through the magwell. The bottom of the carrier was broken and angled downward. It would not clear the receiver lug as it was. I disassembled the upper to remove the bolt and carrier. funny thing was the cam pin and firing pin seem fine, The bolt still freely rotates in the carrier.

Did you look at any of the brass from previous rounds fired?

Yes, I have the brass. I closely examined the brass. No bulge on the base of the fired brass.

I would be willing to bet that there would be some bulging near the base of the shells. Is there a bevel at the beginning of the chamber? How is the headspacing?

Barrel was cleaned before installation. The barrel and bolt passed the Go Gauge before testing. The fired cases measure .374-.375" at the base just as the unfired cartridges.

It would seem to me, from what I see from the pictures, this round had too much pressure.

I agree. After showing the case and the Ballistics Advantage barrel to 2 other smiths, we agreed.

The round was my reload. The loaded cartridge passed the Sheratan slotted case. It was a 1 X fired FC 5.56 x 45 case. 24 grains of Ramshot TAC, 2.2 COAL, 55 grain Hornady FMJ-BT, That is the higher than starting load for 223 which is 23.3 grains with a max of 25.8. The load is lower than the starting load of 24.5 grains for 5.56 x 45. The primer is still in the case head although there is pressure signs on the primer and head stamp. I suspect the failure was caused by a faulty case.

The over pressure inside the carrier from previous rounds might have work hardened the carrier or that one round had way too much pressure. When the gas over pressured the carrier and caused the failure of the bottom of the carrier, it also caused the failure of the base of the brass case. I don't know as I would call this an out of battery. It seems to me that the mechanism did what it was supposed to do. I think that the mechanism was subjected to more pressure than it was designed for and failed. This is just my opinion.

Scott

Good observations. Thank you for your input.

.

 

[smdub]

Late to the party but received mine this week. I think my number was in the upper 600s. Probably won't be able to get it to the range until the 28th when we have a MG shoot scheduled.

Strobo32,
Those pics are pretty crazy. I too think it looks like overpressure. The brass flowed out into the ejector hole. I've never seen that on an OOB (as the pressure doesn't get high enough before the case blows out.) Reloads or factory ammo?

 

[M10]

I worry about early detonation, or an OOB det. Seems the few jams I've had, the bullet was set-back, and the cartridge never made the chamber. As a cartridge jams in the barrel's locking lugs, what's to stop the bolt from hitting the primer, and making a kaboom boom? The primer does not care what hits it, as long as the force is adequate to trigger it.

I suppose that could happen with a semi-auto, as well, but in decades of shooting AR platform rifles, I've only experienced one bullet setback. (Interestingly, a 55gr IMI cartridge, the same type ammo that I had setbacks with in my Lage upper.)

 

[rsideout]

Late to the party but received mine this week. I think my number was in the upper 600s. Probably won't be able to get it to the range until the 28th when we have a MG shoot scheduled.

S, I had mine at our last shoot on 8/7. It ran 100% regular and suppressed. But a bit gassy suppressed.

 

[smdub]

I worry about early detonation, or an OOB det. Seems the few jams I've had, the bullet was set-back, and the cartridge never made the chamber. As a cartridge jams in the barrel's locking lugs, what's to stop the bolt from hitting the primer, and making a kaboom boom? The primer does not care what hits it, as long as the force is adequate to trigger it.

If your primers are flush or below, like they are supposed to be, I don't see how the bolt itself would set them off. You'd have to catch one of the locking lugs just right. Not sure there is ever enough angle there even as it starts stripping a round.

OOB is theoretically impossible in an AR. The firing pin is not exposed until AFTER the bolt lugs rotate and then the bolt goes into the carrier enough to allow the firing pin to be exposed. It simply can not touch the primer until the bolt is collapsed into the carrier, which can only happen if the lugs are fully locked in battery. Even if you welded the firing pin in the forward position in a semi auto AR, as you released the BCG, it should start stripping rounds from the mag and firing them in full auto until the mag is empty. Prove this to yourself: Go grab an AR BCG, hold the firing pin fwd w/ your finger and play w/ the camming of the bolt. It must rotate (=in battery) and then go into the carrier before the firing pin will ever protrude. The MAX11A/15 is using the same principal. (I'm fairly certain the open bolt Colt LMG ARs work the exact same as the Lage.) Firing pin doesn't extend until the lugs rotate fully into battery and the bolt and carrier are allowed to collapse. The Lage /15 is NOT using API like the pistol caliber uppers do.

Now, I said theoretially impossible. A broken firing pin tip that gets stuck protruding from the bolt could cause an OOB. A broken (or missing) cam pin could cause the collapse of the bolt into the carrier without any lug rotation if its stopped at just the right angle to go into the barrel locking extension smoothly. So if stuff is broken in a particular way it is possible. Nothing is ever truely impossible.

 

[smdub]

S, I had mine at our last shoot on 8/7. It ran 100% regular and suppressed. But a bit gassy suppressed.

Cool. I know Brian has his already too. Did you adjust the gas block when suppressed? I should go put an OSS muzzle device on mine so I can test those.

 

[rsideout]

Cool. I know Brian has his already too. Did you adjust the gas block when suppressed? I should go put an OSS muzzle device on mine so I can test those.

I didn't adjust anything. It worked great out of the box. I put an AAC 51T flash hider on and ran it with my old AAC M4-2000.

 

[CKxx]

Late to the party but received mine this week. I think my number was in the upper 600s.

Are you saying 600 on the wait-list?

 

[m11stuff@hotmail.com]

Not likely.

 

[A&S Conversions]

If your primers are flush or below, like they are supposed to be, I don't see how the bolt itself would set them off. You'd have to catch one of the locking lugs just right. Not sure there is ever enough angle there even as it starts stripping a round.

OOB is theoretically impossible in an AR. The firing pin is not exposed until AFTER the bolt lugs rotate and then the bolt goes into the carrier enough to allow the firing pin to be exposed. It simply can not touch the primer until the bolt is collapsed into the carrier, which can only happen if the lugs are fully locked in battery. Even if you welded the firing pin in the forward position in a semi auto AR, as you released the BCG, it should start stripping rounds from the mag and firing them in full auto until the mag is empty. Prove this to yourself: Go grab an AR BCG, hold the firing pin fwd w/ your finger and play w/ the camming of the bolt. It must rotate (=in battery) and then go into the carrier before the firing pin will ever protrude. The MAX11A/15 is using the same principal. (I'm fairly certain the open bolt Colt LMG ARs work the exact same as the Lage.) Firing pin doesn't extend until the lugs rotate fully into battery and the bolt and carrier are allowed to collapse. The Lage /15 is NOT using API like the pistol caliber uppers do.

Now, I said theoretially impossible. A broken firing pin tip that gets stuck protruding from the bolt could cause an OOB. A broken (or missing) cam pin could cause the collapse of the bolt into the carrier without any lug rotation if its stopped at just the right angle to go into the barrel locking extension smoothly. So if stuff is broken in a particular way it is possible. Nothing is ever truely impossible.

You are certainly entitled to your opinion about an OOB in an AR. I have had one using my DIAS. I had a bad mag. The round popped up and the point of the bullet went into the top of the upper. The upper was fairly new and the corner of the bolt was sharp ,hitting squarely on the primer and the round went off. Luckily for me, the round exploded toward the inside of the upper instead of toward the port door. I bet over the years that I have shot close to 100,000 rounds in closed bolt machineguns. The vast majority in the AR platform. That is the only time I have had an OOB. I have had three OOBs in my Mac's in factory configurations.

Scott

 

[techspy]

I have had what appears to be an OOB discharge twice with my 762x39 setup. I have a whole new barrel, bolt etc to test but haven't had time yet. Def doesn't seem to be over pressured rounds. Same thought as others, how is it possible with an AR BCG? One thought I am exploring is the possibility the barrel rotated a little. Def putting the wrench on full when tightening now. Info and picts in this thread http://www.uzitalk.com/forums/showthread.php?97796-MAX-10-15-11-15-Caliber-Mod-Thread

 

[smdub]

You are certainly entitled to your opinion about an OOB in an AR.

I covered your exact example in literally my second sentence: "You'd have to catch one of the locking lugs just right." I've never heard of it happening but could imagine it. Interesting to know that it is actually possible. 1 out of 100,000 rounds is pretty much a fluke though.

 

[smdub]

Are you saying 600 on the wait-list?

Not likely.

I looked back into this. Per my Jan 9, 2018 email from Jackie: "I have added you to the list and you are #688." I see now that was for the original MAX11/15. When my number came up for that one and Jackie contacted me, I had learned of the MAX11A1/15 and I asked to be put on that list instead over the phone. I now see I was never given my number for the new A1 list. Sorry for misleading folks.