Adam Arms piston kit failure

[KBScobravert]

I've never had any issues with any of my other AA piston kits, but this is my first pistol length. Keith has like 10 AA kits and has never had an issue.
I decided to just send Adams Arms an e-mail explaining what happened, and I linked this thread.

To the future AA employee to read this page.
My name is Keith, send me free shit.

CJ, we need some slow motion cameras, and lets take pics of a pistol rod, carbine rod, middy and a rifle all being fired.

I also think you were on to something with the spring and cup locking back on the rod.

[CJ]

So, I received a call from Matt at Adams Arms today. We went over the usual suspicions and he settled on the gas port being too large possibly. I honestly had never measured it. I was able to find a drill bit that fit into my gas port pretty snug with a few thousandths of play. my digital caliper read .078" so the port is around .080" or more in size - aka fucking giganic. Spec is .065" so it appears the problem is the barrel. I plan on contacting red-x arms tomorrow to see if they can swap me out for a spec barrel. If not I will weld the barrel and re-drill it to the proper size. Come hell or high water I'm having a piston damnit! Matt at AA is still working with me but was super cool and informative on the phone.

[inline 6]

Warranty Denied I take it? Will turning down the gas block not fix this? I thought this was the whole reason of having an adjustable gas block was to fine tune around things like that.

Are the holes larger on shorter barrels for a reason? Or do you think this is a quality issue?

[GAP]

Turn down a bushing with a .065" hole and press it into the underside of the gas block.

[phaux]

I would go the bushing route first if possible. Make sure you use some type of adhesive and that it's wedged in there super tight. I would be afraid of it falling loose from the extreme heat and jarring of the blast.

In regards to welding I would tig it at as low a heat as possible as I would be terrified to warp a barrell. Weld it as little as possible, the last thing you would want is to get even a tiny bit of warpage in that barrel.

[CJ]

I would go the bushing route first if possible. Make sure you use some type of adhesive and that it's wedged in there super tight. I would be afraid of it falling loose from the extreme heat and jarring of the blast.

In regards to welding I would tig it at as low a heat as possible as I would be terrified to warp a barrell. Weld it as little as possible, the last thing you would want is to get even a tiny bit of warpage in that barrel.

I'm going to go with welding it, only a few hundredths of penetration will do the job. You're not going to warp a 1" thick piece of stainless with a TIG. Red-X stated that they worked the barrels to be the most reliable. They said there is no standard for pistol length barrels, but since they run these barrels once every 1-2 months I'd have to wait, so I'll be welding it up. As far as AA I think they are going to take care of me.

[KBScobravert]

Turn down a bushing with a .065" hole and press it into the underside of the gas block.

CJ, I think this is the best option vs modifying the barrel.

[GAP]

I can even machine one for you if you like.

[KBScobravert]

I can even machine one for you if you like.

I would bet you could make a holley carb jet work with minimal work. They are already sized and labeled. Just need to get the height right and maybe trim down the OD. Doesn't need to be a press fit either. The barrel and the piston plug will keep it from moving.

[GAP]

I would bet you could make a holley carb jet work with minimal work. They are already sized and labeled. Just need to get the height right and maybe trim down the OD. Doesn't need to be a press fit either. The barrel and the piston plug will keep it from moving.

What is to keep the bushing from shooting up, into the piston plug? Isn't the hole in the plug the same size as the hole in the block? I dont remember on mine, and looking at it wont help since i've oversized the gas system when I was trying to get it to work on a 16" carbine gas 300BLK. Everything is .156", if memory serves me.

[CJ]

Yeah that's a whole lot of shit I don't want to deal with. 1 second with a welder and all of this is solved.

[bigshoe]

I would bet you could make a holley carb jet work with minimal work. They are already sized and labeled. Just need to get the height right and maybe trim down the OD. Doesn't need to be a press fit either. The barrel and the piston plug will keep it from moving.

How big is the hole in the gas block? An air bleed might work better than a jet, I think they are 10-32. You can get them blank and drill out your own size. Just tap the hole in the gas block and screw in the bleed.

[ThreeFingerPete]

Yeah that's a whole lot of shit I don't want to deal with. 1 second with a welder and all of this is solved.

CJ, I agree with you. It's ridiculous to go through all of that trouble to avoid a tack weld, polishing it smooth and redrilling.

[Nash B.]

I see what you did there.

[ThreeFingerPete]

I see what you did there.

No, seriously. Trying to reinvent the wheel to mill a spacer into the gas system is ridiculous. A gunsmith would just weld and redrill.