Adams Arms Piston Upper

[johnhmpg]

Went to FreeState today and finally got to shoot my new build.
LRB Lower
Daniel Defense LPK
Wilson Combat Single Stage TTU
Hogue Grip
PWS Enhanced Buffer Tube
Spikes ST-T2 Buffer
Tubb Precision CS Buffer Spring
Magpul ACS

and my new Adams Arms Mid Length Gas Piston Upper.

Fun to shoot. Accuracy seemed good. I'm sure it is much more accurate than I am. Awesome trigger. Put 120 rounds through it.

Shot both 223 and 556 ammo. Had some short stroking with the 223. Was a little concerned about this when I put the T-2 buffer in it. Going back next week with a friend of mine and going to swap buffers/springs with him and see how it does.

 

[BradMacc82]

What type of lube are you using?, on the gun of course...

 

[johnhmpg]

Had it very lightly oiled with FP-10. Might try some Slide Glide I have a tube of it somewhere around here. The charging handle did seem a little "gritty?" Did fire all the 556 ammo without a hitch.

 

[BradMacc82]

Slip2000 has worked very well for me and both my upper's, d.i. and piston, doesn't burn off and cuts friction down. Charging Handle you can use hi-temp grease, feels a little cleaner also when you use it.

What brand of .223 were you using?

 

[johnhmpg]

I will get some of the Slip2000 and give it a try. I was using PMC Bronze 223A. Also used the PMC X-Tac 5.56 XP193 and I don't believe I had any issues. Unfortunately I ran out of the X-Tac before I could prove it was the ammo. BTW I did try various magazines so it wasn't a feeding issue with them.

 

[BradMacc82]

You may have just gotten some softly loaded rounds or had too much drag on the bcg, my piston experience was the other way around, I was having extraction issues vs short-stroking. Diff't buffer spring solved that. Heavier Buffer's made it more enjoyable too.

Now, at the risk of being the sole target of Lord Chad's rage, I actually enjoy shooting my piston upper.

Was your bcg dry when you went to clean it?

 

[johnhmpg]

It seemed fairly dry. Wiped it off with a paper towel and other than a little black residue there wasn't much oil on it.

I think my combination of the PWS Buffer tube "A dead blow buffer is securely installed in the rear of the buffer tube to reduce carrier speed by an average of 10%, and dramatically reduce felt recoil."

and the Spikes T-2 Buffer and Tubbs spring might be too much.

 

[BradMacc82]

Very possibly, I'd throw the stock buffer spring back in first and see how it does, but the Slip2000 is still recommended either way.

 

[clandestine]

Get rid of the tubb spring. They are worthless unless the gun is overgassed.

 

[johnhmpg]

Get rid of the tubb spring. They are worthless unless the gun is overgassed.

I figured you would have a quick diagnosis. I will try out a Milspec spring this week.

 

[Russ D]

Perhaps next time on a new build start with all standard parts and then add one at a time. Its hard to dignose an issue with multiple "upgrades". You can't do better than reliable functioning. Trying to adjust recoil with the buffer system is for games rifles.

 

[johnhmpg]

Perhaps next time on a new build start with all standard parts and then add one at a time. Its hard to dignose an issue with multiple "upgrades". You can't do better than reliable functioning. Trying to adjust recoil with the buffer system is for games rifles.

I agree but its a little late for that now. I'll get it sorted out.

 

[BradMacc82]

First off, I'd go back to your original buffer spring, if it still s/s - original buffer as well.

I'll have to agree with Russ, playing with buffer's for recoil is a 'games rifle' thing to do, but I like to tinker, even if it's at the cost of my sanity and spare cash at times.

Nothing ventured nothing gained. Guess that's why I went down the Piston rabbit-hole to begin with...

 

[johnhmpg]

Day Two: Went by 2A Sales and picked up 120 rounds of 556. Also showed Mark the AR and he noticed that the bolt was not going as far back as it should. So home I went an snipped off one coil at a time on the Tubbs spring and around 5 coils later it was locking back where it seems it should. On to FreeState where it ate up all 120 rounds without a hitch. Fed it 40 rounds of 223 and had 3 FTF. Think I will leave it alone and run a couple hundred more rounds of 556 through it and then try out the 223 again. If its still an issue then I will snip off a few more coils.

All in all very happy with the piston system.

I never purchased a Milspec spring or buffer so I didn't have that to try out. Might go get one of each just to test and see what happens.

 

[BradMacc82]

Standard carbine buffer I can give you if you need one, although they're not expensive by any means either..., should be able to find one without any issues.

 

[johnhmpg]

Standard carbine buffer I can give you if you need one, although they're not expensive by any means either..., should be able to find one without any issues.

Thanks for the offer. I am going to pick up a spring and give it a try first. If that solves the issue with the 223 ammo then I think i am going to snip of a few more coils on the Tubbs and see how that works.

 

[Russ D]

Day Two: Went by 2A Sales and picked up 120 rounds of 556. Also showed Mark the AR and he noticed that the bolt was not going as far back as it should. So home I went an snipped off one coil at a time on the Tubbs spring and around 5 coils later it was locking back where it seems it should. On to FreeState where it ate up all 120 rounds without a hitch. Fed it 40 rounds of 223 and had 3 FTF. Think I will leave it alone and run a couple hundred more rounds of 556 through it and then try out the 223 again. If its still an issue then I will snip off a few more coils.

All in all very happy with the piston system.

I never purchased a Milspec spring or buffer so I didn't have that to try out. Might go get one of each just to test and see what happens.

Do you know anyone who will lend you another lower to try? That would be the easiest way to figure out the issue. I'd be more than happy to let you try one of mine. Not really sure why you are happy with a system that isn't performing correctly, but am willing to help you get it where it should be.

 

[johnhmpg]

Do you know anyone who will lend you another lower to try? That would be the easiest way to figure out the issue. I'd be more than happy to let you try one of mine. Not really sure why you are happy with a system that isn't performing correctly, but am willing to help you get it where it should be.

I have a coworker who is going to try and go to the range with me this weekend with his totally stock Bushmaster. We will try his lower.

Thank you for the offer. Amazing how many good folks there are on here.

I'm happy with the system since it is functioning perfectly with the 556 ammo and its a pleasure to shoot. I had never shot a piston system.

I am 99% sure its the Tubbs spring. I was originally unaware that they send you the same spring for rifle and carbine. Its a one size fits all...except it doesn't in all cases so trimming a bit off at a time until it stops short stroking with the 223 ammo.

I have ordered a stainless Milspec carbine spring as well just in case I get over zealous and snip off one too many coils. Its a $9 insurance policy.

 

[Russ D]

Do yourself a favor and get a Colt carbine spring and be done with it. Most aftermarket springs are +10% minimum.

 

[BradMacc82]

I did a Wolff Extra Power spring in mine to slow the bcg down in mine on the recoil stroke(dwell time was too short on the very well-worn factory spring). Russ is definitely right there, the Wolff was safely 10% longer, and get a Colt spring and be done with it. If your enjoying the tinkering, that's one thing, but if you just want to shoot .223/5.56 reliably and quickly, get the Colt spring.