Who can help me with the Adams Arms conversion?

AR/M4 AR Technical Discussion
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Hello all, I’m pretty new here, after having wasted a LOT of time on the other site.:mad: I currently own a M&P 15T. It was my first AR and admittedly I bought it during the Obama rush. Don’t get me wrong I really like the rifle and it’s been rock solid so far, but now I want to build my dream rifle.

So far I have a Noveske blem lower(not my dream but affordable), CTR, H buffer, Miad, and RRA NM LPK. I am going to SBR the lower and eventually run a suppressor on it. After doing a lot of research I have decided I want a 10.5 even though they are louder and more destructive on the can, I want the overall package to still be shorter than my 15T. And I just love the way a 10.5 looks:D

First of all the rifle will be used as a range toy, SHTF, and home defense weapon, pretty much all purpose. I’ll be building a KISS rifle next so that’s one role it won’t have to fill.

Now for the questions. Do any of you have any experience with Adams Arms piston conversion? I searched and only found a couple threads with very little info. I know a piston doesn’t mean I’ll have less cleaning to do but I do like the fact that it lower the heat in the chamber. I also like the fact that I can tune the gas output. My thinking is that less gas pressure will help cut down on failures and increase the reliability of the rifle. I know it won’t keep it from breaking, just maybe slow down the process. Are there any brands of barrels that are better suited for the conversion? I have narrowed it down to BCM, Noveske, or DD. Are there any that I’m overlooking?

As for the rest of the upper, I want to finish it off with a DD FSP 9.0, DD fixed sights, (maybe BUIS for the rear), and BCM BCG and charging handle. What kind of upper receiver will match the finish on the Noveske lower? Considering the rifle will be used for HD and SHTF what optic would you recommend? Should I look at fixed low power, like an ACOG? Or maybe a RDS?

Sorry for all the questions. I just want to get it right the first time. Oh, and I know I could probably just buy a piston upper and be done with it but I want the experience of building one and I think it will be cheaper this way. Please correct me if I’m wrong.

Thanks for all the great info on this site.

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I had ADCO do the AA Retrofit kit on my LMT 10.5" SBR. 1400 rounds so far, no problems. No carrier tilt, at all, so far. I use an H Buffer. After about 400 rounds I noticed some wear on the upper from the cam pin. I got the POF Roller Cam Pin and I haven’t seen further wear. I think that it added front weight to the SBR, which has helped with muzzle jump. I’m happy with it.

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Thanks for the tip. I wasn’t even aware that cam pin wear could be an issue. Is that a symptom of using a piston system. Not that it matters really, for $20.00 it’s worth it to reduce any friction you can on the BCG.

What are your feelings otherwise on the conversion. Do you notice less heat in the BCG area, how clean does the system run? Most importantly, have you run it with a suppressor yet?

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I believe that the cam pin wear is an issue for all AR pistons.

I have not run it w/ a suppressor yet:(. The BCG stays cool. Although, I do want to mention that when comparing the AA Kit to my DIs, I have to say the DIs stayed much cooler than I expected. One of the biggest advantages I have found in this kit is it’s significantly cleaner than DI. After about 400 rounds, the AA Kit only required minimal cleaning with no carbon caked on. The DI was much dirtier, and had carbon build up. BUT, where the gas vents at the end of the forearm, you will get carbon build up there on the rail/forearm, and you will need to clean that (where as on the DI, you would not). No free lunch.

*Lots of folks ask if I’ve run steel cased ammo through it. I won’t run steel cased ammo through any of my ARs. I spent a decent amount of $, and I won’t feed it the crappiest ammo. Wouldn’t put the cheapest oil in a Corvette, right.

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Have on and love, runs cleaner, cooler, and after 1000 rounds no real problems to report. Some minor ware in the buffer tube, but it is barley noticeable. Great upgrade for me, just wish that I would have waited until now to do it, they are a lot cheaper now.

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How hot does the piston block get? Would it be too hot for a Magpul flip up front sight?

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Yes, I’d think it would be too hot for an MBUS.

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Anyone else have any experience with the Adams Arms piston conversion?

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Yes. Pistons have a much sharper, noticeably stiffer impulse in their recoil. The replacement parts are more expensive than a standard gas tube. Don’t spend the extra money on the op rod kit, it’s not worth it.

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Is this the consensus on piston rifles in general or the AA kits. I can live the sharper recoil if there is a defined advantage when running a suppressor. Is there?

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Take both NEGATIVE opinions & POSITIVE opinions concerning piston systems with a grain of salt. They are usually HATED or LOVED. There are two distinct camps. The haters cant say anything nice about them as they see a piston as a waste of $'s, the lovers usually cant say anything negative.

That said…

I have done 3 AA piston conversions. a Carbine & two Middies.
Negatives? Well… I bought mine when the kits were $499 WITHOUT a bolt carrier included. Yeah OUCH! It hurt… but my only regret is I didn’t wait till a year later when the kits were <$350 WITH the carrier.

The kits go on very easily, IF you are mechanically inclined. You must follow the instructions, and verify the gas port alignment as well as ensuring the proper gap between the piston rod & carrier. But beyond that they go together painlessly.

Carrier tilt? I’ve run ~750-1000 ( I dont keep a log, but just considering the # of rounds I’ve reloaded ) rounds through each of the three rifles. There is NO sign of abnormal wear on my Receiver Extensions when compaired to my DI rifle.

Cleaning? Honestly… I wipe the BCG down with a rag & re-lube after each range session hardly any carbon & nothing caked on enough to need scrubbing. There is a little carbon out on my DD rails, but that comes off easy, Barrel is the same, and a wipe of the piston spigot & rod & you are done.

Gas Block Heat? YES… I have accidently grabbed the gasblock a couple times & while I didn’t exactly burn myself, the gasblock was above painful temperature. A Magpul AFG took care of my reaching up too far forward on the rail. So it may be too hot for a MAGPUL BUIS, but it really depends on whether or not you will be doing Carbine classes or slow fire strings. But really need to find out from Magpul on max temp of their BUIS.

Reliability? 100%… Well yeah so has my DI rifle. So not an issue either way.

Cool factor? PRICELESS! It works… Worth the money? well thats totally up to you. To ME… YES. But at the time I had the $'s to spend. I really LOVE my AA pistons, I’m going to build a 10.5" SBR soon ( getting ready to submit paperwork ), It will have an AA piston on it as well.

Ty Hoeffer
Palmyra, VA

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Nice review…

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Yes I would say that. I have a buddy that messed up his troy front sight. He said that it got so hot that the plastic pin in side melted. I personally run a fixed DD sight. Great sight and love using it.

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Thanks for the review.

But what about running one with a suppressor? I am building a SBR and want to maximize the reliability. Everybody says running a suppressor on 10.5" will be hard on the gun, will the AA lessen the likelihood of failure due to overpressure.

I am also assuming the AA kit will eliminate the gas blowback in the face from the suppressor, is that correct?