Advise on Gas Piston Upgrade

[Rick Means]

I am thinking of a gas piston upgrade for my M&P AR-15. I have looked on line at the Adams Arms, The Osprey, and the CMMG. Do you guys have any advise on which one works best, and if they are a bad idea in the first place?

 

[drmitchgibson]

I used to want to do this, but I'm off that band-wagon. A free-floating barrel is going to wring out all the accuracy you can hope for. Attaching the barrel to the receiver at two points defeats the accuracy because of unequal heat dissipation, plus you'll be putting pressure on a handguard attached to the barrel and gas system, further degrading accuracy.

 

[DoctorJJ]

They are a solution to a non-problem.

 

[argyle64]

They are a solution to a non-problem.

This is true.

 

[TroyF]

To expand on what JJ is saying, Rick....

The upside to the piston system is they are suppossed to be cleaner. This simply isnt true. They still get dirty, just in a different place (not in the bowels of the receiver). You still have to clean them.

Stick with the design that has been working for 40+ years. No need for the added expense of converting to a piston.

 

[Chambers]

I am thinking of a gas piston upgrade for my M&P AR-15. I have looked on line at the Adams Arms, The Osprey, and the CMMG. Do you guys have any advise on which one works best, and if they are a bad idea in the first place?

Hey Rick - a purpose-built piston gun is one thing, but these kits are mostly marketing hype. A properly lubed AR will run and run.

 

[Rick Means]

You'd think I'd know better. Like grandpa used to say - "don't try to fix what isn't broke!" Thank you all for the reality check. I'll save the money and spend it on a free float handguard instead.

 

[argyle64]

Also, from what I've been told, and I may be wrong here. I've been told direct impingement systems produce less recoil resulting in greater accuracy.

 

[Matt1911]

I haven't heard of a piston "upgrade" kit that's reliable yet.
Don't try to fix what isn't broke.

 

[bsmith918]

I'm not a fan either. It just seems like there's more to go wrong and no tangible benefit.

 

[Scott Hearn]

You'd think I'd know better. Like grandpa used to say - "don't try to fix what isn't broke!" Thank you all for the reality check. I'll save the money and spend it on a free float handguard instead.

Wise choice.

My M&P15 just runs and runs. I don't even know how many rounds it's been since I cleaned it. Lets just say that to get it cleaned properly is going to require a good long soak in kroil. As in a couple of days soak.
I just re-wet it with CLP and it's keeps on going. It's the energizer bunny of rifles.

 

[dennishoddy]

I haven't heard of a piston "upgrade" kit that's reliable yet.

Don't try to fix what isn't broke.

I don't have any experience in trying one, but have seen several folks at the range have major problems doing a conversion.

 

[aestus]

The conversions are hit or miss. If you want a piston, save the money for an AR built from the ground up for a piston like an LWRCi or the piston LMT's. However, what makes LWRCi and LMT's run so flawless is less the piston, but the fact that both companies are top tier companies that buids top shelf rifles. The same can be true for DI guns built by Noveske, Daniel Defense, JP, ect. If the rifle is built right with quality parts, it's going to be pretty darn reliable regardless if it's piston or DI.

Upsides to piston AR's:

• Unless you're running a can, the chamber can be cleaned by wiping it down. Leave the carbon scraper in the toolbox
• Bolt is kept cool enough to touch even after hundreds of rounds. This means bolt stays lubed and doesn't get burned off
• Proper piston systems are usually "self regulating" so there is less worry about improper amount of gas being routed back into the BCG due to out of spec gas holes, ect.
• Cleaning takes maybe slightly longer than cleaning a glock. (Pistons are usually self scrapping / self cleaning. No need to clean the piston, maybe a disassembly and inspection every 1000 rounds)

Downside to piston AR's

• Adds weight to the front of your AR. Depending on what rail / handguard you use, it can get front heavy very fast.
• Depending on the type of piston system, it may affect accuracy a little.
• If the piston system is an older gen model or improperly made, it could cause wear in the buffer tube due to carrier tilt and abnormal wear in the upper reciever due to the cam pin. Also can cause peening in your barrel extension.
• Cost - upgrading or buying a good piston AR is going to cost you $$$$. An LWRCi can get you 2 decent DI AR's.

I own both DI and piston AR's and I do enjoy my piston AR's a lot. The biggest benefit for me is the reduced cleaning time and that I don't have to worry about squirting lube in the bolt after hundreds of rounds. The piston stays wet even pushing about 1000 rounds and hiking all with it on my buddy's land. What I hate the most about it is the weight. I would much rather hike around with my Loki than my LWRC.