Maxim Defense RDS

[M90A1]

Anyone tried one of the Maxim Defense RDS, roller delayed blow-back setups for 9mm AR PCCs? Should make a 9mm blow-back AR a mite softer to shoot. Might be good for Steel Challenge type competitions. Anything to make a 9mm AR act more like an MP5.

[Stickman]

Anyone tried one of the Maxim Defense RDS, roller delayed blow-back setups for 9mm PCCs? Should make a 9mm blow-back AR a mite softer to shoot. Might be good for Steel Challenge type competitions. Anything to make a 9mm AR act more like an MP5.

I have a MP5 and a 2 Stribogs are are RDS, and the difference is notable when compared to direct block back systems. The 16" Stribog is so much fun it is obscene.

[Screwball]

I just ordered one from Optics Planet…

Only negative I’ve heard was it can be a little stiff running the bolt due to the rollers. But if I can take out the bolt weight and 11 ounce buffer, I’ll be happy.

Big thread on the other site, if you wanted some more input.

[Screwball]

So, I got mine today... plain white box, no paperwork.

Started off with weighing my AR-9... 6 pounds, 12.7 ounces. Stern conversion that I swapped a slick upper on (6" barrel, 8" forend), Dead Air Odessa, SIG Romeo5, Surefire Scout light, Magpul MBUS, MFT Minimalist stock and an 11-ounce buffer (runs the suppressor at all times). SBRed... in case ATF is looking in.

Pulled out the buffer and retainer pin... put it back together to see how bad it is to charge... DOESN'T MOVE! Duh, got to remove the bolt weight.

Do that, put it back together and noticed that it was preloading the buffer (bolt pushing back on buffer when I closed the upper). Wasn't too bad to charge. Since I had it somewhat apart, I backed the buffer tube out a turn. It seems like the bolt and buffer are just touching, but not to the point that it is pushing back on the buffer assembly. Put it back together... it was tougher, but not too much more. Charging handle is a Gas Buster 9mm with the Combat Latch.

I'm leaving it in the backed out position, mainly because I want as much delay as possible... being the gun runs suppressed 100% of the time.

Final weight after the Maxim install... 6 pounds, 6.3 ounces. All the parts removed (buffer, spring, bolt weight, retainer pin/spring) come out to 14.8 ounces. It feels noticeably lighter but did get slightly nose heavy. I'm not off for a decent amount of time until the middle of the month, but I'll be going to the range with it to test it out. Recoil and suppression are the bigger things. If I get the extra turn on the buffer and no worse in the sound department... I'll likely do that (slightly easier to charge). But I have a feeling this is the answer to the 11-ounce buffer.

[joedirt199]

I have one I am about to finish when my lower parts arrive today. Making an MP5 wannabe out of a PSA AR-V reciever set. Was getting fed up with my CMMG RDB not working and went this route.

[joedirt199]

Finally got to shoot my Maxim buffer system with my new Palmetto State AR-V setup. Had mixed subs and supers in the mag and the sound difference was great. Ejection was positive vs my CMMG RDB that has been nothing but problems when the ejector spring gives up. Had a Silencer Central Banish 45 on it. I have the Palmetto mags so far but have some Magpul CZ Evo mags on order to try. Was really impressed with the Palmetto reciever group and bolt. Should be a fun little PCC. I used a PRI gasbuster charging handle with large latches and if you leave the buttstock in your shoulder it is not that bad to charge the gun.

[Screwball]

I yanked mine out of my suppressed 9mm SBR. Too much more gas to the face, and it was a pain to charge. Put the weight back into the bolt and reinstalled the buffer and retainer.

I have a DOE upper that I’m planning on running with the binary lower I have (11.5” SBR). Probably will use the Maxim with that setup.