Posted: 7/28/2026 9:38:04 PM EDT
[Last Edit: willi3d][Edited]
|
I bought a DDM4 PDW upper in .300 BO, mated it to a lower fitted with the Maxim CQB stock with the H1 buffer, and was amazed how much gas was coming out of the ejection port with each shot. Also, when removing the magazine after firing, there was gas wafting out of the top of the empty magazine. This happened with both subs and supers, both unsuppressed and suppressed with a low backpressure suppressor (Sig Hexium 762). Anyone else experiencing this? I also have a Maxim 8.5” and a Gemtech 8” GVAC upper (same as the S&W Axe) and both have barely any gas coming out of the ejection port and nothing out of the same mags, all using using the same ammo and same suppressor. The only real difference that I can see is the DD has a 7” barrel and the gas block is right behind the muzzle. On the other uppers, there is more distance between the gas block and the muzzle, plus the Gemtech upper has their GVAC gas mitigation system. Is this normal for the DD? It’s a real delta with my other uppers. I’m considering trying to go up to the H2 buffer, and even trying a Griffin gas pocket BCG. I really don’t want to get into having to install an adjustable gas block. Note, I using buffer spring from Maxim, which came with the Maxim H1 CQB buffer. I believe this is the same as the silver spring included with the full factory gun. |