Greetings,

I don’t see anything .40 caliber on your website.
What are your thoughts on a short .40 upper? Is it not a suitable round for a PDW build based on pressures or other factors?

I have a dedicated Glock magazine lower SBR that I’ve only had in 9mm.
Thinking multi caliber options but am limited by magazine size to 9mm,.40 and .357 Sig.

While I’m riffing here, would it be possible to do a .22LR using G44 mags?

Thanks in advance for your input.

Here is a picture of a Glock G44 magazine next to a Black Dog Machine AR magazine. The Glock G44 mag is too wide to even fit between the rails on a 22 bolt. It would never feed unless you modified the G44 mag to sit high enough inside the bolt rails.

Attached File

I have a 4 ib bbl in 40 S&W I built to run suppressed. You'll need a heavy buffer & make sure your brass is sized eright.

I have to agree on a heavier buffer for 40S&W. While my 9mm runs fine with a 5.5oz buffer, I would go with a heavier buffer for 40. I would probably go with Rudy's adjustable extended buffer and run it at 7.5oz.

Rudy replied in a thread in the AR-15 Rimfire and Pistol Caliber section that he recommend a 8oz buffer for 40S&W.

Pardon for the tardy reply......but working about 60 to 70 hours a week to try and keep up....:-) 40 isn't on the website simply because of demand......I can and have built a bunch of them over the years as special orders. One of these days we'll get the time to update the website......but being a two man shop I prefer to spend my time in the shop filling orders.... Let me know what you'd like and I'll be happy to build one up for you.
As far as the 22.....it can probably be done......but getting time to look into it will be tough for now......I have three development projects on the bench right now that I have significant investment in that I can'
t get too.....
Rudy

Thank you all for the information.
I will email you Rudy, the .22 thing was just a random idea but I will want a .40 upper.