build advice, I guess?
Posted by PhilosophyEnough1866@reddit | GunnitRust | View on Reddit | 19 comments
anybody have recommendations for the thinnest thickness of sheet metal I can get away with building a direct-blowback 7.62x25 pistol from? I can provide the blueprints if that would help. I do not trust the sheet metal I have, so I'm gonna buy some, but I couldn't find anything about what the thickness ought to be. this is my project for spring rust. I appreciate any help, but if there is none, I'll just err on the side of caution.
GunnitRust@reddit
https://old.reddit.com/r/GunnitRust/comments/1s6jgnb/winter_rust_2026/
Join us please
PhilosophyEnough1866@reddit (OP)
will do, that's partly what I planned this for. I think I may have signed up for spring rust as well, not sure.
GunnitRust@reddit
Good to go. Post.
PhilosophyEnough1866@reddit (OP)
okay. I've got something to post, but I'm having difficulties posting the pictures. nothing on gunnitrust's end, the pictures just won't upload to reddit in general. I'll try again later today.
GunnitRust@reddit
I tend to use Imgur
GunnitRust@reddit
What’s the design, chief?
Bolt or slide? Some kind of locking action.
If you’re going a slide look at the old Sigs. Pressed slides with a breech block
PhilosophyEnough1866@reddit (OP)
slide. thank you for the advice, I'll look at them.
GunnitRust@reddit
They used roll pins to retain the blocks. It might simplify your whole build process.
I’m happy to see anything in a bottleneck.
Do you have anything done now or is this your first build?
PhilosophyEnough1866@reddit (OP)
I've done about 8 single shot .22LRs, both rifles and pistols. 8 counting one I made of wood which exploded (mildly) after the second shot. and one open bolt .38 special that's almost impossible to charge. which I haven't fired. so far I've drawn up the blueprints and cut and bent part of the frame and the slide, but I botched the slid. I may end up redoing that part of the frame with some thicker sheet metal.
GunnitRust@reddit
https://old.reddit.com/r/GunnitRust/comments/1nt61e5/summer_rust_2025_complete_year_2025_winter_rust/
You can post that stuff in the contest.
PhilosophyEnough1866@reddit (OP)
oop, never mind. I posted them to r/HomemadeGunSmithing, not here.
GunnitRust@reddit
Fair game then .
PhilosophyEnough1866@reddit (OP)
I've posted all the ones that are still in existence, I think. except for the .38 special. for the first bit of time I was making guns, I pretty much disassembled each of my projects after a bit to use reuse the parts. one of the few I didn't, I gifted to a friend.
ZombieHoratioAlger@reddit
Standard AKs use 1mm sheet for the receiver, "heavy" RPK/Yugo lowers are 1.5mm. They (and basically every other stamped-sheet gun) also have solid trunnions and reinforcement blocks welded in critical areas.
That said, the grade of steel and number/placement of reinforcing ribs are just as important as the base construction material.
RunkkuTunkku74@reddit
There really isn't any one single right answer, it very much depends on the design.
PhilosophyEnough1866@reddit (OP)
okay, yeah. I kinda thought that might be the answer.
RunkkuTunkku74@reddit
I'd start with finding out what you have (material, heat treat, thickness, etc.), and comparing its yield strength to the forces your bolt is going to experience and impart into the rest of the gun.
Or just look at what other guns do, guesstimate, and see if it works, testing with a pull-string recommended.
LocationGlittering44@reddit
I don't think MACs,blowback aks or ppshs are super thick since the trunnion does the work there. Anyway I'm just here to bump the post
PhilosophyEnough1866@reddit (OP)
fair point. I thought of that, but wasn't really certain if it translated to a pistol. thanks for the bump.