I just finishing milling this raw aluminum lower and now I’m looking at options for finishing. The main Reason is the safety/ trigger pins, detent/ etc repetitive rotations and such. Just want to make sure it’s hard and won’t wear out prematurely. Any ideas before I hit it with a coat of clear and call it a day?

Thanks!

my side charging ar that I managed to make able be charged via slap

Otherwise known as sambung rounds

Two steel tubes, a 3d printer, and some steel dowel pins in standardized imperial measurements. Took me around 4 months to polish. PPSH sear and trigger combo. 10.5" Barrel, 9mm bolt & barrel/trunnion combo, 21.5oz bolt, chopped up Glock magwell + sleeve, and a cursed PPSH sear

Needed to mill a 1911 slide for a red dot. Since it was a new footprint for me, the CAD for which is often wrong online, and it needed to be at a 0.8-1 degree down angle. I figured I'd share my process. This is a DPP footprint on a 1911 slide done at 1 degree so it doesn't require a shim. CAD, CAM, workholding, setup, and milling.

tldr: the trigger group could be further back than the bolt moves without a new semi-only end on the bolt that slots into the trigger like a key in a lock, and the whole receiver could be print-in-place so it cannot have parts taken out of it to allow FA.

Could there be some printed receiver and trigger group that limits the bolt travel? That way, you can design a new printed add-on to the back of the bolt which latches onto the sear through some mechanism that could prevent full-auto conversion.

That way, all the metalworking for blocking bars and the like can just be replaced by printing instead. And then there's no way the bolt could be used in FA unless you completely redesign the barrel or trigger group.

You could use a print-in-place trigger group and receiver that you can't even disassemble to prevent parts from being taken out. If it breaks just print a new one.

I've had this idea for a little bit. This is basically a 12ga slamfire pipe shotgun that then feeds into a 1.5" pipe. I plan to shoot it using light hand loaded 12ga blanks loaded with tripple seven black powder substitute. Is there a way to get a rough calculation for the pressures I can expect? Id like a decent safety margin. And are there any other safety concerns with this general setup? I have heard muzzle loader guys talk about barrel obstructions such as a bullet that is not fully seated over the powder causing problems, but this is also functioning like a ww1 / ww2 riffle grenade, so I'm not quite sure which train of thought to follow there.

They're more involved in containing pressure so it seems more difficult. Is anyone working on this? Lots of parts kits could be opened up if we find out a way.

Could you get a PPS-43 or FMK-3 for under $250? Reweld an LMG for $1000? How much would change? How much does a post-sample build cost right now and how simple is it?

The integrated handle can also be used to store a ram rod and extra round parts can be interchangeable.

Recently acquired a thoroughly bubba’d sks. I plan on taking it off the deep end. Want to convert it to take ak mags. Was curious from people’s experience here how difficult and finnicky the conversion is, and if they think it’s worthwhile.

I have a buddy with access to a mill but he’s quite backlogged right now, if I end up taking it to a shop, what’s a fair price for such work?

Sadly I have no tape in my house

This is the next episode in my AK series and goes integrally with the riveting video I posted last week.

I'll try and post the other type of 80% finishing, a pre-bend, within the next couple of weeks which, with these other two, rounds out all the information on receiver finishing.

I have a couple vmac uppers for various builds but I see MPA defenders on sale and I don’t have a conventional mag-in-grip lower yet. Thing is the defenders on sale are top chargers and I want to run an optic. Can I put a side charger vmac uppers on an MPA lower?

Work in progress, will hopefully have a firing model soon.

All I Can Find Are Parts Kit Pdfs With AR15 FCGs, Surely The Original Documents Should Be In The Public Record Already?