I found some 3/16" structural steel blind rivets online. I can't remember the site. I have been staring at a top plate and a sideplate held together with clecos in my office for awhile now and it just got me thinking of the possibilities. I already have the solid rivets and bucking wedge.Is there really any legal prohibition to using screws for assembly of a firearm? I've not seen any reg or letter ruling to that effect. Of course that means little.
Structurally screws are not a bad way to go. I've done a few post samples that way because it was quicker and more readily removable so that parts could be salvaged without damage in case of a sale where the buyer didn't want to get a demo letter.
As for structural rivets of the blind type, what would you use that fits the description? For aircraft use there are a number of possibilities but all of them are aluminum rivets and not safe for use in the 1919. There are some steel pop-rivets out there but I don't think they'd be safe to use. There are some other types like the exploding rivets but I've never seen them in steel and haven't seen any at all for about 30 years....I just don't know of any blind rivets that would be suitable for use in the 1919.
As for legality, I don't see why they would be any different than solid rivets.
I think blind rivets on the top plate of the M2HB would fit unless you had a bolt latch bracket but besides the short rivets on the trunnion nowhere else is possible due to interference. I have been staring at this top plate and left side plate held together with clecos too long lol.Will the blind rivets be flush on the inside of the Side plates? Most I've worked with are not, and that is going to interfere with the internals.