I'm thinking out loud for those who may be trying to make the same decision as I am right now.

I've decided for the first build I'll go with a 100% receiver.  I'll save the bending for a cheap dark bore romanian kit, and spend the $ for a 100% receiver for my underfolder.  This will give me a chance to get over the fear of rivets, barrel pressing, etc, without being tied down by the receiver itself.  It also gives me a receipt to prove when the underfolder was manufactured (as a safegaurd for future bans).   I dont want to give up my first build.

Next, I've been debating over a rivet, screw, or U Drive build.  I had planned to go U-Drive until I found out that I would need screws for part of the underfolder trunion, trigger, and part of the front trunion.  If I have to use 50% screws, what good is it to use udrives? I'd rather not mix and match along the side of the receiver.  At this point I think the U drives are out if I can't use them everywhere.

Next choice....screws... I may go this route. I havent decided yet. It seems like it's the easiest of all, and I could fill the screw heads to make them look like rivets.  As an added benefit, I could remove the screws later and rivet if I decide I want to.  Heard stories of them backing out, but with thread lock I can't imagine how.  I can't imagine any other problems with a screw build. Seems like the absoloute easiest. I could probably finish in a couple of hours.

Rivets... well obviously this is the best choice, but  it requires pressing out the barrel. Maybe thats not a big deal, but I'm still a little hesitant... the more I think about it the more I think this is the right way to go. I mean, if I can make an $18 pair of rivet squashers, then the only hard part is removing the barrel and pulling it back in.  That doesn't sound to bad... I'll have to beat it out with a hammer and pull it back in with a bolt and some nuts.  I think it's ok and a good intro to building.

So far it seems like the rivets wth 100% receiver wins for the first build unless someone shows me some good screw builds and changes my mind. I guess I should also say, I'm not against the screw build either.. I think it looks just fine and haven't completely ruled it out.

Hopefully the kit will arrive today.

Thanks for listening.

I have done all three types of build, but for the Polish underfolder that I am currently working on I chose rivets.  I will do a drive screw or regular screw build on a cheapo Romanian kit or a POS Yugo, but for the Polish underfolder I felt that rivets was the only way to go.

Quoted: Rivets... well obviously this is the best choice, but  it requires pressing out the barrel. Maybe thats not a big deal, but I'm still a little hesitant... the more I think about it the more I think this is the right way to go. I mean, if I can make an $18 pair of rivet squashers, then the only hard part is removing the barrel and pulling it back in.  That doesn't sound to bad... I'll have to beat it out with a hammer and pull it back in with a bolt and some nuts.  I think it's ok and a good intro to building. So far it seems like the rivets wth 100% receiver wins for the first build unless someone shows me some good screw builds and changes my mind. I guess I should also say, I'm not against the screw build either.. I think it looks just fine and haven't completely ruled it out. Hopefully the kit will arrive today. Thanks for listening.

I would go with moding the bolt cutters
you can press the bbl out with a hammer and vice
and press it back in with a hammer,vice and a piece of plexiglass
after doing 2 screw builds and then doing rivets I am kicking myself for doing screw builds I think rivets are easyer than doing a screw build the udrive thing would be easyer

If you want to build something thats worth something in the end rivet it
If you want to build a shooter thats not worth nothing but parts screw it together
If tou want to build a peice of shit that you cant tell if it is riveted or udrived then udrive it
just my 2cents not saying there is something wrong with udrives just not something that I would even think about doing

BLM

Do a rivet build. Pressing out the barrel is not that big of a deal. Just pre-soak the hell out of everything with either PB Blaster or Kroil a few days ahead of time. Heat up the barrel/trunnion assembly before removing the barrel pin and again when pressing out the barrel. Get yourself one of these Power Steering Pulley Pullers from an auto supply place.



It pops out barrels like it was made for it. Just use a couple of nickles to protect the barrel and crank 'er down.

Believe me, I've done both screw and rivet builds. You'll be a lot happier with a rivet build.

Excellent, thanks guys, thanks. Sounds easy as pie. I'll go with the rivets.

I'll have to pick up a bench grinder to make the rivet tool unless someone knows of someone with a set for sale pre-ground.

Quoted: Excellent, thanks guys, thanks. Sounds easy as pie. I'll go with the rivets. I'll have to pick up a bench grinder to make the rivet tool unless someone knows of someone with a set for sale pre-ground.

There are a couple of guys on gunco that have them for sale, also Maas guns has them.

gunco link

coyote3- where'd you get that puller from?  Is there a model/size or something?  

Do you use that to remove the barrel pin?

BLM- when you say you can press out the pin with a hammer and vice, are you talking about a BFH and just beating away with the vice holding it or does the vice play a slicker part in the whole thing?  

When you say to press it back in with a hammer and vice, are you just using the vice to squeeze it all together and using the hammer to get it started?   What is the plexiglass for?  Sounds dangerous to me...

Quoted: coyote3- where'd you get that puller from?  Is there a model/size or something?   Do you use that to remove the barrel pin? BLM- when you say you can press out the pin with a hammer and vice, are you talking about a BFH and just beating away with the vice holding it or does the vice play a slicker part in the whole thing?   When you say to press it back in with a hammer and vice, are you just using the vice to squeeze it all together and using the hammer to get it started?   What is the plexiglass for?  Sounds dangerous to me...

to take the bbl pin out I clamped it in a vice with an allen head socket on one side of the pin and 2- 3/4" nuts  on the other for a space for the pin to go put some pressure on it and then hit the vice with a BFH crank it down again and hit it again and so on untill the pin is out I would not do this with a new vice mine is old back when they where made out of real metal in the usa

when I used a vice to take the bbl out .I put the edge of the front trunion on the edge of the vice like you would clamp the rear site base and the spot where the handgards go in the jaws have someone hold it up for you put a nickel in front of the chamber then I have a 6" steel rod that fits in the trunion and hit it with a 2lb hammer if that makes any sence


putting it back in I used socandys method line it all up put a steel plate in the magwell thats 3/8 thick by 1 1/4 wide and 3" with notches in it to clamp in the edge of the vice then hold a piece of plexiglass on the end of the bbl and pound it in.I have also put a blank firing adapter on the end and just use a good peice of hardwood.It is not dangerous I have done it many times so far so good  It puts pressure on just the trunion, not the rivets or receiver with the allthread method
socandyman did a tutorial on his method with picks that could show this better than I can try to explain maybee he could dig them up

BLM

Quoted: coyote3- where'd you get that puller from?  Is there a model/size or something?   Do you use that to remove the barrel pin?

It's used to push the barrel out of the trunnion. The exact model isn't that important, they pretty much all work the same. You might have to grind the jaws slightly, to get it to fit the trunnion just right. Check out this GUNCO thread. It has all the answers.

thanks for the info.  

This evening I was able to remove the piston from the carrier.  That wasn't too bad.  

I was also able to remove the finish from the f*cking rifle by spraying carb spray on it.  I knew it was a Polish rifle, but didn't think the finish was purely Polish!!  The more I sprayed, the more black paint dribbled off...

Rivets are the way to go. It's not as hard as you think. Harbor Freight's 12-ton press is a great investment if you plan on building a few. Less frustration!