[shadow29483]

From an opinionated view of us board members.
Besides of the lack of tools/equipment for a rivet build could someone explain the pros and cons of a screw build vs. a rivet build.
Such differances may include,
Strength? Longevity? Performance?
Not including originality.

 

[7.62x39]

First off I've never attempted a screw build so I am by no means an expert on the subject.

The part that concerns me, is not so much rivet vs screw, it's the lack of material to screw to.

Especially the front trunnion. IIRC the trunnion is only .100 thick, even with a 32 TPI screw, you're only going to get 3 threads in the trunnion at best. With the swell neck holes probably even less.

The threaded hole must be at least as deep as the diameter of the bolt for proper strength, a 10-32 bolt measures approx .180 in dia.
Back when I was racing NHRA also required that the bolt protrude at least it's diameter from the rear of the nut.

Bottom line, I just don't think there is enough meat there.
I know others have done it, but I just don't like the idea

 

[Grendeljaeger]

From an opinionated view of us board members.
Besides of the lack of tools/equipment for a rivet build could someone explain the pros and cons of a screw build vs. a rivet build.
Such differances may include,
Strength? Longevity? Performance?
Not including originality.

I haven't done a screw build, but I believe if done right, with wire washers or tapered head screws that approximate the swell head rivets for the countersunck holes then the strength, longevity, & performance should be very close. I believe there are many screw builds out there with many thousands of rounds through them. Some of the pioneers like CampyBob used screws in their builds as home rivet builds, and the tools needed, are a fairly recent development.

Edit
See HCPookie's excellent Website for better info. http://pookieweb.dyndns.org:61129/
Also I defer to 7.62's experience.

 

[shadow29483]

Rivet vs. screw build?

To strike interest in this post for feedback.
I'm kind of taking a poll here just to see how many feel about the difference between the two. There's been alot of talk about setting rivets and tapping for screw builds, And many have done it. I too am one of many. To me in my opinion is that for a home builder, the screw build is more efficient and does not require any high priced presses or air tools to build.
I have three builds all with screws and none the less have failed. Sure you have to follow a set pattern each time you build which requires a little guaging in depth and p.p.s.i. but if done correctly and set properly I feel should hold firm and stand strong. With a screw build, if you mess up then you go back with ease. With a rivet it's a lengthy process to correct.
Rivets were the standard forms in factories fifty years ago. That in turn, a high demand for mass production was necessary and that was their key to a faster production of arms with the "Ak". But yet they were equipped for that method. Time costs money and in many cases unfortunantly lives. I guess what I'm trying to say is that, In conclusion if you think about it most rifles and firearms from then untill now show a similiar pattern.............They're built with screws.
Thanks,
-Shadow-

 

[sniper69]

so far I have done screw builds. I bought a triggerguard rivet jig from stickerman and so plan on rivetting the triggerguards. As for the other parts, maybe someday I will rivet them to say that I have done that, but the screws work good too.

 

[hotbarrel]

I have done one screw build and I am very happy with it. what I did was to screw the four against the barrel and used rivets on all others. It was an AMD65 and the barrels and pins come out very hard , mine did not budge so I left it and used screws.
Here is a point mentioned by another screw builder, it is obvious after he said it but I did not think of it till he did say it. I think it could be a big advantage for some guys. WITH a screw build you can put differant set ups on the same reciever. MANY KITS ONE RECIEVER. this could be nice for some guys.

I was against the idea of a screw build till I did one. in my oppinion if done carefully, and properly I think it is fine.

 

[hotbarrel]

I realize it is a lot of work but has anyone ever filled up the space behind the hole , between the hole and the barrel ware the rivet head ends up. anyway if the space was filled up re drilled and taped you would end up with a couple more threads. I do not realy feel it is needed but it could get a full measured amount of thread , and this would answer the only real questionable aspect of the screws so far. honestly their is no need for the empty space with screws , their is no internal head, why not use that space for threads?? I know it sounds far out but it is just a thought.

 

[mbadboyz]

This is just my thought on this.

I have done 4 screw builds and no rivit builds. Except for riviting the rear trunion and center support.

My 1st was a screw build on a vulcan receiver and I have ran about 80 rounds through it. It has held up very well. I plan on testing it this weekend with 300 rounds. I hate burning up that many rounds just to prove a point but I will. The only thing I run into is tapping of the front trunion threads. It can be difficult at times. As for the rear trunion....I have been able to get all the old rivit out and thread both ends all the way threw. I use the blue bottle of thread loc-tite. Its like welding the screw in.

Im working on an underfolder kit right now and Im fitting my flat receiver(bent) for the rivits. This will be the first time with rivits in the front trunion. Wish me luck.

 

[shadow29483]

Hotbarrel,

Great insight! I'll try that on my 74 bulgy build this weekend. :thumbup1:
Just waiting on the receiver from O.O.W.
I'll let you guys know.
-Shadow-

 

[Texxut]

My question for the guys that screw build, is, when the trunion has the counter sunk areas what do you do with that? Just ignore it? Divot the receiver to match and use a screw that mimmicks the swell head rivet? Or something else?

 

[hotbarrel]

some guys use a screw with a head that fits into the countersink other guys put a small ring around the screw and use a standard styl head. you can use a center punch to "fit" the reciever into the countersink before you put the screw in.

 

[hotbarrel]

Shadow
some carefull welding inside the trunion and grinding after. or maby even some thread fixing liquid stealto fill the area. I would honestly recomend you do not get the trunion too hot if welding .. weld , cool, weld ,cool ,weld , cool a lot. do you have a TIG ? if yes you can put most of the heat into the fill rod and just enough into the trunion to flow it in. filling the area with some kind of liquid steal may be easy, less likely to mess up the trunion and allmost as strong. do one side let it harden dtrii tap then do the other side. then shape any high spots with a die grinder.
could you let us know how much thread area will be gained by this, in other words how deep the notches are in the back that will be filled up . we allready have the other measurements on this thread. you may gain 50 precent or so.

 

[Texxut]

Thanks Hotbarrel, that sounds like a good solution.

 

[shadow29483]

I would try to find screws that have the fluted or tappered head to get the depth.
HTH.
Shadow

 

[shadow29483]

Buck the screw as much as possible to pull the screw in to get as much bite as you can. If there's a few hundred thousandths in between it'll be fine.
-Shadow-

 

[mbadboyz]

I have been working on a rivit build since I have done nothing but screw builds. I must say that removing the barrel pin and barrel were not a difficult task. I went to autozone and picked up the pulley puller and it worked like a charm. Every bit of info I have gained is from our fellow members here at gunco.net. Im liking these rivit builds better than the other. I just feel it is being done the right way.

 

[shadow29483]

Mbad,
I agree!
The screw builds starting off, were much easier for a home builder before all of the rivet jigs came along. But now that knowledge and wisdom has played a huge roll in the building techniques for the home builder. The riveting is the way to go. I WILL NOT KNOCK the screw builds though. Seeing that I have almost 8 under my belt. And they have held up through many of thousands of rounds. And still going. That is if the method is done right.
Thanks so much for the pics,
Take care,
-Shadow-

 

[erikk]

I have done 5 65's 1 63, 3 PMKMS & a 74 using the screw build. I havent counted the rounds put through each one however each has had at least 100+ with no problems. The first few were made with the barrel in the trunion but when I got my press I now remove it before getting the rivet stubs out. I get a good thread cut and use 10/32 screws with the heads turned down in the drill press. I also tap the trigger guard, spacer & receiver in one shot and use the 10/32 screws. I haven't gotten around to lock tite the screws yet but so far everything is doing fine.
Going to try the rivet route on the next build just for the hell of it and to see if I can do it. I my opinion a screw build is the way to go for a first build because you will make mistakes and need to tweek things and it is easier to remove a screw than a rivet