rivets

Post by **TOM R** » Sat Mar 12, 2005 8:36 am

we will need a rivit source, I think alum or stainless will work unless you are bluing or maganes finishing, it doesn't look like they take any stress

rat-a-tat-tat · Post by **rat-a-tat-tat** » Sat Mar 12, 2005 9:54 am

Tom, I got a rivet set from the same place I bought the rails, but it seems to me to be a waste of money, as there doesn't appear to be anything special about them. You can get rivets from McMasterCarr for about $6 per hundred (not 16 for $15).

Post by **aftershock2222** » Sat Mar 12, 2005 10:44 am

What kind of rivet tool would be needed?I was thinking before putting in the rivets,it would be good to hold the rails in using round head bolts and nylon locking screws to make sure everything is lined up right.

rat-a-tat-tat · Post by **rat-a-tat-tat** » Sat Mar 12, 2005 11:11 am

oops, I meant to say MSC for the rivet supplier. Rivet tools are available from US Tool at about $6 each.

Post by **TOM R** » Sat Mar 12, 2005 9:03 pm

I am guessing same rivet punch as used in 1919, tanker is working on a bucking bar system using me semi reciever, I need more rivets than the ones for rails, I need to mount rails, the bracket the trigger grip mounts on and one of the blocks at the rear of the gun that holds the buttstock on, I know rivets are cheap, I just don't know how to figure the size specs to order them, one of my big complaints on the 1919 is the cost of rivets, it is maybe $.25 worth of rivets and people charge $25.00 ++++

TANKER · Post by **TANKER** » Mon Mar 14, 2005 9:19 pm

Tom, I got the parts today and I've been looking them over. I emailed you to let you know. I found the BRP site and saw the pictures of the receiver halves, and of the "scrap" receivers. At this point I still don't know exactly what I'm looking at, but I like it! There will be no problem at all adapting my bucking bar system to fit with the MG42. Just a couple of milling operations to make adapters for riveting the rails. I'm thinking of an "add-on" set of small blocks to fit the rails so that if you already own one of my bucking bar wedge sets.....you'll be able to use it. Is there anyone near Paducah, Kentucky who is building an MG42? I'd like to see what all needs to be done. Rivets shouldn't be any problem either....we'll buy in bulk and spread them around. Thanks, TANKER

Post by **Reichpapers** » Thu Mar 24, 2005 9:18 pm

aftershock2222 wrote:What kind of rivet tool would be needed?I was thinking before putting in the rivets,it would be good to hold the rails in using round head bolts and nylon locking screws to make sure everything is lined up right.

NOt sure if that will entirely help. I have seen two builds so far where the bolt rode like a champ when the rails where put on with a not and bolt....but the moment you put those rivets in the bolt seizes up as the rails change when the rivets are in....ask AK47Dennis he'll tell you.

Jason · Post by **Jason** » Thu Mar 24, 2005 10:10 pm

Reichpapers. Do you know what type/size bolts were used?

Post by **Reichpapers** » Thu Mar 24, 2005 10:23 pm

That would also be a good question for Dennis. Not sure if it was a .308 or 8mm bolt...actually shouldn't matter, they only modifed the bolt face and one part I forgot the name of...

ak47dennis · Post by **ak47dennis** » Fri Mar 25, 2005 10:32 pm

The first thing to check is make sure that the rivet holes in the receiver have not been elongated (at all) during the rail removal buy the de-miller. If they have been which is the case with all the I.O. kits I have seen they will need to be re-welded shut and drilled OR drill them out to an fraction rivet which is just slightly larger then the metric rivet.

When I am fitting up the rails I temporarily use 6/32 machine screws w/nuts. The overall length of the rivet will determine how original the rivet heads will look, so you will have to experiment with rivet length and compare the head with original to get it right. You must also pay close attention to the head again to make sure they will clear your bolt. Install the rivet in the rail and thru the receiver, you will buck the rivet on the outside. I have made a tool that slips into the rails and you turn tight to support the rivet head then buck/shape your rivet.

Notes: -you will probably have to rivet & re-rivet a few till you are satisfied.
-If the rivets have any sloop the will move around and bend over, they must fit almost snug
-Your bolt will most likely fit and slide nice in the rails with the machine screws, when you start riveting the bolt will get tight in spots. You will need paint with layout dye and see were it’s tight so you can stone the high spots.

Otis Cambell · Post by **Otis Cambell** » Sat Mar 26, 2005 12:39 am

Sorry Dude - I don't mean to be a wisenheimer, but should that be #8-32 bolts and nuts instead of #6-32 ??? I could be wrong..

ak47dennis · Post by **ak47dennis** » Sat Mar 26, 2005 11:38 am

Hay that’s quite all right, I make mistakes. But #6-32 are what I used because the #8-32's didn’t clear the bolt. Maybe you will be able to find some that do; I just used Lowes grade for this since it purely for mock up.

Otis Cambell wrote:Sorry Dude - I don't mean to be a wisenheimer, but should that be #8-32 bolts and nuts instead of #6-32 ??? I could be wrong..

Otis Cambell · Post by **Otis Cambell** » Sat Mar 26, 2005 12:50 pm

I've had the same problem with #8-32 bolt heads hitting the bolt. Had to grind down the heads flatter if I wanted to exercise the bolt in the rails. The only advantage to using #8 bolts is that the diameter is close to the diameter of the holes in the rails and receiver. The holes I measure around 0.160 - I'd guess they were originally 4.0 mm holes. The #8-32 bolts measure right around 0.158- 0.159.

Also, I'd say 5/32 (0.1562) solid steel rivets would work just fine for sizing and application. The tabs in the rail transfer the shear loads to the receiver. The rivets should see very little loading.

Comments and thoughts ??

Jason · Post by **Jason** » Sat Mar 26, 2005 4:57 pm

so would it be crazy to leave the bolts in and put a spot of weld on the nut to keep it from comming loose and form a round head? wouldent this eliminate the rail/bolt tightness?

Post by **TOM R** » Sat Mar 26, 2005 5:13 pm

here is the prob. no matter how tight the bolt appears to be over time the back and forth motion will work it loose a little and that little is all it needs to realy mess it up, see when you buck the rivets or even use pop rivets (not on a gun just example) the shank of the rivet expands to the size of the hole so it can't work loose, i remember when I used to be a dealership mech. from time to time you would get a car in power window doesn't work rite so you take it apart and so cheap a$$ put in a motor and used bolts instead of the supplied rivets so now the motor mounting holes are oblonged and cracked so the few $ they saved at joes garage is costing them double cause now they got to pay for a motor, window regulater, and labor to have it fixed rite. so sometimes bolts will work and other times they don't.

man thats alot of typing to say nothing

Jason · Post by **Jason** » Sat Mar 26, 2005 5:46 pm

thanks for the reply. that makes complete sense.

Post by **TOM R** » Sat Mar 26, 2005 5:55 pm

glad to help, see guys can get away with screws on the 1919 cause they thread the rsp holes and the gun is welded, if I am mistaken please correct me

Otis Cambell · Post by **Otis Cambell** » Sat Mar 26, 2005 5:59 pm

The bolt vs rivet argument has taken place for quite a long time now with regards to building AKs. There are those who swear bolts/screws hold just fine and others who insist on rivets.

On the MG-42 (at least the way I see is) the shear loads in the rails are transfered to the reciever in three ways;
1) forward direction shear reacted against the trunnion
2) aft direciton shear reacted aqainst the tabs on the rails
3) both fwd and aft via the rivets (that's what rivets do best - react shear loads that is).

I feel no matter how well the rails are fitted to a specific receiver, there is always a likelyhood that you will have a small gap between the rail/trunnion or the rail tab/receiver. You might end up with what Tom R is talking about. I'd prefer to stay with the original design and use rivets. Rivets are amazingly easy to set with a few proper tools and some practice.

Use solid steel rivets - not pop rivets. Pop rivets just won't take the shear loads you'll need for this application

FWIW - I've never build an AK using screws - rivets all the way (swell neck and regular)

ak47dennis · Post by **ak47dennis** » Sat Mar 26, 2005 6:40 pm

Tom is right, don’t even think of not installing rivets.

I am a purist, on this subject if the Germans thought screws were a better method they would have used screws as well. The rails were a wear item and they still riveted them.

Otis Cambell · Post by **Otis Cambell** » Sat Mar 26, 2005 7:05 pm

I've used shear bolts on numerous design projects at work. The ones we use are all speciality bolts that require a very tight tolerance in diameter on both the hole and shank of the bolt resulting in a "tight" fit. They are far from cheap. The use of rivets in my design applications are not appropriate since the hardware is disassembled after one flight.

You can drive yourself crazy finding an appropriate shear bolt (both diameter and shank length) for this application. Additionally, I'm very doubtful that the hole diameters were originally kept to the necessary tolerances during initial manufacturing much less now in their present state.

The Germans could have easily used shear bolts, but the application of rivets in this case was appropriate and cost effective.

BTW - I'm not really the town drunk

www.MG42.us

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