Gunco Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 ·
I am doing my first build and had an idea for installing the lower rails.

I drilled the holes ( 4 per side) and tapped the reciever and the rails.
Now instead of adding a nut I intend to srew the rails to the reciever from the inside out. Will the button heads of the screw interfere with anything on the inside of the receiver? I then intend to cut the screws flush with the out side of the receiver and peen the screws and receiver with a center punch to prevent them from turning out. My big concern is clearance on the inside?
I believe that the rails will hold together fine.
What do you guys think. Help a newbie out!

Thanks for the great board.
:thankyou:
 

·
Registered
Joined
·
1,856 Posts
Cumberland..........

I don't think the receiver is thick enough to support the screw threads. You need to have something for the screws to engage and .045" material isn't enough IMHO.

Guys have used screws for their builds and haven't had any problems with the inside nuts hitting anything (they just have to be small enough). I had a nice picture of a screw build using round head cap screws but I just can't find it to post here.

It's good your thinking of different way to accomplish the attachment of the lower rails but I would stick to the tried and true on this one.

Maybe someone else has some information that could be of help.
 

·
Registered
Joined
·
260 Posts
I screw all my rails from the inside and then weld the outside where the screw comes through the reciever and then grind smooth. It has worked well for me. ak'sr4me
 

·
Registered
Joined
·
4,077 Posts
now that sounds like you may have someting. screw cut weld smooth over.
 

·
Registered
Joined
·
2,836 Posts
ak'sr4me said:
I screw all my rails from the inside and then weld the outside where the screw comes through the reciever and then grind smooth. It has worked well for me. ak'sr4me

Do you have any pictures. I think that is a great ideal. It sounds so simple and yet this is the first I have heard of that idea. :notworthy :notworthy

:useless:
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #6 · (Edited)
I'm using a cold steel receiver which is really pretting thick. I believe I'm catching 3 or 4 threads. I thought about the welding, as described by aksr4me, I have a hobby stick welder and do not think it would work well for me.
 

·
Registered
Joined
·
681 Posts
ak'sr4me said:
I screw all my rails from the inside and then weld the outside where the screw comes through the reciever and then grind smooth. It has worked well for me. ak'sr4me
sounds like a pretty good idea to me... those screws are just as permanant as rivets, and no rivit heads on the outside of the receiver... nice and clean:thumbup1:
 

·
Registered
Joined
·
2,071 Posts
I screwed my rails in as well on my first build. However, I did them from the outside in and used nuts on the inside. I actually used some that Sniper sent me that were very small. They were the button head torx heads I believe. The ones that use an allen wrench but with a button head. I did run into some clearance problems on the very front screws (closest to the front trunnion). I had to cut the screws down really small and then take the dremel to the nuts and thin them out. I think I had to shorten the second one back as well, but not grind the nut down. The last 2 were ok, although I did shorten the screws a bit just so they wouldn't stick out so much. I don't remember the OAL of the screws.

The button head screws that I used were very very small. The heads were much smaller than the nuts and I wouldn't suspect that you would have any problems at all with clearance. It also depends on how far down your screws are drilled into the rails. Of course the farther down you get, the bigger possibility of clearance problems you'll have with the magazine lips. Regardless of the way you secure from the outside, you should be ok on the inside. I would test fit the magazine and see if it hits the front two heads. If it does slightly, you can always go back with the drum sander on the dremel and hit the heads a bit until everything fits right. I would do this after you peen/weld the ends though.
 

·
Registered
Joined
·
260 Posts
scubadvr said:
Do you have any pictures. I think that is a great ideal. It sounds so simple and yet this is the first I have heard of that idea. :notworthy :notworthy

:useless:
I took a couple of pics but can't seem to get them to load. I need to resize them and that option on my computer seems to have disapeared. Don't know where it went??????? Sorry ak'sr4me
 

·
Registered
Joined
·
6 Posts
I know I'm new here but this is what I was thinking about doing too. The receiver is about .040" and the rails are about .06". If you use a fine thread like a 4-40 that will give you 4 full threads. When I was gong to school for my tool and die aprenticeship my teacher gave us a article about how NASA engineers figured that the first 2 threads hold 90% of the load. If that is true which I admit I had a hard time believeing I don't see why four screws on each rail wouldn't be strong enough to hold the rails which basicly are only slide ways and not alot of shear load is going to be on them anyway.
 

·
Administrator
Joined
·
7,143 Posts
yosuthnmasa said:
I screwed my rails in as well on my first build. However, I did them from the outside in and used nuts on the inside. I actually used some that Sniper sent me that were very small. They were the button head torx heads I believe. The ones that use an allen wrench but with a button head. I did run into some clearance problems on the very front screws (closest to the front trunnion). I had to cut the screws down really small and then take the dremel to the nuts and thin them out. I think I had to shorten the second one back as well, but not grind the nut down. The last 2 were ok, although I did shorten the screws a bit just so they wouldn't stick out so much. I don't remember the OAL of the screws.

The button head screws that I used were very very small. The heads were much smaller than the nuts and I wouldn't suspect that you would have any problems at all with clearance. It also depends on how far down your screws are drilled into the rails. Of course the farther down you get, the bigger possibility of clearance problems you'll have with the magazine lips. Regardless of the way you secure from the outside, you should be ok on the inside. I would test fit the magazine and see if it hits the front two heads. If it does slightly, you can always go back with the drum sander on the dremel and hit the heads a bit until everything fits right. I would do this after you peen/weld the ends though.
The screws yosuthnmasa is referring to are 4-40 and are 1/2" long. that way they could be cut to fit. They are button head screws and use an allen wrench (hex key) to tighten.
 

·
Registered
Joined
·
260 Posts
scubadvr said:
Do you have any pictures. I think that is a great ideal. It sounds so simple and yet this is the first I have heard of that idea. :notworthy :notworthy

:useless:
Here are the pics you asked for. I make my own rails and since I don't dimple the magwell, I extend the rails down into the mag area to act as a spacer for the proper fitting of the mag. This area also has 2 screws in it but I have to grind the heads of the 10/32 screws down for mag clearance so they are hard to see in the pics. ak'sr4me
 

Attachments

1 - 14 of 14 Posts
Top