Gunsmithing Need to mount a picatinny rail on my stock which is polymer investing an aluminum frame of sorts.

[want2learn]

I have a sig ssg3000 and it came with a screwed in sling swivel (no nut or backing). i purchased a sling adapter that fit over the sling swivel....but it has since loosened and bent....bad quality part.

So i read about using a T-nut fastener and purchased a set of them. I drilled the requisite small diameter hole through the polymer and aluminum but when i tried the forstner drill bit to inset the T-nut it would not go through the aluminum.

I then figured if there was an aluminum frame sandwiched in there maybe i could use my harbor freight tap and die set.....but that wasn't working out too well.

Any thoughts on how to mount the rail?

I thought perhaps to purchase a wide metal drill bit to fit the diameter of the T-nut but as opposed to a forstner bit i thought it might make too deep of a cavitary cone shaped hole. Then i thought perhaps they make some sort of threaded insert that i might be able to use but the ones i saw at home depot say they're for wood.

For now i just put some epoxy to fill in the hole and letting it dry over night. Our local gunsmith is swamped.

appreciate any help and direction.

 

[dustingaunder]

How thick is the aluminum? How thick is the plastic before you get to the aluminum on top and bottom? If it’s thick enough to get 6 or 8 threads into I’d just drill and tap into the aluminum. If it’s not thick, clearance drill for your fastener and drill a little pocket on top for a nut to sit in. The T Nuts aren’t really needed with the aluminum for support.

 

[want2learn]

thank you so very much...i really appreciate it.

the aluminum is really close to the barrel surface of the stock...that's where my fortner bit wouldn't work., the exterior 3/4 thickness is polymer. i tried to tap the aluminum but was having trouble. not sure if it was the thickness of the aluminum or a bad tap or bad technique.

my regular drill bits should suffice to make a hole for a nut.

 

[want2learn]

Worked out well....thank you again.

 

[dustingaunder]

Pics or it didn’t happen.

 

[want2learn]

you're correct...sorry for the delay, i'm skim bedding the rifle. our hardware store had marine tex and jb weld...the marine tex had some nice reviews so i went with that. wishful thinking perhaps on the value of skim bedding but there always seemed like a bit of extra space fore and aft of the receiver in the stock and it bothered me. fingers crossed i didn't do too bad of a job.

i salvaged an old picatinny rail...will have to get some aluminum paint for touch up and recess the screws just a hair but it's very secure. i made a few facets on the nuts so they're very snuggly fit and do not turn. i chamfered the machine screws on the surface nearer the barrel so there should be no interaction with the barrel.

i only have a hand drill and hand files, one day i will invest in some functional machinery... i hope.

really appreciate all the help.

i'm not too comfortable with the factory stock fit for some reason, i seem to fight it a bit. Not sure if my rings are too high or the pad is not optimally placed. Objectively, the action/receiver/bolt/trigger and barrel should be of good quality and are functionally sound ......so perhaps if Eurooptic has a good sale on the GRS Warg stock for the rifle i'll pick one up. hoping it might afford improved ergonomics, it sounds like the GRS stocks are well fitted dimensionally for the receiver and will be a lot cheaper than purchasing a brand new rifle.

If not then there's still hope for my old almost brand new M595 Tikka.