Drill and tap

[VictorFranko]

Yeah but to a action maker thread milling is new tech. even though it's been around for 30 some years. as soon as they figured out how to punch tape for a helical feed thread mill was borne.. But the residue on my coffee cup is showing.

I started punching paper tape on an old teletype machine for a Bridgeport conversion with a Slosyn NC control. The Slosyn had a mechanical pin reader. Dust from the paper tape would foul the pins making the reader misread the tape. Lots of fun.

[kcstott]

I started punching paper tape on an old teletype machine for a Bridgeport conversion with a Slosyn NC control. The Slosyn had a mechanical pin reader. Dust from the paper tape would foul the pins making the reader misread the tape. Lots of fun.

I here ya. I was coming into CNC when paper tape was on it's way out and Auto cad was on 18 3.5" disks. on a 486 DX

we still had a UV roller for making our own actual blue prints on velum.

So from a younger tool maker Much respect Vic. we chewed some of the same alloy.

[echo1]

The reason for scoping is to improve sight picture and accuracy. You're working with 3 axis, elevation, windage, and parallel to the bore. The lower your mount the better, but on an SKS, you need to remove the receiver cover to thoroughly clean. This means you should have a base and a removable mount that retains zero when you take it of and on, or a fixed mount just high enough to take the bolt & carrier out. The other, simplest option, is to use the see through cover type mount (post #7), pull the retaining lever pin, and use a 1/4 20 tap through the receiver "WITH THE COVER INPLACE" to the other side. This method has been done a lot by folks who say it returns to zero when removed and replaced. I've never done it, but I will. This is the least intrusive direction you can go and return it to stock with no visible marring.

Scoping an SKS kinda falls into the "10 dollar saddle on a 5 dollar horse" category. Used to be not that big a deal if done on an inexpensive Chinese, but there aren't that many SKSs in the pipe these days, and they are appreciating. It's your gun and all that. Lets know how much more accurate you made it. PAX

[WMG]

How mechanically inclined are you in general?
If NOT AT ALL ..... perhaps find someone who is.
A good drill press will be needed.
I drilled and tapped one of those mosin cantilever scope mounts that run about 30 dollars.
20 years later it's hanging on strong.
And minus the drill press it came with the bit and tap and no other tools were required ..................
But you have to be smart about it obviously.

Anyhow , FWIW ... I do use a sks scope mount , it is the type that replaces the original receiver cover.
There are not set screws with this mount.
According to the internet , it will never work and not hold zero ..... and again ... for over 20 years .... it has been fine.
However in my real life experience with it , I have discovered I need to use a recoil buffer with it or the spring rod begins to start chewing a hole in the back of the receiver in as little as 100rds.
Also my mount is so tight that it almost does not fit ..... I'd imagine if the mount was looser it may have a wandering zero

[ronrichards64]

I teach tapping at my work . You will need a Mill and a Center drill ,tap and drill ,A spring loaded center . I am toolmaker in a EDM shop so if I brake a tap I can burn it out .

[101st Airborne]

As a former Machinist turned Engineer, I'd say you're getting some good advice here from good, well qualified sources. The Gunsmith's price seemed reasonable.

[scamp62]

I'm no gunsmith...but I would just J.B. Weld the damn mount thingy to the receiver for $4.00 !!! and pocket the $146.00 !!! that is a lot Old Milwaukee Beer Pal !!!. I find the good old J.B. is better then the hose clamp method I use to use !!!
Yes....... I am a smart @ss !!

[5gnut]

Absolute sour grapes. Heaven forbid i want to ask about the difficulty of drilling and tapping, besides a bunch of snickering about making sure the holes are drilled in the right spot (DUH!). I'm perfectly willing to give it a go and learn some new skills that could be useful in the future, as well as tooling.
The tapping will need to be done with M3-.5 screw pitch. Are there any special concerns i should keep in mind for doing it to a rifle like this in particular? I was going to drill though all the way the reciever on the mounting points first. It would appear i need a 2.5mm bit to drill through first, then follow with the tap, using generous oil and going slow at a fast speed? I can buy these bits for dirt cheap on ebay to do a couple practices with some scrap metal. The sks in particular i think will be easier due to the square nature of the reciever which is going to reduce the need for dedicated fixturing to a great margin. Also can always shim any error out or on my combloc scope mount has the ability to adjust for slight angular error too, it's for a side-mount scope not a rail. Would appreciate any actual advice
Thanks

sounds like you have an idea of how to do it. dont skimp on drill bits or taps. get quality. go slow at low rate of speed with a cutting oil. The key is dont get the bit too hot. Take your time, get a good solid set up. Map out your steps. Yes do a practice run or 2. When tapping, make sure to back out the tap out after a couple turns to get cut material out, when you feel the tap cutting again, one turn back out again. good luck take your time. you can do it

[bigbob76]

Because I enjoyed reading this thread so much I have to add something.
1. Like somebody else mentioned, why put a scope on an SKS? Never mind, who needs a reason?
2. Doesn't anybody see a problem with spending $150 to put a scope mount on a $300 SKS?
3. If there is anything special about this SKS it would be a shame to drill holes in it.
4. Assuming it is an average SKS why not go for it, what is the worst that can happen?
5. I have no idea what anybody charges for drilling and tapping but I'm wondering if maybe this gunsmith really didn't want to do the job. Maybe he hoped the customer would walk away because it didn't make sense to spend that much on an SKS.

[smoothy8500]

I don't think Mr "cut_the_cheese" will ever come back here....

[thetruecheese]

I actually found a smith who was willing to do the job for about 60 dollars, also located in the bay area. I'll post results once i make the drive over.

[wpage]

You can buy a receiver adapter for chump change on ebay...