Shortening an SKS barrel - Issues?

timandkimandshea

timandkimandshea

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I was thinking of cutting a few inches (<3) of the muzzle of my SKS. Mounting a Promag (choate style) optic mount, TRS 125 red dot, so I was thinking why stop there, remove the bayonet/lug, Krylon the stock Khaki green, basically a full bubba job without the tacticool. So I could just grind of the bottom of the lug, but it occurred to me to cut the barrel and remove the whole lug where it wraps around the barrel, to clean up the business end. So my question is, would those 3" impact the way it shoots in any significant way? It shoots pretty well in stock form, I don't want to drastically alter that.
Before you start ragging, this is a rifle I bought for a good deal specifically to do this. I have two others bone stock.
Either way I will post pics for your viewing (dis?)pleasure.
Thx
T
 
You can get pretty good results doing it yourself. Gunsmith fees can make a project like this cost prohibitive. First, throw the notion that shortening a barrel reduces accuracy. Only guys who crookedly hack saw their barrels down will stand behind this flawed law of physics. A properly crowned barrel does not need length to shoot well. The shorter barrel is stiffer thus improving accuracy some. X39 gains little velocity past 12-15" or so, cutting a couple inches off your SKS squarely and recrowning properly can only improve accuracy. I say go for it. If you mess up you get to learn how to do it right anyways.
 
kennymo said:
Would the barrels on the SKS be difficult to re crown due to the hard chrome lining?
Click to expand...

I doubt the chrome is harder than the crowning tool.

I've thought about a cut sks... Except keeping the front sight and sleeve, just cutting the sleeve portion behind the sight off with the bayo lug. You could then slide the sight on the barrel a couple inches further back and re-pin it, then chop in front of the sight and recrown...

I think the most you can cut is like 1.75" or so... I decided it wasn't worth the work.
 
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supernova said:
You can get pretty good results doing it yourself. Gunsmith fees can make a project like this cost prohibitive. First, throw the notion that shortening a barrel reduces accuracy. Only guys who crookedly hack saw their barrels down will stand behind this flawed law of physics. A properly crowned barrel does not need length to shoot well. The shorter barrel is stiffer thus improving accuracy some. X39 gains little velocity past 12-15" or so, cutting a couple inches off your SKS squarely and recrowning properly can only improve accuracy. I say go for it. If you mess up you get to learn how to do it right anyways.
Click to expand...

The point of crowning is to make the barrel even all the way around, correct? How does the curve I see on barrel crowns play into it? And lastly, Counterbore? thats just cleaning up the worn out end of the rifling?
The reason I ask (Sorry to jump in this post, but it is relevant) I recently received a rifle (yes off the EE) that has the definite marks of a hacksaw at the end. Im thinking of trying to fix it myself....
and finally, OP , Its your rifle to do with what you like... I have one I took the bayonet off, but I dont have the heart to take the mount off...... post the pics for sure.....
 
The curve on the muzzle is to create a recessed crown, which can protect it from damage. The "crown" refers only to the edge transition from muzzle to bore.

Counter boring is drilling out the worn out portion from the last few inches of the bore by a hundred thou or more. The tip of the reamer would make the new crown inside the bore.
 
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Hmmm I can't edit my previous post.....

I accidentally hit send while using the iPhone app....

Anyways,

I think if you cut off 3" you will be making a prohib.... So be careful there, measure 18x and cut once!

I ordered a re-crowning kit from brownelles. Worked like a charm! I cut off my barrel with a zip wheel.

Cut back under 18"= prohibited
Cut back between 18&18.5" = restricted.
Cut back over 18.5"=non-restricted

Measured from the boltface with the action closed. To be on the safe side I measured the barrel itself....

It would be much easier to do this job if you weren't worried about re-mounting the front sight.....
 
The curve is just the way they were done, possibly from worn tooling but that's only speculation. There are different styles of crowns from a simple 11° chamfer to perfectly square recessed target crowns. The only important factor is that it is even all the way around the muzzle. A small nick will allow a tiny amount of gas to accelerate past the bullet and upset the converging gas in front of the bullet which it must pass through. If everything is square and even then pressure on all sides of the bullet is even thus not upsetting the bullet. I've seen some pretty nasty marks on muzzles that I've been able to clean up with a jewelers file, emery cloth and sand paper. I wouldn't do this on anything for precision shooting however. I had a SKS with a nasty crown/muzzle face. I took slow, even passes off the face to get it flat again with the file then carefully straightened the crown with a cone stone stopping often to eyeball progress. Emery cloth and fine sand paper to polish the face and it could finally put 5 rds on paper at 100 yds.

wd113 said:
The point of crowning is to make the barrel even all the way around, correct? How does the curve I see on barrel crowns play into it? And lastly, Counterbore? thats just cleaning up the worn out end of the rifling?
The reason I ask (Sorry to jump in this post, but it is relevant) I recently received a rifle (yes off the EE) that has the definite marks of a hacksaw at the end. Im thinking of trying to fix it myself....
and finally, OP , Its your rifle to do with what you like... I have one I took the bayonet off, but I dont have the heart to take the mount off...... post the pics for sure.....
Click to expand...
 
supernova said:
The curve is just the way they were done, possibly from worn tooling but that's only speculation. There are different styles of crowns from a simple 11° chamfer to perfectly square recessed target crowns. The only important factor is that it is even all the way around the muzzle. A small nick will allow a tiny amount of gas to accelerate past the bullet and upset the converging gas in front of the bullet which it must pass through. If everything is square and even then pressure on all sides of the bullet is even thus not upsetting the bullet. I've seen some pretty nasty marks on muzzles that I've been able to clean up with a jewelers file, emery cloth and sand paper. I wouldn't do this on anything for precision shooting however. I had a SKS with a nasty crown/muzzle face. I took slow, even passes off the face to get it flat again with the file then carefully straightened the crown with a cone stone stopping often to eyeball progress. Emery cloth and fine sand paper to polish the face and it could finally put 5 rds on paper at 100 yds.
Click to expand...

That sounds way too difficult.....

Brownelles makes a hand tool to recrown barrels. It's what I used to square it up and reshape the crown on mine when I cut it.

dubbya dubbya w.brownells.com/gunsmith-tools-supplies/barrel-blanks-tools/barrel-chamfering-cutters/79-muzzle-crowning-cutter-prod628.aspx

Cheers!
 
Gotta ask. ;) Doesn't affect function ? Some gas operated guns are sensitive to altering the pressure curve by shortening the barrel.


Grizz
 
When they cut them to 16" in the states they sometimes have cycling issues. Guys with 18.5" SKS don't have issues. If you did you would simply open up the gas port a little until it cycles again.

Grizzly Adams said:
Gotta ask. ;) Doesn't affect function ? Some gas operated guns are sensitive to altering the pressure curve by shortening the barrel.


Grizz
Click to expand...
 
As I am mounting a choate style scope, I think I will leave the barrel (and front sight) as I can still use the irons with the elevated mount. But I will probably cut off the bayo lug. If I feel the need I can still shorten in later. I will post pics of before and after when I get er done.
Thanks for all the interest.
T
 
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