SKS Gas Tube Modification?

Drachenblut said:
Well Gents,
I have some questions then: Firstly. Is it possible to sticky this for a little while, Mods?

Secondly: What ways can you reduce the recoil on the SKS rifle? Now, I know you say "no recoil", and admittedly it is no .577 Tyrannosaur, but it is still there (enough that it shoves my scope nearly into my eye socket every time I fire! (I've adjusted the scope ahead as much as I can without danger of the front getting hit by brass - my main reason for this interesting gas tube mod)

Thirdly - Where can I buy an SKS shell deflector? I used to have one that clipped on the rear sight by using the rear sight's slide. Who has one/where could I get one? I lost mine :(
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Drachenblut

Check out my post and look at the receiver mod I did. No deflector needed. The spent casings go up and out to the right at about 2:30.

http://www.canadiangunnutz.com/forum/showthread.php?t=576609

CT
 
OK, so I had a chance to check my project and as it sits right now I have added the 3 holes they mention. One on each side at the front end of the tube that line up with the factory holes in the rear end and one on the front top slightly further back. Currently all 3 are drilled out to 9/64" ....... I don't have any of the wire gauge # bits so am increasing in 1/64" increments.
I plan to step the holes up to 5/32" and then maybe 11/64"??? Maybe enlarge one at a time & test fire in between as I go. Like FatTony said, waiting for better weather!
Maybe I should try enlarging the original holes at the rear of the tube before adding more holes though I think holes at the front end will be more effective at venting more gas sooner.
Maybe a series of tiny holes towards the front sort of like porting a shotgun barrel?

Mine is now finally to the point it doesn't always bounce casings off the shootin shack cieling! I'd still like to try mellow the ejection out more! Just not sure how much more drilling that'll take. I'm a little surprised how big the new holes are already!

What size & how many holes do others have and what were the results? Any real world experienced input greatly appreciated though I suspect I'll eventually figure it out as I go!:D
 
TERMINATOR101CA said:
Anyone ever thought of putting a spring on that piston instead of the holes ?
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Interesting idea if you have a variety of springs handy but sourcing different strength springs etc will probably be too expensive compared to progressively enlarging holes. I like the idea but I've already started down this path so I suppose I see where it goes!
 
boltonscouter said:
Currently all 3 are drilled out to 9/64" ....... I don't have any of the wire gauge # bits so am increasing in 1/64" increments.
I plan to step the holes up to 5/32" and then maybe 11/64"??? Maybe enlarge one at a time & test fire in between as I go.
Click to expand...

Just so you are aware the original mod post by Larry Gibson on surpulsrifle suggested starting with a #45 bit=0.0820" and increasing by 1 bit size each time ON THE TOP HOLE ONLY. He ended up with a #31 on top and two #45 on the sides. A #31= 0.1200".

You are already at 9/64"=0.140625" and intend on increasing to 0.15625". That's a pretty big jump. Be cautious.

Yes only drill the top hole.
 
CharlesT said:
Just so you are aware the original mod post by Larry Gibson on surpulsrifle suggested starting with a #45 bit=0.0820" and increasing by 1 bit size each time ON THE TOP HOLE ONLY. He ended up with a #31 on top and two #45 on the sides. A #31= 0.1200".

You are already at 9/64"=0.140625" and intend on increasing to 0.15625". That's a pretty big jump. Be cautious.

Yes only drill the top hole.
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I realize that but as stated I am not seeing the degree of decrease in ejection he mentions in his article. As I said, I'm surprised how large the holes are getting but hey, it's a spare gas tube so I'm not too worried. I will definitely enlarge one at a time and test fire in between, proceeding gradually. Maybe it differs from rifle to rifle depending on the fit of the piston in the tube?
Has anyone on CGN been able to make this work successfully yet? If so what size & how many holes? How far/high do the spent cases travel once you were happy?
Like I said, I have 3 holes 9/64"and it still bounces 1/2 the spent brass off the ceiling of the shootin shack hard enough to dent the case mouth :eek:
Maybe the Privi ammo is loaded much hotter than surplus? Maybe I should try some surplus to see the difference!
 
fat tony said:
^ I have noticed the PP ammo tosses the empties much further than the surplus, so you are not seeing things. ;)
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Thanks, glad it not just me! I suspect I'll just be using the modified tube for the PP brass and I'll use the original tube for surplus but it would be nice if it works for both. I suppose time will tell with additional R&D!
 
Well the first guy to test with springs will have to bite the bullet, the rest can follow his footsteps, and if generous give him something back for the invaluable knowledge he offered others.
 
Well gents, to follow up: I went and had 3 holes drilled into the gas tube of the SKS. The right and left are not lined up. However, what it leaves me is left, 0.22", right 0.28", top 0.35". I have yet to fire it, but holes were drilled using 2.015mm diameter drill bits. I had to have it done at a machine shop, as I could not do it at home (yay, student living off campus, no tools, wahoo). The shop did it for 25 bucks tax in. I will test fire it soon, then if successful, I will post pictures.
 
It's not really a one shot deal where you drill 3 holes and it's perfect though. I have found that with this modification, I had to do a lot of step drilling, and it's still a work in progress. $100 bucks for a cordless rotary tool, then $60 bucks for a set of number bits, or x number of trips to the range / machine shop. You do the math. Let me know how it works out though. :)
 
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Drachenblut said:
Well gents, to follow up: I went and had 3 holes drilled into the gas tube of the SKS. The right and left are not lined up. However, what it leaves me is left, 0.22", right 0.28", top 0.35". I have yet to fire it, but holes were drilled using 2.015mm diameter drill bits. I had to have it done at a machine shop, as I could not do it at home (yay, student living off campus, no tools, wahoo). The shop did it for 25 bucks tax in. I will test fire it soon, then if successful, I will post pictures.
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Love to hear how it goes! Your math doesn't seem to add up though? A 2mm bit should give you approx a .08" hole?
Mine are all 3 approx .14" and I still want to go larger. Fat Tony is right, it's not a 1 shot deal. Between replacing broken drill bits (especially the smaller ones) and firing in between sizes of holes, dremmel tools, cordless drills & hand filing burrs it's a process. If your holes really are already .22", .28" & .35"I'm even more curious! Let us know!!!! :D:D:D
 
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