PDA

View Full Version : Recoil spring resistance?


XHardrock
May 20, 2007, 05:37
I finally got an ak conversion to the range yesterday and the bc has too much rearward movement. The conversion is to 7.62x25 and blow-back designed which I thought I would have trouble with too little travel but it is hammering the rear of the top cover, enough to unseat it from the front.
Does anyone make a stiffer return spring, or any other ideas to reduce travel?
I'll catch alot of flack for this but,,,,,,,,,,,I don't care for the buffers.
Thanks
HR

vern357
May 20, 2007, 13:12
I have heard that Wolf springs makes a +15% or +25% return spring.

dstorm1911
May 20, 2007, 14:32
get an extra end stop, slip a 22lb 1911 recoil spring onto your recoil assembly first now install the end stop that normally would go at the front end of your twin wire recoil assembly now install a new standard recoil spring and another end stop as normal ya should now have more than enough resistance ya may find that ya need to trim a few coils at a time from the standard recoil spring untill ya get it right for the blowback operation.. this will create a dual rate setup with the end stop between the two acting as a base for the standard spring, ya might also consider switching recoil assemblies to a two piece solid assembly as was used in the earlier AK47s, if ya aren't familiar they used a solid front rod captured in a hollow rear rod the spring ran on the outside of the two very much like an SKS recoil assembly.....

Good luck!!

XHardrock
May 20, 2007, 15:16
Thanks gents

Hey Vern, have you got a site for the power + springs? I found them for the mags but not return.

Dstorm, I can't wrap my mind around how adding another cam where the spring guides meet is going to allow for compression. The idea sounds right to me as I was thinking of adding a secondary/backup spring but can't figure how without relieving the bc. (too much work) It has the older tube guide and the interior/forward rod is what is dislodging the cover, at full spring compression.


I checked a PSL spring and it is longer but it is also longer fully compressed.

Keep the ideas comin.

dstorm1911
May 20, 2007, 15:37
Originally posted by XHardrock
Thanks gents

Hey Vern, have you got a site for the power + springs? I found them for the mags but not return.

Dstorm, I can't wrap my mind around how adding another cam where the spring guides meet is going to allow for compression. The idea sounds right to me as I was thinking of adding a secondary/backup spring but can't figure how without relieving the bc. (too much work) It has the older tube guide and the interior/forward rod is what is dislodging the cover, at full spring compression.


I checked a PSL spring and it is longer but it is also longer fully compressed.

Keep the ideas comin.

The inner rod should not be able to as even at max compression the inner rod will protrude through the hole in the rear of the recoil/dust cover latch...

But that would take some serious compression as the rod is the same leangth as the outer rod.

Another idea would be to re-work the inner rod by shortening it enough to add a spring inside the outer rod then a cap at the rear of the assembly so that ya could add an SKS operating rod spring inside of the outer rod,

Partner when ya choose to step outa the box on a build ya already signed off that nothing is going to be EASY ya either gotta get all the way outa the box or crawl back in an go build yet another Rommy kit like everyone else :devil:

ftierson
May 20, 2007, 16:20
Conversions to blow-back without the appropriate retardation of the bolt when fired are dangerous...

Springs are not the best way to solve the problem because they offer the least resistance to bolt movement just when you need the resistance the most...

I recommend that you increase the mass of the bolt/carrier along with increasing the strength of the spring...

Also, whether you like buffers or not, I'd recommend adding one (or at least something to prevent the battering of the rear trunion by the bolt/carrier)...

Good luck...

Forrest

XHardrock
May 20, 2007, 18:43
I found the xtra power springs at Brownells, they carry 15%, I'm going to keep looking for the 25%. I believe that would do it.

Yea, I've been in and outta that box for awhile on this project it was set up with a FAL gas system to start but the x25 round didn't have enough gas to fully cycle, I ended up with about 1" travel.

And I agree on the need for extra bc weight (ppsh is heavvvvy) but can't see a good way to add it.

Good ideas, if one doesn't work I'll try the next, or a combination. It'll get done.

Thanks again
HR