New one from SOG

[Loose}{Cannon]

The gap you note is very common, some are more obvious than others. Throw in the fact a lot are plugged with gunk and cosmo many don't realize their rifle has that gap.

+1

Are you sure your ghost does not have a gap?

[brentb636]

The gap you note is very common, some are more obvious than others. Throw in the fact a lot are plugged with gunk and cosmo many don't realize their rifle has that gap.

+1

Are you sure your ghost does not have a gap?

I pulled it out and looked at it.  I tried to clear the area under the sight with a knife blade, but got no traction.  I'm thinking that there might be a tiny gap there, but nowhere near the size of the gap that I see on the two letter guns.  That gap is obvious.   
Here's the ghost....

[Loose}{Cannon]

There's a gap....  simple tolerances differences.  You will need a toothbrush and solvent and maybe a paper clip to get the crud out.

Nice example of a russian proof right thar. 

[brentb636]

There's a gap....  simple tolerances differences.  You will need a toothbrush and solvent and maybe a paper clip to get the crud out.

Nive example of a russian proof right thar.  Q

[armedhippie]

Nice example of a russian proof right thar. 

I  have a 5 digit Ghost with that exact Proof on the front,of the front sight. Along with the single digit fitment #'s that you find on Ghosts...er russians...er...hhmmm makes ya think   

Brentb636  Some beautiful SKS's ya have man. Thanks for sharing.

[Dannyboy53]

Brent those four carbines are definitely drooling material!  Good looking specimens.

[brentb636]

There's a gap....  simple tolerances differences.  You will need a toothbrush and solvent and maybe a paper clip to get the crud out.

Nive example of a russian proof right thar.  Q

I searched all over and found my feeler gauges to measure the gap.

Results:
E1414 - gap 0.020"
K9103 - gap 0.019"
Pл7360 - gap 0.015"
Ghost 131864 - gap 0.010"

Conclusion:  Too small a sample size to think of a conclusion, but my Letter Guns have a noticeably larger gap.   Those feeler gauges are good to clear the gap out, that's for certain.

[Worm]

My old letter gun i use to have had a gap too. Had a horrible trigger, loose bolt & carrier, and just wasn't made all that well.

China's first attempt at creating their own parts though, right?

When I would shoot it, the carrier would actually get hung up before getting to the point where it should have closed the whole way... And that was an all matching gun.

[running-man]

10 mils of difference isn't much when it comes to something like this Brent.  That could easily be a variation in the barrel lug, the rear sight block, or both.  Heck, finding a 10 mil variation between two parts today is not unheard of, even with NC programming and CNC machining. 

It really is a testament to how well controlled the machining and fittment were back in the '50s and '60s.  Of course, you get a story like Worm's and have to wonder how 'hard' the transition truly was when the Chinese suddenly had Russian support change over to Russian animosity.  Even though they have been in the SKS business for several years with at least 450k units under their belts, producing one totally from scratch as opposed to just assembling certain imported/foreign produced parts must have had quite a learning curve.

[Loose}{Cannon]

+1

I would say the under belly of the rsb was minuscule as long as the center/center offset between the bore and operating rod channel were correct.   

Sounds like Worms gun was simply needing maintenance after years of abuse. It couls have been anything from a disconnector issue/adjustment to worn carrier channels. Either way, I bet it was top notch when it left Jianshe.