slide stop pin diameter smaller

[jimbullet]

So I replaced the slide stop on my STI Edge 2011 as it had a built in thumb rest, shot it a few hundred rounds. I just noticed that the diameter of my slide stop was 0.192" and now measured the old slide stop pin and it was 0.197".

 

So my question is, will that ruin my pistol for having a smaller sized diameter slide stop? Is there any negative effects that I should be aware of?

 

[zzt]

That depends.  The normal diameter is .199".  If that is what the barrel ling was initially set for and your pin wore down to .197", you are probably riding on the link and not the bottom lugs.

 

Put some Dykem or magic marker on the bottom lugs, reassemble and cycle a dozen times or so.  Then examine the lower lugs.  If the marking has been rubbed off, you are riding on the lower lugs and the only thing I'd worry about is upper lug engagement.  Your barrel will have between .0025" and .0035" (edited after the fact) less engagement, and that could lead to future problems.

 

If you find you are riding on the link, change it so you ride on the lower lugs.

Edited March 12, 2017 by zzt

[2011BLDR]

.198 is standard for castings. Most custom builders us a billet and or hardened .200.

.197 is undersized, if the lugs were fit correctly to a .197 then you may have a tighter lock up on the bigger diameter or you may have a interference in the lock up. going to a smaller diameter from what was used for the initial lock up can cause issues with link breakage.

 

End result is if you change from what the gun was built with the following needs to be checked:

• lock up on the bottom feet
• lock up on the top ribs
• link clearance
• rear and down barrel lug impact to the frame ramp on unlock ( I.E Timing)

[jimbullet]

I see, so if my old slide stop was 0.197 and say I got a new slide stop which was more to spec at 0.199', will it matter then if its slightly oversized?

 

Its hard to tell as if I put the 0.199 it fits right in and it seem to cycle smoothly too, so I guess its better to do this than use the undersized one?

 

 

[zzt]

The difference will be .001" of increased engagement of the top lugs.  As long as the lower lugs are resting on the SS pin and the link isn't binding, you are good to go.  

[RippinSVT]

If the barrel was hard fit on a .197" pin, there is no additional engagement in the upper lugs. The barrel goes up as high as it can go, and that's that. The larger pin, if it doesn't interfere with the link operation, will simply keep the gun locked up vertically with more consistency since the lower lugs hopefully don't have slop between them and the stop.