Barrel timing shuemann test

[julek]

Hello everyone,

 

I’ve been a longtime reader but am now a first time poster. 
 

This is my third year shooting open and I have managed to go through nearly every possible problem one could have with an open gun. 
 

Last week I noticed that my gun had chewed up its upper barrel lugs pretty badly. I was speaking to a friend and he asked me if my gun passed the shuemann test. I’d never tried it so I have it a go. Sure enough it did not pass the first test where you insert a 0.020 “wide shim into the front of the ejection port when the barrel is 0.25” unlocked. I can’t even stick in a 0.010” shim. I tried the test with a second open 2011 and it’s the same. I also tried with a limited gun by another manufacturer and it’s the same. 
 

so here is my question, in the shuemann test it’s suggested that you need to remove some material from the frame in order to allow the barrel to tilt lower. Problem is that my barrel will not tilt any lower even if it’s removed from the frame with the slide. This is because the tunnel the barrel sits in in the slide doesn’t give it sufficient clearance to tilt more. Is this normal? Does the timing test even apply to a modern 2011 open gun?

 

I’m really confused at this point and hope that a gunsmith will read my post and help me understand. Both open guns have bull barrels. If I need to increase the clearance for the shims do I remove material from the barrel or from the slide?

[CalTeacher]

Just send the gun to a gunsmith.  I’ve built several guns with great barrel fits that are timed properly, but I won’t give advice since I’m not an actual gunsmith. I will say that you won’t remove material from the slide or the upper lugs of the barrel, but rather the vertical impact surface of the barrel or frame.  You want sufficient downward clearance to allow the upper lugs of the barre to clear the upper lug recesses of the slide.

 

I have a question that may sound stupid: what shape was the shim you used?  Remember, you’re measuring the gap between two round surfaces.

[MikeBurgess]

On 6/21/2022 at 12:53 PM, julek said:

Hello everyone,

 

I’ve been a longtime reader but am now a first time poster. 
 

This is my third year shooting open and I have managed to go through nearly every possible problem one could have with an open gun. 
 

Last week I noticed that my gun had chewed up its upper barrel lugs pretty badly. I was speaking to a friend and he asked me if my gun passed the shuemann test. I’d never tried it so I have it a go. Sure enough it did not pass the first test where you insert a 0.020 “wide shim into the front of the ejection port when the barrel is 0.25” unlocked. I can’t even stick in a 0.010” shim. I tried the test with a second open 2011 and it’s the same. I also tried with a limited gun by another manufacturer and it’s the same. 
 

so here is my question, in the shuemann test it’s suggested that you need to remove some material from the frame in order to allow the barrel to tilt lower. Problem is that my barrel will not tilt any lower even if it’s removed from the frame with the slide. This is because the tunnel the barrel sits in in the slide doesn’t give it sufficient clearance to tilt more. Is this normal? Does the timing test even apply to a modern 2011 open gun?

 

I’m really confused at this point and hope that a gunsmith will read my post and help me understand. Both open guns have bull barrels. If I need to increase the clearance for the shims do I remove material from the barrel or from the slide?

I have had a couple guns that when linked down rubbed on the inside of the slide on the lower sides of the chamber area on the barrel, this interference can be relived on either the barrel or the slide, most do it on the slide as the barrel relief is visible 

That said, interference on the bottom of the barrel should not be causing damage to the lugs on the top, so you probably want to get it looked at by someone that can diagnose its issues and make the needed corrections.