View Full Version : HELP ...Gun Smith question?

Eric Larsen
December 30, 2001, 09:47 AM
I had a very slight problem with an occasional FTF. The slide would get sent back and would stop on the return stroke. Usually, just as it was starting to take the next bullet out of the mag. A rack of the slide would clear things up for a couple of hundred rounds or more. I was worried about this prob. as this is a carry gun. 9mm Compact. I took my gun to a good semi smith here locally and after looking at how the action was acting.
He took my top end down and had a look. The top lug on my barrel had a small crown/burr on the very front edge and the same edge on the chamber was starting to get one. This burr was hanging up on the grooves in the slide. Causing friction where it absolutely shouldnt be. Thus my question.
What would cause this to happen.?????????????????????????

Poor materials in the barrel? Tolerances? Am I doing something
wrong? I gotta know as this is a carry gun and cant have this
happening......Please, if you have any experience with this let me know!

The gun has around 1k rnds thru it, from target FMJ to +P JHP's
My guns are cleaned after every session. I use BreakFree clp for lube and cleaning leaving more than enough on the mating parts.
My feedramp in very polished and chamber is throated. I have since put a 20# Wolf recoil spring and cleaned up/lightly polished the barrel. Checked and re-cleaned up my slide, which looks perfect. The action is now smoother than ever and has about 150 rnds without a prob. I feel I can carry my gun again. But
still need to know what the H*LL is going on with the barrel...?

Thanks and shoot well.....

December 30, 2001, 10:36 AM
What KIND of gun?

Eric Larsen
December 30, 2001, 11:03 AM
Its my CZ Compact 9mm ..Poly Coated black. The gun was purchased a month ago. I had the feedramp polished and chamber throated. The back of the slide had more of a "chamfer" cut in it at the same time, to help smooth the hammer transition. (the hammer gets pushed instead of hit hard!) I have a 20# Wolf recoil spring now! I got rid of the Crown/burr on the barrel very carefully, not taking any other metal off of the barrel and lightly polished it. The slide was in great/OEM shape..I just ran some emery cloth over it to help smooth it out a little more...I shoots better than ever now.
But I need to know what made my barrel crown? Is it a bogus barrel. Is my slide made of "unobtanium" and harder than my barrel? HELP????????????? What else do you need to know?
Thanks and shoot well

December 30, 2001, 12:27 PM
Take a fine file (and while repeating the entire time "I can always take more off but I can't add it back") GENTLY radius the edges of the upper barrel lugs.

I've done it to a number of Witness barrels, and Bob Cogan (Accurate Plating & Weaponry) hard-fit a Nowlin barrel for one of my 9x19 Witnesses; it came back with beautifully perfectly radiused edges.)

Eric Larsen
December 30, 2001, 01:29 PM
I did that and it solved the symptom of the problem...I want to know what causes this? I want to carry this gun..why I bought it.
I dont want to have to worry about my slide/barrel interference issues and wanted to know how to remedy the situation. Any thoughts? Thanks and shoot well

James K
December 30, 2001, 09:10 PM
This is sometimes caused by the barrel lugs not fully engaging with the slide. That pistol is a locked breech, like a 1911, and the lugs should be fully engaged when the gun is fired. If they are not, the pressure tends to put too much force on too small a part of the lug and it will peen as you described.