Kimber Gold Match barrel throat issue?

[gregj]

I wasnt sure if this is the correct location for this, mods pls move to approprate board if needed.

I recently picked up a Kimber Gold Match II. I love the gun, wickedly accurate, but I had some issues with my reloads. It appears the throat has a sharp point on it that catches the case lip, causing a FTF. See attached pics. This happened several times today. Each time, I took a marker and drew the outline of the barrel hood on the round. I lined each round up to the barrel hood and where I drew the outline, and each round had the same bad spot in the same location, which matched perfectly with the sharp point on the port side of the barrel throat.

I ran about 20 rounds of OEM ammo through with no issues, so I'm wondering also if there may be something I should differenty with my reloading. The crimp is about .470 - .471 , SAAMI spec is .473, so the crimp should be good to go. I use Hornady dies on a LNL, and the die is screwed down just before it starts putting a crimp on.

I compared this barrel to my Kimber Custom Classic Target, and it has a much smoother throat, with no point on it.

So my questions are:
- Is this farily normal?
- Should this be smoothed out? If so should only a gunsmith do it?
- Would a longer OAL help? My loads are currenlty 1.235"

 

[rcmodel]

I don't know if a longer length would help or not.
But it appears yours is too short if that is a 230 grain bullet.

Standard length for GI 230 FMJ-RN ammo is 1.266" - 1.271".
Taper Crimp should be .469" Min - .471" Max to match factory GI ammo.

The longer length should allow the bullet nose to center itself in the top of the chamber sooner, before the case mouth gets to the sharp edge off-center.

But regardless of that, you need to knock the sharp edges off the chamber mouth so it isn't eating cases, regardless of bullet shape or OAL.

Best way to do it is with a Dremel tool and a bullet shape Cratex rubber abrasive tip.

Do Not remove any major metal or change the shape of anything.
Just slightly round off the sharp edges and polish.
Also polish the feed ramp portion of the chamber.

This is about the only job where I would recommend a novice gunsmith use a Dremel tool on anything gun related.
But there is not much you can do wrong with this job if you leave the course grit grinder stones in the Dremel box and only use the rubber Cratex polishing tips!

rc

 

[gregj]

Thanks RC. My loads are 200gr plated RN, OAL is 1.235.

I cleaned off that point on the throat today. The barrel on the left is from my Gold Match, the barrel on the right from my Classic Target. I used a needle file to reshape it by hand, then a small piece of 800 wet-dry sandpaper on a air die grinder running very slow to clean it up. Looks pretty smooth. I used the Target barrel as a guide and the Match looks nearly identical now.

I think this will work nicely. Going to have to wait till next weekend to run some rounds through it. I'll still look at my loads and see how I can improve there. Thanks again.