My KKM Barrel has a really tight/short throat

[Odawgp]

I just got the barrel yesterday, dropped right in and boy is she a shooter

2.5-3in group at 25yds most of the shots ended up tearing a golf ball size hole with the rest tailing off to the left a hair "to much or to little trigger finger"

only problem is that I will have to shorten my reloads a little bit 20-25thou (currently loading them to 1.150) not a problem when I shoot to SL but when trying to unload and clear the gun in between my strings I had problems getting the loaded cartridge out

My reloads would drop 95% of the way in the chamber but need help for the last 1/16th of an inch. I painted one of the bare lead bullets with a marker and dropped it in and helped it in with my thumb, upon removal I could see where the bullet was engaging the throat holding the round out from going into full battery. shortening the rounds to be 1.125 as the book calls for should put the part of the bullet that is engaging the throat down into the case enough for it to not be an issue anymore

I hope!

[huskerlrrp]

I just got the barrel yesterday, dropped right in and boy is she a shooter

2.5-3in group at 25yds most of the shots ended up tearing a golf ball size hole with the rest tailing off to the left a hair "to much or to little trigger finger"

only problem is that I will have to shorten my reloads a little bit 20-25thou (currently loading them to 1.150) not a problem when I shoot to SL but when trying to unload and clear the gun in between my strings I had problems getting the loaded cartridge out

My reloads would drop 95% of the way in the chamber but need help for the last 1/16th of an inch. I painted one of the bare lead bullets with a marker and dropped it in and helped it in with my thumb, upon removal I could see where the bullet was engaging the throat holding the round out from going into full battery. shortening the rounds to be 1.125 as the book calls for should put the part of the bullet that is engaging the throat down into the case enough for it to not be an issue anymore

I hope!

Did you buy the "match" version? I found out that they undersize those so they work with OEM and aftermarket slides. I didn't have a 40S&W reamer so I sent it to them with some sample rounds and they fit it for me.

[Odawgp]

Did you buy the "match" version? I found out that they undersize those so they work with OEM and aftermarket slides. I didn't have a 40S&W reamer so I sent it to them with some sample rounds and they fit it for me.

No I ordered the drop in, I was beginning to think I may have gotten the "match" (gunsmith fit) but a little online reading lead me to believe that the oversize lead bullets (.401) not seated far enough into the case (loaded long) could be the culprit. We will see I had some other reloads that had 180gr hp xtp's loaded to the same length and they drop right in and come right out. which again lead me to believe that something had to be holding the others out. I gauged some of them and they all drop in the Dillon gauge but not 100% into the barrel.

I also pulled on down to see if the brass itself would drop in and it did, another indication that something was holding it out now to test the theory

[huskerlrrp]

Did you buy the "match" version? I found out that they undersize those so they work with OEM and aftermarket slides. I didn't have a 40S&W reamer so I sent it to them with some sample rounds and they fit it for me.

No I ordered the drop in, I was beginning to think I may have gotten the "match" (gunsmith fit) but a little online reading lead me to believe that the oversize lead bullets (.401) not seated far enough into the case (loaded long) could be the culprit. We will see I had some other reloads that had 180gr hp xtp's loaded to the same length and they drop right in and come right out. which again lead me to believe that something had to be holding the others out. I gauged some of them and they all drop in the Dillon gauge but not 100% into the barrel.

I also pulled on down to see if the brass itself would drop in and it did, another indication that something was holding it out now to test the theory

Good point with the brass. My sized brass wouldn't even chamber. If you still run into problems I'm sure they would fit the chamber for you. They seemed pretty attentive to customer service.

[98sr20ve]

Nearly all the barrels are made tighter. I have to load my Lead stuff to 1.080 with my 9mm 147 gr Lyman mold bullets. It's just not uncommon at all.

Edited October 6, 2010 by 98sr20ve

[Odawgp]

Final determination was the bullet was contacting the throat/lands I had to run it into 1.115OAL the rounds now "chamber" gauge without a problem where as before they would gauge in the case gauge but not in the chamber

[Whitefish]

KKM advised me and also Evil Bill (Open17 here) of Glock fame that a normal reamer for the throat is not advisable. One should use a floating pilot reamer. Otherwise, it is possible to really screw up the throat unless you are very careful and know exactly what you are doing. My gunsmith managed to get it done after talking to Dave Manson of Manson Reamers. He machined the tip of his reamer slightly smaller to get it started and was very careful with the operation. My open Glock 17 will shoot very small groups at 25 yards and consistent hit a 10 inch steel plate at 40 yards, so I guess he got it right. This is the second gun he has done for me and both shoot great. Both barrels were gunsmith fit KKM Glock 9's and the throats on both were very, very tight. BTW - I think KKM refers to their gunsmith fit barrels as "Match" barrels. That is how the package was labeled on two drop in Glock barrels I have used in other guns.

[B_Seehawer]

I had the same problem with my moly bullets in my Lone Wolf barrel. Sent it to Grams engineering and they reamed out the throat. Worked great for the low price of it in my own opinion.

Brad

[Sean Gaines]

I have had hit or miss with kkm, I have had a real good barrel, and one that was horrible, in terms of accuracy. I called kkm, and they said that it was my shooting.Sure! I had the gun sandbagged and it was shooting all over the place at 15yds. I could hit a nat's ass with my .40 cal, the 9mm was up, down, left right, horrible....

[Odawgp]

I think KKM refers to their gunsmith fit barrels as "Match" barrels. That is how the package was labeled on two drop in Glock barrels I have used in other guns.

There is also a part number on the package, mine also says "match" but the part number is #G35D1 which indicates that it is a drop in barrel with a "match" chamber

Part# G35D1G would require a gunsmith to properily fit it with a finishing reamer, this barrel probably wouldn't head space correctly without this fitting in addition to the other problems

I believe it is the larger dia of the lead bullet (.401) and the long OAL that was the cause of the hiccup

a cartridge loaded with a lead bullet with an OAL of 1.115 works anything longer and I start to see were the bullet is engaging the lands. I don't see that with jacketed or plated bullets seated at lengths of 1.145. those are also .001 smaller than the lead bullets.

I didn't try to sand bag the gun It shoots good enough free hand I didn't think it was warranted