RL26 in 280 Imp

[Mhall]

Finally got my 280 Imp done and have been testing the RL26 with 175 X's. I have a 31" barrel and can easily reach 3150 fps (2 grains under max) with RL26. I do get a carbon ring after 15-20 shots but feel that is manageable. Here is a group at 1020yds.

 

[Chad280]

What is causing the carbon ring and how do you find it

 

[Mhall]

No idea what causes it. I anneal my brass and have a warm load. This is the first gun out of 40 builds that has it. I was getting flyers randomly first 2 in one hole then next 1/2" away, next time first and third in same hole etc, etc. I read somewhere about a carbon ring and I have a Lyman borescope so I went searching for the problem. In the neck area of the chamber was black after I cleaned it. Well several attempts with a brush and cleaner on the end of a drill it was spotless. Shot several groups to verify it helped and whoa! I have several targets on my bench of .150"-.250" ctc. Then my ocd kicked in and I checked all my Guns and found one other possibly affecting accuracy. Plan on going out this weekend.

 

[CTK]

I hit pressure signs in mine below Berger max for the 168 VLD. It was quite hot out and got very minor extractor print @ 62gr.. Berger sent me load data showing max @ 63gr. I am going to try RL23 and 7977 next. I shot several groups at a 58gr. and got consistent sub 1/2" (just slightly) groups with RL26. I did not chrono the loads. Shooting a 24" hunting rifle. What brush or patch did you use to get the carbon ring out? I just used the Sinclair Chamber Gauge insert to find out that my chamber is about .040 longer than the published trim length of the SAMMI 280 Ack. Imp. Have read that this can cause a carbon ring. Not sure and also not sure if should trust the $6

 

[Mhall]

Just used a bronze brush and shooters choice on the end of a drill.

 

[smoking-brass]

I have found in my 280 AI if the cases are short you will get a carbon ring ....clean bore with bore tech nylon brushes and patches soaked with bore tech eliminator.
I also switched to H1000 ... shot much better.

 

[CTK]

I just switched to Bore Tech Eliminator and Copper Eliminator. Love the stuff and my wife does not yell about the smell.