Trim length for 7PRCW

[Mahziar]

Hi
what is your trim length COL for this Cartridge?
my chamber reamer print shows the COL of 2.0250.
for my 300PRC and 6.5CM I am usually 0.010 below maximum COL.
Thanks

 

[FeMan]

Measurement "T" on my reamer is is 2.040". I determine the trim length based on how much brass flow/stretch I get in sizing. I haven't chambered a barrel in this cartridge yet, but anywhere up to 0.010" minus your maximum should be fine. Consistency in length is what matters. Keeping them on the long side will reduce the area where you can get carbon buildup and ring formation in the front of the chamber but it wont eliminate the issue.

 

[NorCalMikie]

Most chamber reamers cut about .020 LONGER than "max trim length".
You set your trim to length where YOU want it.

 

[coford]

I usually check by putting a once or two times fired, untrimmed case in the chamber and then run my borescope down the muzzle. You will see exactly how much room you have. I have found that there is more room in my chambers than I think there is. Then trim accordingly. FWIW

 

[Mahziar]

Measurement "T" on my reamer is is 2.040". I determine the trim length based on how much brass flow/stretch I get in sizing. I haven't chambered a barrel in this cartridge yet, but anywhere up to 0.010" minus your maximum should be fine. Consistency in length is what matters. Keeping them on the long side will reduce the area where you can get carbon buildup and ring formation in the front of the chamber but it wont eliminate the issue.

Thanks it makes sense

 

[EdHarley]

I usually check by putting a once or two times fired, untrimmed case in the chamber and then run my borescope down the muzzle. You will see exactly how much room you have. I have found that there is more room in my chambers than I think there is. Then trim accordingly. FWIW

I like that method but I don’t think the bore scope is long enough with a 32” barrel.

 

[Alex Wheeler]

I dont let my necks get any closer than .020" from the end of the chamber. Shorter is better.