case trim length

[42769vette]

im just curious here. i did a search and found nothing.

does case trim length effect accuracy. as long as its consistant does it matter?

say i load a 260 with 142smk and 43gr h-4350

i have 20 cases that are 2.025 and 20 that are 2.035

will one load be more accurate?

 

[Victor N TN]

Re: case trim length

As long as they keep the same neck tension they will be fine. I would not mix them in the same group. But besides that the accuracy thing should be fine.

Cutting the brass too short for a given chamber will cause the throat area to erode prematurely. But that's something you need to measure for and trim to that given number -.005" to .010" Doing it that way will increase the accuracy life of the barrel.

 

[Powder_Burns]

Re: case trim length

Only affects accuracy in terms of consistancy. If all your cases are uniformly trimmed, (they all measure the same) then your seating depths will be more consistant and if you are crimping the amount of crimp will be consistant as well.

Only way to find out if one load is more accurate than the other is to experiment, with as much control over conditions and variables as you can, and examine the results.

 

[42769vette]

Re: case trim length

thanks guys.

i know when hunting for the best load for a given rifle you mess with powder wieght and seating depth but i didn't know if trim length was part of the equation

 

[WayneHS]

Re: case trim length

I use a Sinclair chamber gauge to find the true max length then just subtract .005 or so. It's cheap.