Log in

View Full Version : trim length


RWBlue
05-31-2008, 02:50 AM
How much would inconsistent trimming effect accuracy?

I have been using Fireball brass to make my whisper brass.
I don't think all my brass made it to the trimmer.
Could this be the source of my accuracy issues?
Wouldn't this show up at the chronograph?

abyssdncr
05-31-2008, 12:27 PM
Are you crimping with a roll or taper crimp? If so, the inconsistent trim length would result in inconsistent neck tensions and pressures. This type of variation would definitely show up with a chrony.

Otherwise, with no crimp minor variations in length wouldn't affect much.

What is your load combination?

RWBlue
05-31-2008, 04:11 PM
No crimp.

Multiple loads,
The first round through the barrel is always slower, so I do multiple SD calculations, dropping the first shot for warm barrel.

Slow
240, SMK, w296, 9.5gr, CCI SRM, 1010FPS (old lot w296, without suppressor)
240, SMK, w296, 9.5gr, CCI SRM, 911.2FPS (old lot w296, with suppressor)

240, SMK, w296, 9.5gr, Russian, 942FPS (new lot w296, with suppressor, cold barrel, cold barrel SD22.5, warm barrel SD6)
240, SMK, w296, 9.5gr, Russian, 990FPS (new lot w296, with suppressor, Cold barrel SD19.8, warm barrel SD8.8)