CASE OAL Tolerances for a .270

[Rokbar]

I am resizing my fired cases for a .270. The Lyman book calls for 2.540 on the case, not cartridge. What tolerations are acceptable: 2.536? I guess what i am asking is there a percentage that is acceptable after resizing, trimming, and chamfering. Or after resizing if the case is 2.543 would you just leave it at that. I am not that anal about exact tolerances, butif I can make it happen Iwill try. Thanks in advance!

 

[dla]

Google "SAAMI specifications". Download the rifle pdf.

"Voluntary Industry Performance Standards
for Pressure and Velocity
of Centerfire Rifle Ammunition
for the Use of Commercial Manufacturers"

 

[snuzzo29]

2.540 is listed as max case length and anything over max should be trimmed. So if you have a case that measures 2.543 after sizing it would need to be trimmed to under max length. Your case that measures 2.536 after sizing doesn't have to be trimmed since it is under max case length. If I have cases that need to be trimmed I usually trim everything to trim length for consistency. If I was to trim that 2.543 to the trim length in the Lyman manual at 2.530 I would just trim everything to 2.530 so that everything is consistent. The trim to lengths are usually a mid point between max and min case length.

 

[Rokbar]

2.540 is listed as max case length and anything over max should be trimmed. So if you have a case that measures 2.543 after sizing it would need to be trimmed to under max length. Your case that measures 2.536 after sizing doesn't have to be trimmed since it is under max case length. If I have cases that need to be trimmed I usually trim everything to trim length for consistency. If I was to trim that 2.543 to the trim length in the Lyman manual at 2.530 I would just trim everything to 2.530 so that everything is consistent. The trim to lengths are usually a mid point between max and min case length.

Good info.

 

[deadwolf]

Set up your trimmer to whatever length your brass needs to be, then run all the cases you’re reloading on the trimmer. Those that need trimmed will be and those that don’t, won’t.

But as stated above, if it’s over the called for trim length then you have to trim it.


Sent from my iPhone using Tapatalk

 

[Rokbar]

After trimming the brass is all between 2.539-2.532. I know ideally the cases should all be exactly the same, but through my error of measuring, maybe too much pressure trimming and chamfering there is a difference.Is this normal and Ok? And i'm not going be shooting in any matches, only hunting.