Checked the max case length of my new toy
over the holiday.

.223 Rem. Kimber.

Speer Reloading Manual #13 list the following.
Max Case Length 1.760
Trim To Length 1.75

Actual chamber length is 1.782

The question would be is .032 excessive?
And how does this affect accuracy?

Probably over thinking this but any input
would be appreciated.

Swede Nelson

Almost certainly it is time to trim. Cases that excessively long could easily effect bullet release and cause pressure spikes.

Sorry

My chamber is 1.782 long not my brass.

Checked with a gauge.


Swede Nelson

quote:

My chamber is 1.782 long not my brass

Not an issue. Lenght of the chamber neck should have no effect on accuracy. I've found that actual neck length of the case will have very little as well. On a normal hunting rifle I trim a new case short and let it grow. I might have to trim one more time before the brass is lost. I couldn't measure the accuracy difference between that and triming each time.

I have the same sinclair inserts for most all my guns. What you are seeing is very common and why I love the inserts....I have several guns that never need trimming for the life of the brass! I don't think I have a gun in the safe that has less than .012" more space than sammi spec and alot of them are in the .020" range like yours.
Considering the cheap price of the inserts and what time is worth to me....they paid for themselves really really quickly.

Sorry, I mis-read the original post (silly me!) Probably no need to worry about trimming for at least a while unless you think it is having a negative effect on accuracy.

Another good reason to trim is to be sure all the cases have a consistent length. Will help accuracy and if you are crimping your ammo, will give you a consistent crimp.

quote:

Originally posted by Bob G:
Another good reason to trim is to be sure all the cases have a consistent length. Will help accuracy and if you are crimping your ammo, will give you a consistent crimp.

Agreed, I trim new batch of cases to the same length everytime

It's great when you don't have to trim brass, isn't it!

Consistent length between the cases is still important.