Case trimming

[FLHTC]

What is the typical amount that shooters react to when case trimming? Take for instance the 30-30. The lyman #3 handbook gives a "trim to length" of 2.028 and the SAAMI spec is 2.039 but I'm wondering if I'm being overzealous when reacting to the case stretch. I always trim to the middle(2.033)of those two dimensions and trim again when the cases reach 2.036. There are some cartridges which don't have that .011 spread like the 8mm Mauser. The SAAMI spec is 2.240 and Lyman's trim to length is 2.235. I trim this to the 2.235 and again when it stretches .002. I'm mainly doing this for accuracy and consistency but I'm curious to know what the silver blooded shooters do. Am I over reacting?

[dragon813gt]

Trim to minimum specs, trim again when it reaches max spec. You are going to trim more often if you don't take it to minimum spec.

[FLHTC]

Well this I understand but brass cases never stretch the same and the difference is even more exaggerated between manufacturers. Some cases in my group of the same manufacturer will be between .003 to .004 apart after a summer of shooting and reloading and at what point do you guys react to get them all in line again? With my 22 calibers and jacketed bullets, I keep all the cases within .001 and it pays off in spades. The accuracy with cast just isn't the same as jacketed and I'm wondering if I'm wasting my time to do the same with cast load cases?

[gnoahhh]

Shooting cast demands even more attention to the minutiae than for jacketed bullet shooting, IMO, if utmost accuracy is the goal. That includes keeping brass dead nuts even in length, among a lot of other things. It's just one more tiny variable among many that when added together can spell the difference between "wow" and "good enough" accuracy. The devil's in the details.

[William Yanda]

Is not one purpose of trimming to enable consistent crimps?
Respectfully
Bill

[Scharfschuetze]

Is not one purpose of trimming to enable consistent crimps?
Respectfully
Bill

Yes, it really helps form a uniform crimp.

A good crimp as well as uniform neck tension from case to case will help shrink extreme spreads and help with delivering good groups and uniform performance.

[FLHTC]

Shooting cast demands even more attention to the minutiae than for jacketed bullet shooting, IMO, if utmost accuracy is the goal. That includes keeping brass dead nuts even in length, among a lot of other things. It's just one more tiny variable among many that when added together can spell the difference between "wow" and "good enough" accuracy. The devil's in the details.

Thank you sir. This is what I was looking for. Your location reminds me of an experience I had as a young man. I was getting coffee at the McDonalds on the corner where College Parkway comes out on Rt 50 and a deer walked right through the bank parking lot next door. I was driving all the way to Queen Annes county to hunt and here one walks right by me.

[MostlyOnThePaper]

Already been said, never mind.