nosler book case trim vs lyman and hornady

[theduke]

My Nosler book says for reloading 30-30 pistol 125 bt trim to 2.040 and lyman and hornady say 2.029.  If go with 2.029  lee case trim want work.  How do u know what correct size to trim is .   i will be using in tc contender 14" barrel if that helps.  Also if any one else uses tc contender in 30-30 what length do u oal length to in yours.  Mine seem long when checked in gun to hit rifling .  thanks

[spinafish]

every firearm is going to be different, but in your Contender either trim to length should be fine.  They are usually deep throated.  Color the bullet of a loaded (or dummy)round with a sharpie and chamber and close the action that round.  See if the ink has been removed by the rifling..if not you are good to go.  If that procedure does remove ink, reduce your OAL till it doesn't.

[bilmac]

Being low pressure and shot mostly in springy actioned guns, my 30-30 cases usually wear out long before they need trimming.

[roper]

My Nosler book says for reloading 30-30 pistol 125 bt trim to 2.040 and lyman and hornady say 2.029.  If go with 2.029  lee case trim want work.  How do u know what correct size to trim is .   i will be using in tc contender 14" barrel if that helps.  Also if any one else uses tc contender in 30-30 what length do u oal length to in yours.  Mine seem long when checked in gun to hit rifling .  thanks

You have two Length--Trim length is 2.029" and Max length is 2.039". Hornady gives case trim length and case max length  what that means you should be between trim and max length never over max.

[wncchester]

"Nosler book says for reloading 30-30 pistol 125 bt trim to 2.040 and lyman and hornady say 2.029. "
 
Yeah.  That sort of thing makes a fellow think the max case length probably has meaning but maybe the 'trim to' lenght really isn't all that critical, don't it?   

[necchi]

 +1 to roper,
The MAX length is 2.040, recommended trim length is usually .010 under max as a general rule.
 That re comended trim-too length is far from carved in stone, it's really .010 shorter because it leaves allot of room for case stretch and folks don't have to trim as frequently,
 Theoretically, once it's trimmed .010 short all you need do is measure and not trim again until it's reached it's max sammi length and still fit all sammi chambers.
 I have know idea where Lyman and others got 2.039,?? but .001 isn't a make or break. http://stevespages.com/jpg/cd3030winchester.jpg

[Old Syko]

First rule of handloading.  All available information is only a guideline and not carved in stone.  There will always be exceptions to every situation.  In this case you can get by with cases being much shorter than any quoted dimension but cases being too long can in some cases be disastrous.   

[roper]

+1 to roper,
The MAX length is 2.040, recommended trim length is usually .010 under max as a general rule.
 That re comended trim-too length is far from carved in stone, it's really .010 shorter because it leaves allot of room for case stretch and folks don't have to trim as frequently,
 Theoretically, once it's trimmed .010 short all you need do is measure and not trim again until it's reached it's max sammi length and still fit all sammi chambers.
 I have know idea where Lyman and others got 2.039,?? but .001 isn't a make or break. http://stevespages.com/jpg/cd3030winchester.jpg

There is SAAMI spec on the 30-30 and max trim length is listed  @ 2.395" on the reamer print.

[theduke]

I was just curious.  I am new to reloading and did not understand why using same type bullet 3 reloading manuals had 3 different trim to length sizes.  If case is trimmed short would pressures be higher and unsafe if have long col barrel?

[spinafish]

no...

[necchi]

  If case is trimmed short would pressures be higher and unsafe if have long col barrel?

No, the trim length has little to do with case pressure by itself, it's the seating depth of the bullet that can make a differance. Trim length does affect bullet grip, ya know? as in how much neck is there to hold the bullet.
But a bullet stuffed way down in a case can increase pressure,
Trim length and Bullet seating (Cartridge Overall Length) while related are two different things.
 
When it comes to the 3 manuals and 3 trim lengths,, .001 is nuthing, I have whiskers thicker than that.
Put your caliper at .001 and look at the space. Sometimes we get so stuck on the numbers on the dial, we forget to look at the actually size of the measurement.