30-30 case length question

30-30 is relatively low pressure for a rifle cartridge, and may take several firings to stretch enough to need trimming. I usually trim all my once fired brass to a uniform length, and then trim the whole batch again once the brass starts to get to max length.

usmc0811 said:

Ok thanks. So I know the max trim length is 2.039 as my manuals have stated that but is there a minimum length that I want to make sure i don't trim too short?

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Per Hornady's 9th edition manual: case trim length should be min 2.029. So wherever you decide to trim to in the 0.01" between min trim and max legth should work. I usually go about 0.005 short of max when I trim.

usmc0811 said:

Ok thanks. So I know the max trim length is 2.039 as my manuals have stated that but is there a minimum length that I want to make sure i don't trim too short?

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Most manuals will tell you the max trim length is 2.039" and the recommended trim lengthier 2.029" .

Even that case you measured @2.043" is no big deal and not worth setting up the trimmer for one or two cases.

Is this a lever action rifle and are you going to crimp to the cannular? If you are going to crimp to the cannular of the bullet because of a tube magazine you may want to trim them all to within length of the cannular of the bullet so all your rounds end up crimped and none of them are to short to reach the cannular. Your also supposed to check the lengths of the cases after they are resized, then trim if necessary. Have you resized these yet?
If you are using a bolt action this doesn't matter so much.

FWIW I have a goodly supply of 30-30 brass and still I trim them EVERY time I reload them. I will set up and trim 200-300 each setting. This is for ease of crimping them in the cannalure the same each round to promote accuracy. If you have the Lee FCD then trimming them all to the same length is not so critical but I do have one of those dies and still trim each reload cycle. YMMV

As far as when it's time to trim, If your sizing die is set up to where you can chamber all resized cases, and one day you discover you can't close the lever on one you may want to check the length. If your using a bolt action 30-30 and are not crimping you may not ever find the need.

Reminder: You check brass length after sizing, not as fired. It will normally grow on sizing provide you are moving the shoulder back.

Like others have said it's a recommendation. Some chambers are more generous than others. Most can take a 0.005 over max while others may take 0.010" or more. Then you get some tight match chambers and they may not allow 0.005".

Good, I trim mine so that I can set my seating and crimp die once and I won't have any round that the neck doesn't reach the cannular on the bullet. But I also have a 1952 Ballard rifled Marlin 336 with a tight chamber so I have to watch my neck length. You won't know that with yours until you start experimenting with neck lengths to see what your rifle will accept. Like Blue68f100 said the chambers are all over the place as to how deep they are machined with the lever action 30-30s. When I set up my dies for a 30-30 with raw brass(new, never been resized), I pick out the longest case I can find after resizing and try it in my rifle I'm loading for to see if it chambers. Then I go from there. The longest one in my rifle seldom chambers so I start trimming until it does, then I know where my max is.

If it still won't chamber, then I look at the shoulder length, but that is seldom the problem.

If max is way out there I don't worry about it and just trim to SSAMI specs minus where I need to be to hit the cannular every time when seating bullets, with all of my cases. At this point it doesn't matter about free bore (distance from ogive of bullet to rifling engagement). It is what it is.

If I find I have a nice tight chamber because I can't close the lever on chambering the empty, resized case, then I start working with the neck length of the case until I find out what the rifle needs for neck length. This is assuming my shoulder length with my resizing die is correct or less, so I know I don't have the shoulder stopping me from chambering. But these are new, raw brass that have never been sized in a die before.

Your once fired brass will need to have the shoulder bumped back a few thousands unless you try them all and they all chamber, so you don't get a false positive of them stopping the bolt from chambering, and you know the shoulder length isn't stopping the bolt instead and the length of the neck.

The 30-30s aren't match grade and because of extreme mass production of that caliber in lever action rifles and the fact that 30-30 lever actions were never considered to be more than a 100 yard gun with a deer sized target, by their manufacturers the chambers are rarely tight or short chambered.

Quality Control wasn't the best with Marlin, Mossberg, and Winchester as far as headspacing was concerned because of this and the fact that they were built to headspace off the rim instead of the shoulder.

So the chambers are usually milled to deep so they will accommodate any mfg's ammo out there. This make trimming cases go back to what I said about making the length of the neck fit the cannular on all your rounds, more of a consideration than worrying about max length.