Trimming 30-30 cases

[DeadFlies]

I'm getting ready to start reloading some 30-30 cases, most likely with cast bullets. I have about 250 pieces and after full-length sizing them I measured them all.

There are three groups: one group of about 40 pieces measures exactly 2.030. The next group of about 150 pieces are all somewhere between 2.035 and 2.039, with most of them being 2.036-2.038. The last group of about 60 measures over 2.040, mostly being 2.040-2.042.

Do I really need to trim all of there down to 2.030? Does .005"-.010" in length matter? Will is mess up the crimp?

I guess I could do these in batches and adjust the crimp for each length, but that seems like a pain and then all of my brass will get mixed together again, unless I mark them which is another step...

BTW these will be with MBC 135 or 165 cast bullets over about 8.5 grains (that's where I'm starting anyway) of Unique, it that helps.

Advice? Thanks.

 

[rcmodel]

If you plan to crimp, and plan to crimp in the seating die?
They will have to be trimmed to the same length.

Otherwise long ones will buckle the shoulder and they won't chamber.
And short ones may not get enough crimp to keep the bullet in place under recoil.

If you crimp separately with a Lee FCD, it isn't absolutely necessary, as the Lee FCD operates a collet off the shell holder, so case length is not nearly as critical.

rc

 

[DeadFlies]

They will have to be trimmed to the same length.

rc

I was afraid of that. Any recommendations on a case trimmer?

I know the Lee one is cheap and works but, only trims down to 2.039" so that won't work for me as they all need to be trimmed down to 2.030", the length of my shortest ones, right?

 

[rcmodel]

Yes, but you can pretty easily shorten the depth stop pin .009" to make it cut shorter.

The one I have for .233 had the pin threaded in so I adjusted it to the length I wanted and Lock-Tighted it in place.

I understand the new ones are solid one-piece rods, so you would need to stone or grind off .009" or whatever to make it trim shorter.

rc

 

[DeadFlies]

Yes, but you can pretty easily shorten the depth stop pin .009" to make it cut shorter.

The one I have for .233 had the pin threaded in so I adjusted it to the length I wanted and Lock-Tighted it in place.

I understand the new ones are solid one-piece rods, so you would need to stone or grind off .009" or whatever to make it trim shorter.

rc

Sounds easy and cheap enough. Thanks.

 

[popper]

Brass fired from your rifle? HS set correctly for your rifle? I would recommend the FCD and forget the trimmer. You're talking .012" long, not a problem. After firing in your rifle and FL sizing to your rifle's head space, you will find they are short. Still no problem. I have a trimmer and haven't used in 2 years. Look into the lyman M die for cast boolits. Don't know what rifle you have so I suggest .311 dia. cast boolits.

 

[DeadFlies]

Brass fired from your rifle? HS set correctly for your rifle?

All but about a dozen pieces have been fired from this rifle, most of them multiple times. They have all been FL resized, though I can honestly say I've never read of FL sizing to a rifle's headspace. This cartridge headspaces on the rim, so what can the resizing die do to it to change headspace?

The rifle in question is a 1975 Winchester M94.

 

[R.W.Dale]

There are other reasons besides crimp uniformity to trim cases.

If they get overly long they can impinge into the rifling leade and dramatically raise pressures.

I load for a 30-30 revolver and I simply modified my Lee trimmer pilot to go another .010" under trim to length with the idea that ill probably only have to trim these cases once in their lifespan

 

[homatok]

With "rimmed" and/or "belted" cases it pays to size to the chamber for longer case life. The process is the same as is used to "partial full length" size rimless cases.

 

[R.W.Dale]

With "rimmed" and/or "belted" cases it pays to size to the chamber for longer case life. The process is the same as is used to "partial full length" size rimless cases.

For non bolt actions partial length resizing is a surefire way to create ammunition that wont chamber and or. Will suffer from accuracy issues.

You could buy a couple hundred dollars worth of case and chamber gauges so you can establish exact headspace for that gun and push the shoulder back only the absolute minimum to ensure free chambering. So you can get $12 a box brass to last a couple more loadings in a 4moa gun

Or you can use a $20 saami case gauge full resize to that, have ammunition that will work in all 30/30's and just pick up a fresh batch of cheap possibly free range brass every couple of years

 

[gamestalker]

As already indicated by R.W. Dale, allowing your brass to grow beyond the trim to length could indeed cause unpredictably high pressures to occur. High powered rifle brass that gets longer than SAAMI established length can create a pinching effect when the bullet begins to leave the case mouth, thus causing pressures to rise excessively, and unpredictably high.

GS

 

[Centaur 1]

More important than the crimp is the flare on the case mouth when loading cast bullets. If you adjust the case expanding die for the shortest case, the longer ones get belled too far and may crack. If you shoot cast bullets, go buy yourself the Lee Universal Case Expanding die. It'll be the best $15 you can spend. I take the extra time to trim all my brass the same using the Lee case length gage. I chuck the shellholder in my cordless drill, and clamp the drill to my workbench. Just squeeze the trigger and insert the cutter into the case, it's quick and easy. With all cases the same length it will be easy to set the expanding die.

 

[homatok]

R W Dale---You are correct and I should have included that warning in my post. Thanks!