Let talk about brass trimming???

[ODAVID]

OK I have loaded for a number of years but an old questions has resurfaced. At what length do you trim? Lets say the manual shows a picture of a 30-06, with brass length of 2.494".

Question is do you just trim your brass only when in excess of 2.494" or do you slightly reduce to say 2.300 for uniformity or what do you do?

Do you notice any difference in accuracy?

Actually what difference does it make if the chamber is cut longer then 2.494.

If you are using a lee factory crimp do the trim length make any difference?? Seems like it would but I want to hear from others.

Thank in advance for sharing your experiences.

 

[savagekindaguy]

OK I have loaded for a number of years but an old questions has resurfaced. At what length do you trim? Lets say the manual shows a picture of a 30-06, with brass length of 2.494".

Question is do you just trim your brass only when in excess of 2.494" or do you slightly reduce to say 2.300 for uniformity or what do you do?

Do you notice any difference in accuracy?

Actually what difference does it make if the chamber is cut longer then 2.494.

If you are using a lee factory crimp do the trim length make any difference?? Seems like it would but I want to hear from others.

Thank in advance for sharing your experiences.

If you are going to crimp then yes it makes a difference how long the case is. I use Lee Case trimmers and it is easy to make all cases the same. I stick a case in a base and on the guide and give it a spin and if it bites it needs trimming. If not I load it. Seemple. If all cases are from the same loading batches and reloaded the same number of times all cases should be similar in length. The crimp should then also be uniform for all the cases in the batch.

 

[thatguyshm]

Generally, most manuals will give you a trim to length, and for the .30-06 shows 2.484" in my Lyman manual.. I stick to the suggested trim length to uniform, then see what the brass wants to do.. I let the 257 Roy grow a bit longer than generally recommended, but other than that, I stick to the .010" under max length. I generally watch it more on my auto loading rounds.

+1 on the crimp advice also


SHM

 

[sourdough44]

I trim to the 'trim to length', not under. Now if one is a bit under, I don't worry about it, but try to stay close to the listed length.

After the trim I do my 'Champher/Debur'. Brass prep is one of the more time consuming aspects of reloading.

I use the Lee FCD at times, works for me.

 

[savagekindaguy]

I trim to the 'trim to length', not under. Now if one is a bit under, I don't worry about it, but try to stay close to the listed length.

After the trim I do my 'Champher/Debur'. Brass prep is one of the more time consuming aspects of reloading.

I use the Lee FCD at times, works for me.

Time consuming but effective. I will probably get some type of motorized job to do all the steps but that won't be for a while.

 

[AZShooter]

I hate trimming. Once the brass is determined to be the same length I won't trim depending on the length of the chamber. I determine exactly where the end of the chamber is by using one of these:

http://www.sinclairintl.com/reloadi...s/sinclair-chamber-length-gage-prod32925.aspx

I discovered years ago that many chambers won't require you to trim the brass for many firings/ sizings. Some factory chambers are as much as .070" longer than the recommended trim length listed in the loading books. Why trim if you don't have to?

You will have to remove much of the neck of a case for use with the gauge. Seat the gauge long in the case then close bolt on it. The plug will slide rearwards. Carefully remove and measure the OAL to determine end of chamber dimension. I like to repeat this several times to be certain.

If you have access to a lathe you can get specs on the gauge on Varmint Al's site so you can make your own. I use aluminum or brass:

Varmint Al's Mini Lathe Page:

http://www.varmintal.com/alath.htm

Al also explains how to use:

http://www.varmintal.com/arelo.htm

The only brass I ever crimped was some 375 H and H ammo that was going to go to Africa to hunt dangerous game. It was requested by the owner. Don't blame him as he was looking for every safety precaution. I only crimp for handguns don't ever intend to do so for my rifles.

 

[tbrice23]

I measure all my chambers by cutting half the neck off from a fired case, then neck sizing the left over neck then seating a bullet short and slipping the rest of the neck over the bullet long. Then carefully chambering the cartridge and measuring a few times so that im confident that I have the correct measurement. I use a fire case so that it is formed to my chamber.
My chambers are almost always .030" to .045" longer than book max.
I like long neck so i do let them grow but maintain them all exactly the same length.

I'm trimming with RCBS 3 way trimmer heads on their power trimmer. Best money i have ever spent on reloading equipment!

 

[ODAVID]

Obviously a lot of variety. The best reccomendations seems to be from Savage kindguy.
Which does not mean the others individual are wrong. Their system must work for them.

Thanks
ODAVID

 

[Bill Johnson]

OK I have loaded for a number of years but an old questions has resurfaced. At what length do you trim? Lets say the manual shows a picture of a 30-06, with brass length of 2.494".

Question is do you just trim your brass only when in excess of 2.494" or do you slightly reduce to say 2.300 for uniformity or what do you do?

Trim-to length is based on the SAAMI case maximum length minus 0.010. For Service Rifle cartridges or any other that may be used in multiple foirearms, I trim when cases start to exceed the SAAMI maximum length.

Some rifles have dediceted lots of brass and those are trimmed when they start to approach .010 under chamber length.

Do you notice any difference in accuracy?

I, personally, have not noted or documented any difference.

Actually what difference does it make if the chamber is cut longer then 2.494.

My only concern is having 1 caliber in neck length to apply the amount of neck tension I desire and ensure finished round concentricity. If you have a chamber longer than SAAMI specs, and it's not unusual, you must know by how much to ensure case mouth does not enter the throat if leaving necks longer than specifications.

If you are using a lee factory crimp do the trim length make any difference??

My understanding is NO but there are very limited number of cartridges I crimp at all.

Seems like it would but I want to hear from others.

Thank in advance for sharing your experiences.

That's my 2 cents, FWIW.