brass triming question

gotguns? · February 17, 2009, 02:38 PM

I am to start reloading .308 for my single shot rifle. My question is why should I trim cases if I dont plan to crimp(and I dont)? What harm can come of not trimming cases besides uneven crimps?

snuffy · February 17, 2009, 02:55 PM

This ? sounds like someone has NOT read a reloading manual. That means you're NOT ready to begin loading. Sorry, just the way I feel.

It doe not matter that you're loading for a single shot rifle. You STILL need to keep the cases trimmed. The end of the case, the mouth, butts up against the end of the chamber in any rifle. If the mouth of the case butts/hits the end of the chamber, it can be forced into the bullet. This holds the bullet from moving when the powder burns, raising pressure dramatically. The bullet MUST be able to move freely as the powder burns.

firewrench044 · February 17, 2009, 03:28 PM

The chamber in your rifle is made to acept a cartage with specified
dimentions, what you are doing is returning the case to those dimentions
( resize and triming )

If you use a case that is too long, the case is forced past the area of the chamber cut for the case and into the smaller area made for the bullet and
the cartage can not be fully inserted into the chamberand and can become jamed when you try to close the bolt

The neck of the case needs to be long enough to expand and make a seal
between the case and chamber, if it does not it pushes the case back into the bolt harder than the bolt was designed for

After sizeing you need to check the length to make sure that the cases
length is between the max. and min.case specs.

Also cases with the same length will give you a more consistant and titer patern on your target

lev83 · February 17, 2009, 04:10 PM

I concur with the others not trimming your rifle brass will not only result in decrased accuracy but more importantly it will lead to you harming your gun or yourself secondary to increased chamber pressures.

Slamfire · February 17, 2009, 04:27 PM

You will find out how important it is to trim brass once your rifle starts blowing primers.

I learned that it was important to check/trim cases each reload after my 30-06 started blowing primers. I had made the faulty assumption that once fired brass could not grow overlength, after all it was new, right?

I was wrong. Brass grows the most on the first reloads. My case necks had grown out enough to pinch the bullet in the throat.

Result, blown primers.

Inspector3711 · February 17, 2009, 08:01 PM

What they said... I added a Lee collet die to all of my Redding sets. This cuts way back on how often you need to trim, doesn't cost much to add, and ensures that the bullet and case neck are centered which can improve consistency and accuracy. I typically go 7-8 reloads on a cartridge now before FL sizing and trimming once.

keys85 · February 17, 2009, 10:52 PM

FWIW, my fellow reloader hates trimming brass to the point that when the cases reach their max length, he'll throw them away.

I, unfortunately, don't have the luxury of affording new brass so often and opt to trim them when it's needed. In fact, I just recently went through ALL my brass in every caliber and trimmed to length, including 500 rounds of 9x19 to 9x18 conversion. Fun stuff. ~rolls eyes~

Inspector3711 · February 17, 2009, 11:25 PM

Odd... I've only had to trim rifle cases. My pistol cases either don't grow or actually shrink.

keys85 · February 18, 2009, 12:30 AM

Correct. I was converting brass.

Inspector3711 · February 18, 2009, 02:13 PM

Ahh.. sorry about that...

James R. Burke · February 19, 2009, 04:42 PM

They are all right. I always trim my brass even if it is not at max. I am just one of those guys that like to keep it the same 100% all the time. Takes a little more work if it's not at max yet, but it can't hurt.

February 17, 2009, 02:38 PM	#1
gotguns? Senior Member Join Date: April 13, 2008 Location: Oakland City IN Posts: 136	brass triming question I am to start reloading .308 for my single shot rifle. My question is why should I trim cases if I dont plan to crimp(and I dont)? What harm can come of not trimming cases besides uneven crimps? __________________ "And what country can preserve its liberties, if its rulers are not warned from time to time, that this people preserve the spirit of resistance? Let them take arms. ... The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants." -Thomas Jefferson

February 17, 2009, 02:55 PM	#2
snuffy Senior Member Join Date: May 20, 2001 Location: Oshkosh wi. Posts: 3,055	This ? sounds like someone has NOT read a reloading manual. That means you're NOT ready to begin loading. Sorry, just the way I feel. It doe not matter that you're loading for a single shot rifle. You STILL need to keep the cases trimmed. The end of the case, the mouth, butts up against the end of the chamber in any rifle. If the mouth of the case butts/hits the end of the chamber, it can be forced into the bullet. This holds the bullet from moving when the powder burns, raising pressure dramatically. The bullet MUST be able to move freely as the powder burns. __________________ The more people I meet, the more I love my dog They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?

February 17, 2009, 08:01 PM	#6
Inspector3711 Senior Member Join Date: February 9, 2008 Location: Puget Sound Washington Posts: 1,553	What they said... I added a Lee collet die to all of my Redding sets. This cuts way back on how often you need to trim, doesn't cost much to add, and ensures that the bullet and case neck are centered which can improve consistency and accuracy. I typically go 7-8 reloads on a cartridge now before FL sizing and trimming once. __________________ "If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun." The Dalai Llama (5/15/01, The Seattle Times) "That rifle on the wall of the labourer's cottage or working class flat is the symbol of democracy. It is our job to see that it stays there." George Orwell

February 17, 2009, 11:25 PM	#8
Inspector3711 Senior Member Join Date: February 9, 2008 Location: Puget Sound Washington Posts: 1,553	Odd... I've only had to trim rifle cases. My pistol cases either don't grow or actually shrink. __________________ "If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun." The Dalai Llama (5/15/01, The Seattle Times) "That rifle on the wall of the labourer's cottage or working class flat is the symbol of democracy. It is our job to see that it stays there." George Orwell

February 18, 2009, 02:13 PM	#10
Inspector3711 Senior Member Join Date: February 9, 2008 Location: Puget Sound Washington Posts: 1,553	Ahh.. sorry about that... __________________ "If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun." The Dalai Llama (5/15/01, The Seattle Times) "That rifle on the wall of the labourer's cottage or working class flat is the symbol of democracy. It is our job to see that it stays there." George Orwell

February 17, 2009, 03:28 PM	#3
firewrench044 Senior Member Join Date: July 9, 2007 Location: Fort Pierce, Florida Posts: 381	The chamber in your rifle is made to acept a cartage with specified dimentions, what you are doing is returning the case to those dimentions ( resize and triming ) If you use a case that is too long, the case is forced past the area of the chamber cut for the case and into the smaller area made for the bullet and the cartage can not be fully inserted into the chamberand and can become jamed when you try to close the bolt The neck of the case needs to be long enough to expand and make a seal between the case and chamber, if it does not it pushes the case back into the bolt harder than the bolt was designed for After sizeing you need to check the length to make sure that the cases length is between the max. and min.case specs. Also cases with the same length will give you a more consistant and titer patern on your target

February 17, 2009, 04:10 PM	#4
lev83 Senior Member Join Date: August 2, 2005 Posts: 130	I concur with the others not trimming your rifle brass will not only result in decrased accuracy but more importantly it will lead to you harming your gun or yourself secondary to increased chamber pressures.

February 17, 2009, 04:27 PM	#5
Slamfire Senior Member Join Date: May 27, 2007 Posts: 5,261	You will find out how important it is to trim brass once your rifle starts blowing primers. I learned that it was important to check/trim cases each reload after my 30-06 started blowing primers. I had made the faulty assumption that once fired brass could not grow overlength, after all it was new, right? I was wrong. Brass grows the most on the first reloads. My case necks had grown out enough to pinch the bullet in the throat. Result, blown primers.

February 17, 2009, 10:52 PM	#7
keys85 Junior member Join Date: September 20, 2008 Posts: 199	FWIW, my fellow reloader hates trimming brass to the point that when the cases reach their max length, he'll throw them away. I, unfortunately, don't have the luxury of affording new brass so often and opt to trim them when it's needed. In fact, I just recently went through ALL my brass in every caliber and trimmed to length, including 500 rounds of 9x19 to 9x18 conversion. Fun stuff. ~rolls eyes~

February 18, 2009, 12:30 AM	#9
keys85 Junior member Join Date: September 20, 2008 Posts: 199	Correct. I was converting brass.

February 19, 2009, 04:42 PM	#11
James R. Burke Senior Member Join Date: January 3, 2009 Location: U.P. of Mich/Quinnesec Posts: 1,897	They are all right. I always trim my brass even if it is not at max. I am just one of those guys that like to keep it the same 100% all the time. Takes a little more work if it's not at max yet, but it can't hurt.

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