How important case trim length consistency?

[Dusty Stevens]

If you have differing case lengths there will be carbon in the neck area of the chamber and a longer case will get crimped by this carbon ring changing the pressure

 

[Bart B.]

I've not observed any accuracy difference across a .010" spread on 308 Win and 30-338 Mag cases.

Neither did a friend reloading the same 308 Win case 56 times trimming it back to 2.000" every .010" of case growth. His 100 yard group for all shots was about 3/8ths inch.

Maybe a 1/10th inch benchrest grouper would show a difference.

A national champion had the right attitude about ammo details. If your groups don't reveal detail differences, don't sweat them.

 

[ebb]

I've got a Wilson and a Lee. A few weeks back I had a case where Lee didn't make a trimmer pilot for the chambering I needed so I got the case holder for the Wilson and used it for the first time. I did not have good results with the Wilson trimmer. I know that it was me, and there must be a learning curve or something I don't know about using it cause others get good results. But the Lee works and if I have a choice simpler is better. I will learn to use the Wilson but not if the Lee is available for the case I am trimming, its just too easy and accurate.

 

[fguffey]

Neither did a friend reloading the same 308 Win case 56 times trimming it back to 2.000" every .010" of case growth. His 100 yard group for all shots was about 3/8ths inch.

The last time I read that story he was using max load and he never weighed the case..

I was at a gun show when an owner blamed the builder of building a rifle with head space problems. He asked the owner if he would bring the rifle by his shop to be checked, he agreed. And then? The owner was standing in front of me, I asked to see the case; I asked the owner if that was the only case he had and I asked him if he was firing it over and over and over etc. etc., and I offered to form 200 cases for his rifle for free.

The builder of the rifle got involved and asked to see the case, after looking at the case he sent the new owner to a smith of few words. The new owner was instructed not to tell the smith what I said and he was told not to tell the smith who built the rifle. Any how, the owner of the rifle returned mad and upset. Seems the smith tore the case open and measured it. He informed the owner the case had a good thickness for paper but was too thin for a rifle case.

He never returned to rifle to the smith and he never contacted me with help forming cases for free.

F. Guffey

 

[jackson1]

New guy here, but life long chaser of accuracy. Currently developing a 6BRA. With my 40 plus year old RCBS trimer, I could not keep my trimmed case under +/- 0.003". Switched to Wilson and am now under +/- 0.0005". Another benefit is the ability to make a precision chamfer, using my Wilson 40 degree cutter. Cannot prove this kind of attention to detail will improve my groups and score, but is one less thought floating around in my head.

 

[fguffey]

Cannot prove this kind of attention to detail will improve my groups and score, but is one less thought floating around in my head.

For me it is not a matter of choosing a trimmer, I have trimmers but if having the cases the same length I have form/trim dies. The trim/form dies has two options, first is the hack saw and then there is the file. I also have air craft countersinks that work. When trimming with the trim/form die I find it difficult to beat when it comes to accuracy.

F. Guffey

 

[LHSmith]

For me it is not a matter of choosing a trimmer, I have trimmers but if having the cases the same length I have form/trim dies. The trim/form dies has two options, first is the hack saw and then there is the file. I also have air craft countersinks that work. When trimming with the trim/form die I find it difficult to beat when it comes to accuracy.

F. Guffey

Yep, nothing beats a hacksaw and bastard file on brass for a precise cut

 

[Toby Bradshaw]

http://forum.accurateshooter.com/threads/case-trim-length.3869444/
http://benchrest.com/showthread.php?82114-Does-a-little-difference-in-case-length-matter
http://www.targetshooter.co.uk/?p=1024

"Jack [Neary, HOF BR shooter] admitted that this idea did not work and after extensive tests, he decided to trim his brass to 1.490 inches and to check them often and trim them back to that length. He went on to say that even .002in. to .003in. differences in length can adversely affect accuracy."

Start here and watch them all:

 

[Big Mc]

Can anyone give any examples?

My dilemma is I am switching to 6BR and already have all the LEE reloading gear. So to start trimming the 6br cases all i need is the small $4 dollar part from Lee. I just chuck them in a hand drill and go at them.

However, I've head a lot of people use the L.E. trimmer as it gives very consistent results. But is it really worth 40 dollars compared to the 4 extra for the lee? With my experience in 223 the Lee has been very consistent- are the other, more expensive systems just easier to use or do they actually make a noticeable improvement in accuracy? I guess the real question is is the Lee trimming system ok?

Jake

Make em all the same and go shoot..

 

[Richard Coody]

depends on what you are trying to do. If it is just a hunting rifle or just a range toy and you aren't looking for another 0.10 of group improvement i don't think it is a big deal. if you are loading for a precision rifle consistency in everything is important. just some things more than others

 

[rebs]

I have used the Possum Hollow trimmer for 223 for quite a few years and it works great and is adjustable. It also has a carbide cutter which will last a life time trimming brass. I mount it inmy cordless drill and trim cases in no time at all with minimum effort.

 

[group therapy]

Y’all know this thread was started 9 years ago? Still good information tho

 

[dcali]

I have not rigorously tested this in a benchrest grade rifle, but my experience is that neck length variation of a few thousandths does not matter at all. I routinely let them go for a few firings in my f class rifles and have not seen it impact anything noticeably- I still get exceptional accuracy. We trim necks primarily for safety.

 

[Webster]

Can anyone give any examples?

My dilemma is I am switching to 6BR and already have all the LEE reloading gear. So to start trimming the 6br cases all i need is the small $4 dollar part from Lee. I just chuck them in a hand drill and go at them.

However, I've head a lot of people use the L.E. trimmer as it gives very consistent results. But is it really worth 40 dollars compared to the 4 extra for the lee? With my experience in 223 the Lee has been very consistent- are the other, more expensive systems just easier to use or do they actually make a noticeable improvement in accuracy? I guess the real question is is the Lee trimming system ok?

Jake

If you cannot consistantly shoot 0.25" groups with flags you will never have a chance at seeing any accuracy improvement. Group size is a good rifle with a quality barrel, good reloads, proper bench gun rest, good bench technique and very good reading of wind conditions.

 

[Bill K]

[ With my experience in 223 the Lee has been very consistent- are the other, more expensive systems just easier to use or do they actually make a noticeable improvement in accuracy? I guess the real question is is the Lee trimming system ok?

Jake[/QUOTE]

Jake: If a person takes the time all will trim the cases pretty darn well. It just depends on what you want to invest and buy. The Lee system will trim them just fine.

 

[Webster]

did you mean to say .025 or did you mean .25? .025 is pretty tuff

1/4"