How often do you trim your cases

[Chris338378]

As we all know uniformity is a major component to accuracy and I was wondering how often you guys trim your cases. I always trim mine after the second loading in order to keep everything uniform. Maybe I'm being obsessive but it works for me. What do you guys think?

 

[DrMike]

If I'm attempting to develop an accuracy load, I'll ensure that all brass are trimmed to the same length, regardless of how many times it was shot. If I'm focused on loading for a hunt and the load gives MOA or slight less, I'm less fussy. Then, my concern is that they are not going to cause a pressure spike because they are too long. Plus or minus 0.005 inches is tolerable in these instances.

 

[sask boy]

DrMike +1

Blessings,
Dan

 

[truck driver]

Welcome aboard Chris. If you use collet neck sizing dies you should only need to trim the brass when you first get it or if reloading once fired factory brass to get rid of the uneven mouth left form the factory crimp but then I've been known to be wrong because some calibers tend to stretch like the Weatherbys. Neck sizing helps to relieve the need for trimming.

 

[Darkhorse]

I tend to trim all specific calibers at a time. Usually to -.005. Then sort them and keep them in marked plastic bags. For general loading I use a fresh (trimmed) case out of the bag each time. After each loading the empty case goes into another ziplock marked as to number of times shot.
After all have been fired I start doing random measurements. When the length reaches +.005 or when the length starts varying several thousandth's I trim them all again and start over.
I use the same method for annealing.
My test and/or accuracy loads are kept separate and case work is done as needed.

 

[big rifle man]

I trim after each firing (after resizing case). I've noticed that after firing cases do stretch to different lengths, probably not critical but I'm thinking if each case neck grips the bullet for the same length it can't be a bad thing.

 

[HomerOz]

G'Day Fella's,

Chris 338-378, in my experience, it depends a lot on the cartridge case, the load being used (mild or HOT) and the firearm (chamber etc), that it is being fired in!
In my .222Rem and several others (.308Win etc), I might go 5+ reloads before they need a trim but in my .338 Lap Mag, I have no choice but to FLS/Shoulder Bump Die and then Trim, every second reload! The reason for this is, it is the only way to get the reloaded ammo, back in the chamber in this rifle (with Lapua cases and maximum and safe recommended powder charges)!
Then we have the accuracy of the firearm that we are shooting the ammo thru. If it is capable of and you need it to shoot Sub-1/2" groups, well we have do what we have to do............

Hope that helps

Doh!
Homer

 

[ElmerThud]

I trim after each firing following F/L resizing.
I use a Lee Factory Crimp die so it evens up the case mouth & I maintain constant cartridge dimensions as closely as I can.
I also anneal after max 3 reloadings.

I probably only reload 20 cartridges at any time and these days max 200 a year, so it's not like a great deal of trouble to take some time with brass prep. An extra operation or two in the reloading process is no bother at all and of course it's easy for me to keep track of what my cartridges have done.
Cheers, ATB ET

 

[kraky]

I sometimes NEVER have to trim over the life of my brass.
I use these on all my guns and find many chambers are. 015-.030 over Sammi specs.

http://m.youtube.com/watch?v=JKnXJxaAw2U

As long as my case mouths are square and I'm in spec for my chamber I'm all set.
I even read an article against excessive trimming that made sense. It said the closer the case mouth is to the rifling the better .... it will guide the bullet into the rifling as it slams into it at mega-pressure.....and the less the bullet jacket is likely to distort as it happens. I guess till someone figures out how to film this happening, its all "theory" but I can't see it being a negative.

 

[nvbroncrider]

When the rifle tells me I need a trim job.

 

[SJB358]

So I do this a little differently,

I will start off trimming them after the first firing, but after that I only trim the cases that are out of spec and the others are left alone till they grow out of spec. So, for instance, 50 cases that used for load work, during each firing their may be 3-10 that may need to be trimmed. It seems like the brass grows differently for me, so I found trimming each time to make them perfectly even was a huge chore..

I guess I could be losing out on some accuracy, but so far most of my loads have been pretty consistent for me. I do hate trimming. Worst job in the reloading room!

 

[Oldtrader3]

I usually trim to get them all the same length. After that trimming, I will shoot the cases until they vary enough to trim again (>.005 variance). Most chambers are long anyhow.