Case trim length

[Fng65]

I know I'm going to get a many different answers on this one. How many thousandths do you gentlemen trim the cases back from Maximum case length. Or is it a case of what your rifle likes more

 

[Dusty Stevens]

.010

 

[Straightshooter1]

For me, a lot depends on just how deep or how far out the bullet is being seated. If I'm seating deep, I want to trim shorter. If I have to seat far out to get near the lands, I'll trim longer. Chamber size will also be a factor, huh?

 

[Bc'z]

What D said.
And when you measure after sizing and find a case or two at or very near max length, trim the whole batch to keep everything consistent.

 

[Rsadams]

What D said.
And when you measure after sizing and find a case or two at or very near max length, trim the whole batch to keep everything consistent.

Exactly , consistent is the thing you want... It's really that simple..

 

[varget204]

Most calibers min and max is .010,load some at different lengths and try them,the barrel will tell you how long.

 

[cw308]

I trim every firing , if you take the minimum and maximum I keep it in the middle . Once you trim and trim every firing , it's more like a clean up . Nothing to do with what your rifle likes . More to do with safety.

 

[Dusty Stevens]

Ive never seen trim length be a factor on how good a rifle shoots- except if its too long

 

[Bill K]

In most reloading manuals they show a max length and a trim length. You want to trim all the same and within those measurements, most often it is around .010 shorter than max.

 

[NorCalMikie]

For starters, you need to know the "actual measured length" of your chamber.
Get that measurement, write it down and refer back to it often.
Most chambers are cut about .020 longer than the listed MAX trim length.
I prefer as much bullet/neck contact as I can get. YMMV.
So what it boils down to is... what works best for you and your rig. We all think different so what works for me may not work for the next guy. You'll never know till you try something a little different.
It has been mentioned..."trim the whole batch to keep everything consistent". Not a bad plan at all.
Think about how you resize your fired brass. Button pulls neck longer on the up stroke. I use Precision Bushing Bump Dies and my brass doesn't get a chance to grow so not much trimming needed. More than one way to skin a cat. (if you're a cat lover)

 

[Dusty Stevens]

Get a giraud and once its set just run every one in it. Simple and fast

 

[Texas10]

Your question really only has one best answer, and that is what works best for your particular chamber. And the only way to answer your question definitely, is to model your chamber with a chamber cast, or look at the neck area with a camera or bore scope to see if you're getting carbon build up from a too short neck.

You can also measure your chamber with a modified case you make with your brass:

http://bulletin.accurateshooter.com...-chamber-length-with-home-made-modified-case/

Or buy a tool :https://www.sinclairintl.com/reload...s/sinclair-chamber-length-gage-prod32925.aspx

 

[jackson1]

I try to keep a close eye on my brass. As a rule I like to trim 0.005" of and hold a +/- of 0.001". I cannot hold that tolerance with my green case trimmer but is easily done with my Wilson trimmer. I am retired and shooting and handloading are my main hobby so I have the time and desire to venture down that path. Fng65, even thinking about case trimming puts you ahead of a number of people. Many friends of mine rarely trim there cases or do it poorly. They are lectured regularly by me regarding the safety of this practice and slowly they come around.

 

[mikecr]

I run 5thou short of chamber end where I have that choice. Prefer no more than 10thou off.
Fire-forming will pull mouths back, sizing cycles will move them forward.
Depending on your chamber, it can take 5 or so firings to reach chamber end, and then trim.
In the meantime it won't kill your results if clearance varies a little. It's nothing to the noise in neck tension.

I want tight end clearance like I want all other clearances tight. Here the gain is in reducing carbon blow-back. That sooting on necks to shoulders, and carbon ring formation at mouths, are signs of poor neck sealing. Not what I consider a 'good' condition.

 

[cw308]

Texas10
Knowing your chamber measurement's are very important , from base to case mouth , That Sinclair video made it pretty simple . Thank You .

Chris

 

[Fng65]

Thank you gentlemen for your input

 

[JMayo]

6bra cases don't grow.
I find the shortest of the batch and make em all like that ..

 

[Metal God]

When your new always just do as the manuals suggest at first . COAL , trim to length , start loads etc . Most manuals have a "trim to length" suggested . The Hornady manual has a 243 Win case trim length of 2.035 and that's what I suggest if you're loading for the 243 . When you get more experience you'll start noticing things your rifle likes or doesn't . You can then change things up as need be and comfort level increases .

 

[Sandstorm]

I like what Texas10 said and I use the sinclair tool as well.

 

[Brians356]

Most calibers min and max is .010,load some at different lengths and try them,the barrel will tell you how long.

Actually, for nearly all cartridges SAAMI Min and Max Case Length differ by 0.020", and Trim-to length is midway at Min plus .010".
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