About to start a load development on my new custom built 6.5 Creedmore, but don't have the modern reloading manual for it. I googled some loads from Hornady and Nosler, but I don't see the trim length, would anyone know? Thanks

SAAMI.org will has cartridge and chamber specifications, trim to the minimum listed length and you will be fine.

Nosler has data online as well DATA LINK but do not see the trim length on that page

Max length is 1.920 and trim of course is 1.910.

Measure 10 cases, remember the shortest length you found, trim all of them .001" shorter than the shortest one in the bunch.

SAAMI applies to manufacturers, not hand loaders.

So you don't recommend trimming cases to at least get them back to max length?

I rarely trim mine to minimum as I do what you suggested trim to shortest as long as that is under max.
Well except .223 they all get Girard'd

I want to say all the Hornady new brass I have is 1.917. I need to check my once fired brass.

Who's Max length?

If the brass fits in the chamber and it all matches then everything is fine.

First I agree if it fits all is good. I have 221FB brass that I have reloaded 20 times without trimming but once.
My 17 Rem brass I trim once get about 9 reloads before the primer pockets get loose and I toss.

But I was referring to manufacturers recommendations of max. I do agree that brass can be longer than that and be just fine but if your shortest piece is .008 over max recommended why not trim to there at least. Most folks don't have a chamber cast to know exactly how long a case can be and not give issues.

I'm sure you understand the dangers of excessive case length, JG. I'm not sure how you can be so confident that just because "the brass fits the chamber" that the neck is still going to release the bullet just like it's supposed to---unless you routinely make a chamber cast of any new rifle that comes your way. I'm saying that even though you may be able to easily close the bolt on a sized case, there could still be an issue. Slim possibility, maybe, but it still is there. I'd rather gamble elsewhere. Stakes are too high for me.

I don't worry about trimming exactly to any "trim-to" length, but I ALWAYS make sure I trim to a length under the SAAMI max.

I don't doubt what you're saying.

I'll just say that with everything I've loaded for, including Creedmoor, I've not concerned myself with what the book says is Max length. I just trim to an arbitrary number. When I get brand new brass I size them, measure them, and trim all of them to the same length, whatever it takes to get them all the same. Fire them once, don't trim on the next load, clean, anneal, size and trim, again to a number that gets them all the same.

You say it can cause problems and I don't doubt you. I've just never had a problem. Of course, my situation is probably different from most people's. I've got 500 pieces of brass for my 6.5 Creedmoor that all have the same number of firings on them, which is two. I'm working on a third firing this year.

Just in case anyone does not understand what's being talked about, here's an image:

Where you see LENGTH CLEARANCE, there is the possibility of the case mouth being squeezed down and crimped into the bullet by the chamber itself. If this happens, you can raise chamber pressures to disastrous levels.

Whether or not you would be able to tell when you close the bolt...I'd say that depends on several things. If you use a case sizing technique that gives you a snug fit to the chamber, you might miss the extra resistance.

And if you really want to know how long you can go this is cheaper than doing a chamber cast.


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

Its why I like to trim all my cases shorter than SAMII specs from .005 to .010. But I wanted to ask if there was a measurement from the manufacturers. There is a Sinclair Chamber length gauge that can be used. http://www.sinclairintl.com/reloading-eq...-prod32925.aspx

Or you can make a homemade gauge, just cut 2/3rds of the fired case neck off with a Dremel, carefully smooth out the inside and outside of the case neck and the neck bit that you cut off, pinch the case neck a little then put a bullet upside down into the case and pinch the cut piece a little so its snug over the shank of the bullet, leave it a little long and chamber it and take out the case and measure it for your chamber case length. It's a poor man's tool but I'll go with Sinclair, its not too expensive.

@Stroud, you beat me to it.