To trim or not to trim?

[wanneroo]

I was resizing some 300 blackout for an AR yesterday and did around 140 of them. Checking a couple dozen of them for length I have some at or close to max case length, some in the middle and a few near trim length.

I was wondering if it was worth trimming them to trim length or just let it go for now?

Do people trim every time they resize or do they only do it when brass hits max case length or above?

[redturbo0]

personally I've always trimmed rifle ammo, but I can't really answer your question. I'm here for the answer to the same questions.

[sprrdhawk44]

When I scrolled across the screen I fully expected to see that this was posted in the lounge.

[theunrulychef]

Normal procedure would be to trim them all to the same length so that the bullet is seated with the same amount of neck on each - better accuracy. With precision reloading, of course, we strive to have every round exactly the same - same headstamp, same trim length, flash holes reamed on all or none, exact same powder charge, seating depth etc etc on & on & on. If it's just for plinking ammo & it's in spec, then it's really up to your personal preference. If you're looking to get the smallest group on paper, trim 'em up.

One thing I've noticed about 300 blk cases is that they tend to expand differently - since all of mine are mixed headstamp & I made them from 223/556, the case wall thicknesses are all different. They're still "accurate enough", but I'm not shooting these for precision like I would be with other calibers. I do trim them all each time though, just out of habit I guess.

[theunrulychef]

When I scrolled across the screen I fully expected to see that this was posted in the lounge.

[Mush]

I trim all rifle brass so it will not jam in the chamber or not allow the bolt to go to battery. I like all my semi auto weapons to not jam. I'm funny that way

[Steve in PA]

Unless the brass is longer than max, it can't "jam" in the chamber.

For a precision rifle load, I would trim all to the same length for uniformity.

For a non-precision load, trim length can vary from max to recommended trim length.

[Rblakely]

I like trim....

[Mush]

Unless the brass is longer than max, it can't "jam" in the chamber. .

Very true. But unless you check every case to ensure it is not too long then you might as well trim them all for uniformity.

[RobW]

I trim them all, even plinking ammo, only because it is pretty quick to "touch them up" if you start with all of your brass trimmed to the same length.