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Trimming Cases

BuckeyePrecision

Sergeant of the Hide
Full Member
Minuteman
Sep 18, 2020
109
62
How many of you trim your cases for each reloading. I ask because before I really got into reloading I would set my dies according to the instructions and trim to the length specified every time. When I set the dies up for my current 223 I read a lot about setting the dies up for that specific rifle and did just that and I have noticed after firing and resizing most of the cases would only touch the trimmer in one or two spots and barely take anything off, with quite a few not even touching the trimmer. After running them all through I hit them with the chamfer and deburring tools really quick and reloaded them. My SD/ES were right at the same and my groups at 600 were just as good as before.

I initially though about setting my trimmer back a little more to get a nice square cut, but then thought if the same thing happened on the next firing I would be in the same boat. Is there any detriment to just reloading them until they have stretched to the point they need to be trimmed again?
 
Unless you had an abnormally short chamber you shouldn't need to trim after each firing.

$6 and sacrificing a case and you can find out exactly how long you can let them grow.
 
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Unless you had an abnormally short chamber you shouldn't need to trim after each firing.

$6 and sacrificing a case and you can find out exactly how long you can let them grow.

I made the same thing for 6mm using a dremel, a file, and a 22LR case. Replaces the bullet in the hornady OAL tool.

I usually let them grow to near maximum, then give them a clean up pass each loading with a tri way cutter.
 
I trim mine 0.005" under max case length (Sinclair/LE Wilson trimmer with micrometer). It also results in cases that vary in length but it never varies more than 0.005". I may get more uses out of a case doing it this way before throwing it out.

I used to trim 0.01 under and trim again when it reaches max case length. Some would argue that doing this would give you inconsistent neck tension, affect accuracy, affect SD/ES. I don't shoot well enough to see the accuracy difference nor have I noticed a significant change in SD/ES doing it one way or another. The case length varied no more than 0.005" after FLS doing it this way similar results to keeping it close to max case length trim.

I think it's more important to keep the lot of brass as consistent as possible rather than worry about how much trim. (Separate the new brass even if they're the same trim length).

YMMV.
 
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I use a trim pro with the 3 way cutter. I run my brass through every reload. I don't change the setting on the trim pro or try not to. Some it trims a little some don't but they all have a nice even chamfer inside and out.
 
Trim with a Giraud each reloading cycle primarily to remove peening of the necks from vibratory cleaning. Individual cutters and shell holders setup for each caliber and only a minimal amount of material removed.
 
I have the Frankford Case Prep Center ... and set the trim length to slightly less than the specified max case length. When I'm done sizing, I separate into two piles based on measurement. Over and Under. The overs get trimmed. The unders don't. Short answer ... I only trim when the length exceeds the case length specification.
 
I trim every time now, I tried to resist as long as I could... but for precision, you want things to be as much the same as it can be every time. One less variable.

As far as running the brass and not babysitting it, only trimming when you have to? I don't know how much of a difference you can see downrange really, I've definitely gone long stretches without babysitting the trim length and ammo shot fine.

For me, getting the right tool to trim without it being painfully annoying was key. If you can get a Giraud, get one, it's the Ferrari of case trimming. I haven't gone there yet, but after a few attempts at different tools/methods that sucked to varying degrees, I've finally had great success with the drill-mount Frankford case trimmer. It's fast and painless, and by cutting the bottom out of a giant Costco-sized animal cracker container and using it as a "chip catcher tube", I found a way I can trim all my cases in a fairly civilized way and they all stay within .0005-.001". So now I trim every time - 'cause why not...

Like was mentioned, if the whole lot of brass is kept in good shape together/consistent, trim length seems to not be a huge deal.