Is this acceptable trimmer performance?

[DaddyFlip]

I'm trimming virgin Hornady 375 brass after sizing with a new Forster Original trimmer. About every other piece, it would cut too short. I thought I could get out of it by going slightly long which is why I've got a string of 2.841's. Should I not expect to hit 2.840 +/-0.001 with a hand trimmer? What is acceptable tolerance for hunting ammo?

 

[Javaman]

Within a thou or two is usually fine.

If my target was 2.840, I’d use the .837-.841 for hunting no prob and keep the others for practice loads.

One tip - after chamfering and deburring, I use a green scotch pad on a sponge (stolen from under the kitchen sink) to smooth out any blemishes. Seems to help clean things up and never have any bullet seating hangups.

Good luck.

 

[shootist~]

Are you sure your trimmer was responsible for the too short ones? I'll hazard an educated guess some were below the 2.840 trim-to length before you started. Not too unusual for new unfired brass. Some manufacturers being worse than others.

 

[DaddyFlip]

Are you sure your trimmer was responsible for the too short ones? I'll hazard an educated guess some were below the 2.840 trim-to length before you started. Not too unusual for new unfired brass. Some manufacturers being worse than others.

I setup the trimmer on a couple of pieces that were 6 thou long. Once it's dialed in and locked down, I wouldn't think the cutter could reach a piece that was too short. However, now that I think about it, I'm wondering if the rims weren't perfectly flat on some of these so maybe some were proud in the collet? I'm sure they'll shoot, it was double frustrating because I don't like trimming brass anyway- worst part of reloading.

 

[shootist~]

Agreed on trimming being the worst part. Its why I finally went electric. And later upgraded to a really good electric trimmer (Giraud).

I just checked a bag of Norma once fired, sized/trimmed 338 WM and they run +/- .001", or very close.

 

[Javaman]

FWIW, switching to an electric trimmer is one of the best equipment changes I’ve made.

The Frankford Arsenal case prep/trimmer was an investment, but one well made.

Good Luck.

 

[DaddyFlip]

I had much better results with this Remington 416 brass. The first piece on the left something wonky happened on setup and it went from 2thou long to 2thou short for no reason. After that, pretty smooth; 25 pieces at 2.84", 10@ +0.0005, 4@ +0.001 AFTER chamfer and deburr. Thanks @Javaman I had a pad of steel wool for smoothness. I think the limiting factor is getting a good, repeatable, confident measurement. I'm calling it close enough.

 

[Daryl S]

I'm trimming virgin Hornady 375 brass after sizing with a new Forster Original trimmer. About every other piece, it would cut too short. I thought I could get out of it by going slightly long which is why I've got a string of 2.841's. Should I not expect to hit 2.840 +/-0.001 with a hand trimmer? What is acceptable tolerance for hunting ammo?

View attachment 744416

With 2.850" bring max, I'd say you were likely good to go for a while. If crimping bullets, the length matters. If not crimping, they will likely all shoot identically.

 

[Rez Exelon]

My general setup for case trimming is that I have a Shopfox 1704 benchtop lathe, then toss the Frankford Arsenal Universal trimmer in there. Once I calibrate it, I usually am +/- .002 from my target and I find that acceptable. It's been a while since I've run stuff through, so maybe I am +/- .003. Generally with this setup I'm running high volume of common calibers as compared to my fancy calibers though. When it's time to get the fancy boy's done, I usually hand trim because it's a bit quicker to calibrate and just run them through for the small volume. On that setup I expect a bit tighter tolerance.

Side note, but I love love love my bench top lathe.... I can just chuck in different stuff like primer pocket reamers and cleaners, chamfer/deburr tools, etc. Makes bulk processing super quick. I suppose I could get one of the fancy case prep stations too, but the lathe was free and serves my needs well.

 

[Daryl S]

I use a Lyman case trimmer with the fit's all shell holder. It does a great job, to the thou, most of them.

 

[Grumpy gumpy]

I use a Lyman case trimmer with the fit's all shell holder. It does a great job, to the thou, most of them.

Same as me, only time I had an issue was when I didn’t tighten the locking screw
Gumpy

 

[Javaman]

I had much better results with this Remington 416 brass. The first piece on the left something wonky happened on setup and it went from 2thou long to 2thou short for no reason. After that, pretty smooth; 25 pieces at 2.84", 10@ +0.0005, 4@ +0.001 AFTER chamfer and deburr. Thanks @Javaman I had a pad of steel wool for smoothness. I think the limiting factor is getting a good, repeatable, confident measurement. I'm calling it close enough.

View attachment 744580

Looks like you have a great setup and I bet you are indeed good to go!

 

[coyote wacker]

I reload many custom caliber that need to be formed for other brass, so my trimmer gets a work out !
What I have found is some times long brass will roll inside and no allow it to be trimmed to the set length. What I do is trim until it stops remove the case inside out de-burr then run the case again 9 time out of 10 you can trim of a little more.

 

[C.W. Richter]

What distance do you plan on hunting with your 375? If primarily African PG/DG, you'll be lucky to be shooting 100-200 yds (with the odd 250+/- shot,) so pinpoint benchrest/varmint accuracy isn't critical. You might stretch some of the shorter ones back using max handloads and cheap, lighter bullets. I have two hand-trimmers (diff lengths), but an older (3rd) Lyman was used so much, it had some slop (travel) either in the chuck end and/or the lock/set nut end by the crank. I began to notice variations in case length-it could've been fixed, but I just bought a newer Accutrimmer (the one i mention was the old universal trimmer) and the issue went away. On longer range, more precision cartridges, measure all previously not handloaded brass prior and mark the (too) short ones for sighting/check sighting load use. Also check that the cutting head that holds the caliber pilot IS screwed in tightly to the crank axle. Many are threaded, and if loose, they'll give you a diff depth if they rotate (usually when pulling out of a cut case. It can be tightened but I saw at least 1 shooter use the weakest loc-tite on 'em. GL!