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!