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!

 

[5shot]

A sheet of printer paper is like 0.004. I wouldn’t sweat it. It’s not a BR Rifle.

 

[Certus]

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

Can someone share exactly what model this is? I don’t have a case trimmer.

 

[DaddyFlip]

Can someone share exactly what model this is? I don’t have a case trimmer.

The mentioned Lyman is probably this one Lyman universal case trimmer; they have one with and without a carbide cutter head. Mine is the Forster Original Case Trimmer. If you like the Forster better and you want to trim magnum length cartridges, get the optional long aluminum base. The base it comes with will trim to 2.84 no problem, but there's little wiggle room. I wanted to trim 300/375 H&H and 416Rem without adjusting the length, but you can't change the pilot because the grub screw that locks it down is covered by the bearing. With the long base, the grub screw would be accessible.

 

[Certus]

Anything that does say 3 1/4”?
Thanks for the above links, exactly what I needed provided to not screw up, ha!

 

[DaddyFlip]

Anything that does say 3 1/4”?
Thanks for the above links, exactly what I needed provided to not screw up, ha!

What caliber specifically are you talking about? Many of the "universal" trimmers on the market won't do the big stuff or won't come with the pilot and collet you need to do the big stuff. The Forster Original with the standard base (the gold aluminum) will do up to the 458 Lott and 460 Weatherby; it's not going to do any of the Nitro cartridges or a Gibbs. Below is an already trimmed to 2.84 inches 416 Rem Mag. There's about 35 thou wiggle room left so 3.20 absolute max. This is why I'm buying the long base for more wiggle room.

However, even if you did that, you can't run the Nitro-class cases on the Original; you need the Classic because it takes a different series of collets for the larger bases. It comes standard with the long base also. If I were doing a manual trimmer for big cases, that's what I would do.

I really want to like the Redding 2400 trimmer with the micrometer adjust, but I read a lot of mixed reviews about it. It claims to work with everything up to 50BMG with a universal collet.

 

[DaddyFlip]

By contrast, today I'm trimming 300 Blackout and the process is much breezier because there's plenty of room to slip the case on and off the pilot and line the base up with the collet. There's no variation in my trims. I'm going to buy a second trimmer to have one on the standard base for short stuff and another on the long base for belted magnums. I'm hoping I can leave the long one set for 2.84 and trim the big three by just changing the pilot.