Case Trimmer Query

[montana_charlie]

I've had a Pacific case trimmer since the '70s, and always thought it did a fine job...until I started the BPCR thing.
Now I am not simply satisfied to make cases 'safe to shoot', I want them to be an exact length which (almost) fills my chamber.

When measureing cases yesterday, and being very critical about it, I notice the mouths are not perfectly square. This came to light when I found that rotating the case 90° and re-measuring would give me a difference of as much as .004"

This trimmer (and the Hornady, when they bought out Pacific) use standard shell holders for the case head. A rod is screwed up tight against the head to secure the case, and that causes the case to 'tilt' a bit...even though the mouth is on the pilot.
As you know, a shell holder only covers 3/4 of the rim, so the rod pressure makes the unsupported 1/4 want to 'lean out' a little.
The pilot can't be a 'tight' fit, so the case is allowed to take on a slight angle while being trimmed.

Enter the RCBS Rotary and the RCBS Trimmer 2...they use collets to hold the case head.

It would seem that, with the case head set down against the 'step' in the collet, the case will not be induced to lean, and there is the fact that the case length is now being measured from the cutter to the surface of the head...not the front of the rim.
This second point is important if the rims are not all exactly the same thickness. (I see a difference in mine of about .003")

I have a set of dies from RCBS, and no other equipment made by them.
Does anyone have experience (with these two RCBS trimmers) who is picky enough to have checked case mouths for absolute squareness?

How does the RCBS collet-type trimmer compare to the Forster in that regard?
CM

[fourarmed]

I have used a Forster collet-type a lot, and it does cut squarely relative to the case axis. Forster claims that variation in rim diameter does not affect trim length, but I don't see how it could not to some extent. Probably negligible. The problem with the Forster is that it is too small for the largest rim diameters. I have trimmed 45-70 and 40-65 in mine by unscrewing the collet, and inserting the case from the rear, then using the collet to push it against the housing. Slow, but it works.

[Scrounger]

Another vote for Lee here. Their case trimmers are almost fool proof, cheap, and portable. Which means you can do them while watching TV or whatever...

[grumpy one]

It is worth pointing out again that the Lee case trimmer unavoidably trims cases so that the mouth ends up out of square with the base. This is because it locates on the flash-hole, not the outside diameter of the base or rim. Flash-holes are not especially close to the center of the base - try checking with a dial indicator. Runout of .035" is not unusual.

I use a Forster trimmer, and believe it stays very close to zero runout of the case mouth relative to the base. I have four different collets, each with about four steps for different sized case bases, so if you have trouble fitting one, you are probably using the wrong collet. Because the collet closes in equally from all sidies, like a Lee factory crimp die, variations in base diameter have no effect on runout.

[lovedogs]

Fourarmed... You need a #4 collet and an opened up collet housing to trim your .45-70's correctly and normally. Call Forster at (815) 493-6360 and they'll fix you up. You can send in your own housing and they'll open it up or you can order one that's had it done. They have very good and fast service. Hope this helps you.

[montana_charlie]

Another vote for Lee here.
Another vote, Scrounger?

Just looking around, I think yours is the only one.
In any event, if I'm going to cut something which needs to come out within a thousandth or two of a given measurement, I sure want it to be adjustable.

They don't make a trimmer for .45-90...and if they did, it doesn't appear that theirs are adjustable.

But, keep voting. It's a right (and a duty) which should be exercised at every opportunity.
CM

[Scrounger]

OK, no vote. Lee will custom make those little cutter rods to whatever length you want and I doubt that they have anymore runout error using them versus using the Forster. I have both. I don't believe accuracy to a thousandth or less is required, given shot to shot velocity variations and the multitude of other variables we deal with everytime we fire a shot, especially the way I shoot. But you are right in trying to eliminate as many of them as possible.

[GP100man]

MC
i have the rcbs trimmer & if the case head isnt beat up to bad itll hold the case where the pilot will line up exactly ,if it doesnt then i run the case head over a file litely to level it up.
ive never measured the cases as described , but will & post my findings on 44 mag
cases.
GP

:cbpour:
MC
i measured 25 cases& the most i got was .0015 difference measured with caliper not micrometer

[DLCTEX]

You are sizing before trimming, are you not? That's the only way I can see getting enough slop to make much difference(not sizing first). Are the bases square before trimming? I've seen cases out of square from an out of square bolt. Just thinking. Dale

[DLCTEX]

I'll vote for Lee. You are sizing the necks before trimmimg, are you not? That's the only way I can see getting enough slop to make much of a difference. Are the bases square before trimming? I've seen cases out of square from an out of square bolt. Just thinking. Dale
Oops! I posted, it wasn't there, so I redid it. Now there's two. My bad.

[tommag]

I have an RCBS that came with the collet type holder. I found it to be a pain to tighten, so I bought the upgrade to the U-shaped case holder plates. Now it cuts out of square. So much for upgrading. It's quicker, but not as accurate as before.

[454PB]

After owning several of the collet type trimmers, I bought the Hornady like you use. I size before trimming, and the pilots from Hornady are too big. I started making my own pilots to snuggly fit the sized cases, and I now get extremely square case mouths and consistent lengths.

[Cherokee]

For many years I have used the Lyman lathe type trimmer and it is very accurate. This year I bought a Giraud for volume use for 223 and 308 - a really great tool.

[warriorsociologist]

I too prefer lathe-type trimmers and in particular I like my Wilson (admittedly, it is the only powered trimmer I have used). I have a power drill (horizontal chuck) set up for when I am doing a batch of cases, but I also like the Wilson primer pocket reamers for removing mil. crimps and such. Having to buy the case holders for the "families" of cases you trim is somewhat of a pain, but they never wear out and work well. That's my .02

[rmb721]

I use a Lyman universal trimmer with a power adapter and a 3/8 variable speed drill that I am very happy with.

[montana_charlie]

You are sizing before trimming, are you not?
That is an 'informed' question, and goes along with the comment from 454PB.

To answer it as completely as possible, I must say that I am not actually doing any trimming. I have been measuring. That's how I found the angle-cut mouths.
I have been measuring to see if (and hoping) the cases have grown long enough to trim, yet...which they have not.

When I did trim these cases, they were brand new, and (in my ignorance) I only ran them through the trimmer to 'square up the mouths'...(snort!)...not to shorten them. Only took off enough brass to get a 'shine' all the way around the mouth.

But it seemed that they fit snug on the pilot, because I remember using a bit of case lube (on the pilot) to stop the squealing. Of course, back then I didn't realize that one side of the neck was being pressed against the pilot.

The comment from tommag confirms my suspicion about the Trim Pro units, as they work against the front of the rim and only support 3/4 of it...just like a standard shellholder in a Pacific, or the older Hornady trimmer.

I suspect that all of your comments have made up my mind about the collet-type trimmers, but I'll wait for that input from GP100man before settling on a brand.

Thanks all,
CM

[floodgate]

The question of varying case trim length for cases with variations in rim diameter leads me to prefer my heavily-used Forster trimmer in preference to my RCBS one. In the Forster, the collet closing sleeve screws into the outer housing and forces the collet against its inner face, giving constant position for the case head regardless of variations in rim diameter. The RCBS tool draws the collet BACK into its closing sleeve, and the trimmed length can change with rim diameter. So, at least with mixed lots of cases, the Forster is - in principle at least - the more accurate. That said, I generally use whichever is handy; and I actually probably use the little hand-held Lee more than either.

As fourarmed says above, you can bore out the collet holder a tad if needed for the .45-70-size rims; mine came with a large enough opening. And the Forster bases can also be gotten in the "magnum" length, for extra-long cases.

floodgate

[454PB]

Notice I edited my original reply. After sizing, the pilots are to big to fit the sized cases, particularly straight walled cases. With handgun cases, I size, trim, then bell the case mouth. Because the case mouth hasn't been belled, the Hornady pilots won't fit into the sized case. You can test yours by simply placing the pilot in the case mouth before placing the case or pilot in the trimmer. This is how I decide the trimmer diameter. I place the new pilot in the lathe, then use a sized case to custom fit it to that diameter. I turn the large "button" first, then the mandrel end that fits into the cutter.

I know a lot of handloaders don't trim or even check handgun cases, assuming that they don't stretch. That may be true to a point in low pressure rounds like .38 special, but my .44 magnum and .454 Casull cases stretch considerably. To get consistent crimps, they need trimming occasionally.

Since all case trimmers I'm familiar with use the case rim as the basis for trim length, any dings or imperfections on that rim alter the length.

What I found with the collet types is that the rim would slide forwards within the collet as it was tightened on some cases, resulting in a shorter than desired case.

[GP100man]

MC
i edited my 1st post but dont know if you saw it ?
let me say the rcbs unit i have has the 2 posts that you slip the holders over
&was not lined up with the cutter sguare, ihad to grind on the outer edge & shim on the inside edge on the end that holds the holding assembly, now when you insert a case the pilot hits dead center when the case is flush on the holder& measuring with calipers .0015 is the extreme that i found on 50 cases.
the crimp is what caught my eye it was out of round when looking at it ,
so i was going to fix it or tear it up . i took my time & used straight edges
& did my best & it turned out useable for once!!!
GP

[montana_charlie]

Well...
While you guys have been trimming, measuring, filing, and grinding, I have been window shopping.
Anybody have anything to say about the L. E. Wilson trimmer?

It looks like a tool that is too simple to go wrong.
CM

[Dale53]

the L.E. Wilson trimmer is just like most all of the Wilson stuff. Precision from the word go.

The Wilson trimmer will do a perfect "tool room" quality trim job. That's because L.E. was a tool maker supreme.

I don't have one (have used a Lyman for years, but the Wilson IS more precise).

Dale53

[montana_charlie]

The Wilson trimmer will do a perfect "tool room" quality trim job.
Not only do I suspect you are right, Dale, the dang thing is cheaper than Forster, RCBS, and the others.

Midway has the trimmer for $31, and the case holders cost about $6.50.
Since there are no pilots to worry about, that pretty much covers it (for one cartridge) unless you want to pick a mounting fixture from somebody. Pretty sure I can build one though...to make a permanent bench mount.

I have an email off to Wilson to see if I can use their .45-70 holder for .45-90 cases. I kind of expect them to tell me to get a custom made holder, but I already know that only runs $14 with a one-day turnaround...not terribly bad, all things considered.

It's amazing to realize I've been missing out on something so good...that was available all along...and now I'm too old to wear it out!
CM

[seagiant]

Hi Montana,
I bought one when I first started shooting my M-1 Garand years ago and have never looked back. The interesting thing about this trimmer is it's built like a little lathe and probably is one of the most lower priced trimmers out there! It also uses a shellholder that supports the whole case so you keep you're 90 degree cuts all the time. Very high quality for the money. I'm only now looking at splurging and buying a $10 adapter so I can try power with an electric screwdriver attached! Bottom line I think it's the best manual trimmer out there!

[tomf52]

+1 on the Lee. Got rid of my RCBS Trim Pro set.

[Newtire]

Does anyone have experience (with these two RCBS trimmers) who is picky enough to have checked case mouths for absolute squareness?

How does the RCBS collet-type trimmer compare to the Forster in that regard?
CM

I have them both and will just say that the RCBS unit is a little stouter but the Forstner seems to be about the same nevertheless.

[buck1]

I use a Lyman universal trimmer with a power adapter and a 3/8 variable speed drill that I am very happy with.

me too!

[Maven]

mc, The L.E. Wilson is the Rolls Royce of hand-cranked trimmers and is reasonably priced too. E-Bay sellers get almost as much for used ones in questionable condition as Sinclair gets for new ones. Btw, CH once made a virtual clone of the Wilson trimmer + a built-in clamp to hold the "shellholder" (still available from CH-4D) in place. Occasionally a nice (used) one shows up on E-Bay @ 1/2 - 2/3 the price of a new Wilson.

[Shiloh]

I finally went with the Wilson case trimmer. After years of using the Forster trimmer with having to measure each case I shelved it. I get more consistant results with the Wilson. THe Wilson does require a seperate holder for each caliber though.

Shiloh

[warriorsociologist]

^^^

Yep.

Speaking of that... Has anyone ever tried using a .284 Win case holder for 7.5x55 brass? Wilson doesn't make a 7.5x55 specific holder, but I was thinking the one for the .284 brass should work....

[montana_charlie]

CH once made a virtual clone of the Wilson trimmer + a built-in clamp to hold the "shellholder" (still available from CH-4D) in place.
Yep, they still make 'em, but...

I want to accurately trim .45-70 cases (right now).
Wilson's case holder is $6.50. The CH4D holder is $72.50.
I hate the term 'no brainer', but this seems to be one...


Wilson doesn't make a 7.5x55 specific holder
But they will custom-make one for $14 plus shipping (and they claim a one day turn around), if you supply two cases.
CM

[bigborefan]

Montana Charlie, I use the L.E. Wilson trimmer for my 45/90 and it works great. They make a holder for new brass and one for fired brass. At $6.50, it would be a good idea to buy bought of them at the same time and save shipping. I should add that I used the 45/70 holders.

[Dale53]

If you want absolutely accurate work go with the Wilson trimmer. If you need to do volume, use the Lyman powered by a variable speed drill. Lyman also makes a set up that requires a drill press. It works very well.

Dale53

[qajaq59]

It looks like a tool that is too simple to go wrong.Now there's a statement that will get Murphy to apply a few of his Laws. :-D

[bigborefan]

Below is my Wilson trimmer with cordless screwdriver and holder. Everything came from Sinclair International.

[dromia]

I asked them if they would make a one off for .577" Snider, but they declined, Ho Hum!

[warriorsociologist]

...they will custom-make one for $14 plus shipping (and they claim a one day turn around), if you supply two cases.
CM


Thanks! Good to know!

[montana_charlie]

Montana Charlie, I use the L.E. Wilson trimmer for my 45/90 and it works great. I should add that I used the 45/70 holders.
Thanks, bbf.

A guy on another forum told me he uses a .45-70 case holder for .45-90...but he doesn't know if he has the 'fired case' or 'new case' holder.

Since I am changing to the Wilson, I'll need holders for all of my calibers...and buying holders doesn't cost much more than getting pilots for the other brands.

My Wilson came with a holder for .38 Special (but it's not the Q-type). A fired case will not go in deep enough to trim, so I guess the case needs to be resized.
I don't have those dies set up in the press, so...does anybody know (for sure) if this holder will work for .357 Mag.?
CM

[jerrold]

L. e. Wilson
There is no better at any price:-D :-D

[warriorsociologist]

My Wilson came with a holder for .38 Special (but it's not the Q-type). A fired case will not go in deep enough to trim, so I guess the case needs to be resized.
I don't have those dies set up in the press, so...does anybody know (for sure) if this holder will work for .357 Mag.?
CM

My guess is that you will have to full-length size your cases before trimming. FWIW, I have a q-type for .38/.357 and a regular shell-holder for .41 mag. Both usually require me to FL size before trimming (which is a good idea anyway as sizing can affect OAL of the case). Your .38spec holder will work just fine for .357 mag cases.