I think you're confusing 'shell holders'. I don't know the Lyman trimmer you speak of but trimmer holders have to hold the case for the trimmer to do its work. I've got several trimmers and they all work on collets that clamp the case base.

 

. . . I've got several trimmers and they all work on collets that clamp the case base.

I'm no longer a "fan" of the collet-type case trimmer. IME, The collet-type case holder depends on the case rims being "in specs" to cut the case accurately. Cases that have been used a lot tend to pick up "dings" on the rims from extractors, "grow" in size from use, or hitting the ground. These "dings" prevent the collet from being drawn into the same exact location in the collet housing which result in length variations after the case has been cut.

I've switched to a case trimmer that uses the (for want of a better word) "horseshoe shaped" spring loaded shell holder that grabs the case rim from the top and pulls the cartridge base up against the shell holder housing. Dings on the case rim are less relevant since the base is always up against the shell holder housing. This style of case trimmer uses a handle, that when depressed, retracts the spring that pulls in the shell holder allowing the case to be inserted or removed so no more twisting of a handle to secure the case.

This makes a difference especially when trimming large quantities of pistol cases and it's much easier on the hands. YMMV or to own his each.

 

Looks like the Lyman Accutrimmer does use conventional shell holders from pictures on the web. I vote "should work fine" because correct for cartridge shell holders interchange among makers OK.
No personal experience with that trimmer though.

 

That would sure be an odd way to design a trimmer and can't figure out how it would work....

I just looked it up. That is a multi-step collet. I have one of them. The tee handle pulls the collet in and tightens on the rim. The Lyman Universal is, I think, a better system. It is a centering ball for the primer pocket and flat indexing surface for the base of the case. The case is held by 'extractor fingers' that engage the rim of the case and pulls it back against the index surface with the op lever.

Edit--Another picture shows something different and not NEAR as accurate. I'd NOT BUY the Lyman Accu-trimmer.

 

The Lyman Universal is, I think, a better system. It has a centering ball for the primer pocket and a flat indexing surface for the base of the case. The case is held by 'extractor fingers' that engage the rim of the case and pulls it back against the index surface with the op lever.

I have one. I have to use a box-end wrench to tighten the clamp-down lever, else the case spins in the fingers and buggers the rim. I use mine to trim my mildcat cases. I am taking off hunks of length of the 375 Ruger Basic brass while it is still in cylinder form. I had a mandrel custom-machined to fit the mouth of a raw brass. I guess there's a lot of friction, there, in such a large diameter and a cut of around 0.200 inches long. If I go forward slowly, it's less likely that I'll spin the case in the fingers...

 

I'm going to be interested to know if the maker of the shell holder matters. Outside diameter is critical?

 

What I see in nothing but a picture is the 'head-stock' end is slotted to accept any shell holder and then a screw in the back to force the case against the shell holder from the bottom, like a press mounted primer seater does. That means cases of varying rim thicknesses will be trimmed to different lengths.

 

Yes, the issue with the rim is there, but using only one single brand should should eliminate the worst differences.

P.

 

Short question: will the Lyman Accutrimmer work with case holders of other brands as RCBS or Lee?

Pete

For these trimmer kits. is a "standard shellholder" for the trimmer the same as a shellholder used in a press? The reason I ask is because Lee uses proprietary shellholders for their trimmer tool, and they are of course NOT shellholders we use on the press ram.

If it's a press shellholder, they are all the same (aside from numbers indicating the size case they handle). If it's the Lee trimmer shellholders, then the Lyman Accutrim will have to have a Jacobs type chuck to hold the Lee trimmer lockstud, because that's the only thing the Lee trimmer shellholders will fit..

 

On the left - Lee #2 trimmer shellholder and lockstud.

On the right - Lee #2 standard shellholder (for press operations)

 

I mean usual case holders, not those for the Lee hand trimmer..

But - btw - is the Lyman quality that low as mentioned above?

P.

 

Pete, Someone correct me if I'm wrong, but the normal shellholder for the press will do nothing for holding the case during trimming. There needs to me something that grabs and holds the case securely, like a three jaw chuck or a pressure holder (like Lee's) or some other type of surround-the-rim constrictor.

Maybe I'm not reading your initial post accurately, but I think you're asking specifically about the Lyman Accutrimmer. Now if the Lyman Accutrimmer system uses a standard shellholder such as used in press operation then, yes, all the press shellholders are the same (again, except for their letter or number designation indicating which cases they work on).

ON EDIT: Looking closely as an advertisement picture will allow, it looks like the Lyman IS using a standard press shellholder. In that case, there must be something they insert inside the fixture that presses the case rim up against the shellholder in order to secure it. Or maybe it pulls the case back against the head of the lathe, trapping the case between shellholder and fixture. Either way: Yes, Lee (or any other) standard press shellholder will work.

 

Nvshooter---I'd say you picked the wrong holder for heavy trimming. The ball bearing in a primer pocket offers very little friction but a lot of precision. The Forester collets will hold your cases without spinning at ALL. They work on 360 degrees of rim.

 

nvshooter-- I'd say you picked the wrong holder for heavy trimming. The ball bearing in a primer pocket offers very little friction but a lot of precision.

I chose the Lyman over all of the others offered at Scheels because it looked to me to be the best one to do what I wanted. I learned over the initial weeks of use that I had to advance the cutter slowly else the case would spin in the clamp. That's when I figgered-out that I would have to really cinch down the clamp. That's what eventuated the use of a box-end wrench. So now, after several years of using the Lyman, I can trim big chunks off the cylindrical cases without spinning them in the clamp or cutting a "sawtooth" lip onto the cases. The sawtooth pattern only exists until the case is fully trimmed. I just keep pushin' hard at it until I get to the length I want, then it just gets cut away. I plan on doing several dozen today.

I have to pre-trim the raw cases because they are too long for the FD1 die. If I do not pre-trim them the first die forms a small roll-crimp on the lip, which makes trimming it a bit difficult after the brass has gone through the FD2 die...

 

Check out #6, Stretch.

I think that tee handle pushes the base of the case against the 'top' of the shellholder. Rim thickness determines case length in that case.

 

Ok. I missed that.

 

Inputs from people who have experience of using the Accutrimmer, regarding the case holders as regarding the quality, would be appreciated.

P.

 

"Quality" is a moving target.

The Accutrimmer uses extruded aluminum to hold the two ends straight. That would be the worst of terrible cheap and chintzy for a tool room lathe, but SHOULD be accurate enough for a handloader. If not, go to the old cast iron models that were bored straight. RCBS made one and Lyman did and Forster did at one time. When you buy by price you accept lowER quality as a fact of life.

 

I don't own one, but I do think these tiny lathes are cool tools, dedicated to case trimming and such. But it's tough to beat the speed, simplicity, and cost of Lee's case trimmers.

 

Nvshooter--It sounds like you need a trim die and a jewelers saw.

Many years ago at a machinery auction, I bought a little 'Swiss Box lathe' that was missing the parts to make it a lathe but made the fanciest neck turning tool, trimmer and precision 'holder of cases' you ever saw. It had small collets impossible to buy but easy enough to make. Just as I got it painted a guy came by with green money just burning holes in his pockets and I helped him extinguish the pain....
Its easy to get TOO fancy when you have a machine shop. I'll post pictures later.

 

Yes

The answer to the OP is YES.

 

I've used a Lyman Universal for about 30 years, no complaints. I can't imagine using one that requires a shell holder.

 

I have several trimmers, the lathe type...but I have found the file trim die to be so much more accurate that I hae one of those for every rimmed caliber and double rifle or rounds that I intend to crimp..The file trim die also save you money for reforming such cases as the .25-35 from 30-30s and some others..Reforming dies cost a bundle but one pass thru a file trim die, trim to length, and resize in a 25-35 die gives you a usable case..For the last few years 25-35 brass was impossible to find..plus you get a positive and consistent length for crimping use in a Win 94.Works on a lot of calibers..