Load development has been easy with my 300WSM. I have a feeling I could pretty much load it with anything and it would shoot nicely, however...

There are a few quirks of the WSM case.

#1 It won't fit in my Lee Auto Prime hand primer. There is a shell holder for it, and it's listed on the LEE shell holder list. It even fits in the shell holder, if you take it out of the tool. But it's too wide to fit in the Auto Prime!

#2 It won't fit in my RCBS inertia puller. Again, too wide to fit in the shellholder.

#3 I don't have a shell holder that will worl for my RCBS case trimmer. I assume they make one that works, but I haven't seen one yet.

#1 and #2 are minor- I can prime on the press and I've got pliers Of course the pliers will ruin the bullet, luckily I don't pull too many bullets!

#3 is a little more serious, because I'm going to need to trim at one point.

Anybody else witgh similar problems or solutions? I'm going to try another collar for the puller, and I guess I could use a dremel on the Auto Prime, but I don't really want to..

Ah Gatehouse, this was interesting. An axample of the SNAFUs nobody thought about until practical experience with the new cases has been obtained.

As you say, eventually you'll need to trim. A lot (most?) factory chambers fortunately seem to be cut a bit larger than SAAMI specs. In particular, there is often room to let the case stretch somewhat longer, and thus leave you some extra time before you have to trim - perhaps by then, RCBS will have come up with a solution to the trimmer problem??

To figure out how your chamber measures up, one option is a gizzmo Sinclair sells - I think they call it a "Chamber Length Gauge". Don't know if you have used one of these?? If not, they are cheap and simple to use, except you have to drill your case to retrieve the gauge, since your case won't fit in your inertia bullet puller
- mike

Gatehouse:

If you pull enough bullets for you to mention it, I would get a RCBS collet type bullet puller which fits in your press. I've read good things about the Hornady Cam Lock puller but have not used it. After practically beating one of my 4x4 loading bench legs off with the inertia puller, I decided thare had to be a better way, and there is.

Check with LEE, I think they have a fix for your autoprime.

Aren't the wsm's just shorter ultramag cases or are their different dimensions at the case head?I use my lee autoprime to prime ultramags.I also trim them in my rcbs trimmer and it works just fine.

Gatehouse, Use your #3 RCBS collet for the trimming, fits perfect. It Also fits, albiet tight in my Quinetics inertia puller, would be a royal pain if you had to pull alot of bullets though. I've got no problems priming with my Hornady priming tool, and it's very similar to the Lee auto prime. Jay

Gatogordo, Try using your basement(concrete) for pulling bullets with the inertia puller, I've done hundreds with no breakage of my puller. Jay

[ 07-01-2003, 18:49: Message edited by: Jay Gorski ]

I shoot a 416 Howell, which is similar in size at the head. I had to take the dremel to my auto prime and "open" up the sides a little. It just took a few seconds and it fit right away.

I've had problems with some shellholders for Lee's excellent, cheap, and disposable ( ) priming tool being too tight for the case they are designated for. For example, I have two heads for the .222-series, one of which will typically not accept about half of the cases I try to insert in it and the other of which never presents a problem. Lee products are cheap enough to just buy another one if the first isn't right. Try another shell holder head and see if it solves the problem.

If that doesn't work, slather the head of a surplus case with abrasive compound, place it in the shell holder head, chuck it in a drill and proceed to lap the devil out of the shell holder.

Also, it sounds as if the lips of the priming tool itself may be catching on the body of the fat case. If this is what is happening, arrange to machine away a little of the soft aluminum of the priming tool itself. This might be accomplished with a drill bit of the proper size. And, if you ruin the tool in the process, plop down $11 more and go buy a new one. This one will likely work just fine without modification.

Even after buying the Lee tool twice, you're still money ahead of its competitors!

Gatehouse,

RCBS does make a shell holder for the case trimmer in 300 WSM....I have one and have used it a bit but I don't know the shellholder #

stubblejumper

The WSM case is a few thousandth's bigger than the RUM's. The RUM's are based on the 404 Jeffery (.544" case head), the WSM's are based on a rimless 348 Winchester (.550" case head).

My RUM cases wouldn't fit in the autoprime,..it is the body of the tool at the opening. they are fairly soft metal,..so what i did was to take a dremel and a gringing bit,..and opened up the top section of the Autoprime. Voila,..it fits nicely now.

The case web rubs the lips on the Auto Prime because it's just a tad too small, dremmel, file, sand paper cures that. New cases might fit, but once they expand after being fired they will be tight or just too tight. Easy fix though.

The kinetic puller bore just needs to be drilled out with 9/16", 19/32" drill bit to fit them in there, it doesn't hardly take anything out off it when drilling it either. 460 WBY size cases work if a 19/32" or 5/8" bit is used to bore it out. Another easy fix. Use a normal shell holder in the kinetic puller too, it's a hell of alot faster and easier than screwing with the holder they gige you for use with the puller.

Both the WSM and the Ultra Mag have a .535" dia. case head, exactly. The body near the web is a couple thou to a few thou larger on the WSM than the Ultra though. .550" vs. .552"-.555" if I remember correctly. Chambers may vary, but it seems larger overall on the WSM at the web.

Good luck.

Gatehouse, I use my "belted mag" shell holder on the RCBS trimmer. It's a tight fit, but it works. I know there is a separate holder, but screw it, I've bought enough stuff for a while. FWIW, Dutch.

I'll order a case holder for the trimmer...I CAN force a case into a shell holder (#3 or #4...can't remember) but when I say FORCE, I mean it...

The problem with the Lee Auto Prime is the tool itself- not the shellholder I guess I'll do a little grinding!

And for the puller, yes, I guess I should just use a regular case holder! I only have one or two that I need to pull- both with high primers...

I have never measured an Ultra Mag case, so I don't know how the two measure up!

The WSM is a few thousandths larger than the RUM at the HEAD and in the Body of the case.Brent Moffits above measurements sound right
The WSM will not Fit the RCBS Shell Holder for the RUM,at least mine dosen't.

[ 07-02-2003, 10:48: Message edited by: Tiny ]

Gatehouse, Yes, I put a 300WSM case in the #3 RCBS collet, and it fit perfectly, for sure, get the #3 collet. Jay

I use the RCBS Automatic Priming tool for all my priming. The unit uses the standard shellholders, so the shellholder for the press is for the priming. Also have the die-type bullet puller, that also uses the shellholder for bullet pulling using the press. I have not needed this as of yet, but have it for other calibers, so if I need it, I got it!

Case trimming is done on a Forster, but I do not remember which collet it requires...This I do know: it is the same collet as for the .22 Hornet!

My biggest "problem" with my 300WSM has been the powder funnel. It doesn't fit. I read here somewhere to just trim it about a 1/4" and it'll work fine...just haven't gotten around to it! For now, I just use a primer feed tube! It acts like a long drop tube; something I don't need, but it works for the time being.

Gatehouse & All
As listed on Sierra Web site or in their manual or RCBS web site, or outside of Die Box the Rcbs number "43" shell holder for the press and no."43" shell holder for your trimmer are the proper ones! Same number for both types of shell holders. No modifications needed. I can't help with your other problems, maybe switch to Redding or RCBS equipment? No problems.

[ 07-02-2003, 19:34: Message edited by: Marsh Mule ]

I load SAUM,WSM and Ultra hulls on a #4 RCBS shellholder. Trim with a #4 holder(RCBS),as well................

I too opened up the throat on the AutoPrime with a dremel tool...no big deal. I trim with the Lee system after I modified a .303 Brit case length gauge...much better to spin the case than the cutter...IMHO

WOW, Disregard my last transmission, WSM fit even more perfectly in #1 RCBS collet, that's the same collet you can use for 6mm Rem, 30-06, 308 etc. but like I said, shell did fit in #3 collet(not shellholder)too, but fit just right in #1 collet. Jay. You guys must all have the new RCBS trimmer, that's why you guys are talking shellholder instead I'm talking collet, #43 shellholder it is.

[ 07-02-2003, 21:03: Message edited by: Jay Gorski ]

WSM fits great in the RCBS #4 shellholder for my Rockchucker...

I've heard various experiences in all of this stuff with the WSM..

I guess there are some shellholders etc. with different tolerences.