Gents

I have two shot out WSSM rifles and about 500 243 WSSM cases, I want to convert both to a more useable 308-243 WSSM, the rifles are just too good to give away for next to nothing and Ive changed over to different calibres for varmint shooting

The problem I have is most drawings I have seen have either an improved shoulder or a turned down neck

I DO NOT want to turn down the necks, improve the case taper or alter shoulder angle, I just want nice short carbine style bolt actions rifle with a simple neck up design of the 243 WSSM case, load and shoot. These will be hunting rifles for my kids not bench rest rifles

I have about 15-20 dummy rounds loaded up with various 308 projectiles and the necks are all coming up with a very thick average of about .348, so I need to see a reamer drawing that accommodates the thicker neck



I have sent PTG, Manson and JGS requests for any drawings they have that have ORIGINAL 243WSSM SAAMI case specs with just a simple NO TURN NECK up and have had NO reply to date




I find it hard to believe this hasn't been done yet, Surely somebody has done a simple neck up of this case......if so whats it called

If any of you have drawings or even a reamer that will accommodate these specs please let me know and were I can order it from

Thankyou
Joe

Look up 300 OSSM it's a "proprietary" Olympic Arms cartridge that's geared towards lighter .308s for feeding through AR-15s. Dedicated Technologies did the same thing with their string of SSMs from .264-.35 caliber. www.dtechuppers.com

Search the 'net for "Reloading The 300 OSSM" and you should find a PDF with load data generated by Olympic Arms.

I've got four wildcat wssm prints roughly with the same shoulder dimensions you have above. None are .30 cal though. One 6.5mm (.300 neck) and the others are 7mm (.325 neck). I have several different lots of Winchester and Federal brass. Annealing, weight-sorting and turning the necks just enough for a concentric/consistent neck-wall thickness made a significant difference in grouping as well as velocities.

Seems that the Olympic Arms forum might get you some details on reloading practices and dimensions too.


FYI, all the SAAMI WSSMs have 30˚ shoulders except the .223 at 28˚.

For reference

Thankyou for feedback

Think you might have SAAMI specs wrong on 243 WSSM

223/243 28deg
25 30deg

Sorry for the poor quality photo, but I highlighted shoulder angle,, its 28deg



I'm aware of the OSSM case and have seen a couple of conflicting cartridge specs of the OSSM case, but it doesn't matter either way both have an alterned neck angles and the neck has been turned down about .008 thou

Im simply not interested in any more work to the case or fireforming, other than necking it up and shooting it, I literally have half a bucket full of 243 WSSM brass, so thats what I'll use, these rifles are going to be 2 short, light, 20 inch barrel bolt action cabines that I'll give to my boys for pigs or deer in the woods, we wont be target shooting with these rifles

In addition, Proprietary generally means I wont be able to get a reamer and/or dies out here in Australia, because they wont put their good name on it unless they make it, and your USA protocol with exporting to Friendly Allied countries is crazy ridiculous now, we can hardly order anything from the USA now,

I already have the bolt action rifles, heaps of brass, and a couple of 308 barrels, ready to go and a cheap set of LEE dies ready to bore the neck out, I just need a NO TURN NECK reamer

As I said surely you guys in the USA have done a neck up of this case without altering it in some way ????

regards
Joe

quote:

Think you might have SAAMI specs wrong on 243 WSSM

You got me there.

Get some 50¢ mics, stuff a .308 bullet in a few pieces from your bucket-o-brass and measure what you get. Add .003" and go spec a reamer. It's not hard.

Good luck.

I only have a CIP chamber drawing nothing in SAAMI.