Home Forums Hunting & Shooting Ask The Gunwriters 8x57 IRS (JRS)???

I've been searching for some info on this cartridge and have found much more data on the rimless version. Just wondering if the rimmed version can be loaded using the rimless data, or how much it should be reduced? Mostly would need one good barnes tsx load, as I see norma has some loads for other bullets using their powders. Might try the 196gr oryx as well.


Considering a Merkel k3 jagd in this round, just seems more interesing than the 308 or 30-06. I would imagine the gun is a pretty strong platform, as it is available in the 300 win mag.

Any experiences / tips with the 8x57 rimmed are appreciated.

Thanks!

forgt to ask: do you use standard 8x57 rimless dies for the JRS? thanks.

Load 10% back from the 8X57 IS loads for the JR. You can load with standard 8X57 dies, as used for the .323 diameter bullets...usually. I substituted the .323 neck expander with one from a set of 303 British dies I have, so the necks don't get expanded after sizing. It just keeps things lined up a little and holds the de-priming pin in place. You can also take an expander for a 32 Special and put the rod and expander in a drill. Use a medium fine emery cloth and burnish it down to .317.

We did this for many years, before we could buy standardized 8X57 JR dies with the smaller expander for the .318 bullets. We also shot a lot of old Remington 170gr 32 Special bullets in the J bore guns; they are .321 diameter. Most J bore guns have a .319 to .321 bore, but not all. Since the bullet sizes into the bore early on, before pressures spike, this works well.

I actually got better accuracy in my J bore guns with the 32 Special bullets. I've done this in 25 to 30 or so drillings and other combo guns since 1959.

Use Reloader 15 powder, also. It seems to have been made just for the 8X57.

Hawk and Woodleigh make good .318 bullets. I would and do use theirs nowadays.

OOOPS



You were asking about the "S" bore round.

What was said above before my post...use any standard 8X57 Mauser .323 dies.

Remember to try R-15, also. You'll thank me.

Now, off to WallyWorld for a stronger pair of reading glasses.

+ 1 on that RL-15 suggestion.

Thanks for the info!
Benny

Looking at the CIP drawings for the rimmed and rimless versions, there are minor differences in shoulder dimensions; I think the dies for the rimless would work fine.

To nit-pick, the rimless runs at pressures nearly 20% above the rimmed. For that Merkel, it won't matter, of course.

Nosler and barnes both verified that their 8x57 data is interchangeable with the rimmed in the merkel. Sounds like fun!

I have neither of those books. Are they loading the rimless to the wimpy SAAMI levels (35 ksi) or to the modern CIP levels (57 ksi)? Both the Merkel and the brass should be good into the lower 60's. All of Hodgdon's current data is to the CIP levels. I wonder, has SAAMI finally agreed to the modern levels, too? My copy of their spec book is not recent.

Check the Vihta Vuori loading tables. N135 and N150 are terrific in the 7,92x57 rimmed or rimless.

Good. Let them pay to have over-sized hinge pins installed after a few boxes of ammo at the rimless pressures.

Don't really know anything about the .318 but had a new Merkel 8x57Rimmed SxS a couple of years ago and used both regular 8x57 dies and load data. After several hundred rounds I experienced absolutely NO problems. Accuracy was superb. I mounted a Leupold 1.5x5 Vari XIII in MAK mounts. Best $4000 rifle I ever had. As is usual sorry I traded it.