LRM primers ok to use on 257 WTHBY

[rcs33]

I recently got a second-hand 257 WTHBY and noticed that all of the reloading books I have spec fed. 210 or "regular" rifle primers. I have several thousand magnum rifle primers for our 300 and 340 WTHBY mags, but no std primers. I would expect to have to tone my loads down a little with the LRM primers but does anyone know how much? I have H4831 and IMR 4350 and 4831 and was wanting to run 120g noslers at around 3100fps. I know how I should do this--but i was hoping someone might have prior experience with this issue so I'm not starting totally blind with limited powder to burn on dead ends.

 

[rcs33]

Any thoughts are welcome, but I've largely answered my own question-- I looked through some of my ancient manuals (pre-1985) from hornady, Sierra and hodgdon and discovered they used cci 250s and fed 215s on their test loads.

 

[tribb]

I use

Any thoughts are welcome, but I've largely answered my own question-- I looked through some of my ancient manuals (pre-1985) from hornady, Sierra and hodgdon and discovered they used cci 250s and fed 215s on their test loads.

I use Fed 215 match in mine with
Reloader 25 and nosler 120 partitions

 

[FEENIX]

Any thoughts are welcome, but I've largely answered my own question-- I looked through some of my ancient manuals (pre-1985) from hornady, Sierra and hodgdon and discovered they used cci 250s and fed 215s on their test loads.

Yes, use the same primers as your 300 and 340 WBTY. H4831/SC burn rate is probably a good starting point.

 

[snox801]

I also use 215 match. Rl33 or h-1000

 

[Wolf76]

Same here...mag primers.
Many loads are about 70 grs of powder, which is mag territory.

 

[Wrenches]

I have been loading and shooting a 257 Wby with 117 grain Sierra Pro Hunters since IMR 7828 was released to the public early eighties. My load is 70.0 grains of 7828 and a Fed 215 primer behind the 117 Sierra. Works great

 

[Hoss50]

I always used mag primers in my 257 weatherby.

 

[Makaira]

The federal mag primers, 7828ssc ,a hammers shoot great.

 

[droptine]

If it says mag I'm I use a mag primer. I use 215, win LRM, whatever I have. Prefer 215, always have for some reason.

 

[Aussie Hunter Steve]

I have used both the Fed 210 and 215 in 257 WM. The magnum primers reached max pressure with less powder....it was like using a faster powder. Main thing is, do not interchange. Start low and work up if changing primers.

 

[basinman]

I use magnum primers for all of my rifle loads and I get very good SD from them all.

 

[Calvin45]

That actually surprises me, that the load data is with standard primers.

Not that there's anything wrong with using standard primers, you won't have trouble using standard or magnum primers. Magnum primers give a little extra ignition insurance, especially in cold weather with compressed loads of slow burning powder. But in nearly all cases they're not needed but neither does it hurt anything to use them, and in the current supply climate just use what you have/can find and think about it no further!

Some think the magnum primers are REQUIRED…fun fact, federal developed the 215 primer in conjunction with weatherby's development of the mighty .378 wby in the 50s. Before this there was no such thing as magnum or standard primers, just primers. That means the .300 hh, 375 hh, the original weatherby cartridges, the 404 Jeffery (RUM parent case), the 416 rigby (338 lapua parent case) and even the colossal .505 Gibbs (cheytac parent case) were all somehow functioning flawless with ordinary primers!!!!!

 

[Ardon]

I recently got a second-hand 257 WTHBY and noticed that all of the reloading books I have spec fed. 210 or "regular" rifle primers. I have several thousand magnum rifle primers for our 300 and 340 WTHBY mags, but no std primers. I would expect to have to tone my loads down a little with the LRM primers but does anyone know how much? I have H4831 and IMR 4350 and 4831 and was wanting to run 120g noslers at around 3100fps. I know how I should do this--but i was hoping someone might have prior experience with this issue so I'm not starting totally blind with limited powder to burn on dead ends.

I have 2 257 WBY's and have always used LRM primers with great success. Just use the data and work up to your max loads. Have fun and I hope you really enjoy your new rifle. It's a great caliber