257 PRC (300 PRC necked to .25)
- Thread starter 284winner
- Start date
AckleymanII
Gold $$ Contributor
Market is moving slow, 284winner. Covid out of stocks, world at war scare, hyper inflation is taking it's toll.
I did a 6.5-300 PRC. I mastered the neck down process. Happy to help the bro's if needed...
My reamer is the 25-284, not the 25 PRC. I'm helping a buddy with his 257 Weatherby while doing a 300 PRC improved currently for myself. I'm comparing brass on the 300PRC and 257 WBY. Very close to the naked eye. Just a curious why I haven't heard anyone building a 25 caliber on the 300PRC case. Seems like a pretty easy task necking down the brass and good brass available as well. Apparently we've reinvented the wheel with the 300PRC while still having the 300WM. It's pretty much the same as doing a 25-300PRC while having the 257 WBY still going strong. It may turn into more than just an itch.
Sigh...
Fine...
I'll spec a reamer & order one.
Not sure what kind of freebore to go with though.
Something with that much powder really deserves to push some heavies.
Guessing H1000 or Retumbo
I know the 257WSM will surpass the 257 Weatherby. The PRC should be about the same. Case capacity comparison will tell you a lot.
After looking at the case dimensions the 257 PRC based off the 300 PRC would get into the 257 STW range.
After looking at the case dimensions the 257 PRC based off the 300 PRC would get into the 257 STW range.
Last edited:
DaveTooley
Gold $$ Contributor
I did a wildcat on the 8X68 case years ago. Similar to the 25 Banshee. You reach a point of diminishing returns quickly. I did. Same with a 6.5 on that case. Sometimes more powder is just more powder.
Kurz
Silver $$ Contributor
I still have my 25 Banshee reamer, untouched for years for that very same reason...
Ya know, if you keep after these 25 calibers, we are gonna have to change your screen name.
But then mine too.
crystalgayleguy
Gold $$ Contributor
Still using the 284 parent case. No real need for the 257/300PRC. Just teasing myself a little. I sure do love the 130+ class bullets offered tho.Ya know, if you keep after these 25 calibers, we are gonna have to change your screen name.
But then mine too.
B23
Gold $$ Contributor
The 257 STW was a fairly popular 25cal hot rod for awhile and a 25-300PRC would be damn near a ballistic twin to that.
I don't know what the brass is like but if you have a standard bolt face long action to build off of, like say a LA Rem 700, necking down the Weatherby 6.5RPM to .257 would probably make for a pretty sweet setup and not cost a whole lot to build. I don't know if anyone makes bushing dies for the 6.5RPM but if they do that would be an easy way to go.
And, since you're a fan of the 284 anyway the 6.5 RPM is basically a stretched out 284 case. A 257 RPM would have pretty much identical case capacity of a 257 Weatherby but on a standard bolt face action and no belted case.
I know Kirby Allen did a couple different hot rod 25 cals. one was built off the 300 Dakota case and the other used 338RUM as the parent case but they all were "improved" variants with Kirby's shoulder angle and case taper. I'm not sure what they were or where he got them but he was shooting some really heavy 25cal bullets if I recall they were 156's. He used 28-30 inch barrels and slowwwww powders like H870 and US869. I don't know what the BC was on those 156's but it was pretty high and if I recall he was launching them 3300-3400fps and the 115-120's were leaving the barrel at 3800.
Something that overbore would probably be a good test for one of Bartlein's 400modbb barrels that's supposed to last longer.
I don't know what the brass is like but if you have a standard bolt face long action to build off of, like say a LA Rem 700, necking down the Weatherby 6.5RPM to .257 would probably make for a pretty sweet setup and not cost a whole lot to build. I don't know if anyone makes bushing dies for the 6.5RPM but if they do that would be an easy way to go.
And, since you're a fan of the 284 anyway the 6.5 RPM is basically a stretched out 284 case. A 257 RPM would have pretty much identical case capacity of a 257 Weatherby but on a standard bolt face action and no belted case.
I know Kirby Allen did a couple different hot rod 25 cals. one was built off the 300 Dakota case and the other used 338RUM as the parent case but they all were "improved" variants with Kirby's shoulder angle and case taper. I'm not sure what they were or where he got them but he was shooting some really heavy 25cal bullets if I recall they were 156's. He used 28-30 inch barrels and slowwwww powders like H870 and US869. I don't know what the BC was on those 156's but it was pretty high and if I recall he was launching them 3300-3400fps and the 115-120's were leaving the barrel at 3800.
Something that overbore would probably be a good test for one of Bartlein's 400modbb barrels that's supposed to last longer.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.