Looking to load up some loads this weekend. i haven't loaded much 257. but have a lot of Nosler partition in 120gr and also have 115 Barns TSX. I mainly want to use the Barns tsx. The load i have for this bullet is 70.2grs of RL25 using weatherby brass, win large rifle primers, and no crimp moving at just 3500 fps. Seeing how this is my first full power load for said caliber would any of you have any tips for me. is this load to hot? Any help would be great.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
257 Weatherby and RL-25?
- Thread starter slammedsi
- Start date
Brian Pfleuger
Moderator Emeritus
Based on QuickLoad predictions, I would say that 70.2gr Rl-25 is WAY too high for a starting load.
Especially since the 257Wthby is on the high end of "over bore", it's a little tough to know where to set the QuickLoad variables without having some real data from your gun.
Also, I recently ran QuickLoad using IMR 3031 and the Barnes 110gr TTSX bullet in 7mm-08. QuickLoad's predicted max load was way, way, WAAAYYYY over true max. I don't yet know if it's the 3031 predictions that are wrong or something with the TSX bullet. QL has been very accurate with the same gun and other bullet/powder combinations.
My guess is that 70.2 is AT LEAST max load and probably over. Were it my face behind the gun, I'd start at about 60gr, with one round over a chrony, just to get a good number. Depending on how that looks compared to QL predictions, I might skip 2.0gr at a time, up to around 66, before I dropped down to .5 or .6gr increments.
All of this depends, of course, on exactly what sort of results are obtained at each load.
Especially since the 257Wthby is on the high end of "over bore", it's a little tough to know where to set the QuickLoad variables without having some real data from your gun.
Also, I recently ran QuickLoad using IMR 3031 and the Barnes 110gr TTSX bullet in 7mm-08. QuickLoad's predicted max load was way, way, WAAAYYYY over true max. I don't yet know if it's the 3031 predictions that are wrong or something with the TSX bullet. QL has been very accurate with the same gun and other bullet/powder combinations.
My guess is that 70.2 is AT LEAST max load and probably over. Were it my face behind the gun, I'd start at about 60gr, with one round over a chrony, just to get a good number. Depending on how that looks compared to QL predictions, I might skip 2.0gr at a time, up to around 66, before I dropped down to .5 or .6gr increments.
All of this depends, of course, on exactly what sort of results are obtained at each load.
Brian Pfleuger
Moderator Emeritus
You shouldn't use load data for other bullets with solid copper bullets. The start pressure to engrave the rifling into the bullet is higher than with standard bullets.
Brian Pfleuger
Moderator Emeritus
Do you have any information on this? I have never herd of having a problem with using jacked bullets for solid copper? Should i back off more then the start load or what?
It's out there.... Barnes has info somewhere on their site. Most makers warn against using standard data for their copper bullets, I believe.
QuickLoad increases the start pressure from 3625 (IIRC) for standard lead core bullets to 4350 psi for the Barnes TSX. Other copper bullets may be the same as Barnes, I've never looked, but they're certainly higher than lead-core jacketed bullets.
Anyway, for START loads, you'll USUALLY be fine, but not always. Some start loads are too high already, without making substitutions. It's not likely, but you could get into trouble.
Brian Pfleuger
Moderator Emeritus
If it were me, and seeing what I just saw with in my gun with 3031 and the TSX, I'd load one round at 60.0gr, one at 62.0, one at 64.0 and one at 65.00
Theoretically, between 60.0 and 65.00 should be very low pressure. Theoretically. But, for my guns and my face and hands, for the cost of 2 or 3 extra bullets and the powder behind them, I'd start low.
Preferably, I'd shoot them all over a chrony and verify that I was getting what I expected. After that, assuming all was as expected, I'd start at around 65.0gr, following Dan Newberry's load development system.
http://optimalchargeweight.embarqspace.com/#/ocw-instructions/4529817134
Theoretically, between 60.0 and 65.00 should be very low pressure. Theoretically. But, for my guns and my face and hands, for the cost of 2 or 3 extra bullets and the powder behind them, I'd start low.
Preferably, I'd shoot them all over a chrony and verify that I was getting what I expected. After that, assuming all was as expected, I'd start at around 65.0gr, following Dan Newberry's load development system.
http://optimalchargeweight.embarqspace.com/#/ocw-instructions/4529817134