I am running 7mm rem mag brass thru a 257WBY full length size die. It looks great but ends up about .05" shorter than the recommended trim length for the .257WBY. Is this something I should worry about? It is a Weatherby rifle. So it should have a lot of freebore. Do I need to worry about advanced throat erosion? Or should I just go ahead and shoot it? Will the brass eventually reach the recommended length? Thanks for your help!!
turning 7mm mag brass into .257 Weatherby brass
- Thread starter filamb
- Start date
odawgp
New member
Are these once fired or new brass
anyway I did some research and there is a lot of info on the net about this
google "257wby from 7mm brass" and you will see a bunch of threads like this one I found link
I also have a 257 and have been picking up 7mm brass to sell as once fired and this process never occurred to me.
Good luck let me know how it turns out
anyway I did some research and there is a lot of info on the net about this
google "257wby from 7mm brass" and you will see a bunch of threads like this one I found link
I also have a 257 and have been picking up 7mm brass to sell as once fired and this process never occurred to me.
Good luck let me know how it turns out
Last edited:
Thanks for the info guys. I found this site by searching for .257 Weatherby brass. Where I found a thread from a year ago. I didn't know you could turn 7mag into .257wby either. They were very informative. They discussed everything but the questions I had. I may send a personal message to Ackleyman, if he is still out there. He seemed pretty knowledgable.
I have run 10 new R-P cases through the FLS die and the brass looks good. It even makes the double radius shoulder. It's not perfect. But it may fire form with shooting. I have no idea. Does not matter. They chamber ok.
I was just worried about the excessive throat erosion. It's probably nothing to worry about with the large free bore anyway. It's probably getting it's far share of blow by as it is. These small high velocity rounds are suppose to erode barrels faster.
I am really worried about nothing. If I shoot the thing out. I will just put a new barrel on it, get rid of the free bore and start banging away again.
I will let you know how it turns out.
Love the site!!
I have run 10 new R-P cases through the FLS die and the brass looks good. It even makes the double radius shoulder. It's not perfect. But it may fire form with shooting. I have no idea. Does not matter. They chamber ok.
I was just worried about the excessive throat erosion. It's probably nothing to worry about with the large free bore anyway. It's probably getting it's far share of blow by as it is. These small high velocity rounds are suppose to erode barrels faster.
I am really worried about nothing. If I shoot the thing out. I will just put a new barrel on it, get rid of the free bore and start banging away again.
I will let you know how it turns out.
Love the site!!
odawgp
New member
Post your thread over @ Gunbroker and this is what I got back
Odawgp,
"It looks great but ends up about .05" shorter than the recommended trim length for the .257WBY."
This is not surprising since the 7mm Rem. Mag. case is 2.500" in length and the Weatherby case is 2.560" in length. The case will not get longer when you're trying to compress it into another shape.
"Is this something I should worry about?"
Maybe, maybe not. It depends on the rest of the chamber in front of the neck.
"So it should have a lot of freebore."
It does, to certain extent. But it's not the freebore (leade) that is a potential problem.
The problem has a red square around it. This is named the 'Transition Angle' which is a 45 degree angle that acts as the step down from the chamber neck diameter to the chamber leade diameter. The length of the neck area in the chamber is always a little longer than the actual neck length of the cartridge case. The problem with this area being 0.050" longer yet is that it can become an area that collects fouling and carbon. In the shorter version, the plasma jet or stream usually misses this area. But, make this area longer (further away from the end of the neck) and the plasma not only impinges on this step but makes this area more susceptible to collecting fouling and worse, carbon. This can contribute to a building of pressure that may not be immediately understood.
"Do I need to worry about advanced throat erosion?"
Throat erosion is a factor of the plasma temperature, the angle of impingement and the type and hardness of the steel used in making the barrel. These cases minimize the angle of impingement and the temperature can be partially controlled by powder selection and balance with the bullet weight.
"Will the brass eventually reach the recommended length?"
Highly unlikely. Growth is experienced when a case has someplace to grow. So if the chamber has more space from the first radius up through the end of the neck, the case might grow. This is a problem that occurs with resizing. Don't set the shoulder back while resizing. You will eventually see case separation just above the belt if you do. Know the length of of your chamber and set your dies correctly.
Cases will usually grow when the design features a shallow shoulder like the .30-06 or the .220 Swift. The double radius Weatherby shoulders curtail case growth.
Best.
Odawgp,
"It looks great but ends up about .05" shorter than the recommended trim length for the .257WBY."
This is not surprising since the 7mm Rem. Mag. case is 2.500" in length and the Weatherby case is 2.560" in length. The case will not get longer when you're trying to compress it into another shape.
"Is this something I should worry about?"
Maybe, maybe not. It depends on the rest of the chamber in front of the neck.
"So it should have a lot of freebore."
It does, to certain extent. But it's not the freebore (leade) that is a potential problem.
The problem has a red square around it. This is named the 'Transition Angle' which is a 45 degree angle that acts as the step down from the chamber neck diameter to the chamber leade diameter. The length of the neck area in the chamber is always a little longer than the actual neck length of the cartridge case. The problem with this area being 0.050" longer yet is that it can become an area that collects fouling and carbon. In the shorter version, the plasma jet or stream usually misses this area. But, make this area longer (further away from the end of the neck) and the plasma not only impinges on this step but makes this area more susceptible to collecting fouling and worse, carbon. This can contribute to a building of pressure that may not be immediately understood.
"Do I need to worry about advanced throat erosion?"
Throat erosion is a factor of the plasma temperature, the angle of impingement and the type and hardness of the steel used in making the barrel. These cases minimize the angle of impingement and the temperature can be partially controlled by powder selection and balance with the bullet weight.
"Will the brass eventually reach the recommended length?"
Highly unlikely. Growth is experienced when a case has someplace to grow. So if the chamber has more space from the first radius up through the end of the neck, the case might grow. This is a problem that occurs with resizing. Don't set the shoulder back while resizing. You will eventually see case separation just above the belt if you do. Know the length of of your chamber and set your dies correctly.
Cases will usually grow when the design features a shallow shoulder like the .30-06 or the .220 Swift. The double radius Weatherby shoulders curtail case growth.
Best.
Predator257Roy
New member
Filamb,
Ackleyman is still around, and would tell you everything you need to know, although what has been said is all good information. He's answered a bunch of questions for me, both in posts and PM's. He's got to be the expert on all things .257Wby. My custom rifle (haven't gotten it yet) is a .257Wby and I will be forming brass from .264 Win Mag since it is supposed to be a little easier, but 7mm mag works well too. Good luck!
Ackleyman is still around, and would tell you everything you need to know, although what has been said is all good information. He's answered a bunch of questions for me, both in posts and PM's. He's got to be the expert on all things .257Wby. My custom rifle (haven't gotten it yet) is a .257Wby and I will be forming brass from .264 Win Mag since it is supposed to be a little easier, but 7mm mag works well too. Good luck!
firstcoueswas80
New member
I have a .257 wby and have tried the 7mag trick (used to have one). IMO, its not worth the hassle. Buy Norma brass and it will be good for 7+/- loadings. My Norma brass is on about 4,5 or 6 right now (Cant remember, and have different batches... POI stays consistent)
deerhunterjj
New member
Quote:
Thanks for the info guys. And going the extra mile. The reply from Gunbroker was great. I am just trying to save some money on brass. Midway has raised their prices again. Brass is getting very high. And you know how high Weatherby brass is!!
In my opion and things i have run into when you try to save a dollar you end up spending 2.00 in the end. Just like said before break down and get the right stuff the first time and you wont have to worry in the long run. Take it for what its worth.
Thanks for the info guys. And going the extra mile. The reply from Gunbroker was great. I am just trying to save some money on brass. Midway has raised their prices again. Brass is getting very high. And you know how high Weatherby brass is!!
In my opion and things i have run into when you try to save a dollar you end up spending 2.00 in the end. Just like said before break down and get the right stuff the first time and you wont have to worry in the long run. Take it for what its worth.