Home Forums Hunting & Shooting Ask The Gunwriters 25 WSM

I did a search for threads about the 25 WSM wildcat but did not find any. I am thinking about doing this off of the 270 WSM case. Can someone tell me the case capacity of this wildcat compared to the 257 Weatherby? Would one expect higher or lower velocities than the WBY? If any one can point me to already existing threads on the 25 WSM I would appreciate it. Thanks, Rufous.

I think it would be less velocity that a 257 Weatherby.

Link 1

RH

Thanks for that link. I also found this on a recent thread:

Here are the approxmate useable powder room (NOT the amount of powder that fills the case to the mouth) of each of the case so far mentioned:

.257 Roberts: 52 grains
.25-06 Rem: 62 grains
SAUM case: 70 grains
WSM case: 75 grains
.257 Wby: 80 grains

If i ever re-barrel my Model 70 270 WSM it will be to the 25 or 6.5 WSM . The difference between the 257 Wby and the 25 WSM would be about like the 243 Win and the 6mm Rem

I have one. Here is what I experienced with mine:
1. It equals wby speeds with about 4 grains less powder. (I have a wby too.)
2. Fast throat erosion.
3. At max loads, there is still a lot of extra case capacity. I like high load density. In hindsight, I would have done a 25SAUM. In fact, I will probably have my barrel set back and have it rechambered to a 25SAUM.

Thanks for the input WSMAN. Maybe I will just go with the 257 WBY.

If you want top speed go with the 25 STW

+1

Its a 25-300wsm Rick Jammerson did this 10 years ago with more then the 257 weatherby In one of the hunting mag. hunting or shooting times I belive 03-or 04

I built a 25/270 wsm on a savage model 16 when the wsm's first came out. Decent caliber, great accuracy, tickles right up against a 257 weatherby. Killed a real nice 7x7 bull with mine and 115 gr partitions. I used 270 wsm cases necked down with no other changes.

I changed mine out to a 223 AI, the caliber was over bore. I had around 1400 rds through mine and the throat was starting to get pretty rough. It was a fun project but I have moved the other direction in my caliber choices recently, looking for better efficiency and much better barrel life.

I really liked the performance of mine but I like to shoot to much and would rather not have to replace barrels that often. I did find a problem with the 25 wsm as it was prone to weird pressure spikes. Loads would go from no pressure sign to "hot" very quickly. If I were to do it again I would build the 25 SAUM.
Which equals the case capacity of the 25-06AI in a short action and has about all the case capacity you can effectively use in a 24-26" barrel.

If you decide to build one and would like a set of dies I will sell my reasonable. They are redding dies.

I thought of this but didn't come up with a thing so far

A few years ago Buck Pope did a 25 270 wsm that he called the
25 Pronghorn. There may be information listed for the cartridge under this name.

Ernie

I went with the .284 case necked to .25. The .284 case seems to have all the goodies, without all the baddies. I thought about the .25 SAUM as well, but I like to shoot a lot and the .25-284 got the nod. 100 grain bullets easily do 3,300-3,400 fps. I mainly use 100 grain Barnes XLC's, which fetch an additional 100 fps. They hover around 3,500 fps and are a hammer on anything they connect with. The 115 grain bullets run about 3,250-3,300 I don't like cleaning copper out of a barrel. I would rather shoot more and clean less. This round provides a fast, fun, flat shooting platform. Flinch

Jon Sundra did the .25 SAUM about 6-7yrs ago. I believe Ralph Lermayer (newly signed on here as "predatoreditor") did some work with it as well. Jon felt the WSM case was a bit too much of a good thing, IIRC.