257 wtby or 257 stw

[338]

I am going to build a rifle and I can't decide between the 257 wm or the stw. The gun will be used mostly for hunting trips mostly whitetail. I am having a hard time coming up with ballistics for the stw, I have read it will push a 100gr bullet a little over 4000 mark. Does anybody know where to get any reloading specs or have any input on either? .Thanks Bill

[Duckbutter48]

http://www.reloadersnest.com/frontpage.asp?CaliberID=239

Just scroll down and you'll see some load info. Do a google search on the STW a good bit of stuff came up.

[Roskoe]

The .257 Weatherby is a factory caliber with a reputation for fairly short barrel life. It can make 3600 fps with 100 grain bullets and almost 3400 fps with 117 gr. bullets. Brass is relatively expensive if you wish to handload. And so is factory ammunition. Great long range caliber for deer and caribou. With certain bullets and in the hands of a good shot, it is an adequate elk rifle.

The .257 STW is a caliber that is only suitable for experienced handloaders. You make cases my necking down 7 STW brass, and you need to outside neck turn each case. It offers about 200 fps more speed than the Weatherby. Very loud bark. Barrel life is about 800 rounds tops with full throttle ammo. Trajectory for long range shooting is almost off the charts. Only premium bullets are recommended for this rocket. Standard bullets will often blow up on close and medium range impacts.

[ejpaul1]

Roskoe, what is the FPS threshold for burning a barrel? I am loading my 7mm WSM to 3200 FPS with 139 grain hornady interlock btsp's. I dont think I'll have issues with barrel damage but just wondered if you had any insight. EJ

[Roskoe]

ejpaul - what I have found is that velocity in itself doesn't burn out a barrel. It is the gobs of powder it requires to get a bullet going real fast that does it. The heat and pressure of the powder charge tends to erode metal from a rifle barrel just ahead of the throat area. Worst case scenario is a small diameter bullet, that is heavy for its diameter, being driven by a very large capacity case. Fast twist .22/6MM shooting 75 gr. Hornady A-Max bullets at 3800 fps. 6MM-284 with a 8" twist shooting 107 Sierra VLD bullets Or even a .30-378 Weatherby with a 8" twist shooting 240 Sierra Matchkings. These are all serious barrel burners.

The long heavy bullets are actually worst of all because, although they aren't going as fast as the light ones, it takes them slighly longer to get moving when they leave the case (basic inertia) - and this gives the hot gasses and particles a little longer to erode the barrel just ahead of the throat.

If you study the various calibers and look at how much of an increase in powder it takes to get a bullet moving even 200 fps faster - then compare that to the reduction in barrel lifethat comes with that bit of extra speed - there is somewhat of a point of dimishing return here. My choice for a fast .25 caliber is the .25-06 Ackley Improved.

[ejpaul1]

Well then, I should be OK with me 3200 fps with a 139 grain boat tail for my 7mm wsm. Thanks, EJ

[338]

Thanks for the input, I am still undecided but I found that the STW might be a hair long for the magazine on the montana rifle..

[338]

Roskoe .. Just to let you know Midway carries brass with the 257STW head stamp ..

[Ridge Runner]

If you want the most bang for the buck out of a 257 cal. and your not afraid to reload look into a 257 Allen Mag, developed by kirby Allen of fort shaw montana, a 338 RUM AI'd to the max and necked to .257, its the flattest tragjectory you can get to 500 yds and shoots flatter than the 338/378 weatherby to 1500 yds.
Kirby claims that if you shoot ball powder (WC872, a milsurp powder developed for the 50 BMG and 20 mm vulcan cannon, I shoot it in my 7mm AM, and its 5 bucks a pound) you can see 1000 rounds from a barrel before its done. I believ this cause an aquaintance has a 270 AM (270/338RUM AI) that has 900+ rounds through it and throat erosion is almost non-existant.
Kirby himself gave up the 257 STW when he developed the AM.

[338]

I did find a little info on the 257AM on the net but just that it out does the stw, Where can I get more info? I would like to compare it to the STW ..Thanks