I’m Making The Switch

[VinceMule]

Moreover I don't see what's so bad about the original .257 weatherby. Or a .257-7mm rem. Or doing a .257 WSM or SAUM. or heck even a .25-300 PRC or .25-300 wby if you needed a notable increase in capacity over the 25-06 and .25-06 ai. All of those possibilities have waaaaay more brass options available than the RPM case and the weatherby has boring cheap over the counter dies and stuff too .

This is a dumb butt simple fix for a guy that likes the 257 Weatherby but does not like the cost of the brass.

Take Winchester brand of 264 Winchester, lube the neck and shoulder, run it through a 257 Weatherby full length sizer. You will get a perfectly formed 257 Weatherby case every time....this is about as idiot proof as it gets. The neck will be approximately .050 shorter than the Factory weatherby case.

I sent 5 cases with the bullet seated to where I wanted it, and had PTG grind a reamer to those specs. I did change the neck dia on the reamer print and freebore of .020, very short. All barrels off of this reamer have shot 1/4" groups with vel of the 100g being in the 3850 range on 26", 10T barrels, 115's at 3600, all with amazing accuracy.

You can neck down 7 Rem mag brass, but neck turning will be required, use the 264 Win neck sizer on the first neck down, then the 257 Weatherby.

Some may think that with the short freebore, stuffing the bullet down in the case would leade to inaccuracy, but we have never seen it on 6 barrels. The Double radius seems to impede the formation of doughnuts. It is important that the neck dia on the reamer be large enough to where you get good bullet release, and this will be evident by your ability to stick the bullet down in the case neck past the shoulder neck junction with ease. Adequate bullet release helps eliminate flyers.

With the new Hornady and Berger high bc bullets, the 257 Weatherby will be dramatically improved.

 

[Calvin45]

This is a dumb butt simple fix for a guy that likes the 257 Weatherby but does not like the cost of the brass.

Take Winchester brand of 264 Winchester, lube the neck and shoulder, run it through a 257 Weatherby full length sizer. You will get a perfectly formed 257 Weatherby case every time....this is about as idiot proof as it gets. The neck will be approximately .050 shorter than the Factory weatherby case.

I sent 5 cases with the bullet seated to where I wanted it, and had PTG grind a reamer to those specs. I did change the neck dia on the reamer print and freebore of .020, very short. All barrels off of this reamer have shot 1/4" groups with vel of the 100g being in the 3850 range on 26", 10T barrels, 115's at 3600, all with amazing accuracy.

You can neck down 7 Rem mag brass, but neck turning will be required, use the 264 Win neck sizer on the first neck down, then the 257 Weatherby.

Some may think that with the short freebore, stuffing the bullet down in the case would leade to inaccuracy, but we have never seen it on 6 barrels. The Double radius seems to impede the formation of doughnuts. It is important that the neck dia on the reamer be large enough to where you get good bullet release, and this will be evident by your ability to stick the bullet down in the case neck past the shoulder neck junction with ease. Adequate bullet release helps eliminate flyers.

With the new Hornady and Berger high bc bullets, the 257 Weatherby will be dramatically improved.

I have done this very thing. Have about 90 pieces of 264 formed brass and 49 (wrecked one like an idiot) of Peterson 7mm rem brass formed to .257 wby. I do still prefer the full length neck and have 150 Norma/weatherby cases of the correct headstamp as well.

 

[VinceMule]

Calvin, we were using the 257s, losing brass hunting. 100g nosler ballistic tips at 3850 really wrecks a coyote's day!

Using short neck brass in a standard-length chamber leaves some carbon in the throat, and a couple of twists with a bronze bristle brush at cleaning gets the carbon out.

Since I do not shoot a 270 or 7mm Weatherby, head stamps are a moot issue, and they will not chamber in my 7 Mags.

This is just a fun project, easy with amazing results on paper targets and in the field.

85g Nosler ballistic tips, R#19, accuracy node is at 4130 fps with the short freebore. I would like to try the 80g Barnes TTSX.

 

[Calvin45]

Calvin, we were using the 257s, losing brass hunting. 100g nosler ballistic tips at 3850 really wrecks a coyote's day!

Using short neck brass in a standard-length chamber leaves some carbon in the throat, and a couple of twists with a bronze bristle brush at cleaning gets the carbon out.

Since I do not shoot a 270 or 7mm Weatherby, head stamps are a moot issue, and they will not chamber in my 7 Mags.

This is just a fun project, easy with amazing results on paper targets and in the field.

85g Nosler ballistic tips, R#19, accuracy node is at 4130 fps with the short freebore. I would like to try the 80g Barnes TTSX.

Holy smokes that's cookin! And I thought I was pushing the envelope. Might I ask what barrel length and powder is being used to go this fast?

I have two good loads in my .257, with it's short 24 inch barrel (vanguard stainless)

100 grain Nosler b tip at 3720 with imr 7828ssc.

75 grain hammer hunter at 4170 with rl 17.

Also have a less crazy fast but very accurate 100 Barnes tsx at 3450 or so.

Still to try but in my current possession are 90 grain absolute hammers and 115 berger vlds.

 

[VinceMule]

Calvin, all my factory and custom 257s shoot a load of 72-73g of R#22, fed 215, with the 100g bullets at 3600 in the factory chamber and 3850 in the customs with short freebore. Even the 100g Partition shot 1/2" groups at 3850 in the Pac Nor three groove super match.

All the barrels are 25-26" in length, and subtract 15-30 fps for 1 less inch.

I tried IMR 7828, and speed was less with great accuracy, not by much on the speed.

Groups on the custom barrels was never over .325 on three shot groups, never with the 100g.

The 115g Bergers make deer collapse so fast it is just beyond belief. My nephew is recoil sensitive. I gave him a Rem 700 with a 25" Pac Nor 9T, with a Gentry muzzle break. He sees the bullet impact on the deer and often the bullet impact behind the animal on trees or hill side. You could not ever pry that rifle out of his hands. He was missing deer with the recoil of his 7 Mags and 308s even though they had Gentry muzzle breaks on them. 257 Weatherby, 25" #5 contour, boyds laminate stock, fixed his missing problems. He shot a large sow at 560 yards last year with it, 115 Bergers planted that large hog on the spot.

The last two X caliber 9 twists are shooting tiny groups, 110g Nosler accubonds and 115g Bergers, 3/8" and smaller groups, R#22

I am hoping to get some 5 lb jugs of R#23 for the 257 Weatherby, should be the cats meow.

 

[ButterBean]

#2 is in the works, 300 WSM 9 twist X-Caliber

 

[ButterBean]

I'm Tickled
243 AI
Savage 10
26" Criterion 7 twist, Suppressed
Lapua Brass
.003 Neck Interference
1/8th FCD
CCI 200
****Varget@ 51g 4379fps, SD 9.0*****
Case fill@ 98%
55 Hammer Hunter

46g 3922fps
47g 4061fps
48g 4152fps
49g 4269fps
50g 4324fps
51g 4391fps
52g 4519fps ( Cratered Primer and Shiny Ejector Swipe, On The Ragged Edge )

 

[QuietTexan]

Bean does it again.

 

[Calvin45]

I'm Tickled
243 AI
Savage 10
26" Criterion 7 twist, Suppressed
Lapua Brass
.003 Neck Interference
1/8th FCD
CCI 200
****Varget@ 51g 4379fps, SD 9.0*****
Case fill@ 98%
55 Hammer Hunter

46g 3922fps
47g 4061fps
48g 4152fps
49g 4269fps
50g 4324fps
51g 4391fps
52g 4519fps ( Cratered Primer and Shiny Ejector Swipe, On The Ragged Edge )

View attachment 480374

With an sd of 9 and no pressure signs 51 seems like a no brainer. I honestly suspect that even that would be overpressure according to a strain guage or whatever they use but you're a big boy, you know what your doing. I only suspect that because in my very limited experience if you're getting ejector swipe and such on lapua or Peterson type brass y'all have already been over that 60 (ish) kpsi mark for a while. I assume your paying attention to ease of case extraction, primer pocket expansion, and any signs of excessive web expansion or necks splitting, excessive case growth (though with an AI I don't know)

Congrats on the killer speed man!

Did the math. 55 grains at 4391 fps is 2355 foot pounds. Not that this really matters but that's pretty impressive regardless. A lot of energy concentrated in a very tiny package.

Any plans for terminal testing any time soon? Do you worry 55, even in hammer form, is too light for deer?

 

[FlGunner]

That thing is smoking

 

[VinceMule]

Bean, what are you hunting with that 243 AI? Absolutely astounding success! Congrats!

 

[jessej]

Do you worry 55, even in hammer form, is too light for deer?

 

[ButterBean]

Bean, what are you hunting with that 243 AI? Absolutely astounding success! Congrats!

Deer and Coyotes

 

[ButterBean]

With an sd of 9 and no pressure signs 51 seems like a no brainer. I honestly suspect that even that would be overpressure according to a strain guage or whatever they use but you're a big boy, you know what your doing. I only suspect that because in my very limited experience if you're getting ejector swipe and such on lapua or Peterson type brass y'all have already been over that 60 (ish) kpsi mark for a while. I assume your paying attention to ease of case extraction, primer pocket expansion, and any signs of excessive web expansion or necks splitting, excessive case growth (though with an AI I don't know)

Congrats on the killer speed man!

Did the math. 55 grains at 4391 fps is 2355 foot pounds. Not that this really matters but that's pretty impressive regardless. A lot of energy concentrated in a very tiny package.

Any plans for terminal testing any time soon? Do you worry 55, even in hammer form, is too light for deer?

No disrespect meant but none of your math applies to Hammers, this load is safe in my rig and no I have no worries about shooting a deer with it, absolutely none