.25 WSSM thread.. I'm starting over.

[jeffreybehr]

I have simply given up trying to find a subhalf-minute load for the 6XC after spending hundred$ sending about a thousand rounds thru the new barrel...SO...I'm starting over with a new bullet diameter, .257", and a new caliber, the Winchester Super Short Magnum.. I've always liked 25s, and my first real rifle, about 50 years ago, was a '98-Mauser (commercial SantaBarbara action)-based .25-284 with a Douglas 26" barrel. Sold that a million years ago; I wonder where it is?

My intention is to keep my Savage 12BR...

...which will need a new bolt and barrel.. This decision is just a day old, and I have Winchester brass, Hornady 117g. bullets, Forster dies, and ammo boxes ordered, and bought my first K of large-rifle primers (CCI 34s) in decades this morning @ Bruno's.. Have ordered the backordered Blackjack 131s and will get the Berger LR Hybrid 135s from Bruno's..

Haven't decided on a barrel; a 28" Savage-large-shank Shillen is 2 to 3 months away thru Northland, and I've contacted Blake Barrel and Rifle here in Phoenix to see what they can do.

I hope to get shooting again before I have my right-shoulder joint replaced (again!) this summer, but all this may happen months AFTER the surgery.

FWIW, I'll shift my load-development filosphy, after initial break-in and brief powder-charge pressure testing, to seating-depth testing in an effort to get 'there' more quickly than my older filosofies got me there (IF they ever did!).

Meanwhile, all my 6mm supplies, tools, and rifles (but the 12BR) will be for sale.

 

[std7mag]

I ordered my barrel from Northland last week. (Or was it the week before?)
Was told up to 12 weeks.

If your running the heavies, you'll probably want a 1:7.25-1-7.5 twist.

Please keep us updated!

 

[jeffreybehr]

I ordered my barrel from Northland last week. (Or was it the week before?)
Was told up to 12 weeks.

You're right, and that's what James told me; I've corrected my note.

If your running the heavies, you'll probably want a 1:7.25-1-7.5 twist.

Why 7.25 - 7.5 and not 8? Berger's calculator indicates 8 makes the bullet 'stable'.. Seems to me a higher twist rate simply consumes more of the bullet's energy.. But all I know is that I used to be able to do this development work fairly well, and now I can't.

Please keep us updated!

You betcha.

 

[std7mag]

With the speed you'll get from the WSM case, you might get away with 1:8.
Contact Blackjack. Very helpful as far as those things go with their bullets.

 

[284winner]

With the speed you'll get from the WSM case, you might get away with 1:8.
Contact Blackjack. Very helpful as far as those things go with their bullets.

An 8 will work for the .257 Wby mag. Not sure what kind of performance the 25 wssm makes but may work ok. From what I can tell, the 25WSSM has around the same case capacity as the 25/06 maybe a bit less. Basically equal to the 6.5-284 case also. 3200 fps with 131s should be real easy with a 28" barrel. A 7.5 twist should do fine.

 

[jeffreybehr]

An 8 will work for the .257 Wby mag. Not sure what kind of performance the 25 wssm makes but may work ok. From what I can tell, the 25WSSM has around the same case capacity as the 25/06 maybe a bit less. Basically equal to the 6.5-284 case also. 3200 fps with 131s should be real easy with a 28" barrel. A 7.5 twist should do fine.

FINALLY I've chosen a cartridge for which lots of reliable loading data is published! I've found data in EIGHT manuals that I already have.

The highest powder charge with at-least-110g. bullets that these manuals list is 49.5g. of Hunter with a 110g. bullet.. Based on that, it's around 8 to 10g. smaller than the '06 or 284 cases and just a few grains larger than the 6XC.. I think something in the 2900s with a 28" barrel with the 131- and 135g. bullets is a reasonable goal..

The Berger calculator...

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

...using their 135, 2900FPS, 89dF, and 1200 feet elevation. indicates that an 8" twist produces
"Your bullet is STABLE.
Your bullet is flying with full stability. You can expect good groups and your BC is optimized."

So I'll order a Shilen Stainless Select Match in 8" (I hope; NSS's site indicates that 9" is the fastest twist rate available in .257).

 

[284winner]

FINALLY I've chosen a cartridge for which lots of reliable loading data is published! I've found data in EIGHT manuals that I already have.

The highest powder charge with at-least-110g. bullets that these manuals list is 49.5g. of Hunter with a 110g. bullet.. Based on that, it's around 8 to 10g. smaller than the '06 or 284 cases and just a few grains larger than the 6XC.. I think something in the 2900s with a 28" barrel with the 131- and 135g. bullets is a reasonable goal..

The Berger calculator...

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

...using their 135, 2900FPS, 89dF, and 1200 feet elevation. indicates that an 8" twist produces
"Your bullet is STABLE.
Your bullet is flying with full stability. You can expect good groups and your BC is optimized."

So I'll order a Shilen Stainless Select Match in 8" (I hope; NSS's site indicates that 9" is the fastest twist rate available in .257).

Berger calls for an 8 twist. Blackjacks call for a 7-7.5 for most cartridges. I chose the 7.5 from others choices with the same cartridge. My suggestion would be to call BJ and ask one of the guys there. They have extensive knowledge of what twist you'll need. The 7.5 will still run those 133/135 Berger's just fine as well.

 

[jeffreybehr]

Berger calls for an 8 twist. Blackjacks call for a 7-7.5 for most cartridges. I chose the 7.5 from others choices with the same cartridge. My suggestion would be to call BJ and ask one of the guys there. They have extensive knowledge of what twist you'll need. The 7.5 will still run those 133/135 Berger's just fine as well.

Yup.. Turns out that Shilen does have a twist faster than 8", a 7-inch 'rachet' type.. Ordered a 28" Shilen select match SS barrel today from NSS.. It'll be drop-shipped in maybe 16 weeks.. And it'll be custom-throated to what I send them, so now I'm waiting for imaginary bullets, too.. In the computer-software business, they call that 'vaporware'.

 

[284winner]

Yup.. Turns out that Shilen does have a twist faster than 8", a 7-inch 'rachet' type.. Ordered a 28" Shilen select match SS barrel in 7" today from NSS.. It'll be drop-shipped in maybe 16 weeks.. And it'll be custom-throated to what I send them, so now I'm waiting for imaginary bullets, too.. In the computer-software business, they call that 'vaporware'.

Blackjack is out of stock. They should be getting some bullets in pretty quick. I'll order another 500 when they do show up. I'll order 500 Berger's also.

 

[STOMP442]

Never heard of a 6XC that wouldn't shoot sub half MOA with relative ease. The .25s are sweet too, I hope this one turns out better for you.

 

[jeffreybehr]

Never heard of a 6XC that wouldn't shoot sub half MOA with relative ease. The .25s are sweet too, I hope this one turns out better for you.

TYVM..

 

[AlNyhus]

Hopefully you've done your homework on the brass and appropriate chamber neck dimensions? -Al

 

[boltfluter]

Sorry, but I think you are headed for a bigger nightmare with anything in .25 caliber. A good 6XC should be the easy button. Very limited choices in match bullets for the .25 cal. Good luck, your gonna need it.

Paul

 

[AlNyhus]

Sorry, but I think you are headed for a bigger nightmare with anything in .25 caliber. A good 6XC should be the easy button. Very limited choices in match bullets for the .25 cal. Good luck, your gonna need it.

Paul

There might be a worse case to build an accurate .25 on than the WSSM case.

But not many..... -Al

 

[Bobthenailer]

Don't worry bout that 25wssm it'll shoot.

25 wssm coyote

25WSSM (Winchester super short magnum) The series of Winchester super short magnum cartridges never really started any fires with the interest of shooters. You can read many threads of why t…

knowyourzero.com

25 wssm coyote, part 2

25WSSM (Winchester super short magnum) Varmint loads……….velocity velocity with a good bit of accuracy to boot! The target fps I wanted to have was 3600 along with tight accurate grouping. I had som…

knowyourzero.com

 

[jeffreybehr]

Hopefully you've done your homework on the brass and appropriate chamber neck dimensions? -Al

I'm getting whatever chamber Shilen uses, and they'll throat it to whatever I send them.. That doesn't have to happen for about three months, and by that time I'll surely have both the bullets I want.

 

[Ccrider]

What type of barrel was on your 6xc? Most that have a 6xc brag about your accurate they are and how easy they are to make shoot. Less than 1/2 moa does it seem like asking for much.
Also, I would not be afraid to try a Criterion barrel if I were you. I have one on one of my 6br savages with unknown shot count that count that shoots .25 or better with 87gr vmaxs and Varget. My other 10tw CBI savage has 450 rounds and will shoot .2 or better 5 shot groups and routinely shoots zero and low .1 three shot groups. The CBI shoot well and are reasonably priced. I don’t know if they come prefit in wssm.

 

[AlNyhus]

I'm getting whatever chamber Shilen uses, and they'll throat it to whatever I send them.. That doesn't have to happen for about three months, and by that time I'll surely have both the bullets I want.

Respectfully, taking whatever someone gives you for a chamber w/o having any input into the final chamber dimensions is not a recipe for accuracy....especially as it relates to neck diameter. Double that as it relates to the WSSM cases/chambers. -Al

 

[jeffreybehr]

What type of barrel was on your 6xc?

Criterion stainless-steel bull barrel.. First one was 30" (8" twist), 2nd was 28" with 7" twist.

Most that have a 6xc brag about your accurate they are and how easy they are to make shoot. Less than 1/2 moa does it seem like asking for much.

Also, I would not be afraid to try a Criterion barrel if I were you.

I haven't been.

I have one on one of my 6br savages with unknown shot count that count that shoots .25 or better with 87gr vmaxs and Varget. My other 10tw CBI savage has 450 rounds and will shoot .2 or better 5 shot groups and routinely shoots zero and low .1 three shot groups. The CBI shoot well and are reasonably priced. I don’t know if they come prefit in wssm.

They don't.

 

[338bigdog]

I have had 3 6xc and all shot phenomenal. I would go the 25sst or 25creed route way easier to find brass if you are doing .25cal.