257 Weatherby pet loads

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Redmist257

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Any one have any info on some pet loads for a 257 Weatherby I can try ? I have yet to find the sweet spot from mine and have used R25,H1000,MagPro ,7828ssc, and IMR 4831 . With bullet weights from 100,110,115and 117 gr . Seating them by books and trying different lengths. And this rifle is killing me . Any info would be greatly appreciated.
 
Welcome! What size groups at what distance have you been getting? What difference in seating depths have you tried? I always go with 5-7 groups each seated 0.003 deeper starting at the factory length.
 
In all my shooting, RL25 has given good speed, but less than stellar accuracy.

The Weatherby magnum chamberings tend to have a long throat/freebore.
An old time trick used to help keep pressures in check.

That being said, most manuals will give the SAAMI COAL.
Hornady, i've found will actually give a longer length to use with their bullets, and works well with the longer throat.

You list many different bullet weights, but not the actual bullet used.
115gr for example could be a Ballistic Tip, or a Berger VLD.
These will like very different distances (jump) to the lands.

Shadow9mm,

The OP is shooting a 257 Weatherby, in a time where components are in short supply.
Even when components were in good supply i wouldn't do 5-7 rounds at only 0.003" for a hunting rifle.
At those distances he'd go through 3 barrels before finding an acceptable seating depth.
Larger jumps, with 3 rounds to get close. 0.015", or even 0.020", then you could fine tune if desired.
 
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As always it would help to know the specific rifle you are reloading for, the specific components being used and accuracy obtained. Not all 257 wbys have the long throat. And other brands of brass may have significantly differing internal capacity from the Wby/Norma brands. And the velocity's, charge weights and primers being used.

It's been awhile, but relied on RL 22 with Nosler 100 partitions for best accuracy and velocity.
 
std7mag said:
In all my shooting, RL25 has given good speed, but less than stellar accuracy.

The Weatherby magnum chamberings tend to have a long throat/freebore.
An old time trick used to help keep pressures in check.

That being said, most manuals will give the SAAMI COAL.
Hornady, i've found will actually give a longer length to use with their bullets, and works well with the longer throat.

You list many different bullet weights, but not the actual bullet used.
115gr for example could be a Ballistic Tip, or a Berger VLD.
These will like very different distances (jump) to the lands.

Shadow9mm,

The OP is shooting a 257 Weatherby, in a time where components are in short supply.
Even when components were in good supply i wouldn't do 5-7 rounds at only 0.003" for a hunting rifle.
At those distances he'd go through 3 barrels before finding an acceptable seating depth.
Larger jumps, with 3 rounds to get close. 0.015", or even 0.020", then you could fine tune if desired.
Click to expand...
I find jump does not matter. Its about where the bullet leaves the barrel in the harmonics. There will be multiple seating depths that may work well, you just have to find one of them. Tuning .003 adjusts when the bullet leaves the barrel to a stable point in the harmonics and will generally find one to two good nodes. To be clear i mean 1, 5 round group at each seating depth, with 5-7 seating depths. Your talking 25-35rnds total and your done.

I went from 1.5in groups down to .75in groups in my budget hunting rifle, all i did was 25rnds, 5 round groups, 5 groups total.

I tried measuring off the lands and using the comparitor tools and had nothing but problems as well as wasting a lot of bullets, powder, and primers trying to do it. The lands erode as you shoot, your measuring off a moving point that is guaranteed to change. I have seen people on YouTube use much bigger jumps in seating depth and have trouble finding a good node. I found the method from eric cortina doing the 0.003, and it worked like magic

Heres the video from Eric
https://youtu.be/oRXlCG9YZbQ
 
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As far as bullets , I have trued everything from Nosler to Hornaday Sierra,Barns . Some I’m getting a little over a inch to 3 inch groups . I will try the on load at different seats with the most accurate load a book shows next
 
Shadow9mm said:
I find jump does not matter. Its about where the bullet leaves the barrel in the harmonics. There will be multiple seating depths that may work well, you just have to find one of them. Tuning .003 adjusts when the bullet leaves the barrel to a stable point in the harmonics and will generally find one to two good nodes. To be clear i mean 1, 5 round group at each seating depth, with 5-7 seating depths. Your talking 25-35rnds total and your done.

I went from 1.5in groups down to .75in groups in my budget hunting rifle, all i did was 25rnds, 5 round groups, 5 groups total.

I tried measuring off the lands and using the comparitor tools and had nothing but problems as well as wasting a lot of bullets, powder, and primers trying to do it. The lands erode as you shoot, your measuring off a moving point that is guaranteed to change. I have seen people on YouTube use much bigger jumps in seating depth and have trouble finding a good node. I found the method from eric cortina doing the 0.003, and it worked like magic

Heres the video from Eric
https://youtu.be/oRXlCG9YZbQ
Click to expand...
Specifically to a Japan produced 257 wby with sporter barrel, the jump certainly did matter, and repeatedly with all bullets tried (back then). Found this out by picking the bullets out of a factory (Wby) loaded Hdy 100 gn sp that had more full dia exposed. Am attributing this directly to the free bore in wby factory rifles, and the col the factory uses. I can use the col that the magazine allows to get better accuracy.

There have been other manufacturers of wby's, that reportedly (belive it was Ken Waters) did not have the extended free bore.

The trouble i had with doing large amounts of test firing through a Wby is bullet velocity. The barrel heated up very quickly, which affected accuracy. Even with a free floated stock. The barrel also coppered up quickly, and needed to be thoroughly cleaned and cooled to repeat accuracy and poi.

In my direct experience, handloading for the specific rifle owned with overbore wby cartridge does not follow some things that may work for other cartridges/rifles.
 
zeke said:
Specifically to a Japan produced 257 wby with sporter barrel, the jump certainly did matter, and repeatedly with all bullets tried (back then). Found this out by picking the bullets out of a factory (Wby) loaded Hdy 100 gn sp that had more full dia exposed. Am attributing this directly to the free bore in wby factory rifles, and the col the factory uses. I can use the col that the magazine allows to get better accuracy.

There have been other manufacturers of wby's, that reportedly (belive it was Ken Waters) did not have the extended free bore.

The trouble i had with doing large amounts of test firing through a Wby is bullet velocity. The barrel heated up very quickly, which affected accuracy. Even with a free floated stock. The barrel also coppered up quickly, and needed to be thoroughly cleaned and cooled to repeat accuracy and poi.

In my direct experience, handloading for the specific rifle owned with overbore wby cartridge does not follow some things that may work for other cartridges/rifles.
Click to expand...
Now i want to get a weatherby to play with !
 
Shadow9mm said:
Now i want to get a weatherby to play with !
Click to expand...
Might want to look at brass and die cost, then figure in amount of powder required per round. :eek: Am appreciative of the 257 mags capability's, but if doing over would just get a 25-06, 6.5 cm or 270 win.
 
So a weatherby has always been on my bucket list. Had some distant relatives that worked for weatherby My grandfather had weatherby rifles. However his first wifes kids got all the stuff when he passed. I did wind up with a 460 weatherby magnum dummy round from him. No powder or primer. Makes 30-06 look tiny.

I have looked into die and brass prices before. And loaded ammo will give you sticker shock. But as a reloader i think i could manage it.

Plus i wanted a mk v, and they are not exactly cheap either. I need to start putting some money back and decide on caliber.
 
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Reloader 26 with 117gr sst prints tiny little groups for me. Unfortunately those bullets dont hold together at all on deer even at 350yds. Rl26 with 101gr barnes lrx runs 3680fps and shoot just over half inch @ 100yds. Only taken 3 deer with that combo so far but I got exits on all 3.
 
All factory rifle builders put the SAAMI long throat in their .257 barrels, otherwise factory ammo is way over-pressured. I had a custom barrel built by Jarrett without the freebore, and had to reduce listed charges between 4 and 6 grains to avoid expanded primer pockets. Ken Waters did not say that factory rifles lacked the freebore in his Pet Loads article, I checked.

My most accurate loads (3/4”) in a Mk5 factory barrel are with the Hornady 120 HP bullets, sadly no longer available, seated to just fit in the magazine, and near max charges of IMR7828 with F215 primers.



.
 
TX Nimrod said:
All factory rifle builders put the SAAMI long throat in their .257 barrels, otherwise factory ammo is way over-pressured. I had a custom barrel built by Jarrett without the freebore, and had to reduce listed charges between 4 and 6 grains to avoid expanded primer pockets. Ken Waters did not say that factory rifles lacked the freebore in his Pet Loads article, I checked.

My most accurate loads (3/4”) in a Mk5 factory barrel are with the Hornady 120 HP bullets, sadly no longer available, seated to just fit in the magazine, and near max charges of IMR7828 with F215 primers.



.
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You're right , but was thinking on his article on the 270 wby made by winchester. Rechecked the article and it did not reference a shorter free bore. He did make a reference to shorter free bores by custom manufactures in a 340 wby article, with the same results you described. Good catch, and it be appreciated. Likely there are other manufacturers using wby calibers, but am not up to date.
 
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