257 WBY Pressure/accuracy question

[rcol317]

I posted this question on other sites and am anxious to get some feedback.

Was helping a friend that is just getting into reloading and was having accuracy problems. I've loaded for 40 plus years and am puzzled. He's shooting 115 VLD's and @ 100 yards and 200 yards is getting 1 1/2 MOA groups but @ 400, 500 and 650yards is getting 1/2 Moa accuracy. at 650 yards 3 shot group can cover with a coffee cup? I shot the load and found he is WAY over loaded for pressure and will need to back off the load quite a bit. When I asked him how he came up with load he said "just kept adding .5 grains until is shot well. Lucky is a high dollar custom rifle the action held together. Note: PRINTED LOAD DATA IS IMPORTANT

I was stumped why it didn't shoot well 100/200 but shoots well @ 400 yards plus?

Thanks Rick

 

[HARPERC]

Use the search bar in the upper right hand corner, and enter Applied Ballistics Shoot Thru Target Challenge.

A good thread, current and pretty credible folks trying to answer the same question.

 

[rcol317]

Thanks for the suggestion! I've loved reading Brian's articles over the years he definitely has the ability to scientifically address question. After reading the thread I think its a parrelax issue. The side focus knob on the scope was goofy and came out of adjustment with the recoil of each shot. thank's again for the heads up on Brian's thread. Rick

 

[scottishkat]

I posted this question on other sites and am anxious to get some feedback.

Was helping a friend that is just getting into reloading and was having accuracy problems. I've loaded for 40 plus years and am puzzled. He's shooting 115 VLD's and @ 100 yards and 200 yards is getting 1 1/2 MOA groups but @ 400, 500 and 650yards is getting 1/2 Moa accuracy. at 650 yards 3 shot group can cover with a coffee cup? I shot the load and found he is WAY over loaded for pressure and will need to back off the load quite a bit. When I asked him how he came up with load he said "just kept adding .5 grains until is shot well. Lucky is a high dollar custom rifle the action held together. Note: PRINTED LOAD DATA IS IMPORTANT

I was stumped why it didn't shoot well 100/200 but shoots well @ 400 yards plus?

Thanks Rick

What load is he shooting? How are you determining pressure stiff bolt lifts? Its not uncommon for people shooting weatherby rifles over max especially with the 115 vld and berger data. Regarding shooting better at 500 than at 150 that's not totally uncommon either the bullet can stabilize better at extended range after losing some velocity.

Shoot straight especially with the 257 wby.

Bob

 

[AZShooter]

Bob,

You need to read Bryan Litz's recent thread called the applied ballistics shoot thru target challenge.

Bryan discusses why the bullet is not the reason for tighter groups at longer distances.


http://www.longrangehunting.com/forums/f19/applied-ballistics-shoot-thru-target-challenge-144359/

 

[scottishkat]

Bob,

You need to read Bryan Litz's recent thread called the applied ballistics shoot thru target challenge.

Bryan discusses why the bullet is not the reason for tighter groups at longer distances.


http://www.longrangehunting.com/forums/f19/applied-ballistics-shoot-thru-target-challenge-144359/

Thanks I'll check it.

 

[rcol317]

Bob, the article is well worth the read. I agree that weatherby shooters push loads because of the confidence of 9 lugs on the bolt. This is not a weatherby rifle but a custom action and the load was determined to be well over the max. (Many grains over). The load was shooting 250/300 fps over the max I can find published. Thanks for the post. Rick