Need help with my 257 wby and pressure issues.

[Trm82]

Hello all !! So I bought a barely used Remington 700 with a premium barrel (not sure the maker ) and when I first got it the gun had nowhere near the freebore that Weatherby should have.
I tried a few factory ammo through it and they were over pressure and did not group well.
Factory 100 gr scirocco were 3690 fps and the advertised fps on the box says 3575 fps I believe and after just one firing the brass was toast.
So I took it back to where I bought it from and they added some more freebore for me free of charge.
I tried the factory 100 gr scirocco again and they grouped 1" and 200 yards but still over pressure and still 3690 fps.
My goal with this gun was to shoot 100 ttsx with RL 26. I have a buddy that shoots that combo in a WBY MK5 ultra light and is a hair over 3800 fps with no pressure and his load is 75 gr of RL26.
So I started my loading at 72 gr and had lots of pressure there well over 3600 fps.
So I loaded them back up at 70 gr and tried again and same thing lots of pressure and still over 3600 fps.
So I went out yesterday and tried again. This time I started at 66 gr of RL 26 and my first shot was 3460 fps then second two shots were both over 3600 fps with heavy bolt list and scared up the brass.
I'm seating these 100 ttsx at 0.080" off but for the life of me I can not get this gun to shoot with out pressure and I'm almost to the point of scraping the barrel unless someone has any idea of what is going on. I've always wanted a 257 wby and this gun is beautiful and now in Canada our dictator has some what of a registry which this one would have been under the radar so I won't be buying anything new and just playing with the rifles I have or buying used.
Should scap the barrel and start fresh , seat them deeper , different powder ?
I've never had issues like this ever before in my life.
Sorry for long winded post !!

Here's a pic of the gun and my three brass from 66 gr of RL 26

this is before the freebore was added touching the lands

this is the 3 shots from 66 gr

this is after freebore added 100ttsx seated 0.080" off.

this is the rifle

 

[Elk Hunter 338]

try h1000 or retumbo
what barrel , neck dia, etc

 

[Trm82]

try h1000 or retumbo
what barrel , neck dia, etc

I know no details on the barrel other than it's a 26" 10 twist and the shop I bought it from are the ones who built the rifle for original owner and they said it could be a pacnor barrel but were not sure.
I do have retumbo though I could try it and see what that does.

 

[Dmagna]

3600-3700 is pretty normal. I shoot mine right at 3600 with the LRX and 3650 with the TTSX. And that pushing the weatherby brass pretty hard. I don't get many reloads. I am at 71.3 grains of N565, maybe you have a barrel that needs some fire lapping. I have had barrels that need to have some carbon in them or show crazy pressure until they get broken in. Are you shooting a clean barrel?

 

[Dmagna]

Also check your case length, that weatherby brass grows fast.

 

[Trm82]

3600-3700 is pretty normal. I shoot mine right at 3600 with the LRX and 3650 with the TTSX. And that pushing the weatherby brass pretty hard. I don't get many reloads. I am at 71.3 grains of N565, maybe you have a barrel that needs some fire lapping. I have had barrels that need to have some carbon in them or show crazy pressure until they get broken in. Are you shooting a clean barrel?

I've cleaned it once really well since I got the gun and have put maybe at the most 60 shots thru it.
The factory ammo shoots great but the primer pockets are maybe good for one more firing after the first shot.

 

[Trm82]

Also check your case length, that weatherby brass grows fast.

I've been trimming to a bit under the book spec for length.

 

[Dmagna]

I've cleaned it once really well since I got the gun and have put maybe at the most 60 shots thru it.
The factory ammo shoots great but the primer pockets are maybe good for one more firing after the first shot

After cleaning my barrel with copper remover I had to load up some low pressure loads to get some carbon in the barrel or else I would almost instantly copper foil the barrel. After it was fouled it would just ruin brass. I do this will all my rifles now, helps a lot.

 

[Lee7588]

I shoot a Weatherby vanguard sub moa my loads for it using 100 GR tsx over 72 gr 7828 ssc moving at 3550 fps. If you have the powder then it will give you something else to try shooting

 

[Trm82]

I shoot a Weatherby vanguard sub moa my loads for it using 100 GR tsx over 72 gr 7828 ssc moving at 3550 fps. If you have the powder then it will give you something else to try shooting

I have IMR 8133 , retumbo , RL 23 , RL26.
I'm debating on getting rid of gun and putting a proof research 30 cal 1-8 twist on my Rem 700 300 ultra.
My 270 wby Mcwhorter does what the 257 will do so I wouldn't miss it to bad. I'm shooting 110 ttsx in it at 3730 fps.
The 257 is such a beautiful rifle I hate to get rid of it

 

[Lee7588]

I have IMR 8133 , retumbo , RL 23 , RL26.
I'm debating on getting rid of gun and putting a proof research 30 cal 1-8 twist on my Rem 700 300 ultra.
My 270 wby Mcwhorter does what the 257 will do so I wouldn't miss it to bad. I'm shooting 110 ttsx in it at 3730 fps.
The 257 is such a beautiful rifle I hate to get rid of it

I have IMR 8133 , retumbo , RL 23 , RL26.
I'm debating on getting rid of gun and putting a proof research 30 cal 1-8 twist on my Rem 700 300 ultra.
My 270 wby Mcwhorter does what the 257 will do so I wouldn't miss it to bad. I'm shooting 110 ttsx in it at 3730 fps.
The 257 is such a beautiful rifle I hate to get rid of it

I love the round, I had looked at buying a hill country that was in 257 wby I kick myself for not buying. It is nice to have the 270 wby option that out performs the 257 though. But you can never have to many guns lol

 

[Trm82]

I love the round, I had looked at buying a hill country that was in 257 wby I kick myself for not buying. It is nice to have the 270 wby option that out performs the 257 though. But you can never have to many guns lol

I concur !! Never to many guns.

 

[Quintus]

You may have the perfect barrel for Hammer Absolutes. They are slow to start pressure and usually require faster powder. You may have a gem there.

 

[Dr. Vette]

Silly question - have you tried any factory ammo to see if the same thing happens?

And did they re-do the chambering to the correct freebore specs as per Weatherby?

Generally, if the freebore is done per spec it's a waste of time to measure it on a Weatherby chambering. Seat to just shy of mag length, and shoot. 1/2 to 1 groove of the Barnes showing is about right.