Weatherby rifle no free bore.

[rp85]

good morning;

Anyone shooting a Weatherby Magnum rifle without free bore? Trying to get feedback from others with same situation I have with this rifle.

Back ground. Purchase a custom 375 Weatherby Magnum rifle several weeks ago. Rifle has no free bore at all. Free bore spec is .373”. Original owner passed many years ago.

Plans are to shoot only cast bullets in this rifle. Rifle shooting 1” or less with cast bullets at 100 yds. Became concerned how deep to seat cast bullets, Lee 375-250 & Lyman 375 cast. Case mouth extends past the ogive of bullets, only way I'm able to close bolt. All cases are trimmed to spec.

Asked gunsmith to check rifle because of bullet length required to close bolt. Gunsmith express concern shooting Weatherby jacketed bullets ammo in this rifle. Said I should never shoot Weatherby loaded ammo in this rifle because the risk of extreme high pressure with no free bore in the barrel.

Ordered a .373” 4D throat reamer and ask gunsmith to cut throat adding .225" free bore. That length is based on a master dummy round long enough to seat bullet below ogive of bullet, enough to bump into rifling, and still able to close bolt.

Thx for any input.

rp

 

[themcfarland]

wonder if it was set back or if they cut it wrong. I agree it would likely lead to high pressures if loading to length.
Interesting.

 

[Akajun]

You can order reamers with no freebore, some people like to cut the freebore themselves to a certain length not saami
That may be what’s going on here

However first thing I would do is a chamber cast of the barrel including the throat area to confirm that .
Remember cast bullets don’t have the ogive jacketed bullets do. If it has a short throat that may be your issue
Easiest way to fix it is with a uni throaterfrom ptg but a throating reamer will work

 

[highstandard40]

NOE makes sizer dies to size the nose of the cast bullet. I would use this approach before I'd ream the chamber. This is what I do with all my cast bullet rifles. I size to get the bullet nose to become a slip fit into the rifling. Accuracy usually improves.