Considering .300 Wby without freebore

[Delta Hunter]

I've got a Sako 75 chambered for .300 Weatherby. I'm thinking of having it rebarreled by Pac-Nor to one of the following chamberings: .300 Win, .300 RUM, or .300 Wby without the freebore. I would like to know if anyone has any experience with the .300 Weatherby without freebore. I want to be able to play with seating depth and you can't with a standard .300 Wby. Do you have to back off the powder charge and how much does velocity suffer if you do? Is there a potential accuracy advantage without the freebore? The reason I'm thinking of staying with the .300 Wby is because I won't have to buy new dies or brass. I must admit, however, the .300 RUM ballistics look mighty attractive.

 

[Darryl Cassel]

Hello Delta

I have had and still do have several 300 Weatherby rifles mostly for 1000 yard match shooting.
Most free bore rifles such as the factory Weatherby 300s are not very accurate at all.

You change the velocity that's lost from eliminating free bore, by going to a few more inches of barrel length. That is the equalizer plus you will have much better accuracy then the factory chambering that has free bore. With freebore your "jumping" the bullet into the lands and that is where you lose accuracy. Most rifles fire much better when the bullets are NO MORE then .055" off the lands. A soft touch into the lands seems to work very nicly.


With the standard factory Weatherby, it sometimes seems like you can't get the bullet closer then 2 feet from the rifling. Just some humor here on that last statement.
Freebore and excessive velocity== poor accuracy.

Darryl Cassel

 

[Boyd Heaton]

I shot a stock Sendero in 300 Ultra last year.It is possible to get velocity in the mid to high 3400fps range with a 180gr bullet.I have also ran a 220gr MK to 3100fps.But that was a VERY HOT LOAD....

 

[Delta Hunter]

Thanks a lot Darryl. Is there a general rule of thumb for how much to back off the powder charge in a non-freebored .300 Weatherby? For instance, my favorite load with 165 grain Hornady SST's is 87 grains of IMR 7828. Would I have to cut back to, say, 84 or 85 grains? Do you have any personal favorite loads you would be willing to post?

 

[Guest]

I have a 300wby short thoat with a 28" hart barrel. Im currently shootin 86gr H1000 with a 178 AMAX and that is just about top end.