Does anyone know how long the Weatherby factory freebore is compared to other manufacturers?

Thanks,

Dan

Longer. You can look up the SAAMI specs & find the details.

The guy at Pac-Nor quoted me 1 caliber freebore (for a 378). He said they used to be 2 calibers but accuracy suffered.

I'd be a little wary of 1 diameter using factory cartridges. 2 diameters isn't bad if the throat diameter is tight enough to guide the bullet straight in. Some of the old Apollo wildcat cartridges required as much as 3 diameters. Again, a tight enough throat, no problamo.

This is what Weatherby lists on their website as to the freebore for each of their Cartridges.

Cartridge Throat length (free bore)
.224 Weatherby Magnum .162
.240 Weatherby Magnum .169
.257 Weatherby Magnum .378
.270 Weatherby Magnum .378
7MM Weatherby Magnum .378
.300 Weatherby Magnum .361
.340 Weatherby Magnum .373
.375 Weatherby Magnum .373
.378 Weatherby Magnum .756
.416 Weatherby Magnum .239
.460 Weatherby Magnum .756
.30-378 Weatherby Magnum .361
.338-378 Weatherby Magnum .361

http://www.weatherby.com/support/faq/item/view/44332

all of the AccRels have "too much" freebore... and most guys are getting submoa out of them.

taper matters!

quote:

Originally posted by jeffeosso:
taper matters!

Alignment matters.

The lengths listed by Weatherby are the total length of the throat. Years ago, they bragged about their freebore and at times quoted the incremental length above standard chamberings. With the longer ones, you can't seat to reach the rifling. If I remember, the 240 was the first chambering, followed by the 224 which had a normal throat.

I didn't realize that the 416 had such a short throat. I suspect that they realized the case was so overbore (same as the original Rigby) that loads would get painful before pressure became a problem, so they went for accuracy.

Thanks for all the help! The freebore in my Sako rifles was much longer than I expected and wanted some basis for comparison......

Cheers,

Dan

European rifles in general, have longer throats, and greater free bore, than what American manufacturers use.

They tend to use heavier for bore bullets than we do.

As was posted above: alignment matters more than the actual free bore length. I have owned a bunch of Sako rifles over the years. They were all as accurate as my ammunition was straight.

The clue bird finally landed on my left shoulder when I began using L.E. Wilson seater dies. My cartridges became much straighter from stem to stern.

When I have had barrels reamed with standard factory Weatherby dimensioned reamers, the accuracy has usually been .75 MOA for three rounds (Sporters), or .75 MOA for five or more rounds (varmint rigs).

I have always used modern Weatherby pattern reamers. I will never know what ammunition will be used in those rifles after I am gone. I do not want someone putting in factory ammo to a barrel that did not have a free bore - Yikes!