Weatherby freebore - good or bad?

31 December 2004, 02:36

Hi,

I just bought a new factory Weatherby 340 barrel for the Mark V action I bought a while ago.

What are the implications of the Weatherby freebore concept? Does it result in accuracy problems? Any benefits what so ever?

31 December 2004, 02:37

Bobby

There's been so much cussing and discussing this feature of Weatherby that it's hard to keep up with it.
Some Weatherby's shoot really, really well and other don't, just like any other gun. I think we can conclude from that, that freebore is not all together a bad thing. I think it is used to lower pressures and keep reloaders out of trouble, to a certain degree.
My personal theory is that if the freebore is bullet diameter or close, accuracy can be very good, as alignment is assured. If it's much larger than bullet diameter, then the bullet has the chance of entering the rifling crooked, thus poor accuracy. Also, the beginning of the rifling has some play it this too, a coned or ramped rifling is more likely to help with bullet alignment than an abrupt transition, which might help cock the bullet.

In the end, shoot it, if it's accurate, cool. If not it's trading fodder.

31 December 2004, 02:37

Mike375

Bobby has it in one...freebore diamter.

Consider that HS Precision guarantee half inch grouping in their 30 calibre and down rifles and 1 inch for above 30 calibre and they chamber for all the Wby calibres.

Mike

31 December 2004, 02:37

338Lapua

Bobby,

I think you hit the nail on the head. I reload and hunt a little different than most folks. I only load one round in the chamber and one in the mag. The use of the feed ramp allows more room for COL. Since I'm not concerned with factory or manual COL I tend to have pretty good luck with Weatherbys. The worst two I have had have both been the UL models.

FWIW,

Jim

31 December 2004, 02:37

vapodog

Quote:

Does it result in accuracy problems? Any benefits what so ever?

Opinions.......
First of all I have never seen any conclusive data that it hurts accuracy. We have scores of folks that try to handload .001 off the lands for accuracy....and it might be true that it yields a trifle bit of accuracy but we're talking hunting accuracy here....not bench accuracy.

I intentionally freebore even the .375 H&H and they seem to shoot very well anyway. If the rest of the rifle is properly made (and Weatherby does have some trouble here) it will shoot very well.

The benefit is that it lowers pressures.....well not exactly...it allows for more powder because the extra freebore volume acts to increase the boiler space. Supposedly this yields increased velocity. (any bets??)
This too is in doubt in my mind.....same as the "improved" cases.....very little gains for the extra!!!``````

IMO the entire issue of "freebore" is way overworked.

Install the barrel, glass bed the action, install cross bolts and free float the barrel and go shooting. The issue of freebore may actually be more marketing than real and I'd guess that it's at least as emotional as it is real.

Careful now.....I'm not talking about the potential of shooting factory Weatherby ammo in a custom chamber that IS NOT freebored!!!