FREEBORE ON WEATHERBYS

[Nighthawk]

I was told by the creator of the .408 that 8-% of a rifle's accuracy is in the bullet. Yuor rifle should be very though.

[littletoes]

I called Weatherby and asked. I told them I was having problems with SMK's 200 grain in a 300 Wby Mag making anything less than a 3" group. I would get a couple touching, then a really nice "flyer" that helped open up groups. How nice. Had a severe problem with velocitys bouncing around also. They said to try flat bassed bullets, and there was no way possible that the problem could be associated with their free-bore. I also called Sierra, and they told me to try hotter loads. Alliant said it might be the primers, not the powder(R 25). I have tried flat bassed bullets and have shot some nice groups with them. But, Still trying with the SMK's! Possibly its that some companys have trouble changing, regardless if it might be the right thing to do. Us Americans are famous for that! (metric system for example) Good luck! littletoes.

[Delta Hunter]

I own a Sako 75 chambered in .300 Weatherby. It has the freebore, but apparently it's not a detriment to accuracy, because this is the most accurate rifle I own ( All my rifles are bedded, but other than that I don't own any custom jobs). I've tried various seating depths and have achieved the best accuracy with bullets seated deeper rather than shallower. When I seat bullets out as far as the magazine will allow, accuracy gets a little worse, but more importantly, I start noticing some signs of increased pressure when using maximum loads.

The statement regarding flat based bullets being more accurate in the .300 Wby seems to be true for my particular rifle. I recall one day shooting 6 three shot groups using the 180 grain Speer Grand Slam, which is a flat based bullet, atop some IMR 7828. Maybe I was just having a great day, but all six groups measured less than 1/2". The very first group made one hole that measured about .15" as I recall.

You're simply going to have to shoot that rifle with various loads to see if it's capable of good accuracy. But one things for sure, freebore does not automatically guarantee less accuracy.

[bill morris]

Chris Mathews cogent reply to Light em ups query,I have gone and figured quite a bit about factory rifles and seating out to the lands,Oh the botheration,magazine too short,rounds made about 0001"out of true are way crooked once cycled thru the action,and hell and damnation a bullet sticking in a hot barrel at a crucial moment.If your chamber is true to the bore of your rifle and you work your fired brass to keep the bullet looking straight up the bore very good accuracy can be acheived even with "short"rounds.I do not think ammo made like this would be any use to a benchrest shooter or a long range hunter but it can be way good enough for most "hunting" situations.Bill Morris

[LDHunter]

I've had a Mark V Synthetic chambered in 30-378 for several years and have found that it's just as accurate as most of my production target rifles.

Seating a bullet to touch the lands is highly overrated unless you are a benchrest competitor.

Also it necessitates a lot of extra care in loading that is not needed for "regular" hunting or Long Range Hunting.

Ignore the freebore issue and concentrate on bullet and powder selection. Then if it won't shoot... Dump it....

$bob$ [img]images/icons/grin.gif[/img]

[light em up]

Thanks for the info fellas. Just to update on my issue. 101.5 gr of reloader 25 & 180 gr. X bullet b.t. seem to have solved my problem. Its shooting under .5 M.O.A. now. I feel much better. Its gonna be a good fall.

[DANTEC]

free bore on Weatherby came to solve the problem of powder burning rate in the 50's and 60's there is "gap" in burning rate powder from the slowest available in rifle rate as 4831 powder and the very slow powders of 50 BMJ

to try to keep pressure level acceptable ( pressure increase when bullet force in grooves that name ingraving force in internal balistic and this is because when load are in the land pressure are highter tahn with same load of the land ) and get "Weatherby" velocity , deep free bore help to don't rise the pressure curve over safety level with powder burning rate fast ( for the use )

that because after Norma have develop the MRP powder ( specialy design for Weatherby case load ) and now most company have fill the gap between 4831 and 50 BMJ powder ( H1000 , IMR 7828 , RETUMBO , RL22 and RL25 , VITA N165 and N170 ... )

If you check other caliber European you can see that old calibers ( 7x64 6.5x55 .... ) have very deep throat for the same problem of powder ( design in the beginning of the 20° century ).
I have own a 6.5x57 Zoli rifle ( very inaccurate gun ) with a free bore so deep that a 155 SMK seat out doesn't sucess to touch the grooves .....and CIP chambering are not the best in accuracy ...

flat base are more accurate because they are longer on drive band ( cylindral part of the bullet ) and stay more longer in the neck before to reach ( at least ) the grooves .

so Weatherby rifle are not target rifle and this is not the way to try to compare Hunting rifle accuracy to match/target/BR rifle accuracy .

By tuning the load and good powder they can get good accuracy and far enought to take game .

Good shooting

DAN TEC