FREEBORE ON WEATHERBYS

[littletoes]

As an update to my earlier posting, I was able to get groups to under 1" at 3150 fps using 200 grain SMK's with very slight pressure signs, so to do just the opposite, I slowed them down. Now at 2825 fps with the 200 grain SMK's I am getting cute little "tight" clover's. Easily covered with a dime at 100 yards. Haven't had time to try at 200 and 500 yards to start.

 

[VinceMule]

I have had a number of custom barrels installed on Mauser, Model 70, one savage, and several Remington 700's in 257 Weatherby with zero freebore to .030 freebore, and still have the reamer for .030 freebore.

Accuracy with these short freebore chambers is 3/8" and less with the 85-87g bullets at 4100, 100g at 3850, and 115g at 3600. Quick and easy load development with R#22 and fed 215's. One 12T, 30" hart barrel produces 4000 fps shooting groups in the high 2's with Sierra match 100g, rock chuck rifle.

All deer shot with the 100g die at bullet impact, laying in their tracks. With a good muzzle break, you see the bullet impact on the animal, water vapor flying off the hide, bullet impacting behind the animal after a pass through.

12T hart, 30" is up next to shoot the 80g TTSX, got the barrel on a screaming deal.

 

[Tiny Tim]

20 year old thread

 

[Rich Coyle]

I'll probably stir up some stink but here goes- freebore is generally not good for accuracy. I believe Weatherby does it because they think it increases velocity. Which in actually decreases it- the "open" area (freebore) could allow gas to escape around the bullet and decrease pressure thus decreasing velocity.
The reason this is bad for accuracy is the bullet slams into the lands and can cause the bullet to deform unevenly- canting it in the bore. As the benchrest boys have shown us most bullets shoot the best either in three positions: 1-Barely off the lands, 2- Lightly touching them, or 3-Seated firmly into the lands. When bullets are seated like this they are "pushed" into the lands, hopefully engraving straight and true with the bore.
But to further confuse the situation, I have a Howa factory rifle in .223. For those of you who don't know, Howa made actions for Weatherby for awhile. My Howa has an incredible amount of "freebore." Using the Stoney Point OAL guage and a 55gr Sierra BlitzKing to find the lands, I dicovered that left only the boattail of the bullet in the case neck. Seating the bullet as far out as the magazine would allow the bullet was over .100 away from the lands. The whole point to this windy story is the silly thing is a solid 1/2 MOA rifle and I regularly shoot prairie dogs out to 500 yards with it. So go figure!
To sum it up- shoot your rifle at different ranges and let it tell you if it's accurate or not.
Hope I didn't make it worse....

[ 07-14-2002: Message edited by: chris matthews ]

This is a hunting sight.

What I read here is theory over real world experience.

I had a Mark V that would put five of my Corbin home made bullets into 1/2" at 100yds regularly. Also when it was rebarreled to .340 it would put three 250 grain Sierras in 1" or better any time.