reducing freebore in a 300 Weatherby

[Hopkins]

I have a 300 Weatherby Model 70 PF that has the normal .361 freebore.I have gone as far as I can otherwise trying to get it to shoot well. I am considering pulling the barrel and setting it back .250 for a .111 freebore. This gun will never see factory ammo again so that isn't a concern. Anyone have any experience good or bad with a similar project?

 

[Ggmac]

How many rounds thru it ? What is your accuracy goal and what does it shoot now ?

 

[savagedasher]

My experience with short free bore was I lost 100 FPS and it didn't shoot better. Winchester's have never ben know to have great accuracy. I never could shoot a Weatherby load without big pressure signs. Mine was a re barrel with a good aftermarket barrel. When I put the free bore back in it shot the same 1/2 '' as it did without it being there.. Larry

 

[Hopkins]

The round count through the barrel is 125-150. It shoots long bearing surface 180 Fb's best at moderate velocities( 2750-2800fps) near 1 MOA average at 100 yards. Those have to be seated out as far as possible.

 

[savagedasher]

The round count through the barrel is 125-150. It shoots long bearing surface 180 Fb's best at moderate velocities( 2750-2800fps) near 1 MOA average at 100 yards. Those have to be seated out as far as possible.

Put a good barrel on it and keep the long free bore. Mine shoots 3030 FPS with 180gr bullets in1/2'' 3100 it still is a one inch gun. Larry

 

[butchlambert]

If you are setting it back, do you have the proper chambering reamer to do your rechamber. It is a hunting rifle, other than shooting paper what animal requires more accuracy?

 

[Hopkins]

I wouldn't attempt to set it back without a proper reamer. My guess is the freebore greatly contributes to the lack of accuracy.I opened the thread to see if anyone had made a similar modification and had a good result. I'm sure there are 300 Weatherby rifles with .361 of freebore that shoot sub MOA with a wide range of loads but this isn't one of them. If the rifle can be improved to a consistent sub MOA performer it would be put to use on big Carolina bean fields for white tails.

 

[JRS]

I recently had the gunsmith I use to build a 257 Weatherby for me. I went with .090 freebore.

 

[savagedasher]

I recently had the gunsmith I use to build a 257 Weatherby for me. I went with .090 freebore.

Start low and watch for pressure. Larry

 

[JRS]

I recently had the gunsmith I use to build a 257 Weatherby for me. I went with .090 freebore.

Start low and watch for pressure. Larry

Don't need to. This isn't my first Weatherby with less than factory freebore

 

[Hopkins]

A 300 RUM has .110 freebore so my thought was to set back the barrel and load and test with rounds that have less than a .300+ jump.
Just using the .300 RUM as a reference point of an overbore cartridge with less than a Weatherby's freebore.

 

[savagedasher]

I recently had the gunsmith I use to build a 257 Weatherby for me. I went with .090 freebore.

Start low and watch for pressure. Larry

Don't need to. This isn't my first Weatherby with less than factory freebore

With that in mind 71.8 gr of H 1000 and 115 Berger hunt VLD. should work. Larry

 

[watercam]

You COULD use a monolithic bullet as they like being jumped more than conventional jacketed lead bullets. Barnes LRX for example...

 

[tclaunch]

I have a 300 Weatherby Model 70 PF that has the normal .361 freebore.I have gone as far as I can otherwise trying to get it to shoot well. I am considering pulling the barrel and setting it back .250 for a .111 freebore. This gun will never see factory ammo again so that isn't a concern. Anyone have any experience good or bad with a similar project?

I was approached by a guy wanting to build a 270 Wby with all new components, I agreed on 1 condition, to order a reamer to my specs for the job. He agreed, so I asked what bullet he wanted to shoot and we sent a sample round to JGS with 140 Accubond seated properly. That reamer came back, the barrel got chambered and am hearing glowing reports from him on groups out to 500 yds, very pleased. Freebore make a lot of difference. You are on the right track. I would also urge to replace the barrel.