7mm x 300 Weatherby

[autodafe]

I shoot a 7mm x 300 Weatherby. I've searched far and wide for data on loads for this wildcat. Unfortunately, very little information is available through online and other sources.
My rifle is built on a Rem 700 action. It has a 28" Shillen barrel, Kanjar trigger, McMillan stock, etc. I shoot 160 gr Barnes TSX bullets (a hunting round) in a load consisting of 77 grs of H1000 and a Fed 215 primer. This particular load is very accurate and absolutely lethal on game. In arriving at this load, I used data for the 7mm STW and made adjustments.
Does anyone have data on this wildcat or know of sources from which I can obtain reliable data?
Thanks.

[spurly]

you are right there is very little datta ,you may be able to also look at datta from the 7rum or dakota all depends if they have the same case capacity.

[JohninAB]

You can try www.reloadersnest.com if you have not already tried there.

[elkhunter11]

The 7mmstw has almost the same case capacity.I would try 7mmstw starter loads and work up from there.

[eric2381]

To go a bit further on the Reloaders Nest link http://www.reloadersnest.com/frontpa...?CaliberID=240

Good luck to you, Eric

[duffy4]

Many shooters believe the 7mm Weatherby Magnum was introduced around 1944 but this is unlikely since, unlike the .220 Rocket, .270 Magnum, and .300 Magnum, the 7mm didn't start appearing in Weatherby advertisements in the "American Rifleman" until the early 1950's. Some shooters also believe the 7mm has always been one of Weatherby's most popular cartridges but this isn't true either. Roy's 7mm enjoyed only mild popularity among American hunters until Remington introduced its 7mm Magnum in 1962. But then, the same can be said of any other 7mm cartridge. The case capacities of the 7mm Weatherby and the 7mm Remington magnums are close to the same, but freebored chambers in the Mark V rifles allows the Weatherby cartridge to be loaded with slightly heavier powder charges. This, however does not apply to custom rifles with chamber throats of standard length. The freeboring of rifle chambers has long been a controversial subject. Some say higher velocities can be reached while others say its not worth the effort. The fact that the 7mm Weatherby Magnum cartridge produces about 100 fps more velocity than the 7mm Remington Magnum probably proves who is right and who is wrong. Actually, choosing between the two is more of a case of rifle preference than any practical difference in cartridge performance.

I would think loading data for the 7mm Weatherby mag would be a good fit!!!

But then what do I know, I cannot understand with a 7mm Weatherby mag. in existance why anyone would make a wildcat 7mm/300 Weatherby. To me it is like a blond dieing her hair blond.

Robin in Rocky

[Homesteader]

Originally Posted by duffy4

But then what do I know, I cannot understand with a 7mm Weatherby mag. in existance why anyone would make a wildcat 7mm/300 Weatherby. To me it is like a blond dieing her hair blond.

Robin in Rocky

It's a big difference, as the 300 Weatherby case is a fair chunk larger than the 7mm Weatherby case. There's no replacement for displacement.

[elkhunter11]

Many shooters believe the 7mm Weatherby Magnum was introduced around 1944 but this is unlikely since, unlike the .220 Rocket, .270 Magnum, and .300 Magnum, the 7mm didn't start appearing in Weatherby advertisements in the "American Rifleman" until the early 1950's. Some shooters also believe the 7mm has always been one of Weatherby's most popular cartridges but this isn't true either. Roy's 7mm enjoyed only mild popularity among American hunters until Remington introduced its 7mm Magnum in 1962. But then, the same can be said of any other 7mm cartridge. The case capacities of the 7mm Weatherby and the 7mm Remington magnums are close to the same, but freebored chambers in the Mark V rifles allows the Weatherby cartridge to be loaded with slightly heavier powder charges. This, however does not apply to custom rifles with chamber throats of standard length. The freeboring of rifle chambers has long been a controversial subject. Some say higher velocities can be reached while others say its not worth the effort. The fact that the 7mm Weatherby Magnum cartridge produces about 100 fps more velocity than the 7mm Remington Magnum probably proves who is right and who is wrong. Actually, choosing between the two is more of a case of rifle preference than any practical difference in cartridge performance.

All of which is totally irrelevant,since the poster is seeking loading data for the the 7mm-300wby.

I would think loading data for the 7mm Weatherby mag would be a good fit!!!

Actually,it would be a very poor fit,given the large difference in case capacity between the 7mmwby,and 7mm-300wby.

The commercial cartridge with the closest case capacity and ballistics to the 7mm-300wby,is the 7mmstw.In fact the case capacity and ballistics are nearly identical.

[Pathfinder76]

Originally Posted by duffy4

I would think loading data for the 7mm Weatherby mag would be a good fit!!!

But then what do I know, I cannot understand with a 7mm Weatherby mag. in existance why anyone would make a wildcat 7mm/300 Weatherby. To me it is like a blond dieing her hair blond.

Robin in Rocky

[autodafe]

Originally Posted by elkhunter11

The 7mmstw has almost the same case capacity.I would try 7mmstw starter loads and work up from there.

Thanks for the advice. I did use 7mm STW data to develop some loads. Unfortunately, I have experimented only with one bullet weight and powder type. I need to devote some time to developing other loads.

[Anglo]

7MM X 300 Wby. Mag.?? I love it. But of course, I am old fashioned as well.
Back in the 70's and earlier, we, shooters, did a lot of wild cating. I don't remember what years it was but a woman won the Wembledon match with a
7X700 Wby. and so I tried it as well. First was on a Ruger No. 1 which started out as a 25-06. Rebarreled it with a 24" SS Scheilen barrel and a Canjar single set triger. Canjar single sets were the best. Anyway, I mounted a Weaver 20 X to start with with and using 160 grain Sierra Match bullets in front of 87 grains of H870 we chronographed the load at 3400 fps at 5000 ft. altitude. I was killing oil cans at 1000 yards. Recoil? I don't have a problem with recoil as I used to shoot a 375 H&H in a No. 1 Safari grade Ruger. Very accurate cartrige the 375 is. Any way, reloading the
7MMX300 isn't a problem and as far as I am concerned, worth the time. I now shoot the same cartrige in a Browning Eclips along with one in
300 Win. mag. Very accurate platform and with 190 grain match and a 20 mill slope on the scope ramp with an IOR Tact. scop, 1,800 yards is not a problem. The Browning is very accurate in both the 7MMX300 and 300 Win.
Excellent rifle.
I'll stick with my elk gun either for tactical or elk in the 7X300 Wby.

[double gun]

Originally Posted by duffy4

Many shooters believe the 7mm Weatherby Magnum was introduced around 1944 but this is unlikely since, unlike the .220 Rocket, .270 Magnum, and .300 Magnum, the 7mm didn't start appearing in Weatherby advertisements in the "American Rifleman" until the early 1950's. Some shooters also believe the 7mm has always been one of Weatherby's most popular cartridges but this isn't true either. Roy's 7mm enjoyed only mild popularity among American hunters until Remington introduced its 7mm Magnum in 1962. But then, the same can be said of any other 7mm cartridge. The case capacities of the 7mm Weatherby and the 7mm Remington magnums are close to the same, but freebored chambers in the Mark V rifles allows the Weatherby cartridge to be loaded with slightly heavier powder charges. This, however does not apply to custom rifles with chamber throats of standard length. The freeboring of rifle chambers has long been a controversial subject. Some say higher velocities can be reached while others say its not worth the effort. The fact that the 7mm Weatherby Magnum cartridge produces about 100 fps more velocity than the 7mm Remington Magnum probably proves who is right and who is wrong. Actually, choosing between the two is more of a case of rifle preference than any practical difference in cartridge performance.

I would think loading data for the 7mm Weatherby mag would be a good fit!!!

But then what do I know, I cannot understand with a 7mm Weatherby mag. in existance why anyone would make a wildcat 7mm/300 Weatherby. To me it is like a blond dieing her hair blond.

Robin in Rocky

[walking buffalo]

Thanks Duffy,

So, I can use 7x300 cartidges in my Mark V 7mm mag or 7x300 mag, and by the same logic, in the 300 mag? Great news, this will save me a pile of loading time!



Autodafe,

If you still check out the forum, send a pm. I use Norma cases, and have a recipe for 160 accubond and H1000 that's a little more robust than 77 grains. Best groupings I've ever had.

[Alaska_Man]

I have a detailed thread on this cartridge with pressure traces for various loads.
-AM

https://www.shootersforum.com/wildca...s-7mm-stw.html