Resizing 30.378 weatherby down to 7mm or 8mm

[436]

Why stop at 8mm, .338 or .350 might be more fun.

 

[JamesWilson5]

Well I have the 338 378 weatherby so I kinda thinking they have a 284.338 caliber why not get in the middle I have to 8 mm remington mag awesome very underrated I have all the rums except 375 and all the weatherby from 257 up to 375 and 378 above just thinking about something new I'm getting good velocity with the 8 but they have 28 in barrel. I was thinking about 30 inch barrel but need the case compacity that's where the 378 case comes into place slow burning powder and long barrel with added case compacity. Equals extra velocity alot more cause I'm already getting well over 3300+ fps whith what I have with 180 grain bullet not going to say exactly what I'm getting but it will make a 300 rum have to watch it pass by with great accuracy

 

[jessej]

I believe Swamplord is working on something with these.
I speculate you'd get 3300 out of a 30" tube on a 378 way case withum

 

[jessej]

not going to say exactly what I'm getting but it will make a 300 rum have to watch it pass by with great accuracy

Now now. Let's not go that far

 

[Bghunter338]

I believe Swamplord is working on something with these.
I speculate you'd get 3300 out of a 30" tube on a 378 way case withum View attachment 388951

I think it was these.

 

[jessej]

Ahh yes. .900 bc. I hope we see some info from him on this soon.

 

[Bghunter338]

Ahh yes. .900 bc. I hope we see some info from him on this soon.

Me two, I can't stop thinking about it after he teased us lol

 

[JamesWilson5]

Now that would be nice 900 b.c extreme long range

 

[436]

Well I have the 338 378 weatherby so I kinda thinking they have a 284.338 caliber why not get in the middle I have to 8 mm remington mag awesome very underrated I have all the rums except 375 and all the weatherby from 257 up to 375 and 378 above just thinking about something new I'm getting good velocity with the 8 but they have 28 in barrel. I was thinking about 30 inch barrel but need the case compacity that's where the 378 case comes into place slow burning powder and long barrel with added case compacity. Equals extra velocity alot more cause I'm already getting well over 3300+ fps whith what I have with 180 grain bullet not going to say exactly what I'm getting but it will make a 300 rum have to watch it pass by with great accuracy

Well, in the end, you'll be the winner, the guy that dies with the most win!

 

[JamesWilson5]

I know lot of people knock on the 8mm but there is a 323 Jarrett that has very good velocity . The 338 rum with 180 accubond gets over 3500fps by book standard nosler reloading manual out of a 26 inch barrel. But the case is full of 7828ssc barely can seat the bullet. That's why I was thinking the 378 more volume plus longer barrel. Recoil doesn't bother me so not worrying about that . But with a possible 15 + grain of powder slower burning powder to watch for pressure. I could see an easy 3650+ fps with 180 bullets and a good posible of 3500+ with 200 grain bullet that would kill clean and smoke anything in north America at a long range or short with right bullets hammer bullets barnes nosler

 

[Chas1]

That's screaming

And a barrel burner too !

 

[timo308]

I got plenty bullets stored up just trying to get alot more than 8mm rem

Being that they're weatherbies, with his signature shoulder design, you're going to have a custom reamer for each caliber to start. Then I am guessing that you will need a custom die for each, as I'm not sure a bushing die (if anyone even makes one for the 30-378) will work due to the shoulder design. That ought to suck up a quick grand right out of the gate, so to speak. Can't imagine that you will get much more than 4 to 5 hundred shots of usefull barrel life with the 7mm, but the 8mm will be slightly less wasteful than the 30-378 parent cartridge.

 

[338elkhunt]

Got low on brass for a 7mmstw and took 8 mm remington mag brass . Simply ran it through a 7mm stw resizing die worked like a champ and got plenty now . So I was wanting to take a 30 378 weatherby and neck it it 7mm or 8 mm . I have a 30 378 dies but how can I get it down to that caliber and what would I need . Got plenty of brass I know it's crazy but I have a 7 rum and stw also 7mm weatherby but I am looking for so serious horsepower powder or barrel life I'm not concerned with just want to take a Cadillac and turn it Into a top fuel dragster lol .the 8mm would be a very interesting idea especially cause I have 338 378 brass and dies also but how can I size them down. Any ideas would be much appreciated thanks in advance

Where did you get your 8 mm brass from?

 

[jessej]

Being that they're weatherbies, with his signature shoulder design, you're going to have a custom reamer for each caliber to start. Then I am guessing that you will need a custom die for each, as I'm not sure a bushing die (if anyone even makes one for the 30-378) will work due to the shoulder design. That ought to suck up a quick grand right out of the gate, so to speak. Can't imagine that you will get much more than 4 to 5 hundred shots of usefull barrel life with the 7mm, but the 8mm will be slightly less wasteful than the 30-378 parent cartridge.

When you're drivin a top fuel dragster, you're not real concerned with fuel economy.