7mm/300wby

[zorak]

Hello I am new to the site and I did a search but could not find what I am looking for.What I have is a 7MM/300wby and I am looking for some load data from sierra bullet's.I am shooting 150gr barnes x bullet and I am looking for the best powder to use and min and max load for that round.I prefer the imr powder 4350 or 4831 any and all hel would be greatley apreciated.


Thank you.............................Doug

[beemanbeme]

I've got my books put away but aren't the 7mm/300WBY and the 7mmWby almost identical??  Look at a couple of the cartridge drawings of the 300WBY and the 7mmWby.

[huntswithdogs]

Doug, Welcome aboard! You're gonna have to help us a little here. Have ya got a 7mm or a 300 WBY?

This's probably something that would be better address over on the Reloading Section.

[IOWA DON]

The 7mm/.300 Wea is a wildcat cartridge, the .300 Wea necked to 7mm. Guns magazine in April 1991 had a short article on the 7mm/.300 Wea by Holt Bodinson. The balistics of this cartridge are similar to the 7mm STW. I had my 7mm Wea rebarreled to 7mm STW rather than the 7mm/.300 Wea because Weatherby brass is much more expensive than Remington 8mm brass which was used for the 7mm STW. The Guns article indicated he got a velocity of 3270 fps for a 160-grain bullet with 79.5 grains of IMR-7828. This was with a barrel of 26-3/8 inches. A layne Simpson article in Shooting Times shows the 7mm STW giving 3189 fps with 80.0 grains of IMR-7828. This was with a 26-inch barrel. The fact that the 7mm/.300 Wea gave a higher velocity than the 7mm STW with less powder indicates to me that the 7mm/.300 Wea has slightly less powder capacity than the 7mm STW, but it was loaded to a higher pressure. However, the difference may be some other factor. My 7mm STW produces the same velocity with a 140-grain bullet with less poder than shown in the Shooting Times article. I would say that one should begin with published starting loads for the 7mm STW, and use a chronograph so that maximum 7mm STW velocities are not exceeded. Also, look at 7mm STW velocities for the same length barrel as your 7mm/.300 Wea.

[zorak]

Don that is what guy at the gun shop said to do was go off the 7mm STW.But what I see is the STW is alot longer of a shell than my 7mm/.300wby.But I do know that Sierra has the  specs for it I just dont want buy a $40 dollar book for just one caliber.I will try to research that article from Gun Magazine and thank you for the info.

Doug

[jhm]

Sierra faxed me the specs. on a .17 Rem. that I once had but didnt have the info. in my rfeloading books, Im sure if you contact them they would be willing to help you out, and didnt the Barrel Manufacturer have any load recomadations??   JIM

[IOWA DON]

The 7mm Rem Mag and the 7mm Wea mag are both about the same overall length as a .30-06 and I think they were designed to work in actions of that length. They use the H&H belted magnum cases, but are maybe 3/8 or 1/2 inch shorter than the .300 wea, .375 H&H and the 8mm Rem Mag, which use the full length cases. Before the 7mm STW was a factory cartridge one needed to neck down 8mm Rem Mag cases. One needs to neck down .300 Wea cases to form 7mm/.300 Wea cases. If that's what you have, you will need some expensive reloading dies. I think a 7mm Wea cartridge or a 7mm Rem Mag cartridge would chamber in a 7mm/.300 rifle, but I think it would be unsafe to fire. A 7mm/.300 Wea cartridge should be the same length as a 7mm STW but would have the Weatherby radiused shoulder. Maybe it would be worth having a chamber cast made before investing in reloading dies.

[zorak]

I have the dies and I am using the .300wby case necked down to 7mm.We have shot a 8 rounds through it already just off the STW specs and had no problems with them such as case splitting or blowing the primers out.I am just wanting to get the exact specs for the loads just to be safe.

I will try contacting Sierra and see if they will fax me the load data.

Thank you guys for all the help.

Doug   

[Brithunter]

Sorry but somehow this makes no sense at all to me. You have brought a wildcat chambered rifle, brought the expensive brass yet will not shell out a measly $40 for a reloading book?  seems you have you priororities all wrong  .

[zorak]

Well um when we got the rifle 10yrs ago there was no data for it.Now Sierra has the data for it so I don't see shelling out $40 for a book that I am only going to use for one caliber when I have most the other books that cover my common rounds.So brtihunter if you cant post somthing positive or helpful then stay off my thread please .

Because if had the info that someone needed I sure would help .

Doug

[Brithunter]

Well um when we got the rifle 10yrs ago there was no data for it.Now Sierra has the data for it so I don't see shelling out $40 for a book that I am only going to use for one caliber when I have most the other books that cover my common rounds.So brtihunter if you cant post somthing positive or helpful then stay off my thread please .

Because if had the info that someone needed I sure would help .

Doug

Oh well if you don't supply all the information then why should we bother. I actually ahve a friend who has a 7x300 and uses it for hunting or used to until his interests turned to larger bores. However why should I bother him to try and help you. ?

[TXSPIKE]

Try this site,it has a few loads for the 7mm-300 Weatherby. http://www.reloadersnest.com/rifle.asp It is very similar to the 7mm STW.I'm getting 3450fps with a 150gr. bullet out of my 7mm STW with 80grs. of Winchester WXR powder.If you don't have a chronograph,get one.They really help out a lot when working up your loads.I know the 7mm-300 Weatherby is capable of velocities of 3400+,it's a matter of finding the right powder for it.Checkout the powder burn rate chart on reloadernest.com to help you choose the powder to use.

[zorak]

Well um when we got the rifle 10yrs ago there was no data for it.Now Sierra has the data for it so I don't see shelling out $40 for a book that I am only going to use for one caliber when I have most the other books that cover my common rounds.So brtihunter if you cant post somthing positive or helpful then stay off my thread please .

Because if had the info that someone needed I sure would help .

Doug

Oh well if you don't supply all the information then why should we bother. I actually ahve a friend who has a 7x300 and uses it for hunting or used to until his interests turned to larger bores. However why should I bother him to try and help you. ?

 Hey brithunter thanks for all the help:o.

Also txspike thank you for the link that should help out.

Doug

[Graybeard]

I don't often agree with Brithunter but this time I do. You should NOT depend on the internet for your reloading data I preach against that regularly. Buy the manual or at least ask Sierra to provide you the needed data. I suspect they will for free.

[beemanbeme]

Wow, 8 post and he's telling folks who can and can't talk to him.