Has anybody tried this thinking of making a custom job 7mm-378 weatherby. any input would be greatly appreciated. I know i'm gonna use a rem 700 la of course put that in a boyds stock not to sure about the barrel or the trigger yet. Is this idea plasable or should i just start banging my head?
7mm-378 project input?
- Thread starter thumper1
- Start date
Anything is possible when you get your wallet out. And leave it out.
30-378 brass should be easy enough to neck down. Any 7mm barrel would do, the longer the better.
I would think that by the time you got your load development done, it would be time to re-barrel.
R.
30-378 brass should be easy enough to neck down. Any 7mm barrel would do, the longer the better.
I would think that by the time you got your load development done, it would be time to re-barrel.
R.
Remington has never made a rifle chambered for a 378 Wby. cartridge. Opening up a standard belted mag bolt face to 378 would be a neat trick if you could do it at all.
Once this minor inconvenience was overcome you'd have to custom make a magazine....or call it a single shot rifle.
Remington did make a factory 338 Lapua in the 700 action...with a Sako style extractor...so it can be done. The case heads are about the same. But, in my opinion there are better actions for the big Wtby case,....like a Weatherby Mark V
.....or a Sako M995 or the big CZ action.
But that's a LOT of powder to put thru a 7mm bore...quickest and cheapest(?) way would be to grab a Mark V in any of the 378 cased rounds(30-378,338-378,378,416 or 460)...and locate a 7mm Wtby/STW/Rem Mag barrel from a Mark V and rechamber it.......
.....or a Sako M995 or the big CZ action.But that's a LOT of powder to put thru a 7mm bore...quickest and cheapest(?) way would be to grab a Mark V in any of the 378 cased rounds(30-378,338-378,378,416 or 460)...and locate a 7mm Wtby/STW/Rem Mag barrel from a Mark V and rechamber it.......
This is an old thread, but check out the 7mm/338LM AI. It's been done in several configurations and under a few names, the most recent the 7mm Allen Mag. It is hot, real hot, does 36-3700FPS with a 160 Accubond. Keep Rock Creek barrels and your importer on speed dial or have obtunded stock a good Krieger 7mm tube with a little slower twist for you, and keep scheduled 6 month appointments wherever you get you barrel work done. LOL, it might not be that bad, but will rank up there with the 30-378's and 7 RUM's, sounds like good fun. I believe that one did best on Wildcat bullet's 200 grn UBBT(BC.92), which is no longer availible.
If Matrix decides to produce something amazing in 7mm, I may perk up my ears for this round yet, but I'm pretty certain a 30-338LM AI would be about a stupid as I need to get. I already have a steel eating monster mostly built, don't need another one.
Not so fast, Matrix does make a 190 grn 7mm bullet with a .807 BC!!! WOW, that is CRAZY high BC and if you can get that up to over 3000FPS, you would have a serious piece of equipment. I think the 7mm AM was getting 3200 with the 200 grn Wildcat, so it might do a hair more with a 190. LOL, I wouldn't want that work done stateside, to much hassle sending it back every 6 months for it's scheduled maintaince...... That .308 210 grn is pretty impressive too, might be worth giving that a whirl, .765 is not bad either.
If Matrix decides to produce something amazing in 7mm, I may perk up my ears for this round yet, but I'm pretty certain a 30-338LM AI would be about a stupid as I need to get. I already have a steel eating monster mostly built, don't need another one.
Not so fast, Matrix does make a 190 grn 7mm bullet with a .807 BC!!! WOW, that is CRAZY high BC and if you can get that up to over 3000FPS, you would have a serious piece of equipment. I think the 7mm AM was getting 3200 with the 200 grn Wildcat, so it might do a hair more with a 190. LOL, I wouldn't want that work done stateside, to much hassle sending it back every 6 months for it's scheduled maintaince...... That .308 210 grn is pretty impressive too, might be worth giving that a whirl, .765 is not bad either.
Tried one back in the 70's. Could only find one powder that burned efficiently in it (Thunderbird surplus 40mm powder). Was way overbore, might be ok with some of the modern slow powders. You also need premium bullets, they tend to come apart otherwise. - dan
I have thought about it. 30" barrel minimum I figure. You would have to be single shot on a 700. And you have to pull the bolt out of the action to eject a live round. The 700 is not long enough and it gets worse using long VLD bullets. It's real easy to do a MKV. You won't be able to do one cheap either way.
For a reasonably inexpensive (everything is relative) plan, use a modified P14 action. The specs to modify the receiver to monster elephant rifles are widely available (Gunparts corp). Have a P14 prethreaded 7mm barrel rechambered and you are go to go as a single shot. Mag mods are possible but may be challenging. The previously stated Weatherby M5 is another alternative but pricer. Good luck.
