Need re-chamber ideas for old Mk V 9 lug 270WbyMag

Are you talking a new barrel? If so, time to ditch the belt, though the problems with a belted magnum are over rated. Assuming you reload. I'd step up to a .284" bullet if Elk are in the mix.

A 28 Nosler would be sweet as a hunting gun that does not see a lot of rounds down the barrel. 7mm PRC Is perhaps a little kinder to the barrel if you shoot more. For that matter, lots of decent 7mm RM brass out there too, if you want to ditch Wby brass and keep the belt - 7RM does not seem to burn up barrels as fast as the real overbore 7s. You could probably build any number cool wildcats on that action too.

Whatever you do, think it through and research. Decide your personal maximum range I think first. Consider the bullet class you desire thereafter (weight, SD, etc) and then work forward. If its 400 yards, life it easier. You can choose a medium weight bullet and aim for some speed. You want 1000 yards? You are in the swamp. Judging from the 163 posts since 2009, Indypendent is not a sudden 1200 yard shooter, but that's just me making inferences.....

Lastly, should you be partial to the .277 bore, there are lots of manufacturers making tighter twist .277 barrels capable of running the heavier .277 bullets. A 270 WSM, 27 Nosler, or keeping the 270 WBy are reasonable options with a new barrel with an 8 twist or so. But personally, I think elk with a .277 is something left to skilled experienced shooters. If you are in that category, don't need a guide telling you what to do etc, then OK....
 
30 Sherman Magnum. 3000 fps with a 245 Berger or use 300 PRC ammo in a pinch to shoot very accurately and reload to 30 SM.
If you like the 284 bore, 28 SM up to 3200 with a 195.
I have a Bartlein CF 30WM barrel standing by. I had that and another Bartlein turned in 28Nos a few years ago for a LonePeak action. As soon as this 28Nos needs to go, that 30SM is gonna go on. Can't wait. Love your stuff man.
 
Are you talking a new barrel? If so, time to ditch the belt, though the problems with a belted magnum are over rated. Assuming you reload. I'd step up to a .284" bullet if Elk are in the mix.

A 28 Nosler would be sweet as a hunting gun that does not see a lot of rounds down the barrel. 7mm PRC Is perhaps a little kinder to the barrel if you shoot more. For that matter, lots of decent 7mm RM brass out there too, if you want to ditch Wby brass and keep the belt - 7RM does not seem to burn up barrels as fast as the real overbore 7s. You could probably build any number cool wildcats on that action too.

Whatever you do, think it through and research. Decide your personal maximum range I think first. Consider the bullet class you desire thereafter (weight, SD, etc) and then work forward. If its 400 yards, life it easier. You can choose a medium weight bullet and aim for some speed. You want 1000 yards? You are in the swamp. Judging from the 163 posts since 2009, Indypendent is not a sudden 1200 yard shooter, but that's just me making inferences.....

Lastly, should you be partial to the .277 bore, there are lots of manufacturers making tighter twist .277 barrels capable of running the heavier .277 bullets. A 270 WSM, 27 Nosler, or keeping the 270 WBy are reasonable options with a new barrel with an 8 twist or so. But personally, I think elk with a .277 is something left to skilled experienced shooters. If you are in that category, don't need a guide telling you what to do etc, then OK....
I appreciate your wise perspective. I'm leaning towards that 7PRC. Honestly, I'm just trying to take maximum advantage of this action where velocity and round versatility are the main factors in this project.
 
I'm a really big fan of the 270 Wby. Mag in a Mark V rifle. I love mine. I would suggest that you consider a Re barrel to .270 Weatherby Mag, 26 inch with a faster ( 8 ) twist and a longer throat., and threaded for a Muzzle Break. You could shoot the Nosler 150 Grn ABLR's all day long. and also the 160 Grn. Nosler AB; and the 170 Grn. Berger. My old 270 Weatherby mag performed extremely well, with its 1979 stock 26 #2 barrel, at 1000 and 1100 yards at the shooting school. 150 Grn ABLR at 3000 FPS. No Muzzle break, old stock Trigger . For the long Range shooting school, I used a Leupold VX 3 8.5X to 25 X WINDPLEX SCOPE on Steel Dual Dove Tail bases. Its a fine round with respectable ballistics!! You could easily improve performance with a fresh new barrel and faster twist. My Huble opinion.
 

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I have used a similar round (26 Nosler) for the last 5 or 6 years as my primary big game round. Have taken lots of African PG as well as many deer here. Haven't done an elk hunt in recent years though some of the African PG I've taken were are as large/larger than an NA elk (eland, zebra) and ones just smaller (e.g., kudu, waterbuck, gemsbok). Most animals were DRT.

The 6.5-300 came out after I was already underway with the 26 Nosler. It's good for a few more fps. My main 26 Nosler barrel is 28" with a 1/8 twist with no muzzle break. Mostly shoot 142g Nosler ABLRs.
 
There are several calibers that would work/fit in your action. I would lean towards a 7mm depending own what you intend to do with the rifle once rebarreled. I have built, reloaded, shot and hunted with many 7mm and other calibers. If you are headed in the 7mm caliber direction and depending on how much you shoot the 7mm RM is probably your best bet based on current day price of factory ammunition. I love 28 Nosler, however i will never build another due to flat cost of factory ammunition and the amount of shooting i do. These new calibers like the 7mmPRC add nothering to 7mm Rm other than no belt. Since you are rebarreling you can speed your twist rate up to match a PRC barrel. Wildcats and other off brand calibers are fun and expensive to play with. It you have alot of money and want to play with an odd ball caliber then go for it. I am currently shooting a custom rifle in 7mm-08 with a 29 inch tube. While heavy, it is a dream to shoot.
 
I appreciate your wise perspective. I'm leaning towards that 7PRC. Honestly, I'm just trying to take maximum advantage of this action where velocity and round versatility are the main factors in this project.
I think you've actually answered your own question, but think about a 7-300 PRC for a little more reach, but fewer shots.
 
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