Follow along for .257 "Wild" Weatherby Magnum build

[stagpanther]

This one has been in planning for a long time, pretty much all the parts are in waiting for the barrel to arrive. I call it "Wild" Weatherby because I specifically ordered the barrel with a fast twist to accommodate the new generation high SD bullets which run up to 135 grs. Going to be a bit like a wildcat figuring out loads for it. What I didn't know was whether or not I needed to have more freebore added for the longer bullets--probably so, but the standard Weatherby freebore is pretty long to begin with. I was going to go with a MDT chassis at first--and it is still available as a back-up--but I had an old Boyds stock sitting around doing nothing, and the Savage bottom metal for an AICS magnum magazine, so I decided to see if I could get it to work in the Boyds stock. The outside dimension for the bottom metal is about the same as the standard Savage magazine bottom metal--but the inlet clearance is definitely different but fortunately is pretty easy to do the additional grinding/sanding to accommodate. I had already installed pillars and bedded a 110 action long ago.

 

[ligonierbill]

Looks like a lot of fun! Everyone is chasing 6.5mm bullets now. But I think the quarterbores have a lot of potential with today's powders. FWIW, my "traditional" Mark V sends those 120 Nosler Partitions (flat base) at 3,382 and shoots <MOA. If 3" off LOS is your standard, MPBR is 330 yards. Range finders and ballistic calculators allow us to arc bullets in at crazy ranges, but I've started looking more at "hold on hair". Let us know how you do!

 

[sako2]

Along for the ride.

 

[stagpanther]

Looks like a lot of fun! Everyone is chasing 6.5mm bullets now. But I think the quarterbores have a lot of potential with today's powders. FWIW, my "traditional" Mark V sends those 120 Nosler Partitions (flat base) at 3,382 and shoots <MOA. If 3" off LOS is your standard, MPBR is 330 yards. Range finders and ballistic calculators allow us to arc bullets in at crazy ranges, but I've started looking more at "hold on hair". Let us know how you do!

That's a great feature of fast Weatherby's in general--they have such a large MPBR and stay flat pretty far out. That means I can take a new rifle like the 300 Weatherby mag put a new scope on it that has never been used on it and bore-sight a target at 200 yds for the initial zero and chances are fairly good I'll hit pretty close to the scope's POA on the very first shot. Saves me lots of ammo sometimes.

 

[stagpanther]

Barrel was just delivered--being 4 days late from the initial delivery date I was a bit worried about the increasing chances of damage--and unfortunately the simple cardboard box was both crushed in the ends and had a jagged hole torn it. It obviously had been tossed around in the delivery process. I remember the "good old days" when barrels were shipped in reinforced tubes and secured by well-sealed endcaps. Those days seem to be long gone. What I don't get is why scrimp to save a few bucks on packaging for a $500 barrel?

 

[ligonierbill]

Not gone. I just received a muzzleloader barrel from Rice packaged exactly as you described.

 

[stagpanther]

Took only about ten minutes to install the barrel--but then I hit a snag--literally--the heavy sporter barrel (well-named because it is the heaviest barrel I have) was bottoming out and hitting the side of the fore end channel--so that took quite a while to finally get the barrel floating free.

I took it out for a test-firing with a few cartridges I made up out of 120 gr seneca bullets fed from the AICS magazine and everything worked out fine--but 3.850" is a long way to go and I had to remember to fully retract the bolt. Seems everyone is cerakoting their bolts these days--I personally don't like the gritty/raspy feel of them and much prefer simple polished steel, but that's progress.

The one thing that really bothered me--even with 28" of heavy barrel hanging out there--is the propensity of the rifle to want to muzzle jump. I can't remember for sure, but that might be why I side-lined the stock in the first place. The barrel seems well-made, though the grooves are a bit rough and the 4 shots I took left as much copper in the grooves as I typically see in rifles with many more shots through it. Hopefully it will wear-in and shoot well, but I can tell it's going to take a while. For a top-tier priced barrel the finish doesn't strike me as being equivalent of the price.

 

[stagpanther]

I decided to try the action in the MDT chassis--there was no propensity for muzzle jump though I did add a simple side-blow brake to help mitigate the jump. After trying a few combinations of 120 gr senecas and the hornady 134 eldm's, which yielded OK results in the slightly under MOA range--I tried a few charges of the 135 gr Berger target hybrids paired with VV N560. A few of them looked pretty good and today did a labradar test to see if I had possibly found a good node. I only have a couple pounds of the VVN 560--or should I say had a couple of pounds, so I can't be doing big groups routinely so did a compromise group of 7 shots @ 171 yds, the longer range spots are once again closed to use. The .257 wby mag handles the big berger bullets in stride--better than any of the other "super quarter bores" I've tried; I haven't read about any of other 257 chambering that really excels with them.

PS--I used the new White River LR magnum primers--I've used about 100 of them so far and haven't noticed any issues--they seem very well made to me.

Problem is like any Weatherby cartridge the barrel heats up really fast--and unless there is some kind of comp where you are allowed 3 minutes or more between shots I realize I'm sorta stuck with a rifle with no practical purpose--it's too heavy to hunt with and too much of a burner for any kind of competition which involves fast shooting of lots of rounds. Nonetheless the numbers are pretty compelling, not sure what caused the low and high velocity outliers.

I think a cartridge that comes along that can handle the big berger with charges that drive them at 3,100 fps in a 1:7 barrel will be a huge winner--provided someone can figure out how to mitigate the over-bore self-immolation tendency.