I always liked that “kinder, gentler” line from George Bush. We don’t do politics here at ExNotes (we’d lose half our readers no matter which way we leaned), but every once in a while I’ll borrow a phrase if it fits. So, you’re looking at the big photo above showing a 300 Weatherby Magnum, a 7mm Remington Magnum Ruger No. 1, and a custom Howa 30 06, and you’re probably wondering: What is kinder and gentler about shooting those T-Rex cannons?
Cast bullets, that’s what. I started shooting cast bullets back in the 1970s in El Paso and I’ve been hooked on them ever since. I don’t cast my own these days (it’s easier to buy them), but I still enjoy the benefits. Lower cost, exclusivity (far fewer folks shoot cast bullet rifle loads), long brass life, easier cleaning, and the big one: Lower recoil.
That last one, reduced recoil, figures prominently in my mind. I’ve been beating myself up lately shooting full bore .300 Weatherby cartridges and it’s been tough. I have a box of 180-grain cast .308 bullets and I have a bottle of Trail Boss propellant and that got me to thinking: Would cast bullets work in the .300 Weatherby?
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I checked the Lyman manuals and there are cast loads listed for .300 Weatherby. I checked the Trail Boss site and it lists .300 Weatherby cast loads, too. Hmmm. I wondered how good it could be. After all, you could fit the Hollywood Bowl inside a .300 Weatherby cartridge case. There’s a lot of space in there, and not occupying it usually hurts accuracy. With jacketed bullets, the .300 Weatherby usually delivers its best accuracy at max or near-max loads. Would all that volume and the much lighter charges associated with cast bullets make an accurate load?
There’s one powder designed for cast bullet shooting that hits the cartridge case volume issue head on, and that’s Trail Boss. The Trail Boss people tell you to fill the case to the base of the bullet and that’s your max load, and if you take 70% of that, you’ll have your minimum load. My Weatherby brass took 31.3 grains of Trail Boss, but that was in a fired, unresized case, so I figured 30.0 grains would make for a good max load. 70% of that is 21.0 grains. Then I checked the Hodgdon site (they’re the folks who make Trail Boss) and it showed a range of 19.0 to 27.5 grains. That’s close enough for government work…my lower end load would be 21.5 grains, and then I’d try a warmer load with 24.5 grains. You know, to get a feel for what the Weatherby Mark V preferred. So I loaded a few rounds early one morning and I was ready to test the Mark V with cast bullets.
I already had a bunch of 7mm Remington Magnum reloads with Gardner’s 145-grain cast bullets. I had three boxes: One with 18.0 grains of Trail Boss, one with 20.0 grains, and a third with 21.4 grains. My prior reloading adventures with the 7mm Remington Magnum in my Ruger No. 1 indicated that it liked Trail Boss, but I didn’t know what the right dose would be.
I also had a box of .30 06 ammo loaded with cast bullets. I loaded these with SR 4759 powder, a stellar cast bullet propellant. I grabbed that box and my custom Howa.
So how did the cast bullet rifle session go? Surprisingly well. I shot the Weatherby first, as it was the rifle that had prompted the cast bullet theme. The recoil level was low, almost like shooting a .38 Special. That was a welcome relief from the factory-level loads I had been shooting. The .300 Weatherby Mark V printed its best 50-yard group at 1.102 inches (a three-shot group), and that was with 21.5 grains of Trail Boss.
Because I was shooting at 50 yards, I needed to readjust the parallax on the Mark V’s 4-16 Weaver scope. When I did this at 100 yards, the parallax adjustment was right where Weaver had marked it for 100 yards. At 50 yards, the Weaver marking on the scope’s objective was a bit off, but that’s okay. I could move my eye around behind the scope and the crosshair movement had been appropriately minimized.
The Ruger No. 1 in 7mm Remington Magnum printed a 1.107-inch five-shot group at 50 yards with 18.0 grains of Trail Boss.
And my .30 06 Howa did the best of the three, with a 0.902-inch three-shot group at 50 yards. I loaded that ammo with 24.5 grains of SR 4759. I’ve always had good accuracy with SR 4759 when shooting cast bullets.
None of the cast bullet loads leaded the barrels, and that’s a good thing. Take a look (all of these photos were after shooting, but before cleaning):
Cleaning a rifle after shooting cast bullets is much easier than cleaning after shooting jacketed bullets. I run a patch soaked with Hoppes through the bore and let it set for maybe 15 minutes to soften any lead remnants and combustion residue. After that I run a bronze bore brush through the barrel three or four times, and then I push two or three patches through the bore. That’s all it takes to get an immaculate bore. It’s much easier than removing copper fouling after firing jacketed bullets.
On the next set of cast bullet loads, I think the direction is clear. The .300 Weatherby shot better with 21.5 grains of Trail Boss than it did with 24.5; the Hodgdon online data shows the charge going as low as 19.0 grains. My next .300 Weatherby load will be with 20.0 grains of Trail Boss. The 7mm Remington Mag shot better with 18.0 grains of Trail Boss than it did with 20.0 and 21.4 grains; I think I’ll try 17.0 grains in a few to see if accuracy improves. I haven’t tried any 30 06 loads with Trail Boss yet (the loads I shot for this blog were loaded with SR 4759), so I’ll do some .30 06 Trail Boss loads for the next outing.
I was just about out of Trail Boss powder after loading more cast bullet ammo for the next session with the above three rifles, and with component availability today being what it is, that concerned me. I got lucky, though. I found a source with a 5-pound bottle of Trail Boss at a decent price and I jumped on it. I’m set for a while.
I’ll move the targets to 100 yards the next time I’m out. Good buddy Paul set me up with a box of Montana Bullet Company’s 200-grain .308 cast bullets, and I’ll load a few of them to see how they do in the .30 06 and the .300 Weatherby. Montana Bullet Company’s cast bullets have done superbly well in my .35 Whelen and .416 Rigby rifles; I’m eager to see how these do in the .30 06 and .300 Weatherby.
That’s it for now. I intend to be on the range sometime this week to continue the cast bullet testing, and when I do, you’ll read about it here.
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I found their website (Googled Matt’s Bullets). Thanks, David.