How much can you reduce a load for a big bore? I don't own one but I was wondering if you can reduce the charge for shooting medium game. If I were to go DG hunting in Africa and picked up say a 375 H&H or 458 WM or Lott what would I use it for later besides a mantle piece? I have heard of people loading down big bores like the 458 WM but how well do they behave when reduced? I guess this is why the 9.3x62 and 74R interests me so much.

You can have top accuracy all the way from a sub sonic load to full power.

One of my favourites in the 375 is 39-41 grains of one of the Australian powders Hodgdon sell which would be H4227 and the 220 grain Hornady flat nose. Does right around 2100 f/s and no fillers. In a very accurate 375 I have fired a 20 shot group that was just under an inch.

In a 458 70 grains of 4064 or Varget and 400 grain Speer is right at 2000 f/s and with top accuracy.

Of course in the case of a 375 there is no reason not to use for everything and with its normall load. Basically a big 30/06

I second the 375 with a standard load for everything. That way there is only one ballistics curve to remember. A hyper velocity round will ruin more meat than a medium velocity big bore.
If you plan on using lighter bullets in a 458 WM, I would check to see if it will shoot shorter bullets accurately before sealing the deal. The WM has a long, loose tapered throat and some can be finicky with shorter bullets. Most Lotts have a normal throat and are fine with lighter bullets.
Link to discussion of 458 throats-
http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/9201027511?r=9201027511#9201027511
from thread-

Stay at the lower end of published data. There are loads for XMR-5744 that may work for your caliber (which is???) Magnums get in trouble with too low loads -- how powder burns when case not full enough. You need to research this a bit before committing. If recoil is the problem a kinder chambering may be just the ticket. And, you could always shoot for fun after the hunting. Actually do lots of that before as well. :-)

I'm using 5744 in my .458 with 405 grn. GCFN bullets at around 1700 fps. This powder doesn't require a filler.

It's pretty easy to down load the big bores! Just use the right powder.

BTW, that powder seems to burn more consistently with a firm crimp, and a Mag primer.

In 375 H&H I use H4895 with the Horn 220 FP for around 2200 f/s and 3 will cloverleaf at 50.

Pete

AA5744 + Barnes 300gr bullets give me terrific accuracy in my 416 Rigby. Good enough to take out a few ground squirrels with it and have fun while doing so. No fillers needed, would put a deer right on down should I decide to use it for such.

Ditto. I use my .375 for everything. In it I prefer the 250 gr Sierra BTSP over a healthy dose of RL-15. Season 2008 I was using the Speer 270 gr BTSP over 70 gr of IMR 4064. I popped a muley buck @ over 350 yards with that load.

I see it as pointless to load a big bore down for American game..it is not meat destructive with max loads, kills a bit better at full velocity, better penetration especially in brush..Regardless of some claims a 458 or 375 DOES buck brush real well most of the time. If recoil is an issue then I suggest using a smaller caliber to gain the same effect..shooting a loaded down big bore or a 250 Savage is the same thing on that count.

Email Johan at Accurate Powders about reduced loads for the cartridge of your choosing, using their 5744 powder. I use it with 350gr. bullets in my 416 Rigby for about 2000 fps and great accuracy. And in my 375H&H, I use 5744 with 300gr. bullets for around 2200fps and, again, great accuracy. I'd say the 375 is like a .270Win. and the 416 like a 30-06, as to recoil. Nice plinking/whitetail loads. And much more economical to load as well, especially in the 416.

David

The LEE loading manual has a formula for reduced loads.

I know Mike 378, from a while ago... but he knows his stuff when it comes to big bores..

While he mentions the choice of H 4227 that he uses down in Oz... to Americanize that, substitute those charges with SR 4759..it's much more bulkier, but still has close to the same burn rate as H 4227...

just don't start at max, and of course work up..

IMR 4198 or 2400 would also be a good choice..

Cast load manuals can also set you up with data using Red Dot, Green Dot, Unique..

If you can live with the 1000 to 1200 fps range, try Trail Boss.. very bulky to the tune of about 15 grains FILLS an 06 case... looks like cheerio shaped oatmeal..

load data is just don't put enough in that you might compress it... other than that, you can't get enough in the case to over pressurize it..

it was designed for the cowboy action shooting market..

I also know Mike378 and he is a world class authority on rifles and cartridge performance. If he doesn't know, he will ask. He is not arrogant but very straight forward, there is a difference. If he says so, don't bother taking him on, as his experience with generating accuracy from sporting rifles is light years beyond anything ever published. I have seen him load and shoot bench accuracy from rifles that is astounding. I learned much.

JW

The two 458 lotts I had both shot very accurately with 350 gr bullets @ 2400-2500 fps, and I used RL7 to get that performance. I used 458 win mag data for those loads. The recoil is much more tollerable with the lighter bullets, and they'll take any NA game.

If you want really mild, you can download to 45 colt pistol levels using Unique and cast bullets. I've loaded my 500 Jeffrey with 470 gr cast bullets to 1100 fps. Unfortunately with the 45 cal rifles you can't easily use cast pistol bullets due to the difference in dia's, but you could paper patch the 45 pistol bullets to get the correct dia.

IMR 4759 is a good choice for reduced loads.
I had a hangfire with reduced load in .458 Winchester magnum once.(RE 7)
When the rifles fires after you take it off your shoulder it is a little strange.
whelennut

Trail Boss and 5744 ca be your friend for reduced loads. Depending on how low you want to go,I have done sub-sonic loads on .458's and Trail Boss,as well as the .450/400 with cast bullets.I am working on a load now for the 9.3x74R in a Ruger #1

Hangfires can be a problem with light bullets in the 458, especially the 300 grainer and when using reduced loads of rifle type powder like 4198 etc. The problem is due to the huge freebore in 458 Win which in combination with the light bullet provides little resistance. The rifling starts more than an inch from the case mouth. The new SAAMI specifation 458 Lotts don't have the problem as freebore is short, much shorter than a 458 Winchester that has been rechambered to 458 Lott.

I have shot pounds of SR 4759 from everything from .243 through .45-70 with good results. YMMV