Home Forums Reloading Bullet Casting Roundball mould for 7mm-08 ?

I have been reading with interest various threads about shooting plinker cast bullet loadsin the '06, among others. The .311 buckshot (which is true 00?) is mentioned.

I'd like to try this in my 708, and think that a .28ish diameter ball would make a nice buckshot load to boot.

My question, What actual size would be ideal for a 7mm? 284, or bumped up a hair? This seems between #1 and #2 buck.

Thanks for any insight.

For round ball load in 7-08, I'd be looking for about .286. Ballistic Products has a # 2 1/2 buck that measures .290, seems a bit of a pain to have to size round ball but yu could run them through a Lee type sizer pretty quick and easy.

As Trooper said, you can run them through a sizing die. I just did this only with a 45 Colt. My only RB mold for 44 C&B revolvers is .457 but I do have a .454 sizing die. It was no trouble to size the RB's to .454 and lightly crimp them on the little shank the sizing die put on them. In the 3rd Gen Colt I shot them in they weren't particularly accurate over Red Dot.

Have you considered a Hammond Game Getter?

FWIW, I did this with a .44 Mag some years ago using .440 round balls sized with a .422 Lee sizer. 2 wraps of 9# onion skin and careful seating to orient the ball prior to seating. It worked quite well, even with 2 ball loads.

Sizing the round balls works, but it can be a PITA to get the "shank" aligned in the brass. The longer the flat, the better. I've gotten fewer fliers with the balls that were just oversized and crammed into the case mouth. I've done .457 balls in a 45 Colt rifle and pistol. The rifle had a big enough chamber that I could just seat the ball into a very belled case without sizing. I used those same balls sized to .432 in a 44 mag, and they shot straight to longer distance, but with fliers every so often. The plain balls around the same .432" shot more consistently. In various 22 cals from 22 Hornet and 218 Bee to a 22-250, I had good luck with some version of buckshot sized to .225". I did some .244" sized buckshot in 243 Win as well but those did not work out well. Various 30 cals were successful with .311" buckshot, from 30-30 to 30-06.

Over all, fun for plinking, and well worth the experimenting time. Other than the 243, all results were generally satisfactory at 50 yds, and some to 75 yds. I never solved the 7mm ball conundrum, and have never done any round ball tests in 35 cal. Just never found the right mould or shot for either.

A Lee .360 dia round ball mold for my 38/357 hand gun . A Lee .430 dia round ball mold for my 44 mag hand gun.. I cast from pure lead BRN 6 & coat with Lee's liquid alox. Let dry & seat in a well bell case mouth with the flat from the spru cut seated straight up or straight down. Loaded between 600 & 700 fops. Great fun. You should be able to get a mold that is close. Not rocket science. If absolutely necessary push thru an appropriate size sizer then coat with the Lee alox.

Y'all are overlooking the fact that a 7-08 will have a dramatically fast twist relative toward optimal stabilization of a round ball. Tin cans in the backyard kind of accuracy can be expected but don't count on hair splitting accuracy, methinks. I'm harking back to when I tried making round balls work in fast twist conical muzzle loaders - accuracy was ok but lousy compared to balls fired from similar rifles with slow twists. Real world experience among us after experimenting with RB's in 1-8 to 1-12" twist "modern" guns?

Twist does play in this game for sure. Mentioned earlier that RB loads worked well in my .44 and it has a 20" twist. After fiddling around with 2 ball loads I tinkered with single balls, all paper patched. Worked pretty well up to around 1,400 fps and I was inspired! So I loaded one up with a book max load for a 180 grain conical....~2,400 fps over the Chrony, where it went is anyone's guess. Did not hit the target at 25 yards.

That said, I have a friend tinkering with .300 BO rounds with a suppressed Contender and 10" twist. He is shooting in the realm of 1000-1300 fps with cast bullets of about 8-9 BHN and getting some very nice groups with it during initial load work up. Another buddy who tends to leap before he looks ran some of my Sneezer bullets thru another gun with 8" twist and did reasonably well in the 1050 fps range. Good enough for plinking hogs anyway. Alloy he was using was about 11-12 BHN. Softer alloy did not work well in his gun.

Another point to consider, some shot is hardened, some is not. Lead ball of any size purchased is an unknown unless one runs it thru a hardness test.

Twist rate may have come into play in the 243 tests, but the buckshot I was using seemed softer than the stuff I had cast, and some of the stuff I had sized from other buckshot. The twist rates for the 22 cals that shot well are slow, now that I think about it, 1:12 and 1:14. The 30 cals were shot from 1:10 and 1:14 guns. The harder-cast balls shot better than those that seemed softer, and seemed to handle being pushed a little harder. I cast them out of a bullet scrap alloy and dropped them into a bucket. There was a velocity that each seemed to shoot best, and then a velocity at which accuracy fell apart, which I judged to be past the limits of the alloys. They were acceptably accurate to 50 yds, which was a group about 2 inches for three shots, I think. The ones that shot the best to about 75 were out of the slower-twist guns in 44 and 45 cal.

The targets I used started at 50 yards, and then went to 70, and then 75, and then I tried 100 and no shots would hit paper at all, so I moved it in to 85, then 80, then back to 75. There seemed to be a range where the shots lost stability altogether, and a range just before that were some would be stable, and hit to POA, and some would not.