Single Cavity Molds

[1Shirt]

Many, many years ago (far to many really to be comfortable), an old time caster told me that he would only have single cav molds for rifles. Was fine with multi/gang molds for revolver and pistol, but was of the opinion that for rifles, top accuracy with cast could only be achieved with a single cav. Think he said that he did have one double cav in 30 (probably 308291) that he had marked one cav so that it produced a dimple on the blt so he could seperate them. Way back then, I bought a few single cavs on purpose just because of this old gent. Have now gotten rid of most of them or had them made into HP's (which is a different world of single cav casting). T'aint that bad to be casting big 45 cal 4-500 grainers with a single as you arn't shooting them rapid fire, and even with a single, the pot goes down fairly quick. Over the years, most of those single cav. molds that I bought way back and didn't convert have gone the way of e-bay, and been replaced by doubles, 3/4 cavs and a couple of 6 cavs. Just makes me wonder if there are any single cav pursits out there? If so, would be interested in just how many.
1Shirt!

[curator]

Yup, one-holers were the way to go back in the day. I spent many a year sweating over a single cavity #311291 mould to get the best accuracy. My first 2-cavity moulds was an LBT with one gas check and one plain base since I still believed the old wisdom. Lather bored 2 to 4 cavity moulds are so perfect today that marking the individual cavities is no longer necessary. My 4 cavity .310-180 SP LBT mould throws 4 perfect bullets that are exact diameters (.3010/.3102) and 180 grains + or- .1 grains in weight when cast hot. I have had almost the same result with Lee 2-cavity rifle moulds, but not with group buy Lee .310 rifle 6 cavity moulds.

[Bret4207]

IMO for absolute top accuracy a single is probably the way to go. But many of us don't desire that top notch accuracy or prefer to plink or just don't want to go to that extreme. These days I have several multi cav rifle moulds that appear to be virtually identical in all the cavities. I'm not sure but I imagine differences would show up with the right gun and shooter. The variations from cavity to cavity are there no doubt. The center most cavs will run hotter than the outermost cavs. That has to affect the dropped boolits.

[quack1]

I have quite a few single cav molds, mostly for rifle. I don't mind them at all, I usually cast using 2 or 3 at a time. Once I get them all up to temp, I can cast a pile of bullets in a fairly short time. For pistol bullets, though, you cant beat multiple cav molds.

[stephen perry]

I started with single cavity molds for rifle. Particularly 22 and 30 cal. I have since added 6mm, .27, and .338. I have plenty of doubles, fours and a couple sixes.

I Cast my singles regularly, have had oppurtunities to replace to some singles with doubles, don't do that. I have found I can Cast nearly the same rate with a single as a double and generally get better bases with singles. And Cast weights are closer dealing with same cavity.

Stephen Perry
Angeles BR