Huge cavity in the base of my SWCs. Charge weight adjustments?

P

Pond James Pond

New member
My bargain price SWCs have arrived. So I now have 1500 of these bullets that I hope will go on .44Spl and light .44Mag loads for range practice.

Recent threads have warned me of the dangers of leading in the bore largely due to the fact that these are .429" and os is my bore, so I already need to walk a fine line between pressure enough to seal the bore well but not too much speed.

Now these new bullets have arrived and have a cavernous space in the base of the bullet: I swear it could make an echo....

So whatever the OAL, these will have a significant air gap under the bullet, especially as N320 does not fill the case much anyway (a heavy charge for .Spl only half fills the case).

What, if any, adjustments should I consider to offset this large base cavity?
 
That sounds like a skirt meant to fill out the bore. You will need a charge that makes enough pressure to do that at the minimum end, and you will not want a charge heavy enough that it makes enough muzzle pressure to blow the skirt out as it leaves the muzzle, thereby affecting ballistic characteristics. So, smallish charges of fairly fast powder will be best. Just work the loads up for smallest groups at 25-50 meters.

As to seating depth, you will find the density of lead is the same whether a cavity is formed or not, so the amount of space it displaces is the same. The cavity makes the bullet long for its weight, but, at a given COL, doesn't actually take up any more powder space underneath than a shorter flat base bullet does.
 
So these 1500 .429 skirted bullets should, in principle, do a better job in my .429' bore than the 500 .429 flat base bullets, correct?

Also these lack a lube as such but have something the company calls "Silvermoly" on the surface. A dry-lube treatment of some kind?
 
They may or may not do better. It depends on the load being appropriate and on the gun barrel. Did you feel any tightness in the bore down where the barrel screws into the frame when you slugged it? If you did, then the skirts may do better.
 
I have no recollections of any tightness. Once I got it in the bore, the taps needed to keep it moving down seemed pretty much the same.

Oh well, either way this is going to be a lesson in load development so let's just have a go and hope...!
 
If you have pure lead, you shouldn't need to keep tapping it. Once it gets in the bore, you should be able to push it with a cleaning rod by hand and get a feel for the bore surface. It helps if you run an oily patch through the bore just before slugging. Not heavy oiling; just light to reduce friction.

If the slug in a cast bullet alloy, you do need to keep tapping to get it through because it is a little springy. But that also means you get a larger-than-real measurement at the end.
 
I used a .454 black-powder round ball.

I'm guessing that is pure lead.

If it wasn't and my .429" reading is a tad larger than the bore actually is, this works in my favour as it means my bore may be .4285 or .428 making my bullets more likely to seal the bore, so that is no bad thing, I guess....

And when I say taps, they were just that: light taps.
 
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Elmer Keith's bullet designs included a hollow base .44.
It did not become popular but there is no reason not to shoot yours.
 
Load 'em backwards to get a mean hollow point.

Or, if you load them straight, the just keep them as plinkers.

I have witnessed hollow based bullets pull apart at the skirt and leave the tail end in the bore just because the loader was using them outside of their design range.....aka trying to push them too hard.
 
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