Is this normal when sizing a Smith bullet?

[Hal]

I was in the cast bullet world before I got into black powder. Among cast bullet enthusiasts, the general consensus is that .003" is the maximum amount you want to size down a bullet. .002" is even better. It really doesn't matter if you do it in steps. There is a good chance you will deform a bullet by sizing it any more than .003", no mater how many steps you do it in.

Another general consensus is that bullets for breech loaders should be .001" to .002" over groove diameter. Anything under groove diameter requires obturation to fill the bore. If the bullet does not obturate (and unless they are pretty soft and there's a pretty hefty charge behind them, they won't), the gases forcing it up the barrel will blow past the sides of the bullet and can erode lead from the sides of the bullet. This is called "Gas cutting." This lead that is cut from the bullet has a nasty habit of attaching itself to the inside of the barrel, more commonly called "Leading". Granted, there is more than one cause of leading, but the number one cause is an undersized bullet.

[Maillemaker]

OK, I ordered a set of hole gauges from Amazon. It's basically a split sphere with a screw you can screw in and out to expand the spheres, giving two points of contact in a hole.



You screw the screw until the spheres touch on either side of the hole you are measuring, and then remove the tool and measure across the spheres with calipers.

I did this with my Smith bore. Since there are 3 lands and 3 grooves, this gives me the bore diameter + groove depth measurement. This dimension is .508".

Measuring on the slug that I pushed down the barrel, I'm getting about .005" groove depth. It's difficult to get a good measurement on the shelf of such a tiny feature in the lead.

This means my bore diameter is .503, and my groove diameter is .513.



So, I believe .515 bullets should work fine in this Smith.

Note in the above diagram that the .263 groove width dimension does not determine the diameters - it has no effect on them whatsoever.

Steve

[Maillemaker]

By the way, I ordered a .518 and .512 custom sizing die from Lee about 2 weeks ago when I started this thread, and today I got notification that they have shipped.

Pretty good turn-around at the moment.

Steve

[Sven205]

By the way, I ordered a .518 and .512 custom sizing die from Lee about 2 weeks ago when I started this thread, and today I got notification that they have shipped.

Pretty good turn-around at the moment.

Steve

This is good to know! I've been looking at press mounted sizers but their 8 week wait time quote was what was stopping me on ordering the Lee.

I've been thinking I will make a mount for a single stage press to mount upside down so they drop into the hopper instead of pushing up into it.

[Maillemaker]

I've been thinking I will make a mount for a single stage press to mount upside down so they drop into the hopper instead of pushing up into it.

I have heard others do this also.

Steve

[Maillemaker]

Lee sizing dies in .518 and .515 came in today.

When I push through .515 directly, I get the slightest bit of flash on the bottom of the bullet.

When I push through the .518, it barely knocks any off.

I tried pushing .518 first and then .515, still get a tiny fin, so not worth double-sizing.

I'll take some pictures later.

I'm going to try to get to the range tomorrow. I'm going to do some load workups at .515 and .518, pure lead.

Steve

[Harry Gaul]

That is a lot of numbers. Just remember the laws of physics state that two things can not occupy the same place at the same time. You looking at groove, lands, lube, and fouling after the first shot. If you need something smaller, I have a 510, 511, and 512 sizer. I can sell you one hundred Lyman 515139 bullets of different sizes for $40 shipped. The bullets will be soft lead.

true blue and Diamond Hard,
Harry
03626v

[Maillemaker]

OK, all's good. After pushing 7 bullets through the sizer, it eased right up. All the rest pushed through with very little effort and no flash. These bullets size to .515 with no problem at all.

Steve

[Hal]

Steve,

If you are not already, lube them before sizing. You may already be doing this. If so, please disregard.

[Maillemaker]

Well, my first go, I lubed before sizing. I figured this way the grease grooves could be full and the sizer would wipe off the excess. But, I know from modern reloading that the lube can actually swage the bullet smaller. Also someone here suggested lubing after sizing. So, this go-around I lubed after sizing.

I dip-lubed. So-as not to have a big crust of lube on the bullets, I pre-heated all my bullets on the same hot plate that I melt the tin of lube in. Then I dip them, wipe their bottoms on a piece of wax paper, and set them aside to cool. Most of the lube runs off, with a bit being held in the grease groove due to capillary action. But the groove is not "full to the rim" of lube this way.

Steve