Seeking Advice On Possible Misalignment Of Blocks

[AccelR8]

Just signed up, as I said in the c'mon in lurkers thread, I used to cast for handguns many moons ago but got out of it. Now I'm starting up again with my old molds and one brand new Lee rifle mold, the 230 grain AAC blackout bullet.

I can cast good looking, well-filled out bullets with it but I have a problem. At first, it cast bullets with the front driving band diameter at .307" to .311." That's an average of 5 boolits. What I mean is, the measured dia. varies around the bullet. The .311" is 90 degrees to the mold parting line, the .307" is just off it enough that the mic is not measuring on top of the line. The rear band measures .308" to .312."

After sizing in a Lee .309 push-through die, the front band measures .307" to .309" and the rear is .308"-.309.

I just tried enlarging the mold with aluminum tape ("Beagling"?). I started with one layer of tape and went up to three when I finally realized it wasn't going to cure my ills. It did make the boolits larger 90 deg. across the mold line. I went up to a heavy .315" (like .3154) but strangely, measuring just off the parting line I seem to have gotten smaller. I cast a bunch and measured very carefully to be sure I was seeing it right but the dimension is now less than .306", .3054" to be exact. Same alloy as before, same pot temperature and as nearly as I can control it same mold temp.

Here's picture of one bullet out of the Beagled mold that I inked black and ran through the die. It's tough to photo and the more I handled it the more less defined it became but you can see on the rear band but especially the front, part of the band makes good contact with the sizer and gets smooshed down but just at the mold line, there's aportion that doesn't contact the die...like a low spot. On the front band the low spot is 25% of the way around the band. Also as can be seen the low spot is at two points around the band 180% apart, next to the mold line.

I think this indicates the two cavities are not aligned. I also think adding the tape aggravates this misalignment, that's why my smallest dimesnion got smaller. This mold has tapered alignment pins a bushings like the Lee 6 cav. molds.

So I'm seeking advice. Is my thinking correct? And how can I fix this? Should I try lapping the mold? Or should I just shoot them and see? My barrel slugs at .308" groove diameter (as nearly as I can measure).

Thanks in advance!

[41 mag fan]

try placing it on a board and closing them, see if that lines it back up, then if not,looks like the tape is the culprit.

Those low spots are either from shrinking or trapped air, where it's not able to vent out

[Iron Mike Golf]

Are the alignment pins, bushings, or both a little worn? Maybe coaxing the alignment pins out a tad would get you better engagement between pns and bushing and straighten things out.

[runfiverun]

see if it does if off the handles too.
it looks mis aligned.
it could be the hole in the handles is off a titch.
i had an rcbs mold do this same thing and it turned out to be some lead in one of the alignment pin hols shifting everything forward.

[AccelR8]

Thanks for all the replies. I'll look at all of the things mentioned here.
The mold is new so I would think the pins shouldn't be worn. I will look into coaxing them out a bit.
The suggestion about the misalignment being in the handles makes a lot of sense to me. I'll try to investigate that first.
Thanks again!

[Frozone]

If it's a two hole LEE then you may need to align things by tweaking the handles.
Those stamped steel POSes get bent on assembly, or the hole for the pins aren't drilled straight or some such.
you may need to bend one up or down or twist it slightly to get things to align without binding.