What Happens

[wv109323]

What would you expect to happen when you shoot a well over-sized cast bullet out of a rifle?
I know you could expect higher pressures but the load was well below any maximum load.
I confess I did.
I have been trying to get a Marlin 1894 in .44 Mag to shoot a cast bullet and I am about to pull my hair out. I think I have found the problem or a least part of it.
I bought a used Lee 6 cavity mold off Flee-bay. It apparently has problems that I am just discovering. I have only cast with it one time. I just mik'ed all the bullets that came out of the mold. They are running from .431 to .441. Of the 58 bullets that I had left from my casting session 23 of the 58 were well oversized. They ran from .435 to .441 in diameter.
When I first cast with the mold I only mik'ed a couple of the bullets and they were .431-.432 so I didn't expect a problem.
I sized the first ones to .429. They did not shoot very well due to under size. I then began to shoot them "as-cast" not knowing they were some that were oversized.
The accuracy with the "as-cast" was terrible to say the least. The Barrel leaded very badly and bullets would key-hole. Accuracy was 20" from 25 yards. I evn thought I had a scope problem that was not holding zero.
So if you shot a number of over-sized bullets what would you expect?

[williamwaco]

Those oversized bullets are faulty. Most likely cause is that the mold is not completely closed.

Close the mold, open the sprue plate, hold the base of the mold up to a bright light. If you can see light coming through the two halvs of the mold, you are going to get oversized bullets.

See:

http://www.reloadingtips.com/pages/missing_tumble_lube_grooves.htm

for more on this problem.




.

[JonB_in_Glencoe]

I had a Lee 6 cav. mold with on allignment pin protruding a tiny bit too much.
this would cause the mold to not close tightly on one side.
the result is:
the boolits from tightly closed side were near proper size.
the boolits from the loosely closed side were too large.
you might also see flashing on the oversize boolits.

This same problem could also be caused by a damaged corner where the mold halves close on each other or a speck of lead or junk on the mold face.

Look for things like that.
Jon

[MT Chambers]

If the bullets are that much oversize, I'm surprised that the loaded round would chamber!

[PS Paul]

Wow. I just got a modified Ranch Dog mold from another member and it would not close. I took a look and sure enough, there were little "burrs" that were causing this issue, so I put 'er under a microscoope (I am somewhat vision impaired) and used a small razor blade to eliminate those without damaging the actual mold faces/cavities. Voila!!! She closes perfect-like and I am going to use it on Monday for the first time since I bought it. I think the above advice will likely fix your problem since it REALLY sounds as if the issue is at least one of those listed above...... Good luck, man!

[runfiverun]

could just be your thumb on the sprue cutter holding the mold open.

most marlin 44's are using barells that have a twist rate based on the 44-40 which uses 200 gr boolits.

[popper]

.435 to .441 So you slugged your bore and it is < .433? In a 44 MAG? My point is - how do you know they are over sized? What size is a pulled CB? Me thinks you need to make more measurements.

[Wayne Smith]

You also might let us know what alloy you are using. Too many assumptions do cause problems.

[wv109323]

Thanks William for the reloading tips. I may have been gripping all three handles of the mold.
The alloy is range scrap with bar solder added. I have not slugged my barrel. I just assumed that .441 was too large for a nominal .429 barrel.
My neck expanding die is .425. I seated and then pulled a bullet. The before diameter was .441 and the pulled Diameter is .438. The case is noticeably larger where the over sized bullet is seated.
I have a larger neck expanding die ordered. When it arrives I willload the segregated bullets of .431 to .433 and try them. I also have some J-word bullets I will try.

[williamwaco]

Thanks William for the reloading tips. I may have been gripping all three handles of the mold.
The alloy is range scrap with bar solder added. I have not slugged my barrel. I just assumed that .441 was too large for a nominal .429 barrel.
My neck expanding die is .425. I seated and then pulled a bullet. The before diameter was .441 and the pulled Diameter is .438. The case is noticeably larger where the over sized bullet is seated.
I have a larger neck expanding die ordered. When it arrives I willload the segregated bullets of .431 to .433 and try them. I also have some J-word bullets I will try.


Indeed. The largest bullets I have seen fall from a .44 caliber mold were about .432 to .433

[mdi]

Out of my 5, .44 magnums only two are "nominal" .429" groove diameter (and one of those may be going .0005" over that), and one goes .432". For casting/shooting lead bullets, you gotta know some measurements; your gun (groove diameter, cylinder throat diameter) and your bullets (both pre and post sizing), IMO.

I would think a .010" variation is operator error; not holding the mold together, pouring issues, temperature variations, etc. Even if there were a .005" speck of lead holding the mold open, it should be .005" oversize, not vary 10 thousandths.