Lyman 454190 AX

[JohnFM]

Shouldn't this mold drop near .454?
The one I have is consistently dropping around ~.452, or less.
Most will pass through a .452 sizer without touching.
I've checked bullets from another .454 mold I have and that die sizes to .452 right on the nose.
Could it have been the alloy I used?
The under sized were cast with a mostly clip on WW mix, those dropping to size expected from the other mold were cast with a Lyman #2 mix.
I still have some of that alloy batch left and I'm going to try some with it later today.
If I need to I'll just melt all those I have that seem under sized from the Lyman mold.

[theperfessor]

The under sized were cast with a mostly clip on WW mix, those dropping to size expected from the other mold were cast with a Lyman #2 mix.

That's most likely the problem right there. Try casting with your Lyman #2 alloy and then see what you have. And let us know what the result is in case you need more help.

I've been critical of Lyman for a lot of reasons, but since they use L2 alloy as a standard if the size is right using their designated alloy then at least they are meeting their own specifications.

[JohnFM]

Thanks much. I've only got 5 molds, but I've cast many thousands of bullets with them now and this Lyman is the first time I've had a run of so obviously under sized.
If I get back from town soon enough I'll try a run with that alloy I have left in the pot, maybe for that mold I'll just have to be sure to use an alloy rich enough in linotype to keep it at the Lyman #2.

[GLL]

Is yours a new production mold?
I have several old IDEAL and LYMAN 454190s and they all cast at least 0.455" with 50/50 WW/Pb.



Jerry

[theperfessor]

Many people report that a lot of newer Lyman molds do cast undersize. But I would give them the benefit of the doubt and try their recommended alloy before I would complain too much. If it casts undersize with L2 then I would consider what other steps to take.

[JohnFM]

The guy I got this mold from said it was an older type. He said new types had a bigger flat point.
I don't know enough about them to be sure, but the bullet looks just like the one in the picture you posted.
I decided to put off a run to town, so I'll be firing up pretty soon to see what happens with the alloy I have left from casting with a different .454 a few days ago.

[JohnFM]

I just cast about 75. That #2 alloy did help some.
They all seem to run on the heavy side of .453 now, I can feel the .452 die as they pass through ever so slightly.
All I can do now is shoot some. A batch as cast and a batch run through the sizer and see how clean they shoot.

[theperfessor]

Hope your results come out OK, if not there are other steps you can take to get another 0.001 or so larger bullets. Let us know how things work.

[JohnFM]

Hmm, well I dunno about this.
This 45 Colt I'm using is an Uberti New Dakota and must have a nominal .451 bore because I measure ~.4505 on the slug.
I shot this latest batch (unsized) with 6 grns of Red Dot, it's the fastest powder I have and thought it might help bump up the bullet to better seal the bore.
Leading is tolerable, but still there, mostly in the first couple inches; about the same as what I got with what seemed undersized. I don't expect I'll see much if any help with the sized ones, after a pass through the sizer it's hard to see much sign of work by the sizer.
I'll probably just mess around this PM with some different powders, I might come across a good combination.
I'm gonna run out of prepped brass.

[theperfessor]

Have you checked the diameter at the end of each chamber? And slugged the barrel? While not universally true, usually the best accuracy in a revolver comes when the chamber mouths are the same size or slightly larger than the bore size. If the chamber mouths are smaller than the bore your bullet will be undersize as it enters the barrel and will lead just as you describe. Sometimes a fast powder that will bump up the slug as it exits the chamber and enters the barrel can help, but it's better if the dimensions are right to start with.

[JohnFM]

The cylinder mouths on this thing don't have a good finish.
After one cylinder full a bullet won't drop through from fouling.
If I polish the mouths out with a bronze brush and some copper wool they will.
8.5 grns of Unique seems to work pretty well. A few passes with the brush and copper wool and all the lead left behind is gone. I guess I could live with that.
I need to try some 2400 again, I was getting a clean bore with it, but accuracy went to hell for some reason, so I need to try it again.
Best by far has been the Lee 452-300 with Red Dot. POI is right on for this gun and shooting off a bag the accuracy was great. I should cast a few more of them and leave the gas check off and see how they work. I had cast a bunch of them for my 460 S&W, but with the GC installed.

[MT Chambers]

Lyman changed to .452", because over time there is/was less call for .454" bullets as a lot of those old Colt's aren't in use so much anymore.

[Larry Gibson]

Yes many do report Lyman moulds cast "undersized" bullets. The common thread to that complaint is; "The under sized were cast with a mostly clip on WW mix". Lyman's moulds are designed and made to cast to nominal diameter (that's the "454" with this mould) with Lyman #2 alloy. That is evidenced by; "those dropping to size expected from the other mold were cast with a Lyman #2 mix."

JohnFM

I suggest you add 2% tin to your COWW alloy, cast at 725 degrees and let the bullets AC and age for 7 - 10 days. I'd bet you find .454+ bullets are the result. Or, as suggested, try casting some with Lyman #2 alloy. You were absolutely correct with; "Could it have been the alloy I used? Unfortunately many want to blame Lyman for making bad moulds when it is the alloy that is "bad" (not really bad, just wrong). You understood your error which is good.

Larry Gibson

[JohnFM]

Tried to reply yesterday, but something happened. Anyway, I'm still working on it.
Last loads were 8 grns of SR7625 and still quite a bit of leading.
This grouchy old curmudgeon would welcome any further tip, hints, ideas.

[JohnFM]

Size must matter!
I remembered I had part of a box of some commercial cast .452.
Ran some of them, slick as owl snot and not a spec of lead left behind.
I'm gonna regroup and cast a batch with my Lee 452-300 which has been dropping a bullet with my #2 alloy mix that sizes perfectly through the .452 die and then not put on the gas checks.

[theperfessor]

IMHO size is probably the most critical variable. Hardness, etc is all secondary. Sounds like you're getting on track now.

[JohnFM]

I've had a hard time appreciating just how critical actual size is till I ran into the problems with this Lyman mold.
Since I don't have that many molds, I've probably been lucky and they've been casting proper sized.
I'm not going to mess with that 454190 for a while till I get a little tin so I can work on a better alloy to work with it.

[theperfessor]

There are several stickies here about how to lap out a mold to get another thou or so. You could also try "Beagling" (named after a member here), which involves using metal foil tape between the mold halves to make the bullets a little larger. Check out the Classics and Stickies section for more info.

That is a pretty good bullet design, once you get some bullets from it that are the right size you'll probably like it a lot.

[JohnFM]

Well, durn. Still can't find the right combination.
I can get a couple different 300 grainers to shoot sweet out of that gun, but the 250 grain 454190 just won't cooperate.
I guess if it was easy everybody would be doing it.

[runfiverun]

why don't you try letting your boolits set-up for about 10 day's before shooting them.
if you cast and then shoot them in the same day or so you might as well be pouring straight lead.