your preference on kieth boolits

[labradigger1]

I usually use a 4 gang lyman 429421 or a lyman 429244.
Tonight i broke out a new 2 gang rcbs 44-250k dc mould.
After casting several hundred of each i began comparing them (mainly 421 and 250k). The major differences i see are the meplate on the rcbs is about thirty thousandths larger than the lyman and the lube groove is square on the rcbs and rounded on the lyman.
I weighed them and the rcbs comes in at 258 grns and the lyman at 252.
Now i like a big fat meplate and so did Elmer, he also mandated equal length driving bands, meplate of 60% diameter of boolit and a square lube groove.
So what do you say that have both moulds? Any preference to one or the other? I am thinking the rcbs is going to be more accurate and i hope i am wrong as rcbs does not make a 4 gang mould.
Thoughts?
Lab

[runfiverun]

I have a 4 cav 429241 and a 2 cav 429241 one with square grooves one with round grooves.
I see no difference except the square lube grooves holds the lube better and more of it.

[HeavyMetal]

You'll find a lot of controversy on the sq vs round lube groove, for me I never found a difference in performance with either RCBS or Lyman molds same caliber as mentioned by the OP.

Bottom line is I sold the RCBS when I got the 429421 because theLyman was a 4 cavity mold plain and simple!

Ordered two of the cam'd sprue plates from Red River Rick with sprue plate troughs. converted both the 429421 and a 358477 to this style sprue plate so I could run both at the same time.

The RCBS mold made great boolits it just could not keep up with the two four bangers!

It was sold off for that reason alone, it payed for the sprue plates, which was reason enough for the sale.

[Maven]

"So what do you say that have both moulds? Any preference to one or the other? I am thinking the rcbs is going to be more accurate and i hope i am wrong as rcbs does not make a 4 gang mould. Thoughts?" ...labradigger

lab, As it happens, I have both the Lyman & RCBS Keith molds, but have a slight preference for the latter only because it has 2 cavities v. 1 in the Lyman. So far as I can determine, the shape of the lube grooves has made no material difference in the accuracy I get with either mold. I.e., both are equally accurate in my Ruger SBH. Btw, with the correct sabot, both CB's are satisfyingly accurate in my Knight Bighorn ML rifle as well.

[Larry Gibson]

The round lube groove moulds generally drop the bullets easier from the mould is about the only difference I've found. The large square grooves keith liked were best back in the day before our "modern" lubes. I've been using round and square lubed 429421s, 429244s, 429360s and with an RCBS 44-250-KT all with equal success and accuracy. Any accuracy difference was more a function of alloy, lube and load than bullet design.

Larry Gibson

[jmort]

Mine is the LBT style. ;-)

[9w1911]

I love the bullets they just do not feed so well in my 44 lever, if I had a 44 wheel gun I would use them all the time.

[Tar Heel]

I'm with Larry. The rounded lube groove will give a tad less casting trouble. Either way however, you can't lose. They are both great molds.

[TXGunNut]

Uncle Elmer liked the square lube grooves (and lots of lube) but as I recall Ideal/Lyman didn't want to make them that way. IIRC he felt the squared grooves pumped the lube out to the edge of the boolit where it could do it's job. His detractors felt rounded lube grooves hold plenty of lube and drop out easier but for his purposes I have little doubt he was right.

[Shiloh]

I have several molds that the bases have been flycut to remove bevel bases.

Shiloh

[rintinglen]

Ain't a dime's worth of difference between them. I prefer the round lube groove, because they are less prone to sticking, but either shoots fine. I believe Elmer confused pride of design with practical effectiveness, but either way, they are pretty good boolits.

[MT Gianni]

I have owned 5 LY 429421 molds. 22 have thrown similar profiles. I currently use a 2 cavity square groove.

[Outpost75]

I use the Saeco #441 which drops at 270 grains from COWW. From my scoped H&R Handi Rifle with correct loads which do not over-drive the plainbase bullet from the longer rifle barrel, an average of ten consecutive 5-shot groups at 100 yards averaged 2.66". Velocity is 1300 fps from the rifle with 8 grains of Bullseye. Grouping at 50 yards from my 5-1/2" Ruger is under 3" at 1080 fps. Load is a good performer on game.

[MtGun44]

I think modern lubes have mostly overridden the need for the larger square bottomed
lube groove - but I still like them. Never have seen a lot of difference with NRA 50-50 or
LBT soft blue lubes.

I really do like the RCBS interpretation of a Keith - excellent boolit design.

I think my all time favorite is the MP Keith 429421 clone - superb quality mold
and the perfect design, IMO.

I would note that the 429244 that the OP mentioned is not a Keith design, it is a GC
design by Thompson and Keith thought GCs were an abomination for pistol boolits,
and I have to agree that I find no need for them - even full power max loads with
pretty soft alloy seems just fine and no leading or accuracy issues. I do know that
the OP didn't say that 429244 was a Keith design, just thinking somebody may infer
that from the context.

Actually both Thompson .44 molds, the 429244 and 429215 have been mediocre to
poor performers for me - but I haven't tested them in many years, and I was
probably sizing them a bit small back in the "dumb old days" before I read Brian
Pearce's articles on sizing to the throats. And of course, coming here to do my
PhD research on cast boolits. . . . . . . . :-)


Bill

[labradigger1]

Thanks for all the replies, fwiw, the rcbs square groove drops easily from the mould.
Lab