Lube groove size differences

[FISH4BUGS]

I was casting a metric ton of H&G #51's and sizing/lubing them on the Star. Basically a year's worth for the 38's.
Over the years I have noticed that most, if not all, true Keith bullets seem to have a lube groove the size of the Panama Canal.
In contrast, I recently cast a bunch of Lee Group Buy 38 130gr gc bullets that has a very small lube groove, and a tiny space above the gas check for lube. I also have other bullets (9mm, 45acp, 380) that have comparatively small lube grooves.
I was just wondering - what is the determining factor in the width of the lube groove?
Keith seems to love them, others not so much.
Any thoughts?

[popper]

Keith was using a lot of grease lube. Nowadays we have LLA/BLL/PC/HiTek. Not much lube needed. Grooves also serve the purpose of collecting alloy that normally would get pushed all the way to the base as tails. None of my rifle moulds have lube grooves, just a small collector groove.

[kreuzlover]

I tried Lee's .480 design bullet for my Ruger Super Redhawk, and except for low velocity loads, it leads like crazy with loads above 1000 fps. I then bought RCBS plain base mold design, 400 grains, and it doesn't lead much above 1000. I've never liked the Lee design, with the shallow grooves. The crazy thing is, the Lee mold bullet, groups as well, or better that the RCBS! Go figure!

[Winger Ed.]

- what is the determining factor in the width of the lube groove?
Keith seems to love them, others not so much.

In the old days, they were still in more or less uncharted waters as technology was rapidly changing and smokeless
powder, center fire primers, etc. was still sort of new.

They didn't have as much to improve on, or 'tweak' like we do now being so far down the road they pioneered.
A lot of the old mold designs basically started on a blank piece of paper,
and they had to figure out which lube worked best-- axle grease, or chicken fat..
Some worked, some didn't. Some did so well, they hang on even today.

We're just tweaking and making minor changes to their ideas and concepts as better lubes, powders, & such come along.

[GregLaROCHE]

Sounds like the Lee boolits are designed for Alox type lube.

[kreuzlover]

They are, of course. I've never cared much for them, but lots of folks love em. I have 3 Lyman 450 sizers set up on my loading bench, so I pretty much go that way on sizing and lubing.

[Larry Gibson]

As mentioned, with "modern" lubes starting with the NRA 50/50 formula it was found the larger lube grooves were not required. Actually, it also was found the larger lube grooves could be a detriment to accuracy especially when the cast bullet was pushed hard. Note on the NOE 30 XCB the lube grooves are much smaller than with conventional designs. The lube grooves on the 30 XCB hold enough modern lube such as 2500+ and 2900+ that, even at 2900 - 3000 + fps out of 28 - 31" barrels there is no leading and exceptional accuracy. The smaller lube grooves also increase the diameter of the bullet on the inside of the groove which adds considerable strength to the bullet to resist compression during high pressure acceleration.

Attachment 276025

[USSR]

I don't think Keith fired a light load in his life. With stiff loads the large lube grooves are fine. With light loads like .38 Special wadcutters, while they may have several small lube grooves, I typically only fill one with lube. More than enough.

Don

[JonB_in_Glencoe]

Most of NOE's design drawings include capacity of the Lube groove, good stuff to know, if you have a certain application for a boolit and specific amount of Lube you want it to hold.

[kreuzlover]

Another good way to know if you have enough lube is to look for the "lube star" at the muzzle. No lube star, not enough lube.