Bullet design questions

[Dave Berryhill]

I'm getting set up to cast bullets for the first time but I've been reloading for years with commercial bullets. I've read a few articles about "Keith" semi-wadcutters including this excellent one written by Glen Fryxell:
http://www.lasc.us/38SWC.htm

According to Fryxell, a Keith style SWC has the following characteristics:
1. 3 driving bands
2. a beveled crimping groove
3. a large grease groove with a square (not round) profile
4. a large meplat and radiused ogive

I understand that Elmer Keith generally used them for hunting and that was the primary reason for #4 so let's put that aside for now. My questions are about #1 and 3.

Elmer wanted a grease groove with a square profile because it would hold more bullet lube than a round grease groove having the same width. That makes sense but is one large groove necessarily better (more accurate/less leading/more velocity) than 2 smaller grease grooves that hold the same volume of lube? Likewise, why 3 driving bands instead of 4 narrower bands?

I ask this because I've seen many revolver SWC molds having features #2 and 4 but with 2 smaller grease grooves and 4 driving bands. In practical terms, what's the difference?

[Larry Gibson]

We forget that when Keith designed his series of SWCs they didn't have the lubes we have today. Basicly 50/50 alox/beeswax lubes negated the need for the larger lube grooves Keith used. I helped run a test one time with a friend who had a very accurate .44 Ruger BH. we had access to a solidly benched (actually a 55 gallon barrel filled with cement) Ransom rest. We were comparring the original Keith 429421 with square lube groove (his mould) to the Lyman 429421 with round groove (my mould). Load was the classic Keith of 22 gr 2400 under both bullets. Bullets were cast of WWs with some linotype added and lubed with Javelina. We fired 50 shots of each in one string (unfortunely I did not have a chronograph yet - '74 when the test was done) only cleaning between each load of 50 shots. After the 50 shots the revolver cleaned up just as easily for both bullets. There was absolutely no leading with either bullet. The total 50 shot group for each bullet was just under 2.5".

As to driving bands it my experience the bullets with a thick base band that is square instead of bevel will shoot better, especially at magnum velocities. Also my tests reveal that Flat base bullets are almost invariably more accurate than a similar design with a bevel. I believe bevel base handgun bullets and hard wax lubes are made for commercail bullet makers and commercial reloaders, not shooters.

Larry Gibson

[shooter93]

Keith also had in mind extreme range shooting when he designed his bullets but they still work well and the have TONS of nostalgia. Larry....do you remember the range you fired the test at...25 yds...50?

[Dave Berryhill]

Thanks for the info and the interesting test results. Out of curiosity, what did Keith use for bullet lube?

[Nueces]

Dave, Elmer's lube preferences must surely have developed with time, but, in 1936 (by which time, all his revolver bullets had been designed), he had this to say, in his "Sixgun Cartridges and Loads:"

"Use either a prepared lubricant like the Ideal Banana, or a home-brew article of beeswax and tallow, or even pure beef tallow can be made to do."

He was still recommending Ideal lube in the fifties, in the original Lyman "Handbook of Cast Bullets."

My samples of old Ideal lube look like black crayon wax. Keith was able to make this stuff work long before Alox and other modern lubes.

Interesting stuff, huh?

Mark

[Lloyd Smale]

dont know what the differnce would be but i do know one thing. Ive shot just about every swc that i could find over the years in the 44s and 45s and i do know he was on to something. For the most part my favoirte bullets in 44 and 45 are the ones that follow keiths designs the closest. Now im talking plain based mid weight bullets here. Bullets that run around 250-270 grain. I do prefer a couple gas checked designs but thats not what were talking about here. In testing ever gun ive owned and buddys guns ive loaded for the most consistantly accurate plain based 44 bullet ive found is the 250k rcbs. In 45 its the 255 rcbs. Now the problem here is that rcbs made a few varitations of these bullet over the years and it seemed like the more they varied from elmers design the worse they shot. The lyman 429421 is the same story. Its a dammed good bullet but they changed the design of that one a few times too. again the father away from keiths design they went the worse it shot, At least for me.

The round lube grove bullet is a good example. I hear people all the time say it shoots as well as the original. id like to know how they test there guns. Ive ran both side by side with the same loads out of the same alloys and varied both as much as humanly possible and will tell you without hesitation to find the square one if you want to use that bullet. Id say at least 90 percent of the time it has outshot the round lube grove version

Ive shot these and many other swcs (some called keiths) at levels from 44 russian to heavy44 mags and have shot them out of about every alloy and load possible and out of quite a few guns to come up with these conclusions. Granted most any bullet with enough load work can be made to shoot into 2 inches in a good gun but bullets i conider good will do it with about any load.
We can preach personal theroys on how a keith should be but bottom line is there a dammed good bullet as is. Elmer was not a genius. He never claimed to be. He was a shooter and designed this bullet as a shoot would. Maybe he got lucky, maybe he was smarter then even he thought but it worked. If you doubt it why then is it probably the most copied bullet design on the market. Just a look at the group buy section of this forum will tell you that.

Ive seen it for years! Mold manufactures are the worse offenders! Everyone wants to tweek that design to make it better and bottom line is no one has done a pinch of dammed to improve it. To me its about like trying to add a majic fuel additive to your gas to get an amazing improvement in gas mileage. It aint going to happen. Some thing just are what they are. The kieth design works. Its as simple as that.

[44man]

I agree with Lloyd. The old original 429421 I had was a great boolit. I was shooting the .44 to 200 yd's with it back in 1956.
Since I sold it long ago I have tried all kinds in all of my calibers and none equal it. The old 358156 could not be beat either.
The worst now seem to be the various designs for the .475. Oh, they shoot decent enough but I can't quite get real tight groups like I do with the LBT styles. One the average groups will be about twice as large.
Making my own molds and just changing one thing on the boolit results in a bum shooter and I can never put my finger on the actual reason. Another boolit that looks almost the same can be scary accurate.
It will always be a mystery so I can't tell anyone what to use. I have one .475 boolit with a narrow base band and full house loads packs it into tiny groups. I have all kinds of grease grooves and front drive bands on super shooting boolits too.
I just don't know what to tell anyone except to shoot the boolits and see. Boolit design will never be set in stone! [smilie=1:

[9.3X62AL]

There's always a "crapshoot" factor anytime you blend the numerous variables of one firearm to one bullet mould's personality. 44 Man spoke a Great Truth right there.

Still, Keith's designs and their permutations have a pretty good "street credential" for accurate work and decent terminal performance in animated targets. Is all that lube in that One Big Groove required? Not really. My idea for possibly improving the Keith design is to widen all three drive bands a bit by reducing the size of that lube groove--and I'm not sure that square vs. radiused grooves make a big difference. Wider drive bands might enable better rifling grip/less "skating", and a thicker base band might equal better resistance to gas cutting.

All of this may just be taking spray paint to the Sistine Chapel, too--my #358429, #429421, and #454424 all do very well in factory trim with a number of different revolvers in their respective calibers. I have the Thompson gas checked counterparts to all three calibers too, and they get about 15% of the shooting that the plain-based Keiths get. There could be a message in that, beyond the "I'm a cheep rat barstid" part of dodging gas check usage.

[45 2.1]

Is all that lube in that One Big Groove required? Not really. Depends on what your trying to do with the boolit. My idea for possibly improving the Keith design is to widen all three drive bands a bit by reducing the size of that lube groove--and I'm not sure that square vs. radiused grooves make a big difference. Keith knew it did for what he was doing with it. If your doing the opposite of what he did (Really hard boolits with hard or sticky lube), then it might not. Wider drive bands might enable better rifling grip/less "skating" Seems to work fine in that regard now as it is., and a thicker base band might equal better resistance to gas cutting. Gas cutting only goes so far up the band and is dependent on boolit size, temper and load.

Keith said that Lyman ruined his boolit when they changed the length and diameter of the front band AND when they changed the grease groove. You will note that "Elmer never said why". In looking at several early versions of his actual boolits, the reason is apparent. The grease groove has a function other than holding enough soft lube and the front band was for alignment. Lyman changed both and did ruin the boolit from Elmers perspective. If you try the GB Keiths as Elmer originally spec'd the loads, you should better results than what you've experienced before.