Boolit design: Lube Bands

[Zbench]

So, I've bought a few moulds from Mountain Molds. He does a great job, and the turn around it relatively quick.

Since you can design your own boolit the way you want on his site, I've often wondered the virtue of number of lube bands for pistol boolits.

For a .40 SW say, you can make one large band in the middle, or two smaller bands spaced equally. My thought is spreading the lube in several spots along the path of the boolit has to be better than one large one.

I wanted to see what the general consensus and wisdom was on the topic.

Regards,

Pete

[arcticbreeze]

At pistol velocities I don't think it would matter. At rifle velocity I think it would matter more. That is my personal uneducated funky logic.

Marc

:redneck:

[JSnover]

Between the two, velocity might change because of the difference in bearing surface, but probably not much unless you go with a radical groove-to-band ratio.

[geargnasher]

Pete, I completely second Arcticbreeze's statement. My fairly unscientific opinion has been formed on the basis of the .45 ACP. I've shot tumble-lubed 452374s (1 huge rounded groove, plain base) and stick-lubed Lee Tumble Lube microband Trucnated-cone bevel-base, and vice-versa with no probems and very good accuracy. I've used Felix lube, BAC, Alox stick, LBT, and MolyBee, as well as LLA and LLA/JPW. About the only thing I haven't tried is Rooster Jacket. They all work.

In a straight-walled pistol I personally would design one big groove with a flat bottom (like Elmer Keith liked) and 5* sides to the groove so it won't stick in the blocks. I also like a bevel base in my autos which don't get much crimp and it minimizes bellmouthing brass working. I still feel that the pb style boolit has a bit of an accuracy edge, but that difference is only realized in guns that can shoot 1" at 25 yards, and most autos can't do that from a Ransom Rest anyway so go for the easier casting and reloading-friendly BB design.

My 2 cents, others may disagree, but we all have different ideas and shooting objectives.

Gear

[GabbyM]

The 40 S&W tends to end up with short fat bullets unless you get over 200 grains. I like my Magma 155gr SWC that looks to me like a shrunk down 45 caliber H&G #68. Also like the Lyman 170gr TCFP for heavy work. Both are one grove and I can't see room for more. Now the MM bullet in 357 I designed is 170 grains with two groves above the gas check. It's a Marlin rifle bullet with short nose and a body length of a 180 grain bullet. I figured more lube for 357 mag carbine would be a good thing. It's almost like a Loverin design. Note the lube you see above the gas check is the undercut gas check shank MM options.

One thing the short bands do is make it easier to push through a sizer. Again this bullet is specific for the marlin rifles. The front band cast smaller than the body which is sized at .359". My .359" Star size die generally has multiple lube holes opened up for the other 35 caliber rifle bullets I have so this multi lube grove bullet fits in with the production run where a single lube grove pistol bullet would require plugging some of the lube holes in the die. This bullet has been fired at over 1,800 fps with great accuracy and no leading. Don't know that it would shoot any better than my Saeco 180 grain with single lube grove though. But the Saeco won't feed in a Marlin.

http://castboolits.gunloads.com/picture.php?albumid=32&pictureid=1198

[Edubya]

I've used mini grooves and single grooves. Single grooves work better with heated lubes for me. It's easier to line up for my Star lubers and SAECO lubrisizer. The mini grooves might be better for the shake and bake, like LLA, but I never had satisfactory results with LLA. I guess it matters which lube, which bullet, and which style that you and your gun likes.
EW

[Naphtali]

. . . I've often wondered the virtue of number of lube bands for pistol boolits.

For a .40 SW say, you can make one large band in the middle, or two smaller bands spaced equally. My thought is spreading the lube in several spots along the path of the boolit has to be better than one large one.

I wanted to see what the general consensus and wisdom was on the topic.

Regards,
PeteAHA! Two minds with a single thought. In this forum, I have a query about 45-70/425 bullets. So far, it looks like my shooting partner and I must buy the mold, shoot, and compare results with what we hoped for versus our [satisfactory] previous design.

[Zbench]

Naphtali,

Seems like. I guess I am less concerned about the complexities of lining up the lube bands with holes in the dies.

I was more interested to hear if there is any significant advantage with having 2 large bearing surfaces as opposed to three or more smaller ones. Seems like the consensus is that there isn't a real difference.

[Naphtali]

. . . Seems like the consensus is that there isn't a real difference.I hope you are correct.