Has anyone had any experience with the shallow multi-grooved bullets refered to as mini-groove?  I see Sagebrush has a line of moulds for them.  I was wondering how they would work with straight black powder loads?

How are they with smokeless loads?

                         Sendaro

Lee sold a line of bullet molds designed for their liquid alox bullet lube. They were supposed to hold more lube in the mini grooves, vs. full sized lube grooves. I had several of them in various calibers, and used the liquid alox lube with them, with great results. I found they were very nice shooting bullets.
They seemed to mostly be in pistol caliber bullet sizes, and I always wished they would have made them in some calibers for common rifle calibers like .38-55 and .32-40 calibers.

The micro/mini-grove BPCR bullets were designed by Dan Theodore for at least a couple of reasons.  It reduces the tendency of bore leading due to friction and tends to improve the aerodynamics of the bullet.  The negative, if you do not wipe between shots, is the lube capacity can be insufficient for shooting in relatively hot & dry conditions.

Dan has found through rigorous testing that 0.250” of lube contact length is optimum.  Although the lube contact length may be adequate, if the grooves are not deep enough to carry sufficient capacity the bullet may run out of lube prior to reaching the muzzle.  The width and depth of the grooves determines the lube carrying capacity.  Ideally I like to have around 1.75 to 2 grs of lube capacity.   An excellent method to determine if the bullet holds enough lube is to check the muzzle for a lube star, lack of which indicates insufficient capacity or possibly poor quality lube.  Of course that depends on the ambient temp. humidity and other factors.

Wayne

Which bullet is that?
  I'll bet that, minus the GC, it'd work well in my Late-model (late 1920-early30's Int'l. Free Rifle/schuetzen) 7.5x55 Hamm. Martini.

I believe, after looking a a few recovered bullets and picture of a bunch more of them, that the soft lead bullets frequently used tend to 'slump" and distort with the pressure impact characteristic of black powder cartridge ignition. This is considerably more that you get with harder case alloys and smokeless powder.
This forces the lube-filled grooves to close up somewhat extruding the lube out between the body of the bullet and the interior of the rifles bore.  This is a very complex dynamic process with a whole bunch of variables at play.  As a result you get differing results and different opinions depending on who is shooting what, how, and under what physical and environmental conditions.

Dan Theodore designed the mini groove ("Money Bullet") It has an excellent BC & SD, plus being an accurate BPCR reload for shooting long range.  About 4 yrs ago, Keith Lay used the bullet in a 45-70 reload and took First Place at Raton
The 1st time I used the Money Bullet was at Ridgway R&P Club shooting 1000yds with 20 reloads.  It shoots much flatter than a Postell or Creedmoor and is very accurate.  In 30+ Mph winds, after figuring out the vernier setting, I put 7 rounds in a 20" group.  With a windage adjustment to the left, all the rounds would have been in the 10 ring

The lube to use on the bullet is Bullshop's NASA Lube and cast them with 1:16 alloy

I have a Buffalo Arms version of the mini-groove Money bullet in .40 cal.   I don't know how well it would work of blow tubing, but it seems fine with wiping.   I do not use it much as, so far, I've had phenomenal accuracy from the Saeco 740 bullet ( deep grooves ), and only good accuracy from the mini-groove Money bullet.   

I think the tiny lube groove concept is pretty old.  My Zischang highwall came with three of his moulds.  The lube grooves are every bit as narrow and shallow as the modern mini-groove bullets.

Chris.