I am surprised that I have not heard much on the net about the bullet that Steve Garbe has discussed in his latest issue of BPCN.  It's a .38-55 bullet that he intends to use for schuetzen and blackpowder.   I'm skeptical that he will be successful if he shoots dirty as he describes, and I'm not really wild about the super short ugly round nose that he put on it (all bullets should at least look good when they are loaded - but that's just my personal hang up).   

I am really interested in those shallow, wide grease grooves.  The diameter of his bullet in the grooves is the same as the land diameter of his bore.  He things this will give better support to the bullet when it obturates.  I think that's a pretty interesting idea and wonder what others think about the amount of lube this bullet will carry and how it might perform.   

As I mentioned on another thread, I'm interested in having a bullet made that would solve some of my problems and that groove set up he describes is pretty interesting to me.  But I don't know a lot about these sorts of bullets so I thought I'd see what others think.

Brent

40-rod
That boattail thing is pretty interesting.  I don't know if you have heard about the boattail I played with a bit.  Getting it to shoot straight was a challenge that I did not quite conquer, though I didn't give it a lot of work either.  I have a webpage for the project at (You need to Login or Register to view media files and links);

I definitely recommend that you shoot into a box to check what your bullet's base looks like after shooting.  You might loose the chamfer altogether.   

You may also loose the bullet's stability.  If you go this route with a significant boattail effect, you may find that the bullet will tumble unless it is considerably shorter or you find a faster twist barrel.   

The bands on your bullet may or may not affect turbulence much.  They are going to be buried in the boundary layer to some extent and may not be very influential.  A small change in their shape may not change aerodynamics much.  I'm guessing a little here however.   

The thing that I think really kills aerodynamics with GG bullets is the first band at the junction of the nose to the shank of the bullet.  If this is a sharp step up, sort of like a semiwadcutter bullet, then you will loose a lot of aerodynamic efficiency though you may get some added stability.   

I have shot bullets with near identical noses, except one has a small shoulder like a semiwadcutter though somewhat reduced along side a bullet that is smooth in the transition from the nose to shank.  These were all paper patched bullets.  The small step on the first bullet reduced the measured ballistic coefficient by about 25% or more.  This is not necessarily bad, but it might be under some circumstances.

Brent

Don,
I know what Garbe's goals are and I will be interested to see how he fares.  I don't think he will do that great shooting dirty, especially off the bench.   

But what interests me about that bullet are the grooves.  They are so shallow and his logic for that makes lots of sense to me.  I'm very interested in those ideas.  Whether he has enough lube for shooting black is a fair question, but the idea seems pretty good.  I'm probably going to buy a bullet mold and this one's shank design has my attention.  I'm curious if others have thought about this as well.

The nose shape leaves a lot to be desired in my opinion, but it sure won't slump!   

Brent

Long Rifle,
I did get the bullets and sent you a note.  They look really good.  I've got a few loaded and will load a few more.  I was planning on shooting them this weekend but the Iowa Games are sucking up my rifle range for the entire weekend and my backyard range is half underwater and half under mosquitos.   

The bullet looks like an RCBS 317 mold.  Is that correct?

Thanks a bunch for these.  I'm anxious to try them out.

Brent

DWS,
My research and general expertise with these sorts of bullets is nil and not improving a lot.  I started with the RCBS 312 spire point.  It did not shoot well and I sold the mold.  That was last year's experience.  And my suspicions are that the mold was fine, but my reloading techniques were a big part of the problem (excessive run out in loaded cartridges).   

This year, I started with the Lyman 250 gr FN bullet - partly because I like FN bullets, partly because I thought I'd work up a load for targets and then take it antelope hunting as well.  That bullet has been a real wrestling match and finally, with a lot of help from Pete, it shoots sorta antelope-okay but it's not competitive on targets.  I got some persistent leading and finally Pete, who was having similar problems, figurred out that the bullet can be lube-sized as per normal and then resized in a .222 seating die and leading will be gone and accuracy improved.   

This helped for me, but I found that I had to use the FL die instead of the seating die.  It gives a stronger taper.  Now, the bullet is usable for antelope but still not competitive.   

So, in a bit of frustration, I bought a tapered 316 gr Hoch mold from CPA since they have them in stock and boy does this do a lot better in fixed ammo and with my new Leverton-style breech seater.  With the breach seating, I immediately added 10 points to my  bench scores using the very first load/powder combination that came to hand.  But I'm still not quite competitive using bp against the smokeless crowd (I will not shoot smokeless).   

I'm thinking about using the Hoch bullet on antelope, but in fixed ammo, there is not a lot of powder (42 gr of 3fg Swiss highly compressed), and trajectory will be tough to work with, plus it's a pointish roundnose.  Not optimal, but darn it shoots.   

I'm off to the range in a few minutes to try one more 250 FN load and decide which bullet it shall be for the hunt.  But for targets, I'm breech seating.   

That said, the hoch mold has many narrow grooves that are deep enough that they are not engraved by the rifling, unlike Garbe's bullet.  I think Garbe's idea has lots of merit though, and I would consider it, but I think I'll go back to paper patches if I do yet another bullet in the .38.

Brent