Don,
There are some strict traditionalist that really get upset over the use of 2-Diameter Paper Patch Bullets (2-D PPB). I understand wanting to follow tradition, but I don't understand not letting others do it their way. Be an advocate for your way, but don't badmouth the other shooter's bullets. UNLESS they're shooting grease groove, then the gloves are off!
With the 2-D PPB what comes out the muzzle is not significantly different than it is with the more "traditional" straight sided bore diameter PPB that the ODG used. That bullet I recovered is proof of that. With the 2-D PPB it is possible to get a very good level of accuracy from a rifle that is not chambered for PPB.
In my .40-65 with it's .400" long freebore I can't imagine a straight sided bore diameter PPB working well at all. With a 2-D PPB designed to fit the chamber of my rifle it shoots extremely well. And I don't have to size my case necks at all.
If that rifle had a faster twist, it's a 1 in 18, I would be interested in how far a longer, heavier 2-D PPB could be effective. You have a .40-90 SBN that you shoot your 2-D PPB bullets in, right? That would be a interesting long range rifle. What is the ROT in that one. To get a bullet a bit over 1.4" long it would require a 15-twist or better yet a 14.5 twist. I think it would be possible to push a 430-450 grain .40 caliber bullet with enough velocity to do well at 1000 yards, maybe very well and I don't think the case has to be overly huge to be it done. 70 to 75 grains of powder seems to be a sweet spot in .40 caliber. Iy might be possible in a .40-65 case.
My little .40 caliber 382 grain 2-D PPB has competed well against the .45s out to 600 yards. I know others have built fast twist .40s for long-range shooting, but is anyone competing successfully on a regular basis with a .40? With PPB?
I'm hoping some day to give it a try with a .44 caliber and PPB, maybe 2-D PPB, but I don't know if funds or time will be there to try a .40 caliber, though it is an interesting thought.
Anyway, my point here is that in actual shooting there isn't any difference in the 2-D and the more traditional sided bore diameter PPB. We 2-D shooters shouldn't have to hide what we're using!