Howdy El Peludo! Welcome to The Den!
The PRS/MAV/Snakebite bullets: Actually I get a tiny bit of credit for thier creation, I was the first to discover "The Big Lube Theory" with my modified Maxi Ball slugs loaded into .45 Colt cases. It was, and still is, a fantastic idea and extremely accurate to boot. But it had some drawbacks. It wasn't tube magazine freindly, with too much point to make me feel safe about using it in a rifle, and it is slow to cast! The molds can be modified to overcome the tube mag problem, and I have done so with great success.....but it's still awfully slow!
After my initial reports on my discovery, others took the idea behind it and went to new levels! Pigeon Roost Slim (of PRS fame) experiamented wth my slugs and then developed his own design based on the theory that more lube is better when it comes to BP....and the PRS was born. MAV Dutchman wanted something similar in a .44 and downsizing the PRS was the perfect answer, The Snakebite was of similar heritage, but with the added idea to make a slug that would work in .38 Special but could be loaded to give nearly the same OAL as a .357 Magnum for better feed characteristics in in tempermental lever guns. The Snakebite is the only one of the three that I consider to be be "nose heavy". And it's not really THAT much wieght forward compared to many designs.
Regarding the keyholing reports. I have seen posts indicating that the problem exists. However I have some reservations about the nature of those posts. They appear to all have been written by the same poster on various boards, using multiple names/ (Word content, sentance structure, & syntax make me think this, however I cannot make that statement with 100% sureness...call it a gut feeling if you will) When questioned about loads and firearms he has been using the Snakebites in, he never repsonds. Leaving me to wonder if it's the load or the gun, or the bullet..lotta variables there but no answers. Having fired over a thousand rounds of Snakebite, approximantly 20% of them into paper, I have never noticed any keyholing from my guns. I've shot them through a Rossi 92 and an ASM Open Top. Accuracy was always more than acceptable to me (keeping in mind that I am not the worlds greatest shot by any stretch of the imagination). And fouling was minimized to the point that I continue to be astounded every time I use these slugs. I have also shot several thousand of the PRS slugs through a Rossi and my 75 Remmies and have been more than happy with them and have nver encountered any keyholing. I know of a number of shooters who use these slugs in thier guns, Marlins, Rossi's, and various revolvers, and none of them has ever mentioned encountering keyholing in my presence.
The 45-70, called the Dastardly/PRS, is a 400 grain design utilizing two of the PRS style lube grooves. This bullet was not designed with super presicion in mind, it was intend to be a tube magazine design for general use in big bore lever guns and it appears to be near perfect in that task. I have shot about 300 of them through my Pedersoli Rolling Block and I am very pleased with initial results. The bullet gives me all the accuracy I am personaly capable of wringing out of a gun. Again, keeping in mind that I am no expert rifleman! Others have reported obtaining better long range groups than I can manage even with the finest bullets and best guns...my own limitations restrict my participation in reporting on that score...but I can shoot it as well as any design I have ever used. Two things come to mind to mention about this slug, 1. It keeps the barrel MUCH cooler during an extended string. 2. Fouling is MAJOR softer throughout the length of the barrel! My Roller has a 34" barrel and I encountered extremely hard fouling in the last few inches of the bore with conventional style slugs. And using grease cookies turned out to be counter productive in this gun, opening groups considerably for me.
There is a 500 grain version of the 45-70 design in the works but it is awaiting further reporting on the abilities of the 400 grainer, and input from shooters on possible design changes. At present it looks like the 500gr design will have a long, bore riding nose, with a small meplat, and the two lube groove design of the 400gr version. But at this time it is a "wait and see" proposition.
I am not aware of any attempts to create a 32-20 version of the Big Lube designs, but that does NOT mean that someone out there is not working on one. There is no reason that the original design could not be modified to utilize the smaller bores!
I know this is limited infomation, but I hope it helps answer at least some of things that must be running through your mind about these radical new slugs!