Designing the 2-diameter paper patch bullet.

[Distant Thunder]

With interest in the 2-diameter paper patched bullet concept growing I have decided to start a conversation about how I currently go about designing a 2-diameter bullet to fit a grease groove chamber. I hope others who have worked with this concept will speak up and add to the effort. My purpose is to increase the understanding of the design and increase the successful use of paper patched bullets in competition and shooting in general.

First I’d like to mention that writing is not something I’m good at, so if anyone feels the need to point my many shortcomings in that area please don’t. Let’s see if we can instead advance the sport and use of ppb. Please just go to the grammar and spelling forums and trash me there.

I can’t really begin this discussion without first acknowledging that Arnie Seitz, aka beltfed, focused my attention on the 2-diameter ppb idea about 2 years ago with his design idea for such a bullet to fit the Browning .40-65 BPCR chamber. When I had my very first black powder cartridge rifle I bought in 1991 rebarreled to .40-65 in 1995 it was chambered with basically a Ron Long design chamber. It shares the long freebore idea with the Browning chambers. I happened to be in the process of resurrecting this old rifle in hopes of using it for NRA BPCR silhouette matches. I was struggling with grease groove bullets in the 18-twist barrel and not really getting anywhere.

I had been shooting ppb in a Shiloh .45-90 (standard gg chamber) and a Hepburn .45-70 (Danielson pp chamber) in long-range competition for about 6-7 years and doing fairly well. I had dabbled in ppb bullets since I first began shooting BPCR in 1991. The idea of a 2-diameter ppb wasn’t new to me and I had in fact experimented with it before, but never as much as I have in the past couple years.

Arnie knew that I was making my own ppb molds when he came to me with a drawing of his design for the Browning chamber. Having been a tool & die maker before retiring I can indeed make molds which has greatly helped reduce both the cost and the time for experimenting with different ppb designs. While I can make molds there no way I can do it in any volume and my success rate is not even close to 100%, probably 50% really. I have cut many molds that ended up being recut into a larger caliber or scrapped all together. Also, it takes me about two weeks to make a mold and it would in no way be a profitable undertaking. There are several skilled mold makers who can make a mold to any design and that is where anyone looking for a mold should turn. I DO NOT MAKE MOLDS FOR SALE! Just so we’re are clear on that.

When Arnie came to me I saw an excellent opportunity to make the switch from greasers in my .40-65 to ppb. So I told Arnie that I would see if I could make a mold to his drawing and that I was hoping to use what we learned from his mold to make a mold for my rifle.

So I started down the road that has shown me that the 2-diameter paper patch bullet is indeed an excellent choice for rifles with grease groove chambers and especially for those rifles that have any amount of freebore. My .40-65 has a .409” diameter x .375” long freebore. I am happy to say that Arnie’s design worked out very well in his rifle and another shooters Browning. My requirements were a little different. I had a longer freebore, an 18-twist barrel, and wanted enough weight to knock down rams with some dependability. Arnie wanted the most ballistically efficient bullet for a 16-twist. So I cut Arnie’s design for him and a different design for my needs. The same basic 2-diameter principles were used for both and both designs worked out well, proving to be very accurate out to 600 yards.

Now I have the opportunity to take what I have learned in making those two molds and many other ppb molds over the past 10 years to help another shooter by designing a bullet and making a mold for his gg chambered .45-100. I’ve decided to post my efforts here for others to follow and add to in hopes of getting other interested shooters who want to shoot ppb to use the information and have molds made so they can have the best possible chance of success. I want more ppb shooters.

This project will take some time, something that I have in short supply, so be patient. I’ll being posting pictures and details as best I can, when I can.

Please feel free to ask questions or if you have other ideas on the subject please bring that up. I hope to include drawings of successful designs I’ve worked with and anyone is welcome to use them as is or modify them to fit their needs.

I am no expert on bullet design or ballistics, but I have some opinions that I have formed over the past 27 years of shooting BPCR and paper patched bullets. I have not closed my mind to new or different ideas, but rather I continue to try any reasonable idea and I have kept the ones that proved true and let go of those that didn’t. I am not done yet with that process and won’t be until the day I put up my guns for good.

As with any information you read on the internet don’t just accept what I say as correct and use the information I present with caution and safety in mind.

DT
aka Jim Kluskens