Designing the 2-diameter paper patch bullet.

[Distant Thunder]

Finally got a picture of the bullet itself and a couple patched with two different papers I have. The white paper is the stuff I use for both my long range bullet and my silhouette bullet. It is a 9# 100% cotton onionskin that is no longer made. The blue paper is also 100% cotton and is the same .0020" thickness. I can see that my template would need an adjustment for this 2-diameter bullet and I'll tackle that soon, that's not a surprise really, it is a larger diameter bullet so it would need a longer patch. You can see the base band and the "patch to" line on the bullet. It is a good looking bullet for sure. Should shoot great.

   

[Don McDowell]

Dang that's a sweet looking bullet.

[Kurt]

Jim I like that bullets hemisphere for long range. Most of my moulds I use for long range shooting looks very close to yours but what I found I had to keep the ogive shorter than the shank or that bullet would show instability cutting oval holes at around 900 yards when the winds picked up. I had Paul Jones shorten the radius because the 18 twist was not rotating it enough and I could not make the shank any longer because I was right at 1.450" long.
These bullets I tested different alloy mixes to hold the setback.

   

[Kurt]

The bullet on the left is Brents prolate and the bullet on the right is what I had Paul make first and it was not stable at 900 so I had him make a larger hemisphere to shorten the length of the ogive and it shot very good to the 1000 and those bullets in the above shoot well to the 1000 and this bullet shoots very well in the 16 twist .45-90.

   

[Distant Thunder]

Kurt,

I always hold my 18-twist .45s to 1.440" maximum and 1.430" is good too. I cut Brent's first prolate for an 18-twist, one for him and one for me, but at that length they only weighed about 490 grains. We both felt that was too light for long range. Brent had me cut a longer version at 1.520", but that would not shoot in his 18-twist because it was too long. He rebarreled to a 16-twist and that long bullet shot very well for 3 or 4 years, until whatever the problem is that he has had popped up. I haven't spoken to him so I don't know if he has resolved it yet or not.

For me to get to a stable length in for an 18-twist and have the weight something I could live with for long range I just capped his prolate design with a 1/3 caliber nose radius and still pretty much maintain the 50/50 shank/nose lengths. This design will weigh 520-525 grains at 1.435" OAL. That is what I have found to be the best bullet in my two long range rifles. I played with other versions but none work as well as this design.

Too slender of a nose like I see on other bullets being used can cause trouble in switchy winds, especially head winds. They'll work well sometimes and give you fits other times. With just enough weight in the nose this one holds up better when the winds are making other people scratch their heads.

I am pushing it just below 1300 fps and I think I would be better off with just a bit more speed. That might be just what I need to bring those 900 yards score up a little. It seems I can shoot in the high 80s or mid 90s at 1000 and in the mid to high 90s at 800, but I'm struggling in the upper 70s and low 80s at 900. I've been here before with GG bullets and I think I upped the fps a bit and things got better at 900. I need to review my notes from my .45-90 GG days and see what I did.

I should up the powder charge with my 1 1/2 Swiss and find the second sweet spot with more compression. If that proved to be in the 88 grain range I'd be pretty happy. That should give me 1340 to 1350 fps and that just might do it. I can't tell much at 200 yards so there may have to be some more load development at some matches this year. Just when I had decided to leave everything alone too! I guess it never really ends.

[Kurt]

   

Jim I don't know what is going on at the 900 with that sharp nosed bullet before I had Paul make a more blunt nosed replacement.
The first 900 on this score sheet I used the sharper nosed and I could not stay on the paper using it but it did ok on the 800 and the 1000. The next day I used a creedmoor nosed PP.
I still use that bullet in my CPA 1/16 ROT .45-90 and it got me in the triple A class in one years time and it's holding me in the top 15 at the Q.
Strange how a bullet the same length with the same basic ogive radius but a blunter nose reacts so much differently.

[Distant Thunder]

Kurt,

I'm no ballistics expert and I'll probably get myself in too deep very quickly. The way I understand it as the nose profile gets more slender you are reducing the nose weight and pushing the center of gravity farther back toward the base. Even with the same OAL the bullet with a more slender nose or coming to more of a point will require more spin to stabilize especially when bucking quartering headwinds. This problem is also made worse by BP velocities.

In my case I don't think that is the problem. I think it is somehow velocity related and has to do with how my bullet is spinning right at 900 yards. In reality it is probably just the shooter not breaking good shots or not following thru. If I could do some shooting at 900 yards around here I'd test that velocity theory, but that will have to be tested at a match I'm afraid.

[Distant Thunder]

Kurt,

It took me a little bit to figure out what match that score sheet was from! That was from Lodi September 2013. That was the first match with my new Hepburn and the Danielson PP chamber. I hadn't even quite finished building the rifle and didn't have much time for load development before the match. I was shooting 3F Swiss and bullets from the very first mold I made in an attempt to improve on Brent's prolate. That mold was a nose pour and had a flat on the tip. It actually shot pretty well out of my .45-90 but not out of my Hepburn.

By May the following year, 2014, I had cut another mold that fit the Hepburn better and was a base pour mold and worked somewhat better and I finished in 3rd place.

Then in August of 2014 I decided to go back to the bullet that had won 2 matches for me in my .45-90. The bore of my Hepburn is bigger than my Shiloh .45-90 so I opened up the mold to fit my Hepburn. It was only .001" bigger in diameter but what a difference it made. That August match, only the 4th match with my Hepburn, I finished in 1st place. That is the design that I cut for Matt here in this thread. Once I went back to that design and had it sized to fit my Hepburn I don't believe I ever finish lower than 5th place and more often than not somewhere in the top 3. That bullet shoots the best of any PPB I've tried. I have no idea how it will shoot in other rifles but time will tell.

[Kurt]

Yes, unfortunately the matches is where I test my loads also. I usually shoot better at 1000 than I do at 8 and 900 and you could be right I might bear down harder at the 1K than the rest.

[Distant Thunder]

I should say here also that I highly recommend investing is some sort of bore pigs (bore wiping system) for shooting paper patch bullet in completion. They are absolutely necessary for silhouette and a great advantage in paper matches.

I had used them with great success in my Shiloh .45-90 but I kind of got away from using them when I switched to my Hepburn .45-70. Then needing to use them in my .40-65 for silhouette I rediscovered how much they help keep the shooter thinking about making good shots instead of concentrating on running multiple patches thru the bore between shots. I went back to them for long range in the Hepburn at the beginning of last year and I have no doubt they made a huge difference.

From the bench and not on the clock you can wipe with whatever number of patches are needed, but when the clock is running wiping with one push thru is not only a time saver but saves energy and gives you more time to concentrate on shooting well. Fouling control is a big part of competing well with PPB and I finally got that squared away last year.