Interesting read about your work on the Whitworth. Someday I'd like to get one. I have a Pedersoli 2 band; got it used. Always thought it had a 1 in 48 twist. Now I don't want to know
. Cabelas says theirs is 1 in 48. DGW says 1 in 56. Please post when you test the knurled minies.
I had a chance to get out and shoot the knurled minie balls today. Before I get into the results, a little background information is in order.
About 9 or 10 years ago, I made up a bunch of pre-measured charges for the Enfield. I used 70 grains of FG and the minie balls were swaged to a diameter of .575. The sides were left smooth on some and on others I knurled. Long before that time, I started using the bore butter and could shoot all day long with that stuff.
Anyway, these 9 to 10 year old loads were made up with some bore butter and some with SPG. I filled the bases with the lubricant.
Back to the knurled bullets. I knurled them using the Corbin knurling tool. The depth of the knurling is kept shallow as the overall diameter is increased with knurling. So the bullets will run about .578 to .579.
Some of the pre-measured loads were made with the rubber thread protectors. The powder poured in the rubber tube with the lubricated bullet pressed in the opening with a piece of plastic shopping bag as a barrier between the powder and the bullet. Other loads were made up using old plastic 35mm canisters.
Why did it take me so long to get around to shooting these 9 to 10 year old loads? Personal stuff. I've had a lot of things happen to me in the last decade that prevented me from doing things I enjoy; such as shooting black powder and lots of it.
All that has changed and I can start enjoying life again.
That's the good news. The bad news is that all that lubricant; the bore butter and the SPG dried up and got hard. It didn't get real hard like a brick but just imagine 100 year old peanut butter.
Even though all the loads were kept in air tight sealed containers, I suspect the black powder might have attracted some moisture as I had a lot of misfires and inconsistent ignition.
So, I'm going to dump all the powder and will probable switch to FFFG for everything. I use that grade in the pistols and flintlocks. I've used it in muskets before with good results. Prior to today, I also had good results with FG but now want to standardize. I will use FFFG in everything. Besides the finer grade is easier to ignite. I will back off of the amount of powder due to slightly higher pressure.
I left the lubricant on the first ten rounds that I fired. It was the dried up bore butter. It turned brown and was like soft beeswax. These were the knurled bullets. Nevertheless, I smeared white lithium grease on the sides, hoping this would keep the fouling soft.
As expected, the rounds were a little tight. I could load them fairly easily but needed a palm saver to get them seated firmly. After the fifth round, I swabbed the barrel.
Below are the velocity measurements:
Average MV - 895.82 fps
High --------- 948.09 fps
Low ----------762.59 fps
E/S ---------- 185.49
S/D ---------- 55.70
Below is the first target. As you can see the results were disappointing. I believe this was a result of a combination of inconsistent ignition and the dried lubricant in the cavity. I expected this but wanted to try the ammunition out anyway. I was using a 6 o-clock hold on the target. No attempt at windage correction was made.
For the 2nd string of shots, I took out my pocket knife and removed the old lubricant from the hallow base and replaced it with white lithium grease. I did this with 10 rounds.
The chronograph results were a little more encouraging and I still had several misfires. Note that the extreme spread and standard deviation was cut in half from the previous string.
Average MV - 872.58 fps
High --------- 911.51 fps
Low ---------- 819.36 fps
E/S ---------- 92.14
S/D ---------- 26.83
The group seemed to tighten up a little more with using nothing but the white lithium grease. I still had to swab the barrel after the 5th round.
I'm not ready to give up on the knurled minie ball yet. I think it does a good job of holding the lubricant. Like I said earlier these knurled bullets are tight.
With that said, I'll be placing another order with Corbin for a set of dies that will probably swage the bullet to a .568 diameter. So with knurling adding another .004 the overall diameter with be .572. I may even go smaller than that with a .564 diameter swaged bullet and a knurled diameter of .568.
As for the white lithium grease. I will still do some more experimenting. I like the bore butter. If I make anymore pre-measured charges using bore butter I better shoot them in the same decade.
On the other hand, I may switch to a mixture of beeswax and olive oil.
As disappoint as the results were, I learned a few things today. That's what shooting and experimenting is all about. So as bad as the targets look, I can tell you from experience, they would have been worse with hard lead bullets.
Any thoughts or suggestions would be greatly appreciated.
