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rodwha
11-01-2020, 05:13 PM
I have two percussion black powder revolvers that I’ve made a few designs for. What I ended up finding out is that they both seem to have a powder charge they do well with no matter what projectile I use, be it a round ball, my 170, or my 195 grn bullet. I have a new powder measure so I’ll need further testing to find tune my modifications, but will be filling the excess chamber room of these with more lead. From the last measurements I took configuring for their prior powder charges I estimated this bullet to be .497” long and likely 210-230 grns with a .375” meplat. This is the design so far:

https://i.postimg.cc/pXvwt5pm/D276-FFBA-EA5-C-4506-B33-C-02422-D14-F36-E.jpg (https://postimg.cc/MXsP7T0w)

I use energetic powders and have noted similar loads as mine so I estimate a muzzle velocity from my Remington New Model Army 950 FPS +/- and the ROA around 1025-1050. But I have a wild hair in my nether regions that I’d like a muzzleloader barrel to use these as either full bore conicals or paper patched. I’m thinking a nice carbine of 24-28” using peep sights, and pushed by 40-60 grns of powder, the upper level there being about on par with standard .44 Mag performance from a handgun. Sort of like a Jack-of-all-trades I “understand “ a lot of the things that go into bullet designs, but don’t necessarily know the finer details or maybe even old wives tales versus field results. So please bear with me and give me some feedback.

I’ll begin with the lead. As is I’ve only ever cast my projectiles, including my rifle balls/REALs, with pure lead. But I’ve had fill issues, along with having moved to a city that doesn’t sell scrap lead it appears, that have made me contemplate RotoMetals 2% tin when I get lower on lead. I know that for my revolvers and full bore conicals I need softer lead. But I also know that as the velocity goes way up you need the lead harder to keep it from stripping the riflings. So at what velocity does pure lead and 2% tin fail?

Having just read a portion of a sticky on meplats I’m contemplating mine. At .375” I’m at about 83%. At revolver velocities I’m all good, but being fairly light and short for caliber I’m wondering how it would likely behave on medium game. I’m still at a loss for how wide meplat bullets behave coming down from being super sonic. I estimated this being a problem at around 1150 FPS and estimating rifle velocities it looked like effective range would be rather short, ranging from as little as 50 yds and barely getting to 100. And maybe using this bullet from a rifle would only be used with lighter loads to keep the velocity issue in check. And of course I could always just use a better bullet, either commercial or another design (I’m considering modifying that 45-245C for my Ruger, and have a 285 grn version that I no longer had a use for as bears weren’t going to be on the menu after all.

http://accuratemolds.com/bullet_detail.php?bullet=45-285C-D.png

Looking at published loads this lighter bullet would likely start around 1300 FPS on up to about 1600 FPS.

This wobble I’ve read about, does this matter if it happens well before it’s down range? I assume my BC would be rather low (used .150). If I were to start this bullet at say 1200 FPS and it hits this wobble soon after, would it have stabilized by the time it’s 75 yds down range hitting a doe?

I recall reading old stuff on making wide meplat bullets back when I was designing my original bullets. It stated something like them finding ~78% meplat was the maximum one would want as beyond this they found the bullet tended to yaw a bit and not track straight upon impact. I’m wondering if this might have been the “wobble” and not meplat.

Since I’d like for this design to work in a carbine as well I’m wondering how meplat and BC relate when the OAL stays the same.

I must admit that since even my NMA is getting standard .45 ACP performance (~375 ft/lbs) I’ve considered cutting the powder charge a smidge just to elongate my bullet. But accuracy being such an important aspect, and my offhand shooting could use some tightening, I don’t know that I’d want to sacrifice any of it. :D

Earl54
11-01-2020, 10:06 PM
I believe that you will find that the greater the length of the bullet, the more stable the bullet. The heavier the bullet the longer it is for a given bore diameter. Make the bullet as long as you can and still get a useful speed. The closer to a square bullet you get( length = diameter) the less stable it will be. Imho

fcvan
11-08-2020, 06:59 PM
Interesting read, makes me want to shoot mine more. I bought a CVA 1859 REM copy back in 1985 because I didn't own a reloading press yet. I used Pyrodex and corn meal with rb, and later 200 RB conicals. Very fun, very economical for a new reloader. Well, I wasn't new, learned under my dad. but starting out I was limited. I need to shoot the old girl again.

rodwha
11-10-2020, 01:45 PM
Interesting read, makes me want to shoot mine more. I bought a CVA 1859 REM copy back in 1985 because I didn't own a reloading press yet. I used Pyrodex and corn meal with rb, and later 200 RB conicals. Very fun, very economical for a new reloader. Well, I wasn't new, learned under my dad. but starting out I was limited. I need to shoot the old girl again.

Yes! Get out there and shoot it again!

rodwha
11-10-2020, 01:47 PM
I’m still looking for more input, and I still need to run tests with this new powder measure which may change things a little, but I’ve decided to ditch the cardboard over powder card since I’ve never had an issue with lube contamination anyway. I also dug around and found my old notes on this and my Ruger, and this is what I have to work with:

https://i.postimg.cc/GtJFskpQ/C9954-E36-853-C-4693-AAEB-C1160-F7-F2-C63.jpg (https://postimg.cc/30N4s0m4)

Ultimately this is a universal pistol bullet so it needs to work within these parameters foremost. Speed gives the meplat its wound, but mass gives it the go power to keep that wound track going to the end and out. I’m thinking this will weigh 220-230 grns, maybe a little more. This seems nice for the NMA pushing it out around 850 FPS, but from my Ruger with its stouter charge would benefit from this getting closer to 240-250 grns. I’m not sure if I’d want to compromise on say a 240 grn bullet with a slightly reduced charge in my NMA that might struggle to hit 800 FPS.

I must admit that I do like the idea of further lengthening the bullet as Earl54 pointed out, but also to work in more typical twists if I were to seriously work towards being able to use it in a carbine. But he has custom bullets with meplats not quite as wide as mine, and accuracy from his Remington carbine goes out the window after 50 yds. Is this the wobble from the wide meplat? Maybe because his bullets are rather short like mine? I’ve yet to pick his brain some more.

And if it is an issue with the meplat and the sound barrier then adding mass by length and meplat might not be any more of an issue. I’ve read that wide meplats and worse yet, wad cutters, just don’t do well beyond 50 yds anyway, though Keith’s have fairly wide meplats and seem to do fine longer range (length?). My revolvers certainly won’t be shot that far except for fun maybe, and if that’s all a carbine can do, which would be about the extent of my acceptable range considering my eyesight without peeps.

Lloyd Smale
11-11-2020, 03:59 PM
when ballistic cast was up and running and doing custom designs i had them do a swc and a wfn with a bevel base for my old army rugers. I had dave clements back bore the chambers on one of them and it would hold 7 more grains of powder then stock old army. Did it intending on shooting a deer. Never did shoot a deer but the wfn shot 2 inch at 25 yards. Just lost interest in the old armys and sold them both. Sold the molds too. If i remember right the swc casted about 220 with pure and the wfn went about 240.

Earl54
11-11-2020, 05:42 PM
I’m still looking for more input, and I still need to run tests with this new powder measure which may change things a little, but I’ve decided to ditch the cardboard over powder card since I’ve never had an issue with lube contamination anyway. I also dug around and found my old notes on this and my Ruger, and this is what I have to work with:

https://i.postimg.cc/GtJFskpQ/C9954-E36-853-C-4693-AAEB-C1160-F7-F2-C63.jpg (https://postimg.cc/30N4s0m4)

Ultimately this is a universal pistol bullet so it needs to work within these parameters foremost. Speed gives the meplat its wound, but mass gives it the go power to keep that wound track going to the end and out. I’m thinking this will weigh 220-230 grns, maybe a little more. This seems nice for the NMA pushing it out around 850 FPS, but from my Ruger with its stouter charge would benefit from this getting closer to 240-250 grns. I’m not sure if I’d want to compromise on say a 240 grn bullet with a slightly reduced charge in my NMA that might struggle to hit 800 FPS.

I must admit that I do like the idea of further lengthening the bullet as Earl54 pointed out, but also to work in more typical twists if I were to seriously work towards being able to use it in a carbine. But he has custom bullets with meplats not quite as wide as mine, and accuracy from his Remington carbine goes out the window after 50 yds. Is this the wobble from the wide meplat? Maybe because his bullets are rather short like mine? I’ve yet to pick his brain some more.

And if it is an issue with the meplat and the sound barrier then adding mass by length and meplat might not be any more of an issue. I’ve read that wide meplats and worse yet, wad cutters, just don’t do well beyond 50 yds anyway, though Keith’s have fairly wide meplats and seem to do fine longer range (length?). My revolvers certainly won’t be shot that far except for fun maybe, and if that’s all a carbine can do, which would be about the extent of my acceptable range considering my eyesight without peeps.

Hollow base will add length for the same weight, and leave some powder room. Also it will move COG forward and "may" help with stability.