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View Full Version : New boolit for black powder revolvers, 45-250 hollow and rebated base



Onty
08-11-2020, 02:23 PM
UPDATE: Boolit redesign. After making a number of proposals for a new boolit for Ruger Old Army, to make sure that new boolit is sound, I asked for advise and help from our well know member and boolit designer 45 2.1. He agreed, and kindly provided a new design (THANK YOU SIR), see bellow.

I also wanted to have this boolit for Remington 1858, Colt, and other clones in same caliber.

Basic requirements:

- Weight 250 grains
- Hollow base (HB), for better accuracy
- Rebated base (RB), for easier loading
- Protrusion from the cylinder max. .500", so boolit could be loaded without removing cylinder from the revolver frame
- Meplat dia .300" max. so it will fit into rammer

The result of above wishes is boolit 45-250-HBRB-BK (BK stands for 45 2.1 initials):

https://i.imgur.com/cepkfz7.jpg

Because of slight differences in cylinder chambers between ROA and Remington 1858, Colt, and other clones in the same caliber, proposed are two boolits in two nominal sizes:

- .457" dia for Ruger Old Army

- .454" dia for Remington 1858, Colt and other clones normally using .454” dia ball (NOTE: because of smaller diameters, this boolit will have about 246 grains)

Please make note that diameters without brackets are for Ruger Old Army, and second dimensions in brackets are for Remington 1858, Colt, and other clones. Since I do not have any of those Italian clones, and do not know anybody in my area who has one, please review proposal and let me know if main diameters are OK.

This mold will be manufactured by Miha, MP-Molds https://www.mp-molds.com/ . We need commitment of at least 25 buyers before production could start. Molds will be available as 4 cavities and 2 cavities. Also, MP-mods offers their mold handles with discount when purchased with molds:

279481

Prices are:

- 4 cavity mold 128.59 euros
- 2 cavity mold 86.07 euros
- 1 handles 20 euros (when purchased with 1 mold)
- Shipping 18 euros. Cost is the same for 1 package with 1 mold, or 1 mold + 1 handles. If one package contains more, cost will vary.

Please be aware that these prices are just for orientation. Miha will give a final ones.

Potential buyers:

1. Onty, .457" dia, 4 cavities, 1 mold, 1 handles, ibcdiesel AT netscape DOT net
2. alamogunr, .457" dia, 2 cavities, 1 mold, alamogunr AT charter DOT net

tja6435
08-16-2020, 12:10 AM
I’m in for a 4 cavity hollow base

Onty
08-16-2020, 05:26 AM
Just updated drawing, REBATED BASE dia is now .450".

fivegunner
08-16-2020, 07:56 AM
I would be in for a 4 cavity Hollow base

ddixie884
08-25-2020, 04:19 PM
Nice design. Shows a lot of study and thought.......

Ozark mike
08-25-2020, 04:51 PM
Heck my bored cylinder 58 rem could accept that i may have to dig up some cash id kinda like to see a .38 diameter meplat though

alamogunr
08-25-2020, 10:48 PM
Interested but am going to hold off until more discussion.

Springfield
08-28-2020, 07:28 PM
You're going to need more rebated base than that to really get it started straight. Why not half of the bottom base instead of that little sliver?

fivegunner
11-01-2020, 08:32 AM
Bump to keep going

fivegunner
12-28-2020, 06:00 PM
Back to the top.

koyote
02-14-2021, 12:08 AM
I would be in for one of these molds. 4cav, HB

M-Tecs
02-14-2021, 12:23 AM
I’m in for a 4 cavity hollow base.

Dschuttig
02-17-2021, 12:58 AM
4 cavity hollow base please

beezapilot
02-17-2021, 06:54 AM
Following

Mmacro
02-25-2021, 10:42 PM
Following

fivegunner
02-26-2021, 10:41 AM
Is this still going???

Onty
02-28-2021, 03:19 PM
Hello folks. My apology for delayed reply, but I was going through several options, considered your comments, and measuring my ROA countless times. So, I put following goals:

- Boolit weight 250 grains
- Hollow base (HB)
- Meplat dia .300"
- Protrusion from cylinder when loaded .500", so it could be inserted and pressed into cylinder without removing it from the frame.

Anyhow, here is my proposal:

https://i.imgur.com/h0YMyts.jpg?1

Please let me know what do you think.

Onty
03-13-2021, 02:09 AM
UPDATE: Boolit redesign, see post #1

Onty
03-13-2021, 05:07 AM
Gentlemen:


I’m in for a 4 cavity hollow base


I would be in for a 4 cavity Hollow base


Interested but am going to hold off until more discussion.


I would be in for one of these molds. 4cav, HB


I’m in for a 4 cavity hollow base.


4 cavity hollow base please

Since boolit is redesigned, please let me know if you are still interested in the mold(s). Thank you.

Valley-Shooter
03-13-2021, 12:28 PM
I don't think that new design is holding enough bullet lube. Change it to one big lube groove and it will work better with black powder.
Check out this design. http://www.biglube.com/BulletMolds.aspx?ItemID=09d6fdda-c105-4c87-b269-68ebfdaba982

Sent from my Pixel 4 XL using Tapatalk

tja6435
03-13-2021, 08:08 PM
I’d like to see a large, single lube groove as VS suggested.

MOA
03-13-2021, 09:43 PM
I agree with one large lube groove.

alamogunr
03-13-2021, 10:11 PM
I'm not experienced with black powder. The only black powder arms that I have are the ROA and a Lyman Great Plains. I have no problem with the last design. The designs that 45 2.1 has put forward over the years have been widely accepted. But, if the decision is to make the lube groove larger, I have no problem with that either.

One question: Can the .457 boolit be sized to .454? I don't have a clone(never say never) but .0015 less depth of lube groove seems doable if I can accept that it is a compromise.

Put me down for one 2 cavity .457 diameter mold. alamogunr AT charter DOT net

M-Tecs
03-13-2021, 10:22 PM
I am in for the original and/or the current designed proposal. Switching to the Dick Dastardly big lube bullet single lube bullet will probably put me out. I would have to see it first.

I had some of the very first of his designs and the center post would compress. Later they were made larger but with your design and a hollow base that may become an issue.

The Dick Dastardly big lube bullet was mostly geared towards the cowboy shooter were accuracy requirements are very low. I have some of the later designs and not impressed with how they shoot.

Dick is a member but has not been on here since 2017.

http://castboolits.gunloads.com/showthread.php?1658-Big-Lube-(tm)-Bullets

When you design a better mouse trap the world will beat a path to your door. The DD Big Lube designs have been around for a very long time yet they remain a rarity.

The original 45 Colt bullet worked very well with BP and it had relatively small lube grooves. Pic on post #21 below.

http://castboolits.gunloads.com/showthread.php?29012-Original-45-Colt

The Lyman #452664 is a single lube design that works well with BP but so does the 454190.

https://dailycaller.com/2015/04/24/the-45-colt-history-and-surprising-facts-about-this-iconic-cartridge/

On a side note the 454190 holds enough lube to site get a lube star on my 24" lever guns. For a 7 1/2" ROA I don't see a lack of lube being an issue with the current design.

Onty
03-14-2021, 02:44 AM
I'm not experienced with black powder. The only black powder arms that I have are the ROA and a Lyman Great Plains. I have no problem with the last design. The designs that 45 2.1 has put forward over the years have been widely accepted. But, if the decision is to make the lube groove larger, I have no problem with that either.

One question: Can the .457 boolit be sized to .454? I don't have a clone(never say never) but .0015 less depth of lube groove seems doable if I can accept that it is a compromise.

Put me down for one 2 cavity .457 diameter mold. alamogunr AT charter DOT net
Knowing how many very successful boolits 45 2.1 designed, I felt the same, so I asked him for help, and he provided this design.

As for sizing boolit down from .457" to .454", it could be done. However, bottom portion .451" will not be affected, and if chambers are .450", boolit will not slide inside. That will make much more difficult to position/align it properly, and because of the boolit AOL, loading and ramming will have to be done on the bench, using one of those presses:

https://www.civilwarguns.com/gif/revcyl02.jpg

Well, removing cylinder from revolver for reloading is something I wanted to avoid.

alamogunr
03-14-2021, 09:26 AM
I already use a press like the one you pictured for the ROA. Not sure what is involved in removing the cylinder from some of the clones but it may not be a concern since I may never obtain a clone.

Springfield
03-14-2021, 01:19 PM
FWIW I shoot CAS shoots with BP cartridges at least once a month, sometimes 3, for the last 8 years. I use mostly Big Lube bullets or some designs of my own, that hold about as much lube. For pistols the lube requirements are not nearly as important as in a rifle, so one large or 2 smaller lube grooves should be fine. Glad to see the smaller, longer rebate for those of us who shoot Piettas/Ubertis. I have the Dick Dastardly Big Lube version and it just didn't load straight without out a lot of extra work, and never worked loading on the gun. Even though I don't own an ROA I would personally go with the .457 version, as with soft cast it shouldn't be a problem seating the bullet, and make for a better seal.
I'm in for single or double lube groove as long as the base is .450. And either 2 or 4 cavity, whichever one gets made.

GregLaROCHE
03-14-2021, 04:43 PM
Maybe I missed it, but didnít see what material the moulds are to be made of.

Also, width of grease grooves is more important than depth. With deep grooves some lube risks not being used. Is the total width of the two grooves added together more or less than the single groove? If it is more, two grooves could be better. If it is less than a single groove is better.

It would be good to get a guarantee that handles are available with the moulds, if you want them. In the past they have been out of stock when I wanted to buy a stock mould.

M-Tecs
03-14-2021, 05:05 PM
Maybe I missed it, but didn’t see what material the moulds are to be made of.

Also, width of grease grooves is more important than depth. With deep grooves some lube risks not being used. Is the total width of the two grooves added together more or less than the single groove? If it is more, two grooves could be better. If it is less than a single groove is better.

It would be good to get a guarantee that handles are available with the moulds, if you want them. In the past they have been out of stock when I wanted to buy a stock mould.

Miha, MP-Molds https://www.mp-molds.com/ so it would be brass or aluminum. With the hollow base it might be brass only.

Onty
03-14-2021, 05:08 PM
MP-Molds Cramer style are all made from brass:

http://uploads.tapatalk-cdn.com/20170115/2de673fc355353488325d77e4609083b.jpg

Here is mold for .455 Webley, with hollow base.

M-Tecs
03-14-2021, 05:19 PM
UPDATE: Boolit redesign, see post #1

I am in for the one in post 17, I believe I will pass on the single groove design. The longest barrels these will be shot in is 7 1/2". The original design carries sufficient lube for that. Since DD is a member I am trying to not disparage but the last thing I want is more big lube designs clones that shoot marginal at best.

For the people saying the two groove design doesn't carry enough lube explain to me why the original 45 Colt bullets worked so well if they didn't carry enough lube????? Same for the various 454190 designs???? They even hold enough lube for my 24" lever guns and BP.

They tested some originals here in a 24" barrel.

http://www.shilohrifle.com/forums/viewtopic.php?t=12327

279605

w30wcf aka w44wcf aka Jack Christian SASS 11993 was a member here until he passed in 2018.

M-Tecs
03-14-2021, 06:32 PM
I don't think that new design is holding enough bullet lube. Change it to one big lube groove and it will work better with black powder.
Check out this design. http://www.biglube.com/BulletMolds.aspx?ItemID=09d6fdda-c105-4c87-b269-68ebfdaba982

Sent from my Pixel 4 XL using Tapatalk

1. What bullets have your shot in a 7 1/2 or less barrel that didn't hold enough lube?

2. Have you shot the DD Big Lube bullets?

3. Did you have alignment issues with the overly large single groove?

M-Tecs
03-14-2021, 06:45 PM
I want a design that works with pure lead. Not 20-1 or a harder alloy.

Some highlights from an older thread.

http://castboolits.gunloads.com/showthread.php?349257-BigLube-bullet-shape-concern




I, PigeonRoost Slim (aka prs) am guilty most likely. I did the original design in 45 Colt and Dick carried on in transferring the idea to other calibers and applications. The original concept was to be used with wheel weight metal because that is generally what we had available at best price. Even with WW metal the concept is that there would be some minor compression to help force lube to be pressurized (probably folly). I have used WW alloy, Lyman 2 and Lyman 2 cut with lead to get half of Lyman 2. All wonderful in revolver and rifle (rifle being the actual mother of invention). I have cast pure lead in the version for the Ruger cap and ball revolver and no problem with accuracy, but you sure have to gentle in reloading and handling of the boolits -- way soft. Dick has probably shot the 38/40 or knows customers who have and who could advise you..

prs


I got a NOE copy of the Big Lube design in .44-40. When I cast my then-standard black powder alloy, jacketed bullet cores melted out of range scrap, it didn’t shoot as well as the standard Ideal 42798, although the barrel was much cleaner with black powder. When I switched to my other selection of range scrap, cast boolits made of wheel weights and Linotype, they shot just as well or better than the 42798, with more shots between cleanings. I think there is some potential with this design for slumping or other distortion upon firing, if the boolit is too soft.

If you get the BHN up to 9 or so, you should do fine.


Pure lead scrap is Heaven! Runfiverun mentioned to what I alluded about rifle being the mother of invention. I did the HUGE lube canyon because we had crappy black powder back then (early lots of Elephant and Goex; both shot very dry). Revolvers got by well with old pistol bullets from black powder era. The 45 Colt really had no original era bullet really suitable for level rifle as the great 454190 was bit on the pointy side for tube magazine. Swiss and Shuetzen maybe some forms of more recent Goex seem to shoot with softer/moister fouling, but the big lube design still shoots cooler and longer (infinitely so far as I know) at fast paces. They are messy in single action six shooters like my Rugers, but the pistols shoot so cool that I put up with it and simply wipe the grips now and then. There have been some rehashing of the designs to get better long range function, but not by me, Jack Christian and John Boy got into that. A pard by the name of Snakebite did the .357 version and it is a honey for function in 357mag chambered lever guns using 38SPL brass. Mav Dutchman had Lee do the 44/40 version. Dick Dastardly went plumb nuts doing other versions. There is a shorter .452" version too, done by a couple of fellows; Johnston and Peterson IIRC. It is good to have choices! I have never sold molds, so I have no fiscal tie to any of it.

prs


Dick told me to use a 20:1 mix. I hope my scrap is pure, it's mostly old water pipes. I also have some old bullets from 25 years ago but I can't remember what they were made of.

Now I need to find a good lube recipe to fill those huge lube grooves, something that will stay there and not leak in the powder long term. Beeswax and something else I guess. I don't think we have Crisco here in France, some equivalent maybe.. We sure have bees though!

If only lead hardness testing gizmos weren't so expensive!

I can't wait to get that .38-40 SAA next week!

Gil

Sent from my SM-G928F using Tapatalk

M-Tecs
03-14-2021, 07:03 PM
Hello folks. My apology for delayed reply, but I was going through several options, considered your comments, and measuring my ROA countless times. So, I put following goals:

- Boolit weight 250 grains
- Hollow base (HB)
- Meplat dia .300"
- Protrusion from cylinder when loaded .500", so it could be inserted and pressed into cylinder without removing it from the frame.

Anyhow, here is my proposal:

https://i.imgur.com/h0YMyts.jpg?1

Please let me know what do you think.

I am in for one of these. Not interested in the single lube design. I already have the DD version I don't use since there are better options. Also not interested in a bullet that has excess lube capacity even for 30" barrels.

What I am looking for is a maximum accuracy design specifically for ROA for hunting.

Valley-Shooter
03-14-2021, 11:22 PM
1. What bullets have your shot in a 7 1/2 or less barrel that didn't hold enough lube?

2. Have you shot the DD Big Lube bullets?

3. Did you have alignment issues with the overly large single groove?The problems I have is when shooting a black powder revolver and the cylinder starts binding up after 18 rounds because of fouling . I have used the 454-190, Lee 250, rcbs 45-230, and the big lube style bullets.
The big lube style bullets were the best at keeping fouling soft.

Plus the one big lube groove is easier to size and lube in a Lyman 450, compared to the 2 lube groove design.

Sent from my Pixel 4 XL using Tapatalk

M-Tecs
03-14-2021, 11:58 PM
The problems I have is when shooting a black powder revolver and the cylinder starts binding up after 18 rounds because of fouling . I have used the 454-190, Lee 250, rcbs 45-230, and the big lube style bullets.
The big lube style bullets were the best at keeping fouling soft.

Plus the one big lube groove is easier to size and lube in a Lyman 450, compared to the 2 lube groove design.

Sent from my Pixel 4 XL using Tapatalk

So most of them are out of cartridge guns?

Don't disagree that for cowboy action over greased helps but it also turns them into a dirty mess. This bullet is specifically designed for C&B revolvers. They are not intend to be sized.

When shooting a C&B revolvers I keep a spritz bottle with moose's milk and a wiping rag to deal with the cylinder fouling.

Are you shooting any C&B revolvers or just BP in cartridge guns?

I am not that serious about cowboy action and I have only shot a 4 different clubs over the years. I have only seen a couple of shooters using C&B in the Frontiersman class. Both of them were using paper cartridges.

Onty
04-13-2021, 05:04 PM
Looks like there is no big interest for latest design in the first post.

Well, because in this corona time I had nothing else to do, here is another try. Since Miha from MP-Molds https://www.mp-molds.com can make molds with different diameters using same cutter, I designed bullet for ROA in a such way that with reduced dia could be used also to make mold for cal. 44 Italian clones:

https://i.imgur.com/Z4UKTW2.jpg

As you could see, when all 3 grooves are combined, they are almost .160", not far behind BIG LUBE, that has about .180", see http://www.biglube.com/BulletMolds.aspx?ItemID=09d6fdda-c105-4c87-b269-68ebfdaba982.
I think that this is more than enough for revolver.

Let me know what do you think.

koyote
04-13-2021, 05:20 PM
What I am looking for is a maximum accuracy design specifically for ROA for hunting.

myself as well. I'm more concerned with proper size than a single large lube groove.

M-Tecs
04-13-2021, 09:27 PM
myself as well. I'm more concerned with proper size than a single large lube groove.

The original first design was almost perfect except the rebated area is longer than needed. I believe that can be seen in post #17.


Hello folks. My apology for delayed reply, but I was going through several options, considered your comments, and measuring my ROA countless times. So, I put following goals:

- Boolit weight 250 grains
- Hollow base (HB)
- Meplat dia .300"
- Protrusion from cylinder when loaded .500", so it could be inserted and pressed into cylinder without removing it from the frame.

Anyhow, here is my proposal:

https://i.imgur.com/h0YMyts.jpg?1

Please let me know what do you think.


Traditional designs that have withstood the test of time over the past 160 years are still around because they worked. The US Civil war produced great technical advances in firearms, projectiles and cartridges systems. They used what worked. That does not mean this technology can't be improved but what is an improvement?

Increased accuracy or ease of loading are two attributes that come to mind.

I really don't care if it's a single grove or double groove but I DO NOT want a design that carries enough lube for a 34" barrel. This bullet is for 7 1/2" barrels or less.

I also DO NOT WANT a bullet that is mostly all undersize as below. Way to much of the bullet is rebated.


UPDATE: Boolit redesign. After making a number of proposals for a new boolit for Ruger Old Army, to make sure that new boolit is sound, I asked for advise and help from our well know member and boolit designer 45 2.1. He agreed, and kindly provided a new design (THANK YOU SIR), see bellow.

I also wanted to have this boolit for Remington 1858, Colt, and other clones in same caliber.

Basic requirements:

- Weight 250 grains
- Hollow base (HB), for better accuracy
- Rebated base (RB), for easier loading
- Protrusion from the cylinder max. .500", so boolit could be loaded without removing cylinder from the revolver frame
- Meplat dia .300" max. so it will fit into rammer

The result of above wishes is boolit 45-250-HBRB-BK (BK stands for 45 2.1 initials):

https://i.imgur.com/cepkfz7.jpg

Because of slight differences in cylinder chambers between ROA and Remington 1858, Colt, and other clones in the same caliber, proposed are two boolits in two nominal sizes:

- .457" dia for Ruger Old Army

- .454" dia for Remington 1858, Colt and other clones normally using .454” dia ball (NOTE: because of smaller diameters, this boolit will have about 246 grains)

Please make note that diameters without brackets are for Ruger Old Army, and second dimensions in brackets are for Remington 1858, Colt, and other clones. Since I do not have any of those Italian clones, and do not know anybody in my area who has one, please review proposal and let me know if main diameters are OK.

This mold will be manufactured by Miha, MP-Molds https://www.mp-molds.com/ . We need commitment of at least 25 buyers before production could start. Molds will be available as 4 cavities and 2 cavities. Also, MP-mods offers their mold handles with discount when purchased with molds:

279481

M-Tecs
04-13-2021, 09:45 PM
Looks like there is no big interest for latest design in the first post.

Well, because in this corona time I had nothing else to do, here is another try. Since Miha from MP-Molds https://www.mp-molds.com can make molds with different diameters using same cutter, I designed bullet for ROA in a such way that with reduced dia could be used also to make mold for cal. 44 Italian clones:

https://i.imgur.com/Z4UKTW2.jpg

As you could see, when all 3 grooves are combined, they are almost .160", not far behind BIG LUBE, that has about .180", see http://www.biglube.com/BulletMolds.aspx?ItemID=09d6fdda-c105-4c87-b269-68ebfdaba982.
I think that this is more than enough for revolver.

Let me know what do you think.

The rebated area it too long for me to be interested in this. Same for the O-ring groove. I am not interested in using O-ring but it could be viewed as lube groove but that begs to ask the question what's the fascinating with equaling the amount of lube in a bullet design that has fallen flat????????

The original design pictured design below worked very very well. The Big Lube stuff not so much. I have several of them and I don't use them for a reason. Are todays lube's not as good?


I am in for the one in post 17, I believe I will pass on the single groove design. The longest barrels these will be shot in is 7 1/2". The original design carries sufficient lube for that. Since DD is a member I am trying to not disparage but the last thing I want is more big lube designs clones that shoot marginal at best.

For the people saying the two groove design doesn't carry enough lube explain to me why the original 45 Colt bullets worked so well if they didn't carry enough lube????? Same for the various 454190 designs???? They even hold enough lube for my 24" lever guns and BP.

They tested some originals here in a 24" barrel.

http://www.shilohrifle.com/forums/viewtopic.php?t=12327

279605

w30wcf aka w44wcf aka Jack Christian SASS 11993 was a member here until he passed in 2018.

alamogunr
04-13-2021, 10:32 PM
As I said in an earlier post, I'm not very experienced with BP, but all this back and forth indicates to me I had better stick with round ball. I'm not interested in hunting anyway. Don't count on me for this group buy.

Onty
04-14-2021, 08:30 AM
The original first design was almost perfect except the rebated area is longer than needed. I believe that can be seen in post #17.

Traditional designs that have withstood the test of time over the past 160 years are still around because they worked. The US Civil war produced great technical advances in firearms, projectiles and cartridges systems. They used what worked. That does not mean this technology can't be improved but what is an improvement?

Increased accuracy or ease of loading are two attributes that come to mind.

I really don't care if it's a single grove or double groove but I DO NOT want a design that carries enough lube for a 34" barrel. This bullet is for 7 1/2" barrels or less.

I also DO NOT WANT a bullet that is mostly all undersize as below. Way to much of the bullet is rebated.


The rebated area it too long for me to be interested in this. Same for the O-ring groove. I am not interested in using O-ring but it could be viewed as lube groove but that begs to ask the question what's the fascinating with equaling the amount of lube in a bullet design that has fallen flat????????

The original design pictured design below worked very very well. The Big Lube stuff not so much. I have several of them and I don't use them for a reason. Are todays lube's not as good?
Thank you Sir for your comments, I appreciate them.

After studding bullets (all factory made HB are swaged) and boolits for 45 Colt (Remington made), 455 Webley and 38 Special, here are features I would like to have:

1. Distance from the beginning of front driving band, to the end of aft driving band, to be at least 75% of nominal boolit dia
2. Front and aft driving band to have sufficient surfaces
3. Rebated base
4. Boolit, when inserted into cylinder to protrude no more than .5”
5. Grease grooves; 2 or 3
6. Hollow base (HB)

Requirements 1, 2 and 3 are to make sure that boolit is guided straight; when loaded into cylinder chamber, and goes straight in the barrel when lunched forward by powder gases.

You mentioned that you are not satisfied with Big Lube boolits:

http://www.biglube.com/Images/DD-PUK-ROA-II-1045_WEB_PROF.jpg

IMO, fairly large grease groove shouldn’t be problem. I guess problem is that noted boolit is short, and aft driving band is very small, so when loaded, it doesn’t take much to deform it and push slightly crocked. Well, result must be larger group than anticipated.

Since desired boolit weight is 250-255 grains, the only way to load it, without removing cylinder from revolver frame, is to have rebated base and protrusion of front end no more than .5”.

Because of above conditions, and to have sufficient contact surface between boolit and barrel, the only solution is to have a hollow base boolit.

Here is Mike Beliveau https://youtu.be/VVmYRePzoOQ?t=167 , shooting one of those top open revolvers, using Kaido 240 grains bullet (FY information, Kaido boolits have aft driving band reduced). Despite far from ideal rest, Mike managed to get surprisingly good 2.5” group. When he tested boolits using two Ruger Old Army revolvers, with Kaido 255 grains, groups were larger 2.75”-3.75”, see https://www.youtube.com/watch?v=DdauzEFXMNc and https://www.youtube.com/watch?v=LP_dwo2nThA . I know that to get more conclusive results, more revolvers should be used. But still, even that test is showing that top open revolvers could be quite accurate. To be honest, I would expect better results from ROA revolvers; IMO they are better made, and have solid frame.

So, why such large groups when shooting Kaido boolits from ROA revolvers? Well, I believe the culprit is constriction in barrel threaded area. Many revolvers have a such problem, and when shooting lead bullets using light to moderate loads, pressure is not high enough to obturate boolits, and result are large groups. Since black powder develops fairly low pressure, solid base boolit obturation is not possible.

Top open revolvers do not have constriction problem, their barrels are straight and uniform from one end to another. The remedy for solid frame revolvers is hollow base boolit, that will expand once it passes constriction. This works quite well, so even 38 Special ammo with HB boolits, could be used in conversion cylinders installed on 36 cal. (actually .375”) revolvers.

Final issue is what would be better boolit, 2 grease grooves, or 3? To be frank, I am not sure. The only way is to make prototypes and and test them. Unfortunately, that will have to wait. I cannot make molds, and Miha is very busy, so new molds will not happen anytime soon.

However, there is one possibility. I do have .455-265 Webley mold, and I am thinking about reducing boolit height on ,730-.735”. That will give me 250-255 grain boolit. With meplat about .300” dia, just about right for ROA. But, there is no rebated base. That one will be created by making some sort of swagging die, to bump two top driving bands on ,457” dia, and to reduce two bottom ones to .451” dia. Without going into too many details, here is how noted boolit should look like:

https://i.imgur.com/VkKraiQ.jpg

If this version shows to be accurate, I will suggest to Miha to go with it.

Valley-Shooter
04-14-2021, 10:11 AM
Looks like there is no big interest for latest design in the first post.

Well, because in this corona time I had nothing else to do, here is another try. Since Miha from MP-Molds https://www.mp-molds.com can make molds with different diameters using same cutter, I designed bullet for ROA in a such way that with reduced dia could be used also to make mold for cal. 44 Italian clones:

https://i.imgur.com/Z4UKTW2.jpg

As you could see, when all 3 grooves are combined, they are almost .160", not far behind BIG LUBE, that has about .180", see http://www.biglube.com/BulletMolds.aspx?ItemID=09d6fdda-c105-4c87-b269-68ebfdaba982.
I think that this is more than enough for revolver.

Let me know what do you think.That o-ring is interesting .
Do you have any references showing it being used?

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Onty
04-14-2021, 11:24 AM
That o-ring is interesting .
Do you have any references showing it being used?

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No, I don't, and never seen somebody use it that way. I just designed grease grooves to fit 1 mm wide O-ring https://www.mcmaster.com/o-rings/oil-resistant-buna-n-o-rings-8/system-of-measurement~metric/width~1-000mm/ . However, in some BP rifles, where the breech plug is, O-rings are used as a seal:

https://www.modernmuzzleloader.com/threads/o-ring-in-the-primer-pocket.15867/

https://www.traditionsfirearms.com/product/replacement-o-rings-for-accelerator-breech-plug-a1442

koyote
04-14-2021, 04:17 PM
I'm going to go out on a limb here, and say the o ring is probably not a great idea. there may be a material that would work, but here we are trying to rapidly move a slug, engage rifling (with rubber....), and ... I can't see it sealing better than a greased wad, either.

I'd be willing to be proven wrong, if anyone wants to try pushing some at 800fps down a forcing cone and into the rifling.