How do you FIT a boolit or design it for a lever action with a deep throat?

[btroj]

If possible go shoot some at real velocities and see how they group.

[MBTcustom]

If possible go shoot some at real velocities and see how they group.

All in good time Brad. Think first. Do later. Mix those two up and you have typical results.

Exactly right Popper. I can't imagine things working better at higher velocity than they do at low velocity. Thus, the sandbox and cat sneeze loads.

[Tar Heel]

Have you shot that rifle yet or are you going to talk it to death?

[TomAM]

I just finished working up a design for my new Browning model 92 44 mag, and post #22 here mirrors my findings.
"Support" basically means that the boolit needs to be pointed exactly in the correct direction upon chambering, and since you cannot feed what is essentially a shallow seated wadcutter in a lever gun, you won't be getting any support (upon chambering) from lead engaging barrel steel. The only way left to improve alignment is with a boolit diameter that fattens up the case mouth and takes the rattle out of the cartridge fit.
When there's boolit jump, and the boolit can tilt at all when launched, the matching of nose angle and throat is meaningless. The force driving it forward is far greater than the force that's later imparted by the throat to realign the boolits path. The boolit just deforms.
Static fit must be the top priority, and in this situation the fit can only be achieved through the neck of the loaded cartridge.
So personally I use my #43-240A with a large diameter body. The nose has to be lever function friendly, and this one is.

[btroj]

Agree entirely Tom. The 43-250M looks good too.

A leveraction is a pile of compromises.

[MBTcustom]

Makes total sense. Fit is King. Size is not.
BTW Tom, I purly Looooooooove this new mold you just sent me. You're my favorite maker.
Love ya
Mean it.
LOL!

6 day turnaround and the best casting mold I've got yet. That's.......amazing.

[nanuk]

I remember reading about the shutzen (sp?) guys who would make a bullet the EXACT shape of the leade/throat, seat it into the throat, put a powdered cartridge in behind and shoot tiny groups....

makes me wonder about the comment above re/ resistance and deformation....

[btroj]

Tim, I hate to say this but you know who to ask.

[Nrut]

Makes total sense. Fit is King. Size is not.

"Size" ​is part of "fit"..

[MBTcustom]

Tim, I hate to say this but you know who to ask.

Yes I do.

I need to ask my rifle.

[btroj]

Yes I do.

I need to ask my rifle.

not what I meant but that made me laugh.

[MBTcustom]

I can't afford not to.
LOL!

[MBTcustom]

Have you shot that rifle yet or are you going to talk it to death?

Oh yes! I've shot it with boolits from an old Ideal RN. Got about 1.5" groups at 50 yards judging by the rocks. LOL! Just the maiden voyage. I'm rounding up all my 44 brass and I've cast enough boolits to keep me in bidnes for a while. This baby will be with me in November.

[TomAM]

I remember reading about the shutzen (sp?) guys who would make a bullet the EXACT shape of the leade/throat, seat it into the throat, put a powdered cartridge in behind and shoot tiny groups....

makes me wonder about the comment above re/ resistance and deformation....

Schuetzen shooters know that the only way to take advantage of that perfect fit is to have the boolits fully engage the leade before firing. That's why they load the rifle in that manner. A nose which perfectly matches the leade is useless if it is allowed to flop around upon firing before engaging the leade. When exposed to 35,000 psi, the boolit does not pause to re-align itself with the bore. It just mashes into it, while tilted. The only reason that we strive for fit is because fit provides guidance.

[TXGunNut]

I regret having started this in Leverguns forum. I have moved it to Molds Maintenance and design forum.-goodsteel

Glad I found it again. Nothing to offer, lots to learn.

[TXGunNut]

Two questions: Do you know what Felix was loading/casting for this rifle? Could be an interesting read if he posted about it. Second may sound obvious but sometimes we have to step back and ask; what are your goals/expectations for this project?

[MBTcustom]

Two questions: Do you know what Felix was loading/casting for this rifle? Could be an interesting read if he posted about it. Second may sound obvious but sometimes we have to step back and ask; what are your goals/expectations for this project?

The goal is to learn something by exercising the mind.
The trick of fitting the chamber is awesome. I'm remeasuring my pound cast, and I'm going to turn a new dummy to try and see if it feeds. I'm still pondering making it so that I hit the throat at the same angle.
Seems we have the back of the boolit trapped with the brass fitting tight in the chamber. Seems to me that if we want that boolit to launch forward and be supported from the nose, while the base is still in the case neck, then having the exact same angle up front would be helpful.

[Doughty]

A couple years back I played around with the same question. I had several Ruger single actions, a Smith N frame, and a Marlin lever, all in .45 Colt. I wanted one bullet and one load that would work good in all of them. The Marlin chamber and barrel is apparently what is typical; .452 groove diameter and a chamber that is large in diameter and length. I made a swaging of the Marlin chamber. You might be able to see in the picture that the grooves go right up to the case mouth. The case diameter at the mouth is .474, the diameter at the start of the tapered throat is .469. This tapers down to .453 and a slug through the barrel was .452. How they did that I don't know. The point is that my chamber is very similar to yours in general design.

I had a Lee 255 grain bullet that cast at about .452. It shot OK at slower speeds, but started losing it as velocity increased. I made a series of several molds trying various things. In general, I found that as the bullet got bigger in diameter and longer in length, the better it shot. I can just get a cartridge at 1.675" to work through the action. Fortunately this would fit it all the revolvers. I could get a bullet of .461 diameter to easily chamber in the rifle and this gave the best accuracy, however one Ruger would only take a maximum of .457 diameter. Again, fortunately, this still shoots pretty good in the rifle.

The other thing I found was that, the more full diameter area I could get in front of the crimp groove, the better it was. Again, the limiter here was in the revolvers. The full diameter length is also such that the front has a good start into the grooves before the end leaves the case. The design principal seems to me to be pretty simple. Fill up with lead, as much of the neck, throat, lead, grooves and bore as you can, trying to keep the center line of the bullet as close to the centerline of the barrel, before it is fired, and for as long as you can, after it is fired.
I made two four cavity molds to keep them all going and load on a Lee Loadmaster. The Loadmaster took a
little tinkering with to handle these odd .45 Colts. In the first station, the de-priming station I use a Lee carbide sizing die with a de-cap pin in it. I used a diamond point on a toolpost grinder to open the die up so that it would only size the over expanded rifle brass as much as was necessary to go into the revolvers. In the second station, the priming station, I sized another Lee carbide so that it would only neck size the brass enough to firmly hold the .457 bullets. The standard Lee powder through die worked fine to bell the mouths a little and the standard Lee seating die worked okay to seat with. The last die is one of Ranch Dog's rifle type Factory Crimp Dies for the .45 Colt, which does in fact crimp the finished round.

As Phil would say, "Happy, happy, happy."

[MBTcustom]

Wow Doughty, I thought you left us to our own devices! Good to see you sir!

It seems that you have summed up and put nails in the general consensus. This thread has given me a lot to think about.

It appears that I was wrong. Here I thought that dealing with a chamber like this would require a different philosophy, but instead, it's exactly the same as a normal bolt gun. We're just getting there a different way.
Thanks everybody for weighing in!

[TXGunNut]

Thanks everybody for weighing in!-goodsteel

Thanks for the mental gymnastics, it's been very educational.
I always wondered why pistol cartridge leverguns had chambers with such a long leade. Only theory I've come up with has something to do with their black powder heritage. Figured maybe the long leade was to keep powder & lube residue a place to build up a bit and still allow rounds to be chambered. Don't know if that's true or if it will help improve the fit but sometimes the history of an issue helps with the solution.