Testing .44 Caliber Stepped Chambers

[nkbj]

These are from the old standard Lee #45-228-1R round nose mold that looks much the same as those that Lee produces for percussion revolvers. Cast from soft lead they weigh around 237-238 grains, get lard/beeswax/lanolin lube and are pushed through a .451" sizer. Those shown below were recovered from a stacked paper backstop.

The 1858 is a Pietta that's had the chambers reamed and trued up to .450" diameter and then reamed .452" diameter to 3/8" depth. The .451" diameter bullets slip into the .452" portion for primary alignment during seating and are then seated down onto the powder, their bases passing through the beveled step-down of the .450" portion on the way.
The base ring shows the rifling grooves were filled. No signs of gas cutting.

 

[B P Arn]

Who did the work? That is an interesting idea.

 

[cynthialee]

wow
That'll put a hurt on ya won't it...

 

[nkbj]

wow
That'll put a hurt on ya won't it...

Good morning cynthialee.
In fifty years of tinkering with percussion revolvers, well, this might be the way I do things from now on. Still have plenty of testing to go yet with the molds on hand. The frame on this Pietta 1858 just barely lets the bullets align to go into the chambers. I could do surgery on it but haven't so far. There's probably some molds that have a base to shoulder length too long to let the bullet get started into the chambers. And as another matter, .45 molds that run heavy any way, like around 250 grains with hard alloy, they're going to be really heavy with straight lead. I suppose like with everything in life it'll all be a matter of trade-offs.

 

[M. De Land]

These are from the old standard Lee #45-228-1R round nose mold that looks much the same as those that Lee produces for percussion revolvers. Cast from soft lead they weigh around 237-238 grains, get lard/beeswax/lanolin lube and are pushed through a .451" sizer. Those shown below were recovered from a stacked paper backstop.
View attachment 345517
The 1858 is a Pietta that's had the chambers reamed and trued up to .450" diameter and then reamed .452" diameter to 3/8" depth. The .451" diameter bullets slip into the .452" portion for primary alignment during seating and are then seated down onto the powder, their bases passing through the beveled step-down of the .450" portion on the way.
The base ring shows the rifling grooves were filled. No signs of gas cutting.

I still don't understand the thinking of making the chamber mouths a smaller diameter than is the barrel groove diameter in these percussion guns and wonder if it was an original Colt spec or Italian idea.
From what I can tell both ball or conical respond favorably when they are more closely matched.
Other modifications from original design such as straight twist in place of gain twist and apparently shortened arbors have also been made.

 

[nkbj]

Undersized chambers? Makes me remember what Robert Heinlein once wrote about, the weekend of shame for Americans when they rose up en masse and slaughtered all the lawyers.

For these tests I'll be using a variety of other designs of molds and hopefully both FFg and FFFFg and Triple Seven. Have had bad experiences with citric acid oxidizer powder so won't bother with others.

 

[nkbj]

The .450" reaming and the .452" x 3/8" deep steps.

 

[nkbj]

Inserting the 237 grain round nose.

 

[nkbj]

Pushed down with finger pressure.

 

[Gtrubicon]

Looks like they are going in nice and straight.

 

[nkbj]

Seated with the loading ram over 27 grains FFFg taking up all the available remaining chamber space.
Makes a difference it you don't settle the charge.

 

[nkbj]

An unexpected bright spot with the elevation...
In the workups with the 237 grain round nose it's dead on at 12 paces with a filled chamber, the 27 grains of FFFg under the bullet. I'd anticipated it being higher with the longer recoil.
But the side pull on the windage definitely says I need to practice more.

 

[Bad Karma]

An unexpected bright spot with the elevation...
In the workups with the 237 grain round nose it's dead on at 12 paces with a filled chamber, the 27 grains of FFFg under the bullet. I'd anticipated it being higher with the longer recoil.
But the side pull on the windage definitely says I need to practice more.

I’ll bet it’s close to spot on at 50 yards too… also, on several revolvers now I’ve turned a flat inside of the ram so all soft lead or even 30:1 alloy projectiles have a flat meplat after ramming home.

 

[nkbj]

Yeah, been kinda wondering about some bullets' nose designs. With the alignment reaming on these chambers maybe the factory dished face is as good as it gets. Or maybe it could just be filled in level with JB Weld.

 

[AlexB]

They don't back out under recoil and jam the cylinder?

 

[Bad Karma]

I used the JB weld modification as well until I convinced myself that the flat nose profile worked well for me.

 

[DanL]

@Bad Karma, Please provide us with a picture of your ram modification. I am interested in what you are doing regarding the meplat.

Thanks, DanL

 

[nkbj]

They don't back out under recoil and jam the cylinder?

Not so far. The .452" diameter portion of the chambers is 3/8" deep. That depth was chosen as midrange guesstitmate after measuring various .45 pistol and revolvers molds. The engagement between the bullets and the .450" portion of the chambers has been sufficient with maxed out charges to hold those 237 grain round nosed bullets in place. I'd expect that sooner or later I'll try one that doesn't work, a bullet design sized to .451" and powder charge that lets the bullet slip forwards.
So far it looks as though it's a good thing that I didn't go with a bigger difference in diameters. When seating the bullets into that little bit of neck down you can feel a good bit of resistance.
There's some conical nosed bullets made up and ready to go that are longer than the round noses though they're actually a little lighter in weight. Going to be a point of interest to see how much resistance they provide and what their smooshed noses look like after being seated. There's some .454 or .457 round ball around here too that I need to hunt up.

 

[M. De Land]

Not so far. The .452" diameter portion of the chambers is 3/8" deep. That depth was chosen as midrange guesstitmate after measuring various .45 pistol and revolvers molds. The engagement between the bullets and the .450" portion of the chambers has been sufficient with maxed out charges to hold those 237 grain round nosed bullets in place. I'd expect that sooner or later I'll try one that doesn't work, a bullet design sized to .451" and powder charge that lets the bullet slip forwards.
So far it looks as though it's a good thing that I didn't go with a bigger difference in diameters. When seating the bullets into that little bit of neck down you can feel a good bit of resistance.
There's some conical nosed bullets made up and ready to go that are longer than the round noses though they're actually a little lighter in weight. Going to be a point of interest to see how much resistance they provide and what their smooshed noses look like after being seated. There's some .454 or .457 round ball around here too that I need to hunt up.

I've been using these 210 grain ACP bullets in my Walker sized and lubed with good initial results. My chambers have some taper in them that have been keeping these antimony alloyed bullets in place under the full charge loads of 3F powder recoil. The BHN is 12 on these bullets and the nose corner radius is barely deformed from the hemisphere ram face after seating.
I was considering reaming but am going to do some more accuracy testing before getting the reamer out with both ball and different conicals.
The heeled design seems a plus for loading ease, gas seal and base seating square/ alignment.
I'm starting to think that Uberti may have a better mouse trap with the tapered chambers in place of stepping. They're sure easy to keep clean of fouling residue.

 

[nkbj]

Wow, that's a close fit but it works.
In the Walker I used the RCBS #45-225-CAV design that looks like a shorty maxiball but the rear band has to be sized to slip into the chambers.