mirocu 45-90

[Lead pot]

Michael they should fly pretty good if you can get then to stay in the throat straight with the 8# paper. Guessing your 8# paper is .0018" thick.
I would prefer the top at .443" with .0018" paper or .0022" with that .442 top section and push that thicker base through a sizing die if the bore requires it. Head up in the hills and shoot a few into the snow bank to see if you get any finning before sizing them.
That bullet the way it is should work just fine with .002" or + 2/10,000"

[BRUCE MOULDS]

Michael, your concept has proven to work for me.
what happens when you light the fire?
before the bullet starts to move, it bumps up to fill any space available.
this means it has to fill an obturated case neck, and any freebore that exists, as well as the rifling until it cannot do that anymore at some point on the nose.
looking at charlies drawing, and assuming case neck thickness 0f 0.012, the ideal diameter of the larger part of the bullet would be 0.460 to fit the inside of a fired case and the freebore.
however finger seating is hard to do with a perfect fit, so the bullet being a little smaller than this is more functional.
the old pp chambers could do this with a bullet patched to bore, because a fired case had about 0.002 clearance on a bore diameter bullet.
greaser chambers need a thicker bullet to achieve the same., and the dual diameter allows this, while still having some of the bullet in the bore.
there is minimal disturbance to the bullet when it bumps up, and hence the potential for accuracy is greater.
where the diameters change, you can seat up to the leade angle.
dual diameter bullets can require a learning curve where patching and patch templates are concerned, but it is not a major issue.
looking at where your patch goes up to on the nose illustrates a point.
the patch goes that far forward to protect the bore from lead, as that much of the bullet bumps into the rifling.
guys shooting greasers of similar design have that part of the nose exposed to the bore, and assume it is bore riding!
why will a pp nose bump into the rifling and not a greaser nose?
the answer is that the greaser nose also goes into the rifling, potentially causing leading.
guys possibly get some forgiveness from this when blowtubing on all but the first shot.
keep safe,
bruce.

[bignut]

Benn away for a while getting ready to sugar. Thanks to all for the info

[semtav]

If you are going to get serious about shooting PP in a Winchester Miroku 45-90, you first need to get the proper length brass. The chamber is longer than standard. Either buy some 45 2.6 brass and trim to appox. 2.425 length or get a Kal stretcher and stretch your 45-90 brass to that length. I will post some pics tonight of a very accurate load using this rifle.

[semtav]

Br2 Primer
Starline 45 2.6 trimmed to 2.425
95 gr Swiss 1.5
.060 veg wad
.060 ldpe wad
Staedtler 8 lb paper
PJ .454 Money bullet 12.5-1 alloy

this is a Patched to groove load

I haven't had a dirt digger or unexplained flyer in 5 matches now ( 36 shots per match)

I wish I could shoot with C. M. and Bruce Moulds they both know the benefits of Groove dia loads, and it would be fun to compare side by side.