Ok.
So this is for a BP ML.
An old French take on the fabled 451 rifles, rendering a rather sleek gun carrying most of what´s needed.
1:21" twist, 45cal and so forth.
As we were in need for a few different projectiles we CNC´d three molds in one based loosely on the old Postell. Two of them being bore riders, and these work a million bux.
The one for the muzzle loader though, not so much.
As we fire the piece we get poor accuracy at 100 meters, albeit SOME sort of accuracy. Ie; one 8 and one 9 at an intl pistol target, while the 3d round can hit..hold on here, 18 FEET high!
We see clear evidence of key holing at 50 meters. SOME of them.
Boolit loosely based on the Postell. 4 drive bands, just.. ML remember. Weighs around the 500 grain mark. Boolits used weighed to within under 1% weight deviation.
Have tried with loads ranging from 55grains to 90 grains. We at first thought it got a tad better as we increased loads and omitted greased 1/8" wad but.. as it turns out, no.
Now. Obviously boolit to the left at 11,05mm diameter. What is here though is that the rifle indeed carries a 11,05 base but measures a full 11,65mm in the grooves. Ie; a depth of 3/10 of a millimeter, and where we´re at we´re talking this being the culprit.
There´s simply no way we´ll get the base of the bullet to expand that and thus the manner in which to keep some sort of seal is due a greased wad at its base.
In short i believe that we´re experiencing rather advanced amounts of flame cutting, hence the hip hap behavior as we can have a few boolits "semi" on target while all of a sudden we have one massive amounts off. To the point where we said enough due the dangers inherent.
Rifle is on par every aspect there is. It is an old French made Felix Escoffier from 1865, that carries its age with pride.
Has been bedded and all of that, sports a diopter setup. Has been handed a fresh crown aso. In short, as far as the rifle ...count that out. This is a bullet issue only.
Only thing that clogs the picture is this INSANE rifling depth and how to cope with it. It´s to the point where i´m giving thought to getting a 11,35-11,40mm reamer to run through there to get within realms.
The basic projectile in short works da bomb, we know this from the "other two" intended for the just as French Chassepot breech loader and the Brit made W-R Monkey tail, where they run like friggin tractor beams. In these the boolit shape runs very very well, and this at semi extended ranges too (inxs of 300)
As i see it the main culprit here is that one way or another we need that bullet SETUP to seal vs the rifling and the rifling being 3/10mm deep.. not happening in my book.
A sorts of Minie cavity was suggested, but again.. although the bullets are out of pure lead getting them to expand a total of 6/10mm is just out, if we want to see any shape of integrity left of the base projectile.
(Btw. For you fraction guys just divide by 25,4 to get inches).
So.
What gives?
I need ideas guys.