Bottlenecks and accuracy?

[martinibelgian]

For those who still remember the thread some time ago, we were wondering why there were almost no competitive shooters using BN cartridges, and whether this was because of the BN's inherent lack of accuracy....
Well, I am pleased to announce that those urban myths have been proven to be just that - myths.
Lest weekend, we had the annual open Belgian mid-range BP match, with participants from Belgium, Holland, and Germany. Maybe even some French there...
The match consisted of 3 courses, respectively at 200 - 300 - 400m, the aggregate determining the winner. All shooting of course from the prone position, with sling only.
The aggregate winner in BPCR shot a Martini rifle chambered in 500/450 #2 Musket. The rifle was built on a Martini Citadel .303 action, with a 34" Eichelberger barrel, and a Holbrook Dr. Goodwin tang sight. He was the only one shooting a BN round, FWIW.
The load consisted of:
73grs of TPPH, '92 vintage (volume equivalent of 80grs Swiss 1 1/2Fg)
Vegetable fiber overpowder wad .060"
Lyman 457132 bullet, sized to .458, lubed with Paraffin/lanolin-based lube.
CCI BR2 primers
Bertram #2 Musket cases, neck-turned

Conditioins were not too bad, with a moderate wind, although a bit variable in strength and direction, but generally coming from 2 o'clock. Especially the 400m leg was quite demanding, as it was shot on the 300m target, which looks quite small at 400.... This one definitely can make or break the aggregate score!

[StrawHat]

Congrats on the win. (I seem to recall hearing about that Martini before, yes?)

I too have always heard about BN's being less accurate than straight cased black powder cartridges.

Must just be the Sharps cartidges as the 44-77 loaded by Remington was a good performer.

Hope you have continued good luck with it.

[martinibelgian]

Yes, you're right, I did post some pics of the rifle on this board - I won't claim the rifle was a direct reaction to those claims, but I do like things different, and proving 'common knowledge' wrong. Still, the discussion here did result in the project being accelerated, so...
This round also has none of the problems usually associated with the BN breed, like the dreaded crud ring. I never chrono'd this load, but I think I can safely claim that the SD and ES won't be all that bad...
FWIW, this rifle has now maybe 200-250 rounds through the barrel, so it would be time to start thinking about some serious load development. Still waiting for the custom mould to arrive though, but meanwhile I can already experiment with some PP.

[Baron von Trollwhack]

Likely your loading technique is what prevents the "dreaded crud ring" I think. Good for you! BvT