tinker
(.416 member)
09/05/09 05:12 AM
The 16-bore rifle, fiddling with the load

Like they say, no two rifles are alike...


Shooting the rifle with 160 grains Goex 2F was a completely different experience than the 140gr load. The muzzle report was fantastic - much more of a crisp crack than the boom of the first load. My sense says that the increased payload/back pressure yielded a more efficient burn. There was less smoke and a much more distinct flame cone from the muzzles - yet the fouling remained moist and constant from the breech to the muzzle.

The 160gr load hit a bit higher on the target - but not by much. The front sight looked tall to me from the start, and I'm guessing someone had it built to account for their vision issues. Front sights are pretty easy to reproduce in different heights, if necessary the rear could be fiddled with too. My chronograph has had a headache lately and is mid-repair. Hopefully this weekend I'll get it up and running under the next series of loads.

Something else to note, I managed to recover one of the felt wads from the last couple of shots -- at seventy-five yards from the muzzles
It was in excellent shape and still contained lube, also it had eight slender little pinstripes around it's circumference indicating flame-cutting past the wad through the grooves. The ball I'd been running just wasn't bumping up enough to seal, and I'd suspected that would be the case.

To prepare for this I'd ordered some .690 ball from Track to see if the rifle would like it.



The 14-bore ball won't fit with paper hulls, but does nicely in the thin brass CBC cases. The CBC brass is shorter than these chambers though, so there will be about 1/2" jump from the crimp to the leade. I reckon this will be OK, but the .653" 'across the flats' (tightest bore) to .683 'at the corners' (groove) numbers have me thinking it's gonna be a squeeze.
Notice the two balls on the patch in the photo above.
The width (muzzle to breech) of the bearing surface in the grooves ends up being about .100" as-slugged.
That should fix any gas-seal issues.
I'll see how it runs with 150 grains and this ball.
I'm thinking the initial bump, good gas seal, and brisk charge of powder might just raise the rifle to where it's printing hits on the point of aim.

The brass with 14bore ball definitely looks nice...




If from the results on the bench and target, and over the chronograph all together show a good load with this ball I'll look at the sights for the final answer to getting the POA to equal the POI
I have an old bag mould that needs a bit of touch-up work, will likely lap it up to somewhere between groove and .690 to test other ball sizes in the rifle too.


Also, NitroX - that's a Lion on the triggerguard.
I'll get his photo up here later on today.

Daryl, the rate of twist is one turn in 42"





Cheers
Tinker



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