Eureka!!! Flint! Every once in a while someone advances a simple idea that changes humanity forever.
So I went out and ran my experiment this afternoon. I was intending to fire 10 rounds each with 90 gr Pyrodex with each nipple and document the results. My usual spot was occupied by campers so ended up going elsewhere. This time the range was about 80 yd (paced off). I fired 5 with the musket nipple and then 5 with the #11 nipple. First group of five with the musket nipple went about 12". First group of five with the other nipple went about 5". Suddenly I noticed something...what's this? The rail that holds the ramrod thimbles was rattling. So I tightened the screws and reran the test. This time the musket nipple sent 4 shots into about 5". The 5th one was lost somewhere. The #11 nipple made a group of 3 about 12" in diameter. Two of this last group were lost. Duh!!! Not what I expected to see.
Of extreme interest to me what that only one shot with the #11 nipple had any ignition problem at all, and it was a slight hangfire. So what was different? I ran a patch down the barrel and vigorously pumped air through the nipple between every shot.. I wasn't intending to perturb the experiment this way but was getting tired of the black ring around my mouth from blowing down the barrel every time. I also have an extreme aversion to putting my mouth over the muzzle of a gun...any gun! So perhaps now I have a workaround for the original problems I was having, discovered quite by accident.
But yet another difference. The original nipple I was having problems with ended up out in the yard when I accidentally threw it out with the cleaning water after a previous outing. During my rounds with BPI trying to get the musket nipple thing working they had accidentally sent me a #11 nipple instead of what I'd ordered. So that was the nipple I was using today.
Now, here is some data that I found most interesting of all. I took my chrony this time hoping to find something velocity-wise that could explain accuracy problems. Here's what I got for all 20 shots, in the order they were fired:
1763 1899 1873 1895 1910 1889 1882 1913 1905 1850 1932 1921 1896 1905 1927 1883 1921 1950 1873 1904
As a general trend you can see the velocity going up slightly throughout the progression. There are exceptions but mostly thats the trend. My conclusion is that this was due to the barrel getting progressively dirtier and the pressures increasing correspondingly. Whether this is true or not isn't the relevant piece of information I discovered. Guess which one of these is the most important in a hunt? This points out to me that from now on when shooting a muzzleloader for groups, the one to pay the most attention to is the first group of ONE. It's not likely to matter that the 20th one went 1904 fps or that it cut the bullseye dead center!
Sorry for being so long winded but all in all I had fun today and wanted to pass on what I'd learned. Bottom line is that between now and the season I'll be looking most closely at one shot...the first one. Whether to stick with the musket nipple or not remains to be seen.
Incidentally, not having fired the ML over a chrony before I don't know if these velocities are reasonable or not. What has been you guy's experience?