I should state right off the bat - the reason for this post is to show the importance of load testing even after having a load that fills the bore and grooves. As well, the difference
that can happen in changing only 1 of the components. Too- it shows the lack of longer range accuracy with a load that actually shot well at 25 yards, however shot miserably at 50, with the .36 rifle.
Here is a load test I made last Saturday. I was shooting my 14 bore rifle at 50 yards, using the same identical load, except for the patch thickness.
same rifle - .690" bore, .714" groove to groove - grooves .012" deep.
Same powder charge = 85gr. 2F GOEX, straight from my horn into the measure then into the bore.
Same pure (as pure as I have) lead .682" ball, weighing 480gr.
Same range of 50 yards, starting with a clean bore, including the fouling shot.
The group on the left was with a 14 ounce denim patch, twice washed - which I measured at .034" compressed with calipers. This is a tight load.
The group on the right was with a Canvas patch, twice washed .022" compressed with calipers -
this load is also snug and fills the grooves completely, however it's 'fouled' group of 4 shots is
2.44 times larger than the thicker, tighter combination fouled group of 4 shots. The canvas patch produced a 4 shot group of 1.667", while the Denim patch's 4-shot group was .682", which
is exactly ball size - centre to centre for the group.
The .022" patch and ball measurement is .022" + .022" + .682" = .726" which gives .012" compression total or .006" compression in the bottom of each groove.
The .034" patch and ball measurement is .034" + .034" + .682" = .750" which gives .036" compression total or .018" compression in the bottom of each groove. yes - this is tight, but no tighter than what most BR shooters and some chunk/plank shooters are loading.
Because I use wet patches, each shot loads with the same effort as the first one.
The bench & view from and including The Old Man's Blind:
The 50 yard targets are to the left of the 6-bull 25 yard targets where we were shooting Quinn's new .36 Seneca.
Also- the tight patch target has a few .350" holes in it from that little rifle. More testing needed for it yet it shot into a tiny single 3/4" hole
for 5 shots at 25 yards. The 50 yard target's 4 .35 cal. balls spanned over 6".
Notice how the fouling shot went high both times & how the thinner patch grouped approximately 1 1/2" right of the tight patch, except for the fouling shot.
More shooting should be done to confirm the results, however I was shooting fairly well that day & trust the results.