It seems that there are a lot of things you have to know if you want to live in the 18th century. I've gotten a lot of good advice on this forum, so here's another topic. I've worked out a good basic load, plus ball size (530) and patch material (linen), lubed with Hoppe's #9 Plus, and accuracy has improved such that I just put 7 rounds into a 2.5-inch group at 50 yards. But I'm still getting the occasional FITP, so I'm wondering which factors might be causing this irritating aspect. Here's my procedure: I'm primarily a target shooter, with occasional trail shoots with my BP club in Sandy, Oregon. I wipe between shots, and pick the vent then to push out any fouling which might have been pushed into the vent. After loading powder and PRB, I pick the vent again, prime with Goex 4G, and I still get what I consider too many FITP. The vent in my gun is drilled to 3/32, but isn't centered on the pan--it's about 1/16 to the rear. Other than that, it's located flush with the top of the pan, which I've seen in all of the close-up photos on the web. In all the TOW descriptions, they mention that the vent is centered on the pan. So is this the problem, since mine is 1/16 back? The delay caused by a FITP isn't a big deal at the range, but on trail shoots the other shooters in my group would have to wait for me to re-prime and try again. What is a common frequency of FITP when everything is done correctly?