Hot can of powder part 2

Back in February I put together a new set of sights for my son's inline. We both have matching Knight MK85 stainless guns. I got them for a hunt we have here in Idaho that allows scopes. I used mine once and didn't like the scope. I ended up putting Williams FP sights on both of them. The problem is I hated the front sight from Knight. So I added a Lyman AHB front sight and Lee Shavers inserts.
Then Because the front sight was taller I added a shim under the rear sight. I measured the difference and made the shim to put the first line on the sight as my 50 yard mark. Adding this height on the rear sight changed the way the gun fit my face. I had to raise my head and that took my cheek off the stock. I have worked with this on my Hot Rods when I shoot 300 + yards. But my cheek was off at 50. So I added a cheek pad to finish the project.



The first time I took it out it shot well. But I ran out of powder and changed cans. All of a sudden my sight marks were off like the powder was a hot can. So I decided to quit and I also made up my mind to get my Chronograph out on the next trip.
Well Today was the day. The Ohler 35 was going to prove something. I had a small sample of the old powder this can has been open for about 1 year. I had the "hot can" and it has been open since this Feb, and I had a new unopened can.
Hot can shot #1- 1315
#2- 1320
#3- 1345
Old Can from last year.
#1- 1319
#2- 1350
#3- 1310
New can opened today
#1- 1294
#2- 1313
#3- 1324
Last test was two shots with the same powder charge and Lube on the paper.
#1- 1365
#2- 1352

I am not sure what happened with my shooting that day but it is clear that the powder was not an issue. If anything I was impressed with the Pyrodex P and how consistent it was. But with anything I got MORE questions!!!
When I first chronographed that load it was in my Hot Rod Renegade. At that time it averaged 1310 with a 28" barrel. My knight has a 24" barrel but the velocity is basically the same maybe a little faster but not much. After seeing the results I wish I would have taken my Hot Rod to chronograph it at the same time to see if it was still at 1310. It would be interesting if the optimal burn was more like 24" and the extra barrel length was actually reducing velocity. All I know is the Hot Rod is a FAR better shooting gun even with the upgrades to the knight. Maybe the extra barrel length helps with accuracy??? All I know is I wish I had the Hot Rod to compare at the same time. The last time I had shot it across the chronograph was several years ago. I guess I have another test.

according to Hovey Smith, the second shot on a fouled barrel always increases velocity. I just happened to be looking around at how people load a shotgun with a screw choke, and watched his video. He went on about how he always lowers the charge for the second shot.... I cant say personally.. but I have seen that theory expressed before.

Even if 24" is "optimal" the increased sight radius with the 28" barrel is a fine trade off IMO

I agree. The Hot Rod Renegade is a far better shooting gun with the longer barre.