Originally Posted by goodgrouper
I would venture to say that you lost more speed than that but your bc increased.
I'm not busting your chops here, really I'm not but I've got understand your logic on this one.
By firelapping the barrel how much of a BC increase do you think he achived? Even an increase or decrease of 100 points on the BC isn't going to have any significant effect on his muzzel velocity. By removing a carbon build up in the throat any change in BC (if any) would be extremly minute, I doubt it would change less than a point.
Here's what I've seen through a bore scope when I'm looking at barrels when I visit speedy's shop. The barrels with the biggest carbon build up in the throat area are from folks who don't use brushes on a regular basis. The tell speedy they use solvents and patches to clean after shooting. Not saying this is wrong, just an observation.
More than likely Tubb's FF removed the carbon build up and polished his throat decreasing the pressure.
Now the decrease in accuracy. More than likely he pushed his OAL out especially if he used 50 rounds or more of FF. I'm sure that throat area and first few inches are as smooth as a baby's behind. He's going to have to re-measure his OAL and adjust for the longer OAL.
What we don't know is what kind of condition the barrel was in prior to him using the FF. How many rounds had the barrel seen? It there was a large carbon build up in the throat, it probably means a lot. Lots of unknown factors to consider.
Worst case, he could always have the barrel set back and re-chambered which would give him a fresh starting point. Wouldn't cost that much.
The best advice I can offer is for him to take it to someone who has a bore scope. Borescopes don't lie.