Rail accuracy declines about 20-22 rds

[Bob Kingsbury]

I have been working on my rail gun for a number of days now. I am shooting
4 shot groups and not allowing it to heat very much. It does have Aluminum
barrel blocks, 8 bolts and lapped as Jackie did. I have no problem holding
the barrel with 40 in lbs. It seems that following 20-22 rds, it begins to open
groups. When it does, I find no common direction. Bore scope shows no
significant level of fouling. The barrel is only 10 degrees warmer than my hand
forward of the blocks. Does this seem common with BBL blocks

 

[jackie schmidt]

Bob, I don't think I have ever shot single group in my Rail Gun without stopping to clean it before another, whether it be 10 shots, or 5 shots. So, I can't say as I have ever noticed what you are alluding too.

40 inch pounds seems pretty light, I go to 80.

I have had Rail Gun Barrels that would shoot 5 shot "zeros", but simply would not hold for 10 shot groups. By the time you got to 10, it would be wallowed out to a .250. Maybe your barrel just has a few more rounds before it starts to act goofy..........jackie