hepburn45110
Member
What's the barrel life on a 1 7/16 dia. barrel!? (6ppc)
I've been told that the barrel that just won the 200 and Grand at the NBRSA Nationals has over 1,300 rounds through it.
Later
Dave
Dave, I'd say if anyone would know how many rounds the barrel had on that won the UL 200 and Grand, you would. Job well done. Congratulations again.
Mike
Sorry that happened Jackie...wish I could say it won't happen again. I've known folks that would simply quit shooting when their rifle wasn't up to par but I could never bring myself to do that. I'm a bit envious of those folks that can just quit!! You could have saved a pound of powder and 200 bullets if you had just quit.
Coots,
I would not trust that guy that gave you the round count!
Mark
Barrel erosion. Think about it - powder burns at over 5000 F, despite the burn lasting for .8 microseconds (best guess) or so. As the gas expands, temperature drops. Still, the first 3 inches of the barrel gets hit by a wall of hot, reactive gas. Carbide and nitride gasses are the worst at attacking iron atoms in steel - they also produce lower melting or brittle compounds that flake off before the barrel reaches room temperature. Is there a fix? Cheapest answer is stop shooting. Not kidding. 5000 F temperatures reduce most compounds to their basic elements.I'm intrigued that a barrel would go from great to DOA in the course of a couple of rounds, rather than taper off in performance. Any idea what mechanism would cause such a sudden change?
Barrel erosion. Think about it - powder burns at over 5000 F, despite the burn lasting for .8 microseconds (best guess) or so. As the gas expands, temperature drops. Still, the first 3 inches of the barrel gets hit by a wall of hot, reactive gas. Carbide and nitride gasses are the worst at attacking iron atoms in steel - they also produce lower melting or brittle compounds that flake off before the barrel reaches room temperature. Is there a fix? Cheapest answer is stop shooting. Not kidding. 5000 F temperatures reduce most compounds to their basic elements.
The above is a summary of a longer discussion from "Gun Propulsion Technology", which is Volume 109 in "Progress in Astronautics and Aeronautics". Editor is Ludwig Stieifel. Best bet in finding a copy? Engineering university library. Copies of the book are available online - starting at $95. See https://www.amazon.com/Propulsion-Technology-Progress-Astronautics-Aeronautics/dp/0930403207 .
Hope this helps.
I'm intrigued that a barrel would go from great to DOA in the course of a couple of rounds, rather than taper off in performance. Any idea what mechanism would cause such a sudden change? Or is it just that the difference between competitive and DOA is so small?
GsT