Discussion in 'Competition Forum (All Calibers)' started by Alex Wheeler, Oct 29, 2016.
When you have that level of experience and expertise, get back with us
Nope. As Alex mentioned, molecules expand in EVERY direction when heated/ even though you are visualizing the inner walls moving inward, you are negating the fact that the outer walls are moving outward also....the net result is the ID actually becomes larger.
That was my attempt to get him to remember heat = grows and cold = shrinks by association with everyday things and a bit of humor.
I had to 'unignore' JRS to see what you guys were talking about here. Didn't take much reading to remember why I had JRS on that list
Wrong again. The inner wall is increasing in diameter, meaning, outward. Like I said, drill a hole in a piece of plate and apply heat to that piece of plate. The plate isn't going to grow. The hole size will increase. As a barrel heats up, due to the dead end in the action, the barrel is going to increase in length. As an objet increases in length, it decreases in diameter. Kinda like a piece of glass subjected to heat. If that glass is 1/8" thick, once subjected to enough heat, the glass will shrink and pull in to be 1/4" thick. If you start out with 3/8" thick glass, it will expand to pool out so that it is only 1/4" thick. Much like glass, the atoms in steel prefer to be a certain thickness before starting to change direction.
I must admit, I really do not think there is much accuracy to be found in thermal expansion issues regarding a rifle. I never really did. BUT, I did think it could be an interesting discussion and maybe I would learn something I never considered. Thats why I started it the way I did, to see where it would go. Thought it would be a little more interesting than the same old what scope for my deer rifle threads. It does have some good comedic content though lol. Its getting tougher to have intelligent conversation I guess.
Who ever hacked JRS's account, stop F-ing with us!
Tell me, Alex. How much experience do you have designing and manufacturing optical glass and scopes.
Nope...he's the real deal.
Forget about the Jiggery-pokery and Chinese alphabet soup. Step into the world of reality I can take a torch, heat and shrink a crooked section of handrail to make it as straight as a needle. It isn't going to grow.
Edit: Without actual experience, it's easy to believe what you have read, or have heard, without actual hands-on experience.
That is not the reason the bore increases, it is increasing as there is no place for the molecules to go they have to expand outwards not inwards. Think of the arch supporting a doorway in a wall. Expansion has to move outward.
That is exactly what the bore does. It moves outwards, (increasing) though the OD really doesn't change. If the framework of the door expanded outwards, the drywall would crack. That is my reason for the reactor vessel scenario. Only the ID can expand. What happens when you fire form brass with a tight fit in the chamber? The ID increases.
Damn Tom I used to get one of them man time flies from you were young dumb an full of _ _ _ you can fill in the blanks very interesting assumptions though it is confusing me a little though but definitely interesting to say the least.
I learned something today at least, barrels get longer when heated but bridges shrink. Who'd a thunk it?
Stan, skip the stress relieving process and turn the blank down. Bet the bore grows on that one. PS your the one supposed to be teaching us. They threw me out after 10th grade.
If this was the case I would see a drop off in velocity. I never saw that. I believe accuracy falls off because the heat makes the barrel move. Matt
OK, we need to stop with the notions that cold somehow causes expansion, heat causes contraction, and the earth is flat. There are plenty of sites out there that deal in fantasy. I bet Neil DeGrasse Tyson would happily disabuse you of all three of those notions, if you want to go pester him about it.
EDIT: Though I will stipulate the existence of Negative Thermal Expansion, though the use cases are pretty rare.
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