Bedding under the shank of a barrel?

[Sniper338]

WOW... Heat does expand metal, cold shrinks it... I recall an occasion I was putting a barrel on a 10/22 and the barrel would not slip in.... I stuck the barrel in the freezer for a few hours, then heated the tennon of the action with a heat gun a bit.... barrel slipped right in... shrank the barrel OD, expanded the tenon...

each to their own... thats what makes competition possible.

 

[Dusty Stevens]

Ive seen heat do a lot of things and one thing ive never seen it do is contract something. When we put rails down on the railroad in the winter we leave a 4" gap then lay fire snakes beside the rail to heat it. Then it expands together to weld. In the summer the rails look like snakes because they have grown due to heat. In a power plant a hp steam line can grow 30-40' and the steam turbine grows in length a considerable amount. When we put bearings onto a shaft we freeze the shaft and induction heat the bearing. It then slides right on. Im no physicist but i am an engineer. Power lines even sag in the summer due to heat. Just too many examples of excited molecules moving around expanding materials.

 

[JRS]

Well Dan, I worked as an ironworker both in the field, and in the nuclear industry for many, many years.
Steel contracts with heat, and expands as it cools.

Well, Rich, I once was an application engineer in cryogenics. Simply put molecules get excited and expand when heated, when cooled they contract.

Well LH, i'm still one up on you ;D My wife is a registered structural engineer for Exelon Nuclear, and former engineer for Bechtel Corp. She has found this thread to be a "ginormous" form of entertainment

 

[Tim Singleton]

Heat expands, cold shrinks.

In the paper mill where we do over flow maint. We have bearing heaters and pack shafts with dry ice. To get the new bearings on.

Heat expands, cold contracts Steel that is.

 

[logger3006]

I have never heated a bolt to get it out, I heated the nut. Heat expands. I use to change the starter ring on transmission flywheels. You heat the starter ring to expand it and t comes off. heat the new one and put it on, once it cools it doesn't move.

 

[Tim Singleton]

Well Dan, I worked as an ironworker both in the field, and in the nuclear industry for many, many years.
Steel contracts with heat, and expands as it cools.

Well, Rich, I once was an application engineer in cryogenics. Simply put molecules get excited and expand when heated, when cooled they contract.

Well LH, i'm still one up on you ;D My wife is a registered structural engineer for Exelon Nuclear, and former engineer for Bechtel Corp. She has found this thread to be a "ginormous" form of entertainment

Don't forget to tell her we are talking about steel. Not a fluid

 

[JRS]

We're talking about a barrel, not a solid. Completely different animals. From my resident structural engineer: "You guys are dealing with a rifle barrel that is not a solid. To believe the OD of the barrel is expanding from introducing heat, you would have to believe the rigidity of the barrel steel forces the OD expansion to make the bore diameter larger also".

I have watched a few flywheels assembled. The flywheel was heated to a certain temperature, then the ring installed. When it cooled, the ring was tight. As I stated earlier, we heat the enormous turbine shafts (actually performed by Cooper, a specialty contractor) wrapped with an induction type blanket with about 3 zillion wires attached for a 72 hour period. Once it has contracted to the correct dimension, we have a 30 minute window in which to lower the bearing onto the base of the shaft with the crane, before the shaft starts to expand as it cools.

 

[JRS]

Well Dan, I worked as an ironworker both in the field, and in the nuclear industry for many, many years.
Steel contracts with heat, and expands as it cools.

Well, Rich, I once was an application engineer in cryogenics. Simply put molecules get excited and expand when heated, when cooled they contract.

Well LH, i'm still one up on you ;D My wife is a registered structural engineer for Exelon Nuclear, and former engineer for Bechtel Corp. She has found this thread to be a "ginormous" form of entertainment

Don't forget to tell her we are talking about steel. Not a fluid

Structural engineers don't deal with fluids Tim. Their area of expertise is steel

 

[LHSmith]

Your talking about hoop stress.

 

[LHSmith]

Another reason not to bed under the barrel shank is you will have to re-bed that portion when changing barrels. And for a switch-barrel, it leaves you with no option but to free-float the entire barrel.

 

[mr45man]

Steel expands when it is heated at the rate of 6 millionths of an inch per inch per degree of heat rise.
Thats a fact ;D
John H.

 

[Dusty Stevens]

Liquid expands with heat too-ask any power plant boiler operator

 

[JRS]

Your talking about hoop stress.

Hardly, LH. We aren't talking about what pressure does, but rather heat.

 

[Tim Singleton]

Please post something other than an opinion, that contriticts the basic law of physics.



This is a simple expansion coefficient table of several different types of steel
http://www.balseal.com/sites/default/files/tr18_020707131421.pdf

 

[Eddie Harren]

I cannot believe that the ultra wise and all knowing Catshooter has not jumped in on this. LOL

 

[LHSmith]

I cannot believe that the ultra wise and all knowing Catshooter has not jumped in on this. LOL

Why he's out shooting...he shoots more than 85% of the site members. More than likely preparing for a match so he can do well and add to his shooter points. Eddie, he may be nipping at your heels in points for all we know.

 

['Freak]

Heating a steel pipe, tube, rifle barrel, whatever, gonna increase both the inside and outside diameters.

 

[LHSmith]

Two extra pages based on my theory as to why not to bed under the barrel shank. Makes me feel like a hi-jacker
The expansion is hardly measurable, yet it's still there. When in doubt,eliminate the variables.

 

[Alex Wheeler]

Well my wife works at Nasa and she says the sky is green. Thats a fact. ;D
I have tested this (barrel bedding). What you say? An actual test? Not an Opinion? I originally bedded a 1000 yard gun with the chamber bedded. It was a rem clone with a 30" hv barrel. I shot it well for 6 months then ground out the chamber bedding and shot the barrel out. I saw no difference. For this reason I no longer bed the chamber. No benefits, only possible problems.

 

[ridgeway]

I cannot believe that the ultra wise and all knowing Catshooter has not jumped in on this. LOL

Why he's out shooting...he shoots more than 85% of the site members. More than likely preparing for a match so he can do well and add to his shooter points. Eddie, he may be nipping at your heels in points for all we know.

Get ur dern facs rite...it is 95%%%%

lol