Charting Temperature

B

Bob Kingsbury

New member
Shooting from an enclosed bench,, and possibly with preloaded ammo.
What would you record, outside air, barrel temp or inside.maybe ammo temp.
 
Recording Data

Bob

Glad to see you are always so dedicated. At our small range from one end to the other there is big difference in temperature because of the wood stove at one end. Another concern is temperature differences through window and how that affects scope and barrel temperatures. I think you will want to look at these factors:


Powder Charge of Developed Load (Volumetric / Weight)

Temperature at which load is developed
Current powder Temperature

Velocity change


I would be interested to know about the; -Dew point Temperature.
Let us know how you make out.

Ken
 
Hard as it was for me to believe,

I was told recently by someone I TRUST that it's mostly about "Barrel Time" which gets to the air density inside the barrel. This determines how long it takes the bullet to push the ambient barrel air out, thus potentially causing variations in frequencies of vibration.

I must admit, is difficult for me to "drink that Coolaid" but I am going to do it. Temperature sort of dictates the air density but not totally. It would be my guess, based on the simple air density theory, that trying to corelate a number of varying temperatures in a mixed heat invironment would be madening and not productive. Monitoring air density may also prove to be the same.

This "Barrel Time' thing was also discussed with me last March at a long distance range I visited. A man I was talking to there was in the process of developing a long distance Wildcat round. He also said finding the tune was mostly about barrel time. He had a computer program and a hand typed list provided by a ballistition to guide him. It seemed like some sort of Black Magic to me at the time but I didn't discount it out of hand.
 
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Cool-Aid Question

Hi Pete, trust you are soaking in that hot southern ambient air. I am curious as to the correlations you mention: on ambient barrel air and air density. Could you explain?
Thanks.


Ken
 
Bramwell experiments

Bob Kingsbury said:
Shooting from an enclosed bench,, and possibly with preloaded ammo.
What would you record, outside air, barrel temp or inside.maybe ammo temp.
Click to expand...

Bob,
You may be interested in these experiments by Denton Bramwell

http://snipershide.com/Pressure

He found that barrel temperature is most important, followed by ammo temperature, in determining peak chamber pressure. His theory, which seems plausible to me, is that even for the very short time that the bullet is in the barrel, some heat of combustion is transfered to the barrel. Since more heat is transfered to a cold barrel, less energy and, therefore, pressure, is left to propel the bullet.

Cheers,
Keith
 
Franklin W Mann

Bob

While reading Test 35 these quotes stuck out and made me think of your tests.

“We had not discovered for what we were searching and had no idea of the form of the things after which we were looking.” “Our desire was to keep our minds constantly alert by surprising experiments.”

Cheers

Ken
 
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