proof test

[David R. Pennington]

What would be good proof test load for a .45?

[bob in the woods]

13/16th's barrel ? or 7/8  or 1 inch ?    Round ball or bullet ?    Flint or percussion.
Why do I ask ?   Because the loads I would consider might be different for each of the above.   I shot loads in my flintlock
.45 with a 13/16th's barrel that I would never consider safe in a drum type percussion rifle with the same barrel.

[David R. Pennington]

Flintlock of course, 13/16 straight barrel 48 inches long. Patched round ball, fairly deep groove rifling 1 in 54 inch twist. This barrel was made in 1973 and has never been fired. The breech plug is 9/16 - 12 thread. I will drill touch hole and cone from inside.

[EC121]

In normal shooting the most common overcharge is double pouring the powder.  So, a double normal powder charge plus little would be realistic to try the barrel. 

[Daryl]

I would think the most important thing to do with the barrel BEFORE proofing it, would be to mark it and measure, to the nearest ten-thousandth of an inch, with a micrometer (not calipers) on each location/flat/etc, and record that data - fire it then re-measure. To not do that, would create a meaningless 'proof' test.

[moleeyes36]

I would think the most important thing to do with the barrel BEFORE proofing it, would be to mark it and measure, to the nearest ten-thousandth of an inch, with a micrometer (not calipers) on each location/flat/etc, and record that data - fire it then re-measure. To not do that, would create a meaningless 'proof' test.

Exactly right.  Too many people think that proofing a barrel is just testing for rupturing or major bulging. 

Mole Eyes

[JTR]

Daryl, I can see the nearest thousandths ( .001" ).
But measuring down to a ten thousandth ( .0001" ), you'll get a lot of 'growth' just from the heat of firing the barrel.

Or maybe I'm mis-reading your comment?

John

[Daryl]

I doubt one shot will grow the barrel.
 
1/10,000" (.0001") is the measurement you are looking for.  I would think at a full 1/1,000" (.001"), the barrel is already rupturing and is probably visible as a ring inside a clean barrel.  It is certainly something you can feel - WITH A TIGHT PATCH

You can test that of course, with a normal shot before the test, then let it cool and re-test with the proof load.

If you think the heat enlarged the barrel, let it cool and measure it then.

I have never been able to discern the heat of a single shot with my hand, even in the 1 1/8" .69 burning over 160gr. of 2F.

edited to include "With a tight patch"