doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Heating Study

I'm sure a gen-u-wine metallurgist would be unimpressed

Test performed June 2017 at 8:00 am at the Ben Avery Clay Target Center in Phoenix.
Air temperature was 101 and humidity 14%. Haze but bright sunshine.

Guns:12g Benelli Ethos with 1 1/8 oz. 1200 fps factory load.
16g 1906 L.C. Smith 0E "Good 2 Rod" Damascus (used only one barrel for the 25 targets) with 3/4 oz. at 1200 fps reloads.

Barrel steel: Benelli Ethos barrel (likely but unable to confirm on Benelli website) cryogenically treated chrome lined AISI chrome-moly 4140 (Carbon .38% - .43%).
Chemical compositions of 3 Crolle and 1 Twist samples were similar to AISI 1002 � 1005 (Carbon .02% - .05%) low alloy steel by Optical Emission Spectroscopy (OES). This would highly suggest that the iron component was wrought iron (Carbon .05% - .25%) and the steel was (very) low carbon �mild� steel.

Temperatures measured using an infrared thermometer at mid-barrel.
No difference in breech, 15�, or muzzle temps of 16g; 12g muzzle slightly cooler.

Prior to shooting but after guns in rack in full sun for 10 minutes:
Concrete pad Station 1 � 114
16g � 113
12g � 114

AFTER Station 4
16g immediately was 122 but cooled rapidly (in shade) to 112
12g cooled so quickly, also to 112, that unable to record immediate temperature

AFTER Station 8
16g 132 but cooled rapidly to 111 in shade
12g 128 but cooled rapidly to 111 in shade.
After another 25 targets the 12g again cooled rapidly in the shade to 111.

Impression for this non-statistically significant study:
1. No difference in heating between the two barrel steels.
2. The barrels rapidly dissipate heat.
3. Sun exposure contributes to barrel heating.
4. Pain occurs with contact exposure to 111 degrees; 30 seconds of 130 degrees will cause second degree burns to skin.
5. Avoid direct contact with barrels in Phoenix during Hell Season!

Interesting, Drew. Though I have not measured the temps, I have found that when shooting a round of 100 sporting with a double, during hot weather, that it cools much faster, and more, if I break it open and drape it over the seat back of my golf cart. This, as opposed to leaving it closed and standing it up in the scabbard.

I don't know why but it seems my .410s get even hotter, with the same amount of shooting, than my bigger bore doubles.

SRH

.410 wall thickness greater = slower heat dissipation?

I was amazed how quickly both study barrels cooled; literally the time it took to walk from Station 8 back to the covered picnic table.

If one rests the doubles in the sun, especially with blued barrels, the sun alone can make them very uncomfortable to touch.

Drew,

You are using the term, 'cooled rapidly' . Do you have actual times for cooling?

Sun heating: I have not so fond memories of repair work in the field, and grabbing a wrench off the tailgate of the truck. You learn to keep those chrome wrenches shaded. Wicked HOT!

Walking from Station 8 couldn't have taken more than 10 seconds.
After Station 4, we were holding the sensor on the barrels and as we moved them from the sun to the shade the temps immediately began falling to the air temp; 122 to 112 in about 10 seconds. It was weird.

It may not be high volume South American shooting, but every now and then folks ask if they can melt barrel/rib solder from the heat generated by shooting. I can't remember any other reference to steer someone to, to help them make their own decisions. It's not just the numbers, but what it might feel to the touch if someone were deciding if they should let it cool off a bit.

I have known of shooters sticking the barrels into a drum of water for a few seconds in a high volume shooting situation to cool them. I think it was at a flurry shoot. Pull them out and the remaining heat evaporates any moisture in a few seconds.

Re: the .410, I recently shot a .410 S x S sporting clays course and was reminded how uncomfortable they get, and how quickly. After each station I had to try and cool them down before the next. Perhaps it is only perception, and because the fingers wrap around the little splinter forend and barrels so much more readily it becomes more apparent. I dunno. I do know the more people shooting on your squad, the cooler your barrels will be when you get to the next station.

SRH

There were two main complaints when shooters went from Damascus barrels to steel barrels. One was the ringing or sound of the steel barrels was harder on the ears. No ear protection used as a rule. The other was that steel barrels would heat up much faster. Don't know if either was a real issue or just "common accepted knowledge". I do know that we will never see the likes of Lord Ripon and his 1000 plus driven birds killed in a single day. He must have been an awesome shooter to watch and birds must have been as thick as fleas.