Cooling Barrel between shots

[fletch]

Something that has been in the back of my mind for some time is weather it would be better to load the gun while hot with the saboted bullet and then let it cool. If the problem with a warm or hot barrel is a soft plastic sabot then could the heat melt groves into the sabot and then when cooled increase accuracy. You would or could heat a barrel up to a certain temp (unknown) and push it thru to the breach and see if it did engrave better. there could be a lot of problems with doing this and one I can think of right now is the sabot sticking to the metal.

[Deleted]

The sabot only softens in a hot barrel witch leads to blowout, the barrel would take less cooling time without the sabot/bullet in the barrel. I really cant see an advantage in loading then cooling. the barrel would have to be very very hot to actually melt the sabot.

[smokeeter]

The whole idea of letting the barrel cool between shots is so the the plastic sabot is not effected by the heat. You have to do that with a cooled barrel.

[Richard]

Your best bet is to keep the barrel at a constant temperature. By using the cool rod in between every shot, my barrel never really heats up! Both summer and winter I use the rod in between shots.
Richard

[fletch]

Richard
Not being a metallurgist I had wondered about what effect a rapid cooling versa slow would have on the metal over a long time?? Don't they heat then cool copper rapidly to return it to a soft state after stretching.

[youp50]

You do not need to quench copper to anneal it. Warm it up till the color changes and let it cool will work just fine.

Depending on the type of steel, the temperature you heat it to, and the quench media type and temperature is how steel is hardened. The temperature needed to heat teat steel is higher than what you will get by using a muzzle loading rifle.

I have been hearing of some barrels developing internal tiny surface cracks. Not ML barrels, but center fire rifles. The supposed culprit is ammonia based copper removing solvents. Most sabot shooting MLers probably would not use these solvents as they stink and there is no copper fouling anyway. It may be a factor in the sabotless crowd if the solvent is used. It would sadden me to ruin a high dollar after market barrel with such a product. The theory being the ammonia is forming a nitrite of steel and this is cracking under the heat/stress of shooting.

The information on ammonia based solvents is purely second hand. I chose not to use the ammonia based solvents long before I had heard of this.

[joe21a]

I do not thing you get the ML barrel that hot when shooting, that cooling it rapidly will cause a problem. Moisture may be the only problem and a couple dry patches should solve that.

[Richard]

Joe21 is 100% correct. After one shot, the barrel is only slightly "warm" not hot. I have been doing it on my current barrel with has over 600 shots thru it and my Hawkeye borescope shows not problem on the interior. As far as the copper removers with the amonia? Benchrest shooters use it all the time. The topic has been debated by never really proven. Particularly if you do not leave it in for long periods of time. I use Montana Extreme BMG and while it has a lot of amonia, it is also suspended in oil rather than water as most others are. I have actually worked with the company and know for a fact it does not harm a barrel. I use it regularly and leave it in my barrels for days. You have to remember, that after a short period, the amonia dissipates. The guy who put together the Montana forumla has been keeping a piece of a SS barrel in a clear glass bottle for months and months and no sign of any detrimental effects.
Richard

[youp50]

Ammonia is used in the water chemistry treatment in nuclear reactors.