Powder burn temp.

[mdi]

I've been reloading for many years but this never crossed my mind; powder burn temps. I have a new Ruger in .308 Winchester and using a lot of IMR4064, some Varget, and some W748. After a 4 shot string with 4064 or Varget, lower loads, the barrel is quite warm, and after 8 rounds it's hot to the touch (I haven't singled out the W748 loads to check bbl. temps). I have to let the rifle cool, bolt open for several minutes before shooting another string. Now, reading the powder manufacturer's blurbs on powders, Winchester says their 748 is "cooler burning", making for longer barrel life. Is this just Winchester hype or is there truly a difference in "flame temperature" and how much it heats the barrel? I'd also like to know if there is a difference, will I be able to tell by the barrel's temperature? Or is this just a moot/worthless point? :banghead:

 

[243winxb]

Nitroglycerin in Smokeless powders

I have read powder burns close to 5000 F. Double base powder that contain nitroglycerine may burn hotter??? Pure nitroglycerine about 9000 F. Need an expert for this question. Not I. I find the MSDS interesting. Some list what is in each powder, but not how much. http://www.hodgdon.com/msds.html I dont worry about it.

 

[rsrocket1]

I think barrel erosion from gas cutting is more of a concern, but even at that, I think it will take a lot of shots for even that to affect the barrel much less wear it out.

If a certain powder/load heats up a barrel quicker than another load, the main thing to worry about would be vertical stringing of the shots if the barrel is not mounted properly in the gun to accommodate for heating.

 

[mdi]

Yep, I doubt if I would ever wear a barrel out or damage the throat (erosion). I was just thinking about having to "slow down", when testing loads (strings in multiples of 4). I'm playing at working up an accurate load and go slow to avoid vertical stringing due to barrel heat. But I ain't the worlds best shot so I need to do my best with the ammo end...