Cold barrel flier vs. Powder burn rate

hilblly · November 22, 2008, 08:26 AM

Hi Folks
I was having trouble with a particular load for my 270 win
The problem was the first shot was always about 3/4" low.
The rest of the group was touching.
Called the rifle manufacturer with a separate question about the rifle and explained my situation with the grouping.
I was using reloader 22.
He told me to switch to a faster burning powder to elimated the rapid heat build-up in the barrel. He went further to explain that a faster burning powder would contain the excess heat to the chamber where the barrel is heavier.
I was under the impression that barrel heat was caused by friction.
Does the powder speed theory make sense to anyone?
Thanks for any help.
Mike

wncchester · November 22, 2008, 08:39 AM

"I was under the impression that barrel heat was caused by friction.
Does the powder speed theory make sense to anyone?"

The major heat source is burning powder, friction adds little heat. I'm no "expert" but I doubt you will see any difference in barrel heating due to powder burn rate changes.

Allow your barrel to cool between shots - a lot -, otherwise you are testing as for a target rifle, not a hunting rifle.

olddrum1 · November 23, 2008, 02:21 AM

In shotgun barrels where you are out shooting heavy reloads using extremely slow powders this is a true statement I do believe in very cold weather.

FrankenMauser · November 23, 2008, 01:27 PM

The only times I have seen burn rate allow you to keep most of the heat contained in the chamber.... Are the times when my family uses relatively fast powders with light-for-caliber bullets. H4895 with 100 grain hollow points in the .270 Win, for example.

November 22, 2008, 08:26 AM	#1
hilblly Member Join Date: October 8, 2004 Location: Southwest, MT Posts: 94	Cold barrel flier vs. Powder burn rate Hi Folks I was having trouble with a particular load for my 270 win The problem was the first shot was always about 3/4" low. The rest of the group was touching. Called the rifle manufacturer with a separate question about the rifle and explained my situation with the grouping. I was using reloader 22. He told me to switch to a faster burning powder to elimated the rapid heat build-up in the barrel. He went further to explain that a faster burning powder would contain the excess heat to the chamber where the barrel is heavier. I was under the impression that barrel heat was caused by friction. Does the powder speed theory make sense to anyone? Thanks for any help. Mike

November 22, 2008, 08:39 AM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"I was under the impression that barrel heat was caused by friction. Does the powder speed theory make sense to anyone?" The major heat source is burning powder, friction adds little heat. I'm no "expert" but I doubt you will see any difference in barrel heating due to powder burn rate changes. Allow your barrel to cool between shots - a lot -, otherwise you are testing as for a target rifle, not a hunting rifle.

November 23, 2008, 02:21 AM	#3
olddrum1 Senior Member Join Date: March 23, 2008 Location: Mid Missouri Posts: 807	In shotgun barrels where you are out shooting heavy reloads using extremely slow powders this is a true statement I do believe in very cold weather.

November 23, 2008, 01:27 PM	#4
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	The only times I have seen burn rate allow you to keep most of the heat contained in the chamber.... Are the times when my family uses relatively fast powders with light-for-caliber bullets. H4895 with 100 grain hollow points in the .270 Win, for example.