Re: barrel cool-down
Heavy contour barrels don't improve barrel life. It isn't barrel life that's led to use of these in competition. It's benefit is lower POI change over a high temperature shift(stability).
Of course a heavier barrel takes longer to heat up with a given input of energy. That heat is bottled up in more mass, and eventually breaks at a larger surface/diameter. That same heat is felt quicker at the surface of lighter contour barrels. That's all.
Means nothing w/regard to throat temps, and that's where barrels meet their demise. Higher energy catridges(than 6PPC, 223, 30br, 308, etc) for bore, will heat a throat to a point of detriment very quickly, regardless of barrel contour, or overall temp. You have to give that energy a chance to move away from the throat.
So if barrel life is really your concern, for group shooting, the back of a hand check is very flawed.
Group shooting guns are low energy.
Hunting guns are not group shooting guns.
A friend eventully learned some of this with his favorite deer gun, a 25-06 which was very accurate. He used the gun for many years but all the sudden he got caught up chasing ever tighter groups, and bringing them into work for show & tell. 3-shot groups, fast as he could, then 30min cool down between each group. He never let the barrel 'feel' hot.
I thought,, -what a shame he's killing that barrel.
One day he says somethings wrong, & it seems like he has to seat the bullets out further(than logged) to regain tune. He's wondering why that is with just under a thousand round count. 'Never seen anything change before'.
I told him that 3rd shot in each group was ripping throat away. It's too much energy right there, so give it about a minute between shots.
Didn't make sense to him, he couldn't group as well, everybodys group shooting..
Within the next couple hundred, he finds that he cannot stay in tune through a full sitting, and is shopping for a gunsmith.
Ruined a great barrel he and his son could have hunted the rest of their lives with.
Now he's caught the bug and is full blown 30br score shooting.
Doesn't hunt anymore..
Guess that was what he really wanted.
Think about what YOU really want.