Those of us older folks learned a long time ago that it is best to have a hot weather load and a cold weather load, and ask God for the Common sense to know the difference.

I and partners shot 748,335, Win 760, and AA2700 going from 75*-100*, but we knew how to deal with it, the bonus was long barrel life.

Old time favorites like IMR 3031,4895, 4064, 4350 all had at least a .5g pressure spike, so backing off the load a tad was always in order for red hot dog towns...literally.

So, Hellgate, you know how all of old pharts dealt with this through the years. It takes shooting a rifle in the Winter, then again in the Summer recording loads and we used an Ohler 33. The accuracy node was usually at a particular speed.

So, to make the load development easy, we backed off the COLD weather load 2.0--2.5g in hot weather and worked up. When we hit the Winter time accuracy(speed), Accuracy was back again!!! Dumb butt simple! This aint even close to rocket science.

Now, for all of those that have drank the Kool Aid that the NON temp sensitive powder are not sensitive to hot and cold weather...well, You are probably not using a chronograph and shooting very small groups.

If I were out to get a one load do all, I would go to the Enduron series of powders, and look no further. I have found that H4895, Varget, and H4350 do vary from very cold to very hot weather(32-95*) when you are looking for bug hole groups. Varget burns ungodly hot, another issue when it comes to cleaning hard cooked on carbon out of the barrel .

There is a heat index for various powders, and I hope you will take this index to heart as it is will bring front and center how a powder choice will burn up a barrel quicker/slower. Don't confuse the burning rate chart with heat index chart.

Learning to reload is a life time hobby with all of it's various tid bits of information that will add to your education of being your own
ballistician.


Edited by ackleyman (09/04/19 11:16 AM)