Reminder on testing reloads in hot weather

[Big10gauge]

Just a reminder that some of powders out there are VERY temperature sensitive which can create high pressures. We were testing some .20 TAC loads using 40 gr bullets over a chrono and my case of reloads were out in the sun. The weather was around 90 deg. I stuck a reload in the AR and touched it off. The chrono read 4387 fps, visually checking the case there was a cratered primer,the case head stamp was almost smooth, and a ejector mark. Later miked the case head and it was way out of spec. Had to shoot one more and the same results. Decided that that was enough. That particular load would probably be ok if was 20 deg instead of 90.

[carpsniperg2]

yep, good post! something every reloader should be aware of!!!

[700xcr]

Have to test loads in my sons 300wsm this week. That is why we are going early in the moring to the range before weather warms up.

[demontang]

Yea good reminder. People need to remember if they reload in the fall that they need to be careful with those loads in the summer because of this reason. Thats smoking out of a 223 too , I know that snipers will lay there loads in the sun to get the extra fps that a warm round can provide.

[Big10gauge]

Yea good reminder. People need to remember if they reload in the fall that they need to be careful with those loads in the summer because of this reason. Thats smoking out of a 223 too , I know that snipers will lay there loads in the sun to get the extra fps that a warm round can provide.

It's a .223 necked down to .20 with a steeper shoulder

[thinkingman]

I use a couple of Hodgdon powders for their temp tolerance.  H414 is the one that comes to mind, I think Varget is another.  Please don't take my word for it and as always, when talking reloading...trust, but verify.

[demontang]

Lol yea its still fast even for the tac 20

[Buckblaster]

I test my loads in hot and cold weather and compare velocities for temperature tolerance of powders.  The Hodgdon extreme powders are what they say they are, temp insensitive.  I get the same velocities in 80 degree temps as I do in 20 degree temps. The ones I have used are H4895, Varget, H4831sc, H4350 and H1000.  Consistent velocities mean consistent groups.
http://hodgdon.com/extreme.html

[BlackRidge]

I'm fairly new to reloading, so this was news to me (thanks btw)

I finished up a batch of 165gr. accubond rounds for my 30-06 last night, theyre close to the max recommended load, and with the extra warm weather we've had the past few days.... perhaps today isn't the best day to test them 

May blow my 1903 apart!

Great info Big10

[huntlakewood]

I have been reloading for a few years ( 3 or 4) never knew this about the weather thanks for the info.