[willyp]

Over the years i loaded and shoot a lot of rounds.I do feel that hot weather is not a good time to try to find a good load for deer season?
A couple of reasons come to mind:1,The gun heats up and stays hot for too long,2,The powder performs differently in the upper temps {70 and up degrees].
In my ground hog or Br guns,the warm was fine,due to the fact that we hunt them in the summer or go to matches in the heat of the day!
Years ago,when i was a bit dumber then i am now,i would spend lots of time trying to find a real good and accurate deer hunting load,most of the summer?
By August i was happy with my gun and powder/bullet combo and would set it aside! In the beginning November i just had to go get some shooting time in and show off just how well my guns shot? It never missed,that most of the time,i would say 50 to 75% of the time,the guns would make a fool of me at the range?
Who believes everything they read? Well,once i got over my not realizing that they knew what they were writing about,such as Temp and powder reactions to it,things got better?
I blamed my guns,for the change in accuracy and would take them apart and do all kinds of things to them,like,Change scopes and mounts,check my bedding or re-bed them?
Now days,i believe in the powder and temp thing and things sure changed for the better!
What about you?

 

[triggercreep]

Pressures spike in hot weather. Plus if you sight your rifle in 90° weather, your rifle won't be hitting the same on a 20° day in December.

 

[tdd]

Honestly, I don't find it is a HUGE issue. Now, to be clear, when I shoot, I let the thing cool to at or near ambient temps again.

When I shoot for load development, I do it different than most. I learned this from a friend of mine who's very skilled at handloading and shooting.

I'll take no more than 4 different loads to the range for a rifle. I'll post a target with a target dot for each load (I use butcher paper and stick-on dots). I number/label the dots to go with each load. I arrange the loads in my ammo box to match how the dots are arranged on the paper.

I shoot a round from Load 1 into the dot for Load 1. Eject the brass, realign onto Dot 2, and shoot one round from Load 2 into Dot 2, then the same for 3, and 4.

Then the rifle gets racked muzzle up, bolt open, to let the heat out of the inside of the bore (rises from the muzzle when it's muzzle-up). It sits there till the barrel doesn't feel warm any more, right to the receiver face. To make sure I give it enough time, I'll take other rifles/handguns to shoot to keep me occupied. In this part of the year, I know it'll be at LEAST 20 minutes between strings. Sometimes more. I budget LOTS of time at the range for this reason. If I can't go for enough time to cool the rifle properly between strings, I go another day.

Once it's had plenty of time, I go back to the rifle and start with Dot/Load 2. Proceed through 3, 4, then 1.

Cool interval as above.

Back to the rifle, start with Dot/Load 3, then proceed through 4, 1, 2.

And so on till I'm done.

This does a few things.

1- cooling intervals are crucial so that the barrel doesn't keep building heat. I see people shoot 3 shots, leave the rifle sit maybe 5 minutes tops, say "that's not hot" and shoot 3 more. They didn't feel heat on the surface (and they usually check right at the muzzle where the barrel has the least steel), but there was a plenty in the barrel yet, and I guarantee that barrel was hot by Round 2.

2- It gives all loads equal footing, in that the groups are shot over successive strings, meaning each load is given the same access to a cool bore and a warm bore.

I have had very, very little trouble with rifles shooting differently from summer to winter.

Also, I will not shoot mid-day. If I can't get there first thing when it's not yet hot, I'll go in the evening. The range where I shoot is shaded well before dark, so the temps come down a fair bit.

But I will not....NOT....shoot a barrel hot. Period.

I look at it this way....our rifle seasons have seen temps from 20's to 70's. I know temps affect rifles and powders, but a 50 degree swing, especially for PA deer hunting ranges, isn't drastic unless you're right on the ragged edge to begin with.

Even my 264WM that I run pretty hot shoots just as well in August as it did in Nebraska in the snow in November when I killed a 5x3 mulie with it last year at 212 yards.

You can't shoot with abandon in the heat, no. But I don't think that is ever feasible for accuracy/load development, even in winter. You just don't have to wait as long between strings in the winter.

I've chronoed my loads quite often. I have seen temp swings, but not huge ones. And I have never had to change zero with temps, nor have I had a good load go bad in different temps.

 

[6-DASHER]

I've been reloading for about 50 years..the only time I ever see major swings in velocity, pressure and case issues is with ball powders, it can drive you crazy! Using modern Hodgdon powders I've never noticed much difference on the magnetospeed or chrony. Also try to use a covered shooting bench, bright sunshine on a box of shells can really raise pre fire temps and rate of barrel cooling..

 

[tdd]

^^^ Agreed on all points.

 

[aubie515]

When I'm training I like nasty weather such as a lot of snow/ice or rain when I shoot.

When I'm sighting in optics or load development, I prefer nice days. I want to take out as many variables as I can.

 

[Strut10]

I will offer some valuable, first hand advice.......

Do not.......DO NOT......develop a load with Reloader 22 in the cool or cold part of the year then shoot it in the summer !!!

Had a particular load I worked up (in November) for my 7-STW that backed primers clear out the following July.

Lesson learned....... IMR-7828 is much more temperature stable and gives better velocities in my application.

 

[tdd]

7828 gives nearly identical performance to R22, from what I've seen. I haven't checked its temp stability, but you're likely correct in what you've noted.

I developed an RL22 load in my 270 in the summer, running around 2960 for a 150gr bullet. In November it clocks about 100fps slower. Problem is, light-based chrony's ain't that great for reliability, and the one I used was even less so. I don't think they have THAT big a temp influence, as the 2960 speeds were measured in the shade when temps were mid 70's. The 2850 speeds were in the sun in temps in the 40's. I can't see it being THAT sensitive to temp.

 

[Tony300wby]

The only time I could question a issue because of temperature was using H414 in a 30-06 when temps were in the teens. I had a round that seemed to hang fire for a split second? Could have been the cold temps or a million other thing's. Otherwise my experience has been the same as tdd's.

Good luck, Tony