Protocol for testing Hunting Loads? Do you test extreme temp spread?

[liveaxle]

I have been doing some reloading for target shooting and I have had some great results. I have not been hunting in a few years due to life/career/location changes and I am hoping to do some deer hunting this fall.

My number one concern when preparing for hunting is doing everything I can to avoid injuring an animal that I cannot recover, when I hunted previously, I generally took for granted that my factory ammo would perform (looking back that was a less than ideal assumption, but back then I was on a confident side of the Dunning-Kruger curve).

When I start hunting again, I would like to use handloads for the better performance, but before I do that I want to make sure I am in a position to properly document the performance of the ammo I will use. As part of addressing this concern, I would like to do extreme temp testing on my handloads (especially cold testing).

Has anyone here done that testing? What was your testing process?

 

[TaperPin]

My cold weather testing procedure is to call up a buddy, tell him to dump the sand out of his bikini and get dressed in warm duds cuz we’re going to the range despite how cold it is.

If slower velocities are enough to see on target it should be easy to see on a chronograph. Trust the target. It’s as much a rifle test as ammo test. Dirty greasy bolts create sluggish firing pin fall and highlight old worn springs as group size balloons due to wide swings in velocity.

Getting out on a hot day shooting prairie dogs is as hot as any conditions I’ve ever hunted big game in. If you load is going to be over pressure or increase velocity enough to matter, you’ll see it shooting small targets.

If hunting at 100 degrees or more, simply leaving the ammo and rifle in a closed up vehicle on a sunny day will give as much heat as you want. I’ve done that and quickly chronographed a magazine full of cartridges, but for me it’s much to do about nothing. Quickload will estimate velocity and pressure changes with temps if you’re really worried about it.

 

[liveaxle]

I've been using GRT, but I have notice that most of the powder models do not have specific inputs for temp sensitivity (they just use defaults).

The issue I run into with cold testing is that where I want to hunt is much colder than where I live or work. It rarely drops below freezing at the ranges near my home or work, but in the places I plan to hunt below freezing conditions is not uncommon.

I am less concerned with hot testing considering there is summer between now and hunting season.

 

[BCsteve]

What exactly are your concerns? The cold temperatures will affect your velocity to the point of affecting trajectory and/or impact velocity? Or something else? Choosing a temperature stable powder will negate all those concerns.

 

[liveaxle]

I want to generate enough DOPE to be able to confidently predict the trajectory at lower temperatures, and to verify that changes in burn rate will not impact dispersion.

My concern is that "Temperature stable" means different things for different powders. For example, H4350 and Varget are both marketed as "Temperature Stable" but, based on my internet reading, H4350 seems to be almost twice has reactive to temperatures vs Varget. In addition, most of the powders I currently have are not marketed as "Temperature Stable" and I would prefer to not have to buy different powder just for my hunting loads.

 

[N2TRKYS]

Waste of time to worry about it. Develop your hunting loads in the temp range you’re gonna be hunting and don’t worry about it.

 

[wind gypsy]

pretty easy for me to shoot whatever in all temp ranges and I do over the course of a year and that’s enough. Generally with “temp stable” powders there’s no surprises unless you’re loaded to hot. Things speed up and slow down a bit.

 

[Vern400]

Take a quick velocity check on a very cold day, and one of 100 days that are hot here. I do do it mostly to check for pressure signs, and I have had big problems with that. Now that I have a Garmin I can keep the data fairly easily. Most of my loads will very less than 50 feet per second between 32 and 110 F. I have had the hot days go over pressure when I reloaded in the winter.

 

[Koda_]

The only thing you need to worry about is if you develop a hot load in winter that you will use in summer.

Otherwise, put your handload into a ballistic calculator and compare the elevation difference downrange between 90 degrees and 32 degrees and its probably no more than a couple of inches, at that extreme difference.

 

[Bluefish]

My understanding is varget is on the low end of temp stability and is about 1/2 fps/deg f. Cfe223 is not nearly as stable and is 1.5-2 on average. When I went looking for data, I found that it was non linear. So at say 30-60 deg is was .5 and then at 60 on up it was 2-2.5 if I remember correctly. So it could cause issues depending on where in the range your temperature swings.

My big takeaway was develop loads at the temps you hunt if possible.

 

[Vern400]

In case you're still learning your way into this, one additional note. If you're a varmint Hunter and you get your gun really hot, and then leave a loaded round in the chamber, TEST THAT.
Likewise, if you set your loaded rounds in the sun while you're shooting they might get up to 130° or higher. If you do that, TEST THAT.

I cooked a round in hot chamber for about a minute and then fired it. 308. Complete separation, flames out the gasport and around the bolt, and it pretty much ended my day. Couldn't get the case out and I had my gunsmith check it out for damage. Gun was fine but I was down for a while.

One irrelevant point here. I knew a world war II veteran, Navy, who was actually in the battle of Leyte gulf. I understand the 16 inch guns have a propellant charge, and then a 1000 lb explosive round. He said their guns got so hot that once the charge cooked off in the gun and fired inadvertently. He said the scary thing was that the round could have cooked off instead of the charge. That dude was the best Middle School history teacher I could have ever had.

And if you haven't heard of this battle it's worth a watch on YouTube. It's my understanding the USN shredded much of the Japanese Navy on that day. I guess that was a pretty good lesson for me if I remember it 45 years later.....

 

[roadrunner]

I hunt with a rifle from anywhere to 75 deg to -5, - 10, or whatever.

I don't overwork it. I load the most accurate published load and powder for the bullet I'm using and move on to something else.

 

[ropeup79]

According to this chart Varget and H-4350 have very similar temp changes. .13 and .16 fps per degree of change. So a 100 degree change would only be a 13 or 16 fps change. The chart is only a guideline though and bigger or smaller cartridges may have a different actual change.

 

[HuntHarder]

Everything I've read about H4350 has been very temp stable.

 

[Bluefish]

Here is the study I found that showed some real world testing. https://www.wlcastleman.com/equip/shoot/t223/index.htm Used 77 tmk.

 

[KyleR1985]

I’d say over half of my hunting is done between these temps in the southeastern US. I found this interesting.

It’s been nagging at me constantly hearing about temp instability in regards to Lever (apparently a close cousin of CFE223).