What temp is too hot for load development

[WVELK]

We are into June and I am still working on a couple loads for fall hunts. Never been in this position before. Normally by April I have finished load development while temperatures are comfortable and cool. I don’t mind practicing in the summer. Is there a temperature where you say I am just not going to try to deal with load testing at or above? For me, I think if I shoot early in the morning, I can get my shooting in before temps go above 70s. It will just be shorter sessions.

 

[jfk69]

I actually like doing load development at 70+ degrees. Then I know I won’t have a pressure issue practicing all summer and only super rarely do I need a small sight adjustment for very cold weather hunting. I can’t remember a time when I saw a change in poi from loads developed in warm weather down into the mid-20’s. I have down into the teens though.

 

[MuleyFever]

I always wondered this too so I just shot in the morning.

 

[Slick8]

Like jfk, I like working up a load in the summer knowing it's good for all year.

Having said that, I typically start early in the morning so 80-low 90's is the norm.

Headed out late today in mid 90s to test seating depth with a mid sized load. This is more of a timing thing as my weekends are pretty full right now.

 

[mainbeam pursuit2]

Right or wrong, I'm not sure. I've always tried to do my load development in the temperature that would match the warmest it could be during a hunt. Then check again in the cold temps for velocity, grouping and any other changes between the temps. Kind of a longer process, has worked for me so far.

 

[sdupontjr]

South louisiana i don't have a choice. It's hot or hotter. I have done load development at 90*+. What i found was i will hit pressure then back off slightly. If it groups well, then I'm good. Then I recheck as it gets closer to hunting season to see if still applicable, which it has been 100% so far. But by doing development in hot temps, I know that's the peak pressure so I'm good to shoot it anytime of the year. If you load development in cooler temps, you may be over pressure in Warmer. I also use temp stable powders so it doesn't effect me as much. I wouldn't know what it's like shooting with no damn humidity. I'd probably gain 100 -200 fps by not load developing in pea soup like air. Ha.

 

[Ganderzone]

There are some rare cases where powder can actually increase in pressure as temperature falls. 4831sc is labeled an extreme powder so it is stable but there have been test done where they found it to slightly increase pressure. With that being said, I've taken the same load from 90 degrees to 30 degrees in a week time period with no issues. If anything drop half a grain and you should be fine regardless.

 

[WVELK]

Like jfk, I like working up a load in the summer knowing it's good for all year.

Having said that, I typically start early in the morning so 80-low 90's is the norm.

Headed out late today in mid 90s to test seating depth with a mid sized load. This is more of a timing thing as my weekends are pretty full right now.

How on earth do you see well enough in that heat? The mirage has to be terrible.

 

[WVELK]

Well you all make valid points about being a safe bet if you have not hit pressure. I just never hunt when it is very hot so never thought about that. Thanks.

 

[MtnW]

Working up loads now at 95 F outside temps for a .270 Win and 25-06 Rem. Both rifles seem to prefer speed and max loads. As before no pressure problems with the hot summer conditions. Both rifles now have a lead free load in Barnes TSX and TTSX at max loading with no pressure signs and a Nosler Partition load for each at book max. I hunt in early seasons for Pronghorn where it can be 95F to January in WY and MT where it’s been as low as -20F not including wind chill.

 

[Ganderzone]

How on earth do you see well enough in that heat? The mirage has to be terrible.

Mirage in hot weather is challenging. Barrel cooler, portable fan and cool down breaks help. You can make a barrel cooler with a cheap camping pump off Amazon, around $20 give or take but worth it.

 

[Slick8]

How on earth do you see well enough in that heat? The mirage has to be terrible.

Turn the magnification down. Move from 300 to 200. If it gets bad I'm done with precision work and will bang steel or shoot some pistols / rimfire.

Im usually set up at daylight and done with precision by 10ish.

 

[Robobiss]

I do all of my loading in my basement which is 70-80 degrees in the winter and probably high 60’s in the summer.

I very purposely walk straight out the basement door with warm ammo and rifle and shoot into a snowbank. If I am under pressure at 70 or 80 degrees, there is no circumstance that I would reasonably find in which I will be over.

I think load development in warmer temps is the way to go. So I do it on purpose.

 

[2Stamp]

I worked up a load using V560 back in March (probably 30-40F). Looked awesome. Went and shot a couple weeks ago, around 20-30 degrees warmer. Boom, pressure signs. Guess I'll back off .5 grain and go from there. This is a fun that is shot in the fall for elk, so I'm good either way. Double base VV powder.

 

[WVELK]

You southern hot temperature shooting folks are on to something. Shot two rifles Saturday in the heat. There was enough cloud cover that the mirage was not bad but it was in the upper 70s. Both rifles in final stages of load development. One rifle passed with flying colors and move forward with no signs of pressure. The other showed several signs of pressure with both loads being tested. Again, I was doing final seating depth testing. Thought I had the powder charge down.

I am going to post another questions, because I am not sure what this rifle is showing signs of pressure. It is approximately one grain below what many others find stable for a 6.5 PRC. And with both charges it was slightly less than what the Hornady manual says is max for the powder.

No carbon ring and brass was not in excess of recommended OAL used for new brass. Hmm?

 

[Dioni A]

As much as I hate the heat, I almost prefer to do load development when it’s hot out. 90+ degrees. If you know your ammo is safe when it’s this hot out you will not have any issues in the fall.

 

[UKwildcatfan]

I'm not practicing when it's hot, and I'm not hunting when it's hot. My body is made for 70 and below.

 

[sdupontjr]

I'm not practicing when it's hot, and I'm not hunting when it's hot. My body is made for 70 and below.

Don't come down south then, ha. I hunt with a ThermaCell until damn near Christmas. Which is also a main reason I bought the Schmidt Bender Polar T96 because it gets dark fast down here. Most optics barely get to legal light here and a lot of it has to do with the foliage hasn't died yet due to the temps. So yeah, I have to get use to the temps here. I even run a battery powered fan in the stand sometimes.

You southern hot temperature shooting folks are on to something. Shot two rifles Saturday in the heat. There was enough cloud cover that the mirage was not bad but it was in the upper 70s. Both rifles in final stages of load development. One rifle passed with flying colors and move forward with no signs of pressure. The other showed several signs of pressure with both loads being tested. Again, I was doing final seating depth testing. Thought I had the powder charge down.

I am going to post another questions, because I am not sure what this rifle is showing signs of pressure. It is approximately one grain below what many others find stable for a 6.5 PRC. And with both charges it was slightly less than what the Hornady manual says is max for the powder.

No carbon ring and brass was not in excess of recommended OAL used for new brass. Hmm?

Not understanding the question. I think you saying your 1 gr under what others are and its slightly less than Hornady book. But are you showing any pressure signs? My Browning 7mag was 3 gr over book max with H-1000 and still had no pressure signs, so I just stopped because velo was 3050. Which velo is also a sign of pressure. You could also have a tighter chamber or brass with smaller case capacity.

 

[Choupique]

Louisiana as well, so no choice for me. Hot and humid or hot and raining. Everything I load gets tested at 90+ degrees and 100% humidity.

I figure its not a bad thing. One less thing to worry about.

 

[WVELK]

Don't come down south then, ha. I hunt with a ThermaCell until damn near Christmas. Which is also a main reason I bought the Schmidt Bender Polar T96 because it gets dark fast down here. Most optics barely get to legal light here and a lot of it has to do with the foliage hasn't died yet due to the temps. So yeah, I have to get use to the temps here. I even run a battery powered fan in the stand sometimes.


Not understanding the question. I think you saying your 1 gr under what others are and its slightly less than Hornady book. But are you showing any pressure signs? My Browning 7mag was 3 gr over book max with H-1000 and still had no pressure signs, so I just stopped because velo was 3050. Which velo is also a sign of pressure. You could also have a tighter chamber or brass with smaller case capacity.

No worries. I was typing without reading glasses - never good. I was simply saying my load is less than what manuals generally say is max, and below what others find stable. I know all rifles are different. I did some research and there are 3 billion reasons (if I counted correctly) things that can cause excess pressure in addition to too much powder. This load was fine at 50 degrees F. It was not in the upper 70s. I am just going to back off .3 to .5 grains and see where I am. Per ladder testing and OCW testing I may be just outside my node with these weights, but too much pressure even in a node is not good.