Accuracy lost on warmer weather

[Mike Matteson]

It sure got me thinking. Especially as a new reloader. I need to stay away from temp sensitive powders till I feel a bit more comfortable. And even then I may not use them, unless it's just to shoot it up for a day of fun. And a little trigger time. I believe I am going to stock up on powders that are not sensitive to temps.

Got you a thinking. Good! The only thing powder is higher than hell presently. When you see something that can be download do so. Set yourself up a folder with sub folders inside of that. simple example is like Powder, Primers, Brass, Bullets, Barrels & twist rates. A go to place for are selling product. (becareful on just who the supplier is) Powders to be buy in lots. Primers are almost impossible to acquire presently in Large Rifle. Small Rifle is a different story. I would try and stay with match primers if possible. I do use Fed 210 LR primers, and have had very good luck if you want to call it that. There is so many thing to watch for and learn about, and this is the place to do that. My use of hunting rifle is making that cold bore shot no matter what the temp is. I use H4350 and H4831SC mostly.
Don't feel bad, it's a learning cure, and I have been reloading for 61yrs now. I am still learning and by far will until I go to my grave.
I feel that you was a tank jock? Being your handle.

 

[Weatherbyshooter/Hunter]

Your Not Carrying the Cooler? In the past I develop loads in what ever weather it was and petty much do the same now. Being I was mostly in S. Cal it didn't make much differents. I had a load in IMR powder that was grouping under 1/2" @ 100yds. Temp was in the 40's to 50 range. Let it set until later on that year or end of June (80-90 dgrs). I fired round a shot using the same load figuring on shooting 5 rounds. It blew the primer out of the primer pocket. When home that day and took apart 49 rounds. Gave-a-way about 16 lbs of powder.
The other is once I develop a load for that rifle. It's what I stay with. First in grouping, then cold bore shots. If not on the money, I contenue working on the load until I achieve that. Weather be dam. All cold or hot weather does is increase or decrease the velocity of the bullet. Grouping should stay about the same That does change the hit location some. Again it goes back to what type of powders you are using.
What types of powders are you using? Did you open up the chart I sent out?

Well it's going to be over 115 degrees today . Yes it may be 65 degrees difference so let's say the change is 1.5 FPS per degree in temperature rise……. That will be 96.5 feet per second and if your at the threshold or upper limit of the charge and pressure let alone accuracy then the cooler is a good idea.

 

[Eric H]

It sure got me thinking. Especially as a new reloader. I need to stay away from temp sensitive powders till I feel a bit more comfortable. And even then I may not use them, unless it's just to shoot it up for a day of fun. And a little trigger time. I believe I am going to stock up on powders that are not sensitive to temps.

Got plenty of H4350 and Varget.

 

[M1A1ABRAMS]

Got you a thinking. Good! The only thing powder is higher than hell presently. When you see something that can be download do so. Set yourself up a folder with sub folders inside of that. simple example is like Powder, Primers, Brass, Bullets, Barrels & twist rates. A go to place for are selling product. (becareful on just who the supplier is) Powders to be buy in lots. Primers are almost impossible to acquire presently in Large Rifle. Small Rifle is a different story. I would try and stay with match primers if possible. I do use Fed 210 LR primers, and have had very good luck if you want to call it that. There is so many thing to watch for and learn about, and this is the place to do that. My use of hunting rifle is making that cold bore shot no matter what the temp is. I use H4350 and H4831SC mostly.
Don't feel bad, it's a learning cure, and I have been reloading for 61yrs now. I am still learning and by far will until I go to my grave.
I feel that you was a tank jock? Being your handle.

Yeap 19k

 

[Jpron]

I see this often, have a good group in the cold and an average to poor group in the heat. I feel it has more to do with humidity and dew point than temp. I was working on a load last week one evening and getting really good groups. It was around 70 and low humidity. Tried it again yesterday and just stopped, it was 93 and way higher humidity. I was using staball 6.5 and h4831 both.

 

[Teri Anne]

People seem to forget that, Altitude, Temperature, Humidity, Barometric Pressure and level of light all have an effect on shooting performance and one load does not necessarily fit all. If you look at a rifleman's score book you will find entries for all of these to include winds and other important things that affect the flight of the bullet, including mirage which rears it's ugly head when the temperatures rise, especially across things like rifle ranges. If you want to be professional get yourself a shooters log book. I use the MY GROUP THERAPY log but there are many others that are just as good. Keeping a record of your shooting and the conditions will help you, especially when there is a day similar to what the current conditions are. They also have reloading data record books, both invaluable for keeping track of your shooting and loading activities. Do a google search to find one that you like and start recording you shooting and reloading data.

 

[Mike Matteson]

Well it's going to be over 115 degrees today . Yes it may be 65 degrees difference so let's say the change is 1.5 FPS per degree in temperature rise……. That will be 96.5 feet per second and if your at the threshold or upper limit of the charge and pressure let alone accuracy then the cooler is a good idea.

I see you didn't look at the chart I posted in bolg #65. Look at H4350. The way I read the chart with H4350, it change about 4fps from -20 to 125. So just how much it that. Not much. H483SC is 10fps, Varget is 8fps change on 0-125. I normally use H4350 powders.
Now I have hunt in weather from -20 to+110, Never noted any problem with H 4350 if ranges from 30yds to 500yds. Now this chart is from Hodgdon.
The ony thing, I wish for is an extend chart go include more powders.
So I feel you need to go back and study the chart and read what it has to say. Now it could be I am reading the chart wrong. The only thing is I have made shot in both type of weather and ranges with a 2x8 duplex. Not notable change in inpact from 30yds to 500yds other than were I help my my crosshair where they need to be at. That hold wasn't any different in hot or cold weather.

 

[Mike Matteson]

I see this often, have a good group in the cold and an average to poor group in the heat. I feel it has more to do with humidity and dew point than temp. I was working on a load last week one evening and getting really good groups. It was around 70 and low humidity. Tried it again yesterday and just stopped, it was 93 and way higher humidity. I was using staball 6.5 and h4831 both.

So what did you come up with on H4831. I have some Staball powders but haven't tried them yet. I know it can be a lot of work to come up with loading for each rifle. Dealing with primer pockets, case volume, powder, primers and bullets, in searching for a load. Components can be hard to come by and especially primers now. Case are little easier because of being able to get top of the line case. Peterson. Lapua, and others.

 

[Jpron]

So what did you come up with on H4831. I have some Staball powders but haven't tried them yet. I know it can be a lot of work to come up with loading for each rifle. Dealing with primer pockets, case volume, powder, primers and bullets, in searching for a load. Components can be hard to come by and especially primers now. Case are little easier because of being able to get top of the line case. Peterson. Lapua, and others.

With both powders the group opened up quite a bit. I've noticed this many times when shooting in high humidity/high dew point.

 

[skipglo]

Back the load off .5 grain and reshoot it. I'm betting the extra pressure is throwing it out of tune. Also, make sure your BTO measurement is the same as it was in the colder temps. A different lot of bullets can make a difference as well as a different lot of powder can make a difference.

^^^^^this and I was going to suggest 1 gr - 1.
5 grains

 

[Weatherbyshooter/Hunter]

I see you didn't look at the chart I posted in bolg #65. Look at H4350. The way I read the chart with H4350, it change about 4fps from -20 to 125. So just how much it that. Not much. H483SC is 10fps, Varget is 8fps change on 0-125. I normally use H4350 powders.
Now I have hunt in weather from -20 to+110, Never noted any problem with H 4350 if ranges from 30yds to 500yds. Now this chart is from Hodgdon.
The ony thing, I wish for is an extend chart go include more powders.
So I feel you need to go back and study the chart and read what it has to say. Now it could be I am reading the chart wrong. The only thing is I have made shot in both type of weather and ranges with a 2x8 duplex. Not notable change in inpact from 30yds to 500yds other than were I help my my crosshair where they need to be at. That hold wasn't any different in hot or cold weather.

H4831SSC/H4350 I only use for 270 and 30/06, I have several Weatherby Barrel Burning Calibers that require slower burning powders and specifically using US869 for a 6.5-300 at 3450 FPS whereas temperatures in Phoenix heat will without question cause my loads to spike, lose my .44 MOA accuracy and pressure signs is evident. So I'm cooling my reloads when I practice at home. Works for me.

 

[Mike Matteson]

Well it's going to be over 115 degrees today . Yes it may be 65 degrees difference so let's say the change is 1.5 FPS per degree in temperature rise……. That will be 96.5 feet per second and if your at the threshold or upper limit of the charge and pressure let alone accuracy then the cooler is a good idea.

Yep I did that over 20 yrs ago. In about the same spead. Blew a primer out of a cases. Never us IMR powders again. Changed to H 4350. It the chart is correct. it only changes about 3 fps in 125 degree swing. I never had problem with H-4350 in weather from -20 to 110+, with making up to 500yd shots. Now I haven't tested that in a long time.

 

[Eric H]

^^^^^This^^^^^ Research Hodgdon Extreme powders.

 

[Mike Matteson]

Well it's going to be over 115 degrees today . Yes it may be 65 degrees difference so let's say the change is 1.5 FPS per degree in temperature rise……. That will be 96.5 feet per second and if your at the threshold or upper limit of the charge and pressure let alone accuracy then the cooler is a good idea.

You didn't look at the chart I provided. I generally H4350, and I do use H4831. Look at the different in velocity on that chart. It's showing 3fps from 0 to 125 with H4350.