Temperature Learning Experience

[AKBman]

Had loaded up some of the 210gr LRAB bullets in Norma 300 Win Mag brass with CCI 250 primers to light off the charges of MagPro,was also shooting some 200gr Partitions strictly for groups. The 210s and MagPro caused me no issues, the Partitions which I shot an hour later sure did. When I started shooting, the temps were in the low 90s, I shot the 210s, and was very pleased with the results for having no load development, they put 5 into less than 1.5" at 200 yards. The first 200gr Partitions I shot were loaded over two different charges of RL 26, bu this time the temps were just reaching 100, they put 10 shots into a little over 2" for the two different charge weights, at this time I was only able to shoot 2 shots before allowing the barrel a substantial amount of time to cool, I was also shooting my 375 Ruger loaded with cast bullets for groups at 200, shot a little over 3" at that range. By the time I got to the 200gr Partitions with the MagPro load, the temp was reading 109, I fired 1 round, got settled and loaded round two, I should have checked the barrel I got distracted for a few seconds, and when I fired the second round, the primer popped out when the case hit the bench, this was a once fired case. I ended up having to wait 5 minutes in between rounds, and the Magpro group with the 200s was 2 1/2" for 5 shots. When I packed up to leave, the temp read 112, the last rounds I fired were 260gr Partitions from the 375 Ruger, and even though I worked the load up when the temps were in the 50s, the change in POI was less than .75" vertical, I use RL 17 in it almost exclusively. I think in the future, I will be investing in more of the temp stable powders, while they are still affected by 50+ degrees of temperature swing, it is very manageable, the MagPro, while giving me excellent accuracy, is not my way forward, I don't want to have a summer and winter load.

 

[Frank in the Laurels]

Know the feeling well sir, it will drive you crazy in a hurry...living in the NE part of the USA I experience temps from -20 to 100 most years and in hunting season about 10-50 usually. The outside affects the rate of barrel cooling tremendously and group size. The only powders that I have experienced big differences in point of impact and group size are with ball powders...never use them any more as a result... I had a comp quality 22/250 built for bench rest groundhog matches at 200-300-500 yards under bench rest conditions, it loved WW 748 but shooting starts at 9:00 and cool and ended around 3:00, temps could be warm..poi change at 500 was half a foot or more...switched to 4064 and never had a single problem since...I would suggest H-4350 for rifles, I'_be switched all mine to it over temperature and cured their problems also with poi change..

 

[N2TRKYS]

Had loaded up some of the 210gr LRAB bullets in Norma 300 Win Mag brass with CCI 250 primers to light off the charges of MagPro,was also shooting some 200gr Partitions strictly for groups. The 210s and MagPro caused me no issues, the Partitions which I shot an hour later sure did. When I started shooting, the temps were in the low 90s, I shot the 210s, and was very pleased with the results for having no load development, they put 5 into less than 1.5" at 200 yards. The first 200gr Partitions I shot were loaded over two different charges of RL 26, bu this time the temps were just reaching 100, they put 10 shots into a little over 2" for the two different charge weights, at this time I was only able to shoot 2 shots before allowing the barrel a substantial amount of time to cool, I was also shooting my 375 Ruger loaded with cast bullets for groups at 200, shot a little over 3" at that range. By the time I got to the 200gr Partitions with the MagPro load, the temp was reading 109, I fired 1 round, got settled and loaded round two, I should have checked the barrel I got distracted for a few seconds, and when I fired the second round, the primer popped out when the case hit the bench, this was a once fired case. I ended up having to wait 5 minutes in between rounds, and the Magpro group with the 200s was 2 1/2" for 5 shots. When I packed up to leave, the temp read 112, the last rounds I fired were 260gr Partitions from the 375 Ruger, and even though I worked the load up when the temps were in the 50s, the change in POI was less than .75" vertical, I use RL 17 in it almost exclusively. I think in the future, I will be investing in more of the temp stable powders, while they are still affected by 50+ degrees of temperature swing, it is very manageable, the MagPro, while giving me excellent accuracy, is not my way forward, I don't want to have a summer and winter load.

How much of a temp swing does it take before Magpro starts to give you problems? I'm using Magpro in my 7 SAUM. All of my rifles are hunting rifles. I don't shoot when it gets hot. With that being the case, do you think I'll have problems with the Magpro?

 

[J E Custom]

A friend that uses Reloader powders almost exclusively places a freezer pack (The jell kind) in the bottom of a cooler, then places a towel over it and carries his ammo to the range to control the temp. (It keeps it cool but not cold). the good thing about doing it this way, during hunting season when the temperature is colder, his loads are very predictable and the zeros developed during the summer are good.

Also when shooting down here (South Texas) we have to be ready to shoot before we chamber a round in the already warm chamber . If the round spends to much time in the chamber we eject it
and place another round in and shoot as soon as possible. Sounds like a lot of trouble, but it really helps the SDs and the accuracy.

I like to use the extreme powders when I can find a load that works good, But sometimes the rifle just likes one of the "Not so extreme" powders and accuracy force's me to use something else.

J E CUSTOM

 

[AKBman]

How much of a temp swing does it take before Magpro starts to give you problems? I'm using Magpro in my 7 SAUM. All of my rifles are hunting rifles. I don't shoot when it gets hot. With that being the case, do you think I'll have problems with the Magpro?

This is the first time I have had any issues with MagPro other than some slight POI shifts between winter and summer. Honestly, i think it is because this load was approaching maximum (1.6gr below), and mostly because I let the round cook in a hot chamber. I switched to MagPro several years ago because it was giving very good velocities, and would drop 5 208gr A-Max bullets into 3 3/8" at 525 yards. I will say, this new temp stable RL 26 is showing some real promise, and have you tried RL 17 in your 7 SAUM? I will continue to shoot the MagPro, still have about 5# left in this latest 8# jug, but I will be working with the temp stable powders to see if I can make the switch for the future.

 

[N2TRKYS]

This is the first time I have had any issues with MagPro other than some slight POI shifts between winter and summer. Honestly, i think it is because this load was approaching maximum (1.6gr below), and mostly because I let the round cook in a hot chamber. I switched to MagPro several years ago because it was giving very good velocities, and would drop 5 208gr A-Max bullets into 3 3/8" at 525 yards. I will say, this new temp stable RL 26 is showing some real promise, and have you tried RL 17 in your 7 SAUM? I will continue to shoot the MagPro, still have about 5# left in this latest 8# jug, but I will be working with the temp stable powders to see if I can make the switch for the future.

I haven't tried rl17, although I see it mentioned. I only see rl22 listed in the Nosler manual. I' ve noticed some promising velocity and accuracy with imr7828ssc. I just have to give it some more testing.

If you have a pet load using rl17, would you mind sharing it with me?

 

[SnakeRiverEric]

Yes, Magpro did give me temperature issues this winter down in Sonora. Shooting the 150 VLD in a 270WSM with Magpro. Never had any pressure signs for past 2 years hunting Wyoming, Canada. Shot my Coues deer in Sonora on January 20
at about 2pm when temps were 70-80, definitely had hard bolt lift!
After getting home switched to H1000 and was able to find a load that shoots same velocity, accuracy, and match's turret. Tested it here in Wyoming this summer
in same 70-80 temps and no issues.

 

[Darkker]

I like to use the extreme powders when I can find a load that works good, But sometimes the rifle just likes one of the "Not so extreme" powders

"Extreme" properties are NOT a universal property, That is design specific. As an example, Varget was designed to be stable in the 308 when loaded with ball ammo(145-155gr). For that, it works delightfully. Use that powder in the 223/5.56 and it is wretchedly temp sensitive.

 

[J E Custom]

"Extreme" properties are NOT a universal property, That is design specific. As an example, Varget was designed to be stable in the 308 when loaded with ball ammo(145-155gr). For that, it works delightfully. Use that powder in the 223/5.56 and it is wretchedly temp sensitive.

Extreme is a term used first by Hodgdon and is designed to control the heat sensitivity of certain
powders. Hodgdon still makes some powders that are not "extreme" powders. All Powders are not created equal so they must be treated differently. Some powders are very predictable and increase in pressure very linear, other powders will increase in pressure as more powder is added, then all of a sudden the pressure will spike/go critical and max pressure will be exceeded by the addition of only 2/10ths of a grain. so we need to understand the characteristics of each powder we use to stay out of trouble. IT's like gasoline,
you cant change the octane by putting it in another car but you can change the performance.

Other powder manufactures make powders that are designed to reduce the effects of heat on the burn rate, and we tend to call these powders "Extreme" because of the first name given to powders with the ability to lower the velocity/pressure spread.

The cartridge has nothing to do with the powders ability to be more consistent with temperature differences because the powders coating/treatment is the same. differences in case capacity causes different powders to react differently, but the powders ability to reduce the effect of heat/cold remains the same .

I have used all of the Extreme powders in many different cartridges and found them to be very predictable/consistent and to maintain velocity very well. as stated earlier, some of my rifles shoot better with other powders that are not temperature stable and velocity swings are as high as 175ft/sec depending on the temperature so I have learned to live with it and avoid pressure situations.

Extreme powders can be over loaded just like any powder. Some powders will/may go critical and increase the pressure suddenly with only .05 grains more powder, so when this point is reached it is recommended that you back off at least 1+ grain to avoid this situation.

Varget tends to give the 223 the highest velocity within SAMMI pressures but It can be over loaded
like any other powder, but still remains stable if loaded to SAMMI pressures with different temperature spreads.

Where a powder might have a 10 ft/sec shift in a 308 in a 50o temperature change, it is true that a smaller/larger case may have a 15 ft/sec shift with the same extreme powder. BUT other "NON- Extreme powders may/will shift 150 ft/sec through a 50o range.

Temperature controlled powder can only help with Temperature swings not with over pressure loads. We all try to get more than we should from a cartridge (It is the nature of our sport) but this can lead to problems with any type of powder.

Just my opinion

J E CUSTOM

 

[Darkker]

1) Other powder manufactures make powders that are designed to reduce the effects of heat on the burn rate, and we tend to call these powders "Extreme" because of the first name given to powders with the ability to lower the velocity/pressure spread.

2) The cartridge has nothing to do with the powders ability to be more consistent with temperature differences because the powders coating/treatment is the same. differences in case capacity causes different powders to react differently, but the powders ability to reduce the effect of heat/cold remains the same .
3) powders will/may go critical and increase the pressure suddenly with only .05 grains more powder, so when this point is reached it is recommended that you back off at least 1+ grain to avoid this situation.

4) Varget tends to give the 223 the highest velocity within SAMMI pressures but It can be over loaded
like any other powder, but still remains stable if loaded to SAMMI pressures with different temperature spreads.

5) Where a powder might have a 10 ft/sec shift in a 308 in a 50o temperature change, it is true that a smaller/larger case may have a 15 ft/sec shift with the same extreme powder. BUT other "NON- Extreme powders may/will shift 150 ft/sec through a 50o range.

You got a lot of problems here, so let's iron out the facts.
1) Just to be clear, Hodgdon is not a manufacturer, and never had been.
2) The case has everything to do with it. As you yourself said cases cause burning rate shift, what do you think temp insensitivity controls? It's runaway burning rates. If your chrono is good enough, you can see this with the extremes. Do Adobe shooting, then do some soaking in the chamber before firing. The extremes will over compensate and slow the velocity in a larger fashion than non -extreme, early.
3) ALL powders have a happy pressure range that they will operate in, in any given cartridge. The "grains" used isn't terribly important, if you know where you are in the pressure range.
I'm well familiar with progressive burning powders, but you over simplified them. Progressives are the ones that are dangerous for those who don't know what they are doing, because their burning curve changes with pressure.
Here is a VERY progressive powder we tested a few years ago in the Creed. What is important to know is the curve change, the pressure change. And yet how tiny the velocity change.

4) No it does not remain stable to temp. Read work done by Dr. Denton Bramwell. Some of his work can still be found over at RSI.

5) Also not true, but well done on repeating Hodgdon's sales pitch. That large spread is true with ANY powder, that's why we do "load work-up". But to stay in the same Cool-Aid bowl, look at Hodgdon's very own data about how awesome their extreme powder is. Yes, it is certainly true that in stove cases a powder that isn't in production anymore, in fact has a 150+ fps disadvantage to Extreme marketing voodoo. But look at all of them. Several tests show that the difference isn't statistically different at all, and one "difference" is well under any reloaders standard deviation!! They couldn't measure how close a non extreme powder is. You are welcome to look at the naval warfare testing data. They have much larger temp swings than Hodgy, and most of the "good" testing powder is ball powder from General Dynamics.
THales in fact called for a JV with general dynamics, to bring better temp stability tech to them.
In case you are behind, Thales owns ADI, that is where Hodgy bus extreme stuff from currently.
Or head on over to Western powder and check out their web page. Remember they do a significant amount of pressure testing for Hodgdon. They will also tell you it's case/situational dependant.

 

[J E Custom]

You got a lot of problems here, so let's iron out the facts.
1) Just to be clear, Hodgdon is not a manufacturer, and never had been.
2) The case has everything to do with it. As you yourself said cases cause burning rate shift, what do you think temp insensitivity controls? It's runaway burning rates. If your chrono is good enough, you can see this with the extremes. Do Adobe shooting, then do some soaking in the chamber before firing. The extremes will over compensate and slow the velocity in a larger fashion than non -extreme, early.
3) ALL powders have a happy pressure range that they will operate in, in any given cartridge. The "grains" used isn't terribly important, if you know where you are in the pressure range.
I'm well familiar with progressive burning powders, but you over simplified them. Progressives are the ones that are dangerous for those who don't know what they are doing, because their burning curve changes with pressure.
Here is a VERY progressive powder we tested a few years ago in the Creed. What is important to know is the curve change, the pressure change. And yet how tiny the velocity change.

4) No it does not remain stable to temp. Read work done by Dr. Denton Bramwell. Some of his work can still be found over at RSI.

5) Also not true, but well done on repeating Hodgdon's sales pitch. That large spread is true with ANY powder, that's why we do "load work-up". But to stay in the same Cool-Aid bowl, look at Hodgdon's very own data about how awesome their extreme powder is. Yes, it is certainly true that in stove cases a powder that isn't in production anymore, in fact has a 150+ fps disadvantage to Extreme marketing voodoo. But look at all of them. Several tests show that the difference isn't statistically different at all, and one "difference" is well under any reloaders standard deviation!! They couldn't measure how close a non extreme powder is. You are welcome to look at the naval warfare testing data. They have much larger temp swings than Hodgy, and most of the "good" testing powder is ball powder from General Dynamics.
THales in fact called for a JV with general dynamics, to bring better temp stability tech to them.
In case you are behind, Thales owns ADI, that is where Hodgy bus extreme stuff from currently.
Or head on over to Western powder and check out their web page. Remember they do a significant amount of pressure testing for Hodgdon. They will also tell you it's case/situational dependant.

WOW
Sorry, but it is you that has the problem. First, in your post you said Varget was no good for 223s.
you said nothing about Superformance powder or creedmores (It wouldn't matter anyway) so you should at least read your own post before you post a reply like yours.

Hodgdon has a load listed for the 223 using 25.5 grains to 27.5 grains of Varget that exceeds all other loads listed at 50,000 psi by almost 70 ft/sec.

Take Aim at Rifle Reloading Data | Hodgdon Reloading.

Secondly, ball powders are notorious for being heat sensitive. And I have never seen a burn rate chart that had "Runaway" burn rate powders listed or even mention runaway powders and I also have never seen a loading manual with a warning about runaway powders mentioned only warning about going over the listed max charge.

Third= Hodgdon is one of the oldest powder manufactures. and they make extreme powders, heat sensitive powders and ball powders. and I have no stock in Hodgdon and use many other brands of powders.

Also I don't believe any thing I read until I can test and prove it to my self. I have probably been re loading longer than you have been alive and still learn something every day from people that post
good responses to questions and will debate without sarcasm.

So before you start posting venomous post you should realize that most of us try to help others and if they don't agree with the reply, they don't have to use any of the suggestions and can ignore it. I was only trying to help you understand what extreme powders were and who made them. Also testing at 41 to 54 degrees is not a problem for any powder. the problem normally starts when temperatures get near to or over 100o.

You also contributed nothing to the post except criticism. So if I wronged you in another life, please forgive me because I cant remember doing anything to you but trying to help.

If I were you, I wouldn't reload until you know something about the powders and who makes them
for your own safety and the safety of others around you.

I would also recommend that everyone read your post so they know what/why I am even bothering replying.

Sorry guys, you just cant help some people.

J E CUSTOM