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Posted: 1/9/2011 10:33:03 AM EDT
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Will I see that much of a difference reloading/shooting in the winter time vs the summer time?
We are working up a load using H335, and Some hornady ballistic tip projectiles. What concerns should I be aware of when shooting.working up reloads at 15 deg? |
sorry.
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With that powder, if you load to max for your rifle at 15F, the rounds could very well be above max, i.e. too hot, come summer. I wasn't aware that powder's weight changed due to atmosperic tempature! As long as a round is loaded within it's "safe" limits, it shouldn't matter. However some powders are more or less affected by tempature. I assume the burn rate changes? I haven't realy done much research on that aspect. I know that H335 if said to be kind of temp sensative, while TAC is suppose to be much more stable. -Masta |
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Quoted: Quoted: With that powder, if you load to max for your rifle at 15F, the rounds could very well be above max, i.e. too hot, come summer. I wasn't aware that powder's weight changed due to atmosperic tempature! As long as a round is loaded within it's "safe" limits, it shouldn't matter. It does. However some powders are more or less affected by tempature. I assume the burn rate changes? I haven't realy done much research on that aspect. The burn rate changes. Some powders develop higher pressures at 95 degrees than at 15, other powders will develop more at 15 than at 95. I know that H335 if said to be kind of temp sensative, while TAC is suppose to be much more stable. -Masta |
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Some powders are less energetic at low temps than at high temps. Some powders are sensitive to higher temps. Most shooters keep their ammo in the shade at shoots, some are more elaborate.
I do my chronographing and load development at about 70-80 deg as a compromise temp. It is unlikely that temps will get over 100 deg here, although they can get down to less than 0 deg at times. Call it a safety factor of sorts. |
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Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. |
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While I can see how some burn rates can change with temp. I can not understand how a charge that is at max can become over max with a temp change. I have always been told temp changes will rob me of muzzle velocity. Down here its the heat we take into account. I think that a max load is defined as the maximum pressure that is safe in a particular firearm. If you work up a load to max at one temperature and the temperature changes which causes the pressure to rise, it might push that particular load above a safe level. Obviously if you are under the "published max" then it is persumably safe. |
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Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. If this is true how come my carbines run just fine when the ammo gets wet ? Water is also a lube. |
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While I can see how some burn rates can change with temp. I can not understand how a charge that is at max can become over max with a temp change. I have always been told temp changes will rob me of muzzle velocity. Down here its the heat we take into account. I think that a max load is defined as the maximum pressure that is safe in a particular firearm. If you work up a load to max at one temperature and the temperature changes which causes the pressure to rise, it might push that particular load above a safe level. Obviously if you are under the "published max" then it is persumably safe. I can see a temp change lowering the power level of a powder. I do not how ever see a temp change ( higher temp. ) making it more powerful. Keep in mind that after a long string of fire the temp in the chamber is much hotter than the outside temp. I have seen rnds cook off in machine guns they didn't damage the gun. Please post a link to more info about this matter. I could be wrong and would like to know more. |
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Quoted: Quoted: Quoted: Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. If this is true how come my carbines run just fine when the ammo gets wet ? Water is also a lube. Unless you like cracked bolts or catastrophic failures a few inches from your face, it's best to remove lube from cases before firing the ammo. Anything that interferes with the brass expanding and momentarily sticking to the chamber walls causes increased pressure on the bolt. |
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Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. If this is true how come my carbines run just fine when the ammo gets wet ? Water is also a lube. Most firearms, particularly military firearms are designed to run with wet ammo. Water is not a lubricant. If it was, we would be filling up our cars engines with Perrier. |
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Meh. I've been getting great results with 24.5 grains of H335 pushing 62gn SS109's. I've loaded them in Winter and Summer, and seen little notable difference. They DO have SLIGHTLY higher velocities when FIRED in the summer, but they're still well within SAAMI Specifications, and within Hodgdon's specified powder charge range. It doesn't matter WHEN it's Loaded - it's more a matter of the temperature the powder is when it's fired. Yes, it does influence it - but not so much as to make me lose any sleep over it. I regularly shoot my AR-15 in temps at or below zero... Not an issue for me - the rifle usually still cycles just fine, and accuracy isn't really changed much. |
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Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. If this is true how come my carbines run just fine when the ammo gets wet ? Water is also a lube. Most firearms, particularly military firearms are designed to run with wet ammo. Water is not a lubricant. If it was, we would be filling up our cars engines with Perrier. A lubricant (sometimes referred to as "lube") is a substance (often a liquid) introduced between two moving surfaces to reduce the friction between them, improving efficiency and reducing wear. It may also have the function of dissolving or transporting foreign particles and of distributing heat. a substance capable of reducing friction by making surfaces smooth or slippery While water may not be the best lube it can still be use as one. Oh ya if you had a steam engine you would be putting water in it 
So what your saying is water on the ammo is OK to shoot in a AR but with case lube on it its a no go ? |
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Another possible problem (I have recently experienced at about 35 - 40'); I have experienced several stuck cases (well lubed brass). Wondering if tolerances change or the lub (two different types) create problems. All lube should be removed from your brass prior to firing it. It's important that the brass swell and stick to the interior of your rifle's chamber for the split second it takes to contain the explosion. Lube interferes with this process. Virtually all ball powders are more temperature sensitive because of the addition of nitroglyceren to the mix. I wouldn't be surprised if RE-15 was too. Stay within the suggested load data printed by the bullet maker and you should be OK. The closer to maximum you get and the greater the chance you'll have problems. Never let your ammo sit in the sun or leave it locked inside a closed vehicle in the summer. Do that and all bets are off for any powder. If this is true how come my carbines run just fine when the ammo gets wet ? Water is also a lube. Unless you like cracked bolts or catastrophic failures a few inches from your face, it's best to remove lube from cases before firing the ammo. Anything that interferes with the brass expanding and momentarily sticking to the chamber walls causes increased pressure on the bolt. That kind of sounds like your telling me that the thin ring of brass just above the web is all that is stopping my AR carbine from self destruction. For some reason I don't think so. So let me tell ya a story One day a guy shows up at the range to shoot a match with ammo he just loaded and had not removed the lube from. What lube he used I have no idea. After about 100 rnds he starts to get stuck cases. The extractor will come past the rim of the case so ge can get the bolt open He gets a cleaning rod and gets them out OK. At this point I tell him I think the cases lube is getting burned in the chamber and making the chamber sticky. At about 125 rnd he gets one so stuck that he can no longer get it out with the cleaning rod. Other than the stuck cases the carbine was running just fine. He was done shooting for the day though. Much later he told me the chamber was all gummed up. YMMV By the way I remove the lube from ALL my reloads but not because I don't want my guns to blow up. I remove it so they keep running good.
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