I've got load data for my GAP 260 at 68 deg. Taking it out West for a hunt in a few days and wondering how temperature sensitive this powder is? Do the usual +1 MOA for every -20 degrees?
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Temp sensitivity of H4350
- Thread starter superde
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Re: Temp sensitivity of H4350
The Hodgdon Extreme line is very temp insensitive so use the same velocity you get on your chrono now and run your charts at the temps you will be shooting at as the muzzle velocity won't change much but the temp at distance will effect trajectory.
I made my .243 load with H4350 up a couple of years ago in January in CT which was in the teens to get it ready to shoot at Rifles Only in south TX in the 70s. I did what I said above and was right on.
The Hodgdon Extreme line is very temp insensitive so use the same velocity you get on your chrono now and run your charts at the temps you will be shooting at as the muzzle velocity won't change much but the temp at distance will effect trajectory.
I made my .243 load with H4350 up a couple of years ago in January in CT which was in the teens to get it ready to shoot at Rifles Only in south TX in the 70s. I did what I said above and was right on.
Re: Temp sensitivity of H4350
A page out of hodgdon's extreme tour - http://www.hodgdon.com/smokeless/extreme/page3.php#top
It claims 4 fps difference between 0 degrees and 125 degrees. That sounds a little to good to be true to me, but thats what they say.
There is also something to be said about barrel temperature, primer temperature, and atmospheric conditions.
A page out of hodgdon's extreme tour - http://www.hodgdon.com/smokeless/extreme/page3.php#top
It claims 4 fps difference between 0 degrees and 125 degrees. That sounds a little to good to be true to me, but thats what they say.
There is also something to be said about barrel temperature, primer temperature, and atmospheric conditions.
Re: Temp sensitivity of H4350
Also, how far away are you planning on shooting something. Close range shots you probably don't have anything to worry about.
Also, how far away are you planning on shooting something. Close range shots you probably don't have anything to worry about.
Re: Temp sensitivity of H4350
H4350 is one of the best temp insensitive powders. The temps should be very close or the same as your location. Just account for the different atmospheric conditions for longer shots. That would be the main concern.
H4350 is one of the best temp insensitive powders. The temps should be very close or the same as your location. Just account for the different atmospheric conditions for longer shots. That would be the main concern.
Re: Temp sensitivity of H4350
Thanks guys.
When I first went down to Rifles Only, Jacob told me, when he was spalin stuff, that when the temp drops 20-30 degrees you need to add 1 MOA to your elevation.
I'm headed out to West Texas near Terlingua to Mule deer hunt. I don't plan on shooting anything over 350-400 yards with my measly 260. My .338 Lapua and .300 Ultra are staying home this trip. I got a new jug of Retumbo, and it is hotter than my last batch for the .338/.300. I don't have the time to rework the loads, so the 260 gets the nod.
I'll just drop the data into my PDA if I see a Mountain Lion further out.
Thanks guys.
When I first went down to Rifles Only, Jacob told me, when he was spalin stuff, that when the temp drops 20-30 degrees you need to add 1 MOA to your elevation.
I'm headed out to West Texas near Terlingua to Mule deer hunt. I don't plan on shooting anything over 350-400 yards with my measly 260. My .338 Lapua and .300 Ultra are staying home this trip. I got a new jug of Retumbo, and it is hotter than my last batch for the .338/.300. I don't have the time to rework the loads, so the 260 gets the nod.
I'll just drop the data into my PDA if I see a Mountain Lion further out.
Re: Temp sensitivity of H4350
I shoot H4350 out of my 6XC and 260. December / Janruary or july / August no change. H4350 is one of the best powders on the market.
I shoot H4350 out of my 6XC and 260. December / Janruary or july / August no change. H4350 is one of the best powders on the market.
Re: Temp sensitivity of H4350
I'm going to back up everybody else. I shoot it out of my GAP .243 and I have checked the velocity at 90 and 20 degrees F. When comparing my notes, the difference in velocity was a only 10fps between the two temps (obviously it was 10fps faster when 90 degrees). H4350 is a really good powder.
I'm going to back up everybody else. I shoot it out of my GAP .243 and I have checked the velocity at 90 and 20 degrees F. When comparing my notes, the difference in velocity was a only 10fps between the two temps (obviously it was 10fps faster when 90 degrees). H4350 is a really good powder.
Re: Temp sensitivity of H4350
I found H4350X to be very good for temp sensitivity. In the summer here in MN I chrono'd loads @ 90 F, and then chrono'd them again in the late fall @ 20 deg. F. And that got about a 20 fps drop. The real kicker when chrono'ing them at -18 was only 20 more fps. lost. So, 40 fps from 90-95 F down to -18 F.
All the Hodgdon extreme powders are good for that.
I found H4350X to be very good for temp sensitivity. In the summer here in MN I chrono'd loads @ 90 F, and then chrono'd them again in the late fall @ 20 deg. F. And that got about a 20 fps drop. The real kicker when chrono'ing them at -18 was only 20 more fps. lost. So, 40 fps from 90-95 F down to -18 F.
All the Hodgdon extreme powders are good for that.
Re: Temp sensitivity of H4350
Yes, IMR4350 doesn't have the coating that H4350X does. They've gotten better but I've seen as much as 200 fps drop with that powder from 90 deg. to -10.
Last report I've heard, since IMR got bought by Hodgdon, they were going to start coating their powders heavier. I've not bought IMR to verify that since I bought 20 lbs. of H4350 and AA4350.
Yes, IMR4350 doesn't have the coating that H4350X does. They've gotten better but I've seen as much as 200 fps drop with that powder from 90 deg. to -10.
Last report I've heard, since IMR got bought by Hodgdon, they were going to start coating their powders heavier. I've not bought IMR to verify that since I bought 20 lbs. of H4350 and AA4350.
Re: Temp sensitivity of H4350
I guess I'll have to do some testing. I bought a 8 pounder of IMR 4350 last May and haven’t tried it yet. Lately I've been using RE-17 with good results. In years past it always seemed that better velocity was obtained with IMR powders over the same Hodgdon powders and temp sensitivity wasn't an issue for me ... then.
I guess I'll have to do some testing. I bought a 8 pounder of IMR 4350 last May and haven’t tried it yet. Lately I've been using RE-17 with good results. In years past it always seemed that better velocity was obtained with IMR powders over the same Hodgdon powders and temp sensitivity wasn't an issue for me ... then.
Re: Temp sensitivity of H4350
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vinconco</div><div class="ubbcode-body">I guess I'll have to do some testing. I bought a 8 pounder of IMR 4350 last May and haven’t tried it yet. Lately I've been using RE-17 with good results. In years past it always seemed that better velocity was obtained with IMR powders over the same Hodgdon powders and temp sensitivity wasn't an issue for me ... then. </div></div>
It depends on where you live. In Nevada, temp sensitivity wasn't much of an issue for me either. When I moved to Montana it became a bigtime issue. Some loads losing as much as 400 fps. Imagine stepping that up, then shooting in the summertime. Same here in MN. So, for that reason I've pretty much suspended using IMR powders unless I shoot them that day. Or, season at least.
From the first 6 lbs of RE-17 I've used, I think it's going to be a great powder. Since it's burn retardant that everyone is using to get the equal velocities, it seems to have the best mix so far. I haven't tested it in the extreme cold as of yet but I have taken it out on a couple 20 deg. days we've had. I have already switched to using it in my main 1k gun.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vinconco</div><div class="ubbcode-body">I guess I'll have to do some testing. I bought a 8 pounder of IMR 4350 last May and haven’t tried it yet. Lately I've been using RE-17 with good results. In years past it always seemed that better velocity was obtained with IMR powders over the same Hodgdon powders and temp sensitivity wasn't an issue for me ... then. </div></div>
It depends on where you live. In Nevada, temp sensitivity wasn't much of an issue for me either. When I moved to Montana it became a bigtime issue. Some loads losing as much as 400 fps. Imagine stepping that up, then shooting in the summertime. Same here in MN. So, for that reason I've pretty much suspended using IMR powders unless I shoot them that day. Or, season at least.
From the first 6 lbs of RE-17 I've used, I think it's going to be a great powder. Since it's burn retardant that everyone is using to get the equal velocities, it seems to have the best mix so far. I haven't tested it in the extreme cold as of yet but I have taken it out on a couple 20 deg. days we've had. I have already switched to using it in my main 1k gun.
Re: Temp sensitivity of H4350
I'm using 4350 in my 30-06. I was out yesterday and was shooting a load that was shooting 2700fps a week ago and then yesterday I ran 16 rounds through the chrono (all from the same batch shot last week) and came up with a 16 round average of 2740. It may have been a bit warmer yesterday but definitely not more then 5 or 6 degrees.
Is this the norm?
I'm using 4350 in my 30-06. I was out yesterday and was shooting a load that was shooting 2700fps a week ago and then yesterday I ran 16 rounds through the chrono (all from the same batch shot last week) and came up with a 16 round average of 2740. It may have been a bit warmer yesterday but definitely not more then 5 or 6 degrees.
Is this the norm?
Re: Temp sensitivity of H4350
I weigh each charge down to the .1 grain. H4350.
I have the problem with other powders too just more extreme jumps.
I was thinking temperature, neck tension. But this time I loaded all of the rounds at the same time checking COAL on every round and weighing every charge. Then fired them on two separate days with different chrono readings.
So, I'm left with problems with the chrono?
I weigh each charge down to the .1 grain. H4350.
I have the problem with other powders too just more extreme jumps.
I was thinking temperature, neck tension. But this time I loaded all of the rounds at the same time checking COAL on every round and weighing every charge. Then fired them on two separate days with different chrono readings.
So, I'm left with problems with the chrono?
Re: Temp sensitivity of H4350
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Onemoretime</div><div class="ubbcode-body">I'm using 4350 in my 30-06. I was out yesterday and was shooting a load that was shooting 2700fps a week ago and then yesterday I ran 16 rounds through the chrono (all from the same batch shot last week) and came up with a 16 round average of 2740. It may have been a bit warmer yesterday but definitely not more then 5 or 6 degrees.
Is this the norm? </div></div>
What where the lighting conditions? I have a chrono that will give you lower than normal readings late in the evening when the sun starts getting low.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Onemoretime</div><div class="ubbcode-body">I'm using 4350 in my 30-06. I was out yesterday and was shooting a load that was shooting 2700fps a week ago and then yesterday I ran 16 rounds through the chrono (all from the same batch shot last week) and came up with a 16 round average of 2740. It may have been a bit warmer yesterday but definitely not more then 5 or 6 degrees.
Is this the norm? </div></div>
What where the lighting conditions? I have a chrono that will give you lower than normal readings late in the evening when the sun starts getting low.
Re: Temp sensitivity of H4350
Chronos read the bullets shadow as it passes through the sky screens. If you’re testing in varying lighting conditions the readings may be different. Ever shoot through a chrono early or late, no shadow, no reading. Sky Screen placement, their distance from one another and the muzzle and muzzle blast directed at the controller are all very relevant to correct and accurate readings.
Most erroneous readings are chrono/operator error. A friend of mine changed from the 210 Bergers in a 300RUM to the 200 grain Accubonds, same load, different bullet. The 210's chronoed at 3,250fps, the 200 Accubonds...................3,650fps in the shade.
I say error of the chrono.
Chronos read the bullets shadow as it passes through the sky screens. If you’re testing in varying lighting conditions the readings may be different. Ever shoot through a chrono early or late, no shadow, no reading. Sky Screen placement, their distance from one another and the muzzle and muzzle blast directed at the controller are all very relevant to correct and accurate readings.
Most erroneous readings are chrono/operator error. A friend of mine changed from the 210 Bergers in a 300RUM to the 200 grain Accubonds, same load, different bullet. The 210's chronoed at 3,250fps, the 200 Accubonds...................3,650fps in the shade.
I say error of the chrono.
Re: Temp sensitivity of H4350
I've yet to see anyone at my range with a chrono when I'm there. I usually shoot first thing when they open. 8:30 or 9:00 in the morning.
Could have been overcast a couple of days.
I've yet to see anyone at my range with a chrono when I'm there. I usually shoot first thing when they open. 8:30 or 9:00 in the morning.
Could have been overcast a couple of days.
