Is it worth trying to get groups in 90 degrees?

[ccchunter]

I'm wondering how much does temp. affect accuracy and grouping?
I've been playing with my ML .50 this summer. Will my groups, POI, change that much when it's, say , 50 degrees? I reload for my centerfire rifles and I feel like it does change the game some with them. What kind of experience do you veteran ML owners have with the changes in temperatures? I'm working hard to do get a solid 300 yard performing load but will all this work have to be "reworked" when deer season gets here? As you know, it can take alot of time and considerable money to find what a particular gun likes, even with centerfire rifles.

[rangeball]

I would definitely recheck all loads/poi when the weather cools.

[dannoboone]

Now is the perfect time to sight in --- if you're about to take it
prairie dog hunting! ;D

Seriously, aside from getting very familiar with your rifle, you're
wasting your time. There will be some vertical difference in POI's
with many powders if load work is done in the 70's, and hunting
occurs with temps in the 30's or below.

[tar12]

Personally I dont waste my time in these temps for the reasons already mentioned. 90 degree groups will vary with or without a cool rod VS 30 degree groups. You will be told differently but just try it for yourself and see.

[Deleted]

well its not a total waste of time, with a cool rod most loads that shoot well now will likely shoot better in cooler temps but you can get an idea of what your gun might shoot well and fine tune when the temps drop.

i have never had a load that would shoot well in hot temps that would not shoot when things cool off. will poi and speeds change? yep, some but nothing drastic. I have however had loads that wouldnt shoot in heat that do rather well in the cold......just my experience, not a hard and fast rule.....Bill

[ET]

I agree with Tar12 where a saboted bullet weighting 250 and up is being used.

I hunt in the fall in a controlled hunt for 1-week near the beginning of November and temps range from about 30-60F. Here I like to do/check my deer load between 50-60F.

I recently tried to do a PT verification load using 250SST with Blk Harvester sabot and only 44.5gr of 4759 in my 50Cal with temp around 83-85F.
I lost anywhere from 40-80fps than normally seen in cooler weather and with the trace showing lower pressure than anticipated. The sabot looked okay but I suspect the heat soften the sabot altering bore resistance/friction response.

When the temp declines to under 70F I will redo this test and a few others with 250SST again. I already know I’m going to see a difference in velocities for sure, as I have shot enough in cooler weather and know what my Chrony alone has shown in the past.

So save your ammo components for the 50 until a cooler time arrives if you want to do a better evaluation.



Ed

[12ptdroptine]

I believe poi will change with temps varying 60* also.... But from 90 it has to go to 80 then 70 then60 then50 then 40...Its not like its going to happen over night. I still enjoy shooting when I can. dialing in now will get you through to fall..then tweek and re-zero and ready to go. I would rather go in to fall close and tighten things up . Than wait till then to start. I am just backing off a few grains. Drop

[Deleted]

If I get the overwhelming urge to shoot in the summer, and I do....I use two cooling rods, one minute each and then follow up with a 12volt air pump with a 1/4" flexible line that I put down the barrel another minute.... I also drop back a few grains.... No matter what I do in the summer my .45 doesn't shoot as well as it does when the temps drop to 30 degrees.... I hate to see them hanging on the wall so I shoot them as much as I can ;D
Zen

[jims]

I shoot in part because I enjoy it. It is hard for me to enjoy it when the sun is beating down and it is over 90 degrees so generally I do not even without group problems.

[ccchunter]

I'm like you Panhandle, I just can't let my guns alone even if it's hot. I really enjoy shooting and trying new loads. I'm going to keep working my ML and see just how close I can get it to where I want it shooting and then tweak it and recheck it as the weather cools this fall. It may be a waste of time in one sense, but then in another sense it is something I really enjoy.

Conversely, it can be frustrating when your trying to dial in a load and in the back of your mind you're wondering "am I wasting my time here". Oh well, I think I've answered my own question but your imput has been very valuable.
I'm not new to reloading just a new ML owner. I love the gun and want to ring out all the accuracy and long range capability it has to offer me.

[sw]

Jul 22, 2011 17:24:15 GMT -5 tar12 said:

Personally I dont waste my time in these temps for the reasons already mentioned. 90 degree groups will vary with or without a cool rod VS 30 degree groups. You will be told differently but just try it for yourself and see.

I agree with Tar concerning saboted loads with any speed at all. However, sabotless can do fairly well. My 40 shoots a little better in winter but not much.

[lwh723]

In my opinion, my time is better spent getting chores done when it's 70F+, so I have time to shoot when the weather is nice. Of course, when I retire in 20 or 30 years, I may have the time to fiddle with cooling rods and all those gizmos, but until then I just don't shoot in the heat.

[tar12]

Jul 23, 2011 10:43:52 GMT -5 sw said:

Jul 22, 2011 17:24:15 GMT -5 tar12 said:

Personally I dont waste my time in these temps for the reasons already mentioned. 90 degree groups will vary with or without a cool rod VS 30 degree groups. You will be told differently but just try it for yourself and see.

I agree with Tar concerning saboted loads with any speed at all. However, sabotless can do fairly well. My 40 shoots a little better in winter but not much.

Steve if the .40 was legal here I surely would give it a whirl!

[Richard]

ccchunter.............I see you got two positives from Hillbill and drop tine and a "sort of" from Panhandle ;D Of course you will get a big positive from Richard!!! While velocities may vary some from warm weather to cool weather, Its not enough that a click or two on your scope will not cure
I tried looking up some velocities on the .50 when I was shooting it but.................Ok, I started my initial venture into smokeless ML in the fall and by the time the warm weather had arrived I was into the .45 so Not much "cold to warm" data is available in my load book. I did however check a load with my .45 and it goes like this: Winter.........20* Load: 10/60 duplex N-110/N-120 Hor. XTP, 200 gr. Blue Harvester smooth sabot velocity: 3079 fps for three shots....Group:1.067". Summer: 80* same load, velocity 3007 fps for three shots.......Group: .925"
OK, like I said, some velocity difference but nothing a minor scope adjustment would not fix? Accuracy? A slight edge to the warm weather? I use the cool rod after every shot unless some BS takes place and the barrel cools on its own.
Much of the negatives are because people seem to have a pre-conceived notion that you can't shoot good groups in warm weather??? Many of these same folks do not have or do not use a cool rod??? Some just don't shoot in warm weather and therefore have not means to judge the effects a cool rod will make?? On the other hand, I do shoot ALL year, every week, and use my cool rod religiously and keep fairly good notes on my loads and targets. So, what I am writing here is from my notes, not some offhand recollection.
Richard

[boarhog]

Well, if I wait for 60* weather to work on smokeless ML loads, I might as well get out my Santa suit to wear while shooting. We're likely to have 90*+ temps during our first ML season in mid Oct. The Kool Rod works! If you give it an honest try, you will find that it will work for you too. I learned the hard way, to keep my sabots and bullets cool also. Just keep them in a ziploc bag, in your drink cooler between shots. As for hunting in hot weather, you should do your best to keep your loaded rifle out of direct sun, and never leave it to bake inside a vehicle. Since I know that I am likely to be hunting in hot weather, I avoid using max loads that are more likely to blow sabots. Last Summer, I was getting 2900+ fps in my 45 PN with max duplex loads, but hunted with a milder 2600-2700 fps duplex. The deer never knew the difference!
Boarhog

[ccchunter]

Thanks for the encouragement, Richard.
I failed to stress that when I shoot a new load for a trial run I usually only shoot 3 shots and go back to the house. My shooting range is behind the house so I can go shoot 3 shots, go back to the house, then later go shoot some more or maybe the next day.
I don't spend hours at the range with a red-hot barrell, so I feel in my mind that I can still get a fairly good idea of what a load is doing but it maybe a little better come fall weather.
I do have a chrony and I'm getting 2200 to 2300 fps on most of my n120 loads(59-61 grains).
I've shot the 250xtp with 5744 - my gun DID NOT like any variation of this load.
I've tried the Barnes 275 XPB with N120. Got 1.25 to 1.50 in. groups with 59 and 60 grains. (ok, but looking for moa) This load may tighten up come fall.
I'm working now with 300 gr SST and N120. So far, 2 inches is the best group but I'm not done with it. I've not give up on it yet.
Next, I plan to try either the 325 FXT or 300 gr Barnes O, or both.
So it's a work in progress.

[nic58]

Jul 23, 2011 23:00:05 GMT -5 ccchunter said:

I'm working now with 300 gr SST and N120. So far, 2 inches is the best group but I'm not done with it. I've not give up on it yet.

What sabot are you using with the 300 gr. SST? This bullet will fly, you just have to mate it to your barrel with the right sabot. If things don't work out, move onto something else. Like you were saying, the .458's would be my next choice, along with the Parker Ballistic Extreme 275 gr. in a short black MMP or Harvester Red Crush Rib. So many things to try.....but that's the fun of it!

[Dave W]

If my memory is correct, this was an experiment with 4759 and .458 300 Rems at 200yds. Temps were probably approx 70-75* since I typically shot this load in the summer, rarely do I shoot in temps higher than that, just too uncomfortable for me.
The circled shots were with my usual waiting period between shots, the remainder of the shots were rapid fire as quick as I could swab and reload and shoot.

This was a repeatable sub MOA 3 shot load at that distance with adequate cooling. It is possible the load deteriorates with that many shots but I think heat also played a role. JMO

You made no mention of how long you were waiting between shots. Residual heat build up could be a factor depending on how quick you are reloading and shooting.
I ran some loads last week in my .50 in mid 80* temps, actually 81-84* by my thermometer. The barrel was at 80* for the fouler shot. After 10 minutes and swabbing with alcohol, the barrel was at 84*. The barrel hovered between 87-90* for the next 8 shots swabbing with alcohol and waiting 10 minutes between shots. If you are shooting quicker than that, barrel temps are likely even higher.

I would not take a load to the woods that was not shot in actual hunting type conditions, I find my hunting loads after season during winter and spring. The only way to find out what your gun will actually do is by experience. Unfortunately, that may be a waste of time and components in these conditions unless you encounter high temps during hunting season.

[tar12]

"I did however check a load with my .45 and it goes like this: Winter.........20* Load: 10/60 duplex N-110/N-120 Hor. XTP, 200 gr. Blue Harvester smooth sabot velocity: 3079 fps for three shots....Group: .925". Summer: 80* same load, velocity 3007 fps for three shots.......Group: 1.067"
Yet you go on to say the accuracy nod goes to the summer load? Senior moment or off hand recollection? lol

[shooter]

Jul 23, 2011 19:19:17 GMT -5 Richard said:

ccchunter.............I see you got two positives from Hillbill and drop tine and a "sort of" from Panhandle ;D Of course you will get a big positive from Richard!!! While velocities may vary some from warm weather to cool weather, Its not enough that a click or two on your scope will not cure
I tried looking up some velocities on the .50 when I was shooting it but.................Ok, I started my initial venture into smokeless ML in the fall and by the time the warm weather had arrived I was into the .45 so Not much "cold to warm" data is available in my load book. I did however check a load with my .45 and it goes like this: Winter.........20* Load: 10/60 duplex N-110/N-120 Hor. XTP, 200 gr. Blue Harvester smooth sabot velocity: 3079 fps for three shots....Group: .925". Summer: 80* same load, velocity 3007 fps for three shots.......Group: 1.067"
OK, like I said, some velocity difference but nothing a minor scope adjustment would not fix? Accuracy? A slight edge to the warm weather? I use the cool rod after every shot unless some BS takes place and the barrel cools on its own.
Much of the negatives are because people seem to have a pre-conceived notion that you can't shoot good groups in warm weather??? Many of these same folks do not have or do not use a cool rod??? Some just don't shoot in warm weather and therefore have not means to judge the effects a cool rod will make?? On the other hand, I do shoot ALL year, every week, and use my cool rod religiously and keep fairly good notes on my loads and targets. So, what I am writing here is from my notes, not some offhand recollection.
Richard

Richard, I'm not trying to start nothing but don't you shoot from a controlled building in the winter and summer? Say it's 20 degrees outside it might be 50-60 degrees in the building right? I would like to give my thought on why you may get some of the same readings in the the controlled building. I would start by saying you probably keep your powder and gun in your house the night before so your not taking it from hot to cold too many times so it won't draw moisture and then put it in your warm truck before you leave therefore the powder and the gun don't have time to get cold so your not going to see a big difference. Now heres my thought... I don't no if there will or wont be a difference maybe there will be? If I had a building I was going to shoot out of I would leave the powder, the gun & the primer in my truck the night before. I would set me a bench up out side of the building and put all my stuff out there and I would shoot outside. After every shot go in the building and warm up for a minute, then go back out and load and shoot another one just to see if it changes anything. It may or may not but I think you should try that this winter even if it's only 10 shots.

[artjr338wm]

This is a great subject because I have often wondered if I was correct in not shooting when temps get above 80* or so, and by this I mean will the temp be 80* or higher for over half of my range session. When I go shooting it is for 6-8hrs about 99% of the time, as I love to shoot. I get there before the range opens and usually stay till 4-5pm or longer if conditions stay good.

Although I am not 100% certain, I am strongly leaning toward rarely if ever having shot my 10ML-II in temps above 85*.

Having said that, I know with 100% certainty that I have shot 4 or 5 range sessions in temps from 80-85*. I did this only because I had one of RossMan's Cooling Rods and used it correctly.

I was a completely convinced after only one outing that the C-Rod works exactly as advertised.

I was able to shoot quite good groups, but my POI did change, but not enough to cause me to hit outside of a deers vital area.

I must add though I did experience 3 instances of shredded sabots, but I was expecting it as I was shooting my hottest load of a 290grn TMZ, over 75 grains of H-4198. When i went back to using RL-10X with the same bullet, I had no more sabot problems.

I have a question, would using a chronograph be a way of indication problems when shooting in temps FM 70-85*+?
One would think that you should get some noticeably different velocity readings if you are experiencing sabot failures.

But I agree I would not set my hunting zero based on groups i shot in warm temps. As a matter of fact I do not change my zero when shooting in warm temps.

[boarhog]

BTW, I was shooting pretty much every week all last summer. Temps were as high as 104* according to the thermometer I carry in my shooting box. I did decide that it was better to forget shooting at temps above 95*. It can be done when hotter, but is a lot more trouble.
Our shooting benches are covered, but not enclosed.
Boarhog

[Dave1]

In the southern half of the US, daytime temps during the fall muzz hunt season can run into the 80's and 90's with high humidity. Warm weather testing is just as critical for those who hunt in the South as it is for our bretheren that live/hunt in colder climates. We all need to test load and gun performance during conditions that are similar to what will be encountered once deer season opens.

There is a 20+ degree temp swing from early morning to mid afternoon now and later in the year. If we test early in the day now when temps are cool(er), that will be as close as we can get to our actual fall hunting conditions. The first shot out of a cold barrel is the most important one. Test now and maybe confirm and tweak later.

Has there been any indication that any powder or sabot is more or less temperature sensitive?

Dave

[Dave W]

Jul 24, 2011 14:47:13 GMT -5 Dave1 said:

In the southern half of the US, daytime temps during the fall muzz hunt season can run into the 80's and 90's with high humidity. Warm weather testing is just as critical for those who hunt in the South as it is for our bretheren that live/hunt in colder climates. We all need to test load and gun performance during conditions that are similar to what will be encountered once deer season opens.

There is a 20+ degree temp swing from early morning to mid afternoon now and later in the year. If we test early in the day now when temps are cool(er), that will be as close as we can get to our actual fall hunting conditions. The first shot out of a cold barrel is the most important one. Test now and maybe confirm and tweak later.

Has there been any indication that any powder or sabot is more or less temperature sensitive?

Dave

IMO Harvester makes a tougher sabot than MMP in the .50, it is no more accurate for me, but they withstand loads that will blow an MMP. My .45 shoots better with Harvesters.

[Richard]

Tar...........It was a senior moment ;D I rechecked my book and the smaller group was shot in the warm weather Both groups were only .142" apart, so no big deal either way. My point was more the fact that you can, indeed, shoot good groups in warm weather.
Shooter.........You make it sound like I have an air conditioned building to shoot from? We have a thermometer both inside and out side (under the covered overhang). The temperature inside the room and on the outside benches is the same. Yes, it is shaded. In the winter time we generally get the inside temperature up to around 45*. We still have an open slot for the barrel, which is exposed to the cold.
Since right now, I am not hunting, only paper punching, there is no incentive for me going inside and out to shoot? My thing is to keep the barrel as close to the same temperature both summer and winter so I can run valid load tests under similar conditions. If the right opportunity comes along to hunt with the rifle, then I will surely do so and not from my lead sled either.
Richard