Hornady 123G Amax Factory ammo "temperature sensitivity factor"

[lamrith]

Does anyone know what this is for the Factory ammo? I am setting up Strelok+ and that is one of the criteria.

I am going try and chrono tonight and it is a cool day. Supposed to be warm Sunday and there is a 600yrd shoot I might try for and hoping to at least have my data in and solid before I try squeezing off a round at that range for the 1st time.

[1911man]

I used 1.4% because that was what in the calculator to start with and I didn't have the info. I was able to make hits on 20 of 20 silhouettes at 600 with that number but I'm not sure if I could have hit any smaller targets with the dope I used because I didn't have any to shoot at. What size targets are you shooting at?

[lamrith]

I do not know the exact target size I think 13"x16"? It is a fairly large plate, but they have it surrounded by a huge construction tire so if I am off by a foot on any side we will never see where as it does not show hits from being beat up so bad already with daily range use...

Yeah 1.4% is what comes up by default. Our weather is finally showing a chance of changing and all my previous chrono data is from 80*plus days.

[terrywick4]

I do not know the exact target size I think 13"x16"? It is a fairly large plate, but they have it surrounded by a huge construction tire so if I am off by a foot on any side we will never see where as it does not show hits from being beat up so bad already with daily range use...

ask them if you can paint the tire white prior to shooting, then you will see your misses, white can of spray paint is cheap.

[1911man]

I would not think being slightly off on the temp sensitivity number would make 1 ft of difference at 600 yards. Your ability to read the wind and shoot fundamentaly is going to mean way more. I suppose you could call hornady. Just an FYI I never change that number in my calculator but I do check my zero at the range before hand if I know the temp I'm going to be shooting in is dramatically different than when I last shot the rifle. Like is my last time out was in the spring and I am not shooting in the 100 degree Houston summer.

[lamrith]

Finally got some #'s together. not sure how to use these to calculate the sensitivity though.
Old numbers:
123g Amax
Lot#3141968
60*, 30.21inHG, 57%Humidity
Hi 2506
Lo 2437
Avg 2480
ES 69
SD 16

123g Amax
Lot#3131866
40*f, 30.2inHG
Hi 2469
Lo 2411
Avg 2444
ES 58
SD 22

I was able to get out to range Tues and run 5 rounds over the chrono, was warmer, seems like 35* was about 80fps avg increase in same lot of ammo. I would like to chrono the other lot again in warmer temps here soon as I find it interesting the difference in fps between the two batches but I am down to one box of the 3141968 batch

123g Amax
Lot#3131866
75*f, 29.94inHg
Hi 2583
Lo 2544
Avg 2561
ES 39
SD 14

[1911man]

Man, this makes me want to Chrono some Amax rounds on a hot day. My only time out chonoing Amaxs looked alot like your first set of numbers. My average was 2480 with about the same for extreme spread. I would say it was about 70-75 degrees out on a mild day. I wonder what my numbers would look like at 90+ degrees and if I would be getting 2550+ fps.

[lamrith]

Yeah for me this could be very important as I am hunting in AZ in Oct. Temps could be 65-85* and I may need to take shot over 300yrds on a small target so I want to be confident in my drop calculations.

[1911man]

Have you tried calling Hornady Yet? I would bet they have the info.

[GSPHunter]

Finally got some #'s together. not sure how to use these to calculate the sensitivity though.
Old numbers:
123g Amax
Lot#3141968
60*, 30.21inHG, 57%Humidity
Hi 2506
Lo 2437
Avg 2480
ES 69
SD 16

123g Amax
Lot#3131866
40*f, 30.2inHG
Hi 2469
Lo 2411
Avg 2444
ES 58
SD 22

I was able to get out to range Tues and run 5 rounds over the chrono, was warmer, seems like 35* was about 80fps avg increase in same lot of ammo. I would like to chrono the other lot again in warmer temps here soon as I find it interesting the difference in fps between the two batches but I am down to one box of the 3141968 batch

123g Amax
Lot#3131866
75*f, 29.94inHg
Hi 2583
Lo 2544
Avg 2561
ES 39
SD 14

Hi Lamrith,
While I don't have any data for temperatures above 65F, I do have some for going below that. Down to -35F, both CFE223 and LVR tend to lose 3.1FPS per degree Centigrade in my rifles. I think that is typical for most double base ball powders. That's about what you saw for the *1968 batch. It's hard for me to believe that it would deviate to far from that number going up a mere 15degrees F.

Maybe its a batch issue, or maybe could just be the chronograph?

[lamrith]

Hi Lamrith,
While I don't have any data for temperatures above 65F, I do have some for going below that. Down to -35F, both CFE223 and LVR tend to lose 3.1FPS per degree Centigrade in my rifles. I think that is typical for most double base ball powders. That's about what you saw for the *1968 batch. It's hard for me to believe that it would deviate to far from that number going up a mere 15degrees F.

Maybe its a batch issue, or maybe could just be the chronograph?

Great points and I plan to take both batches out again soon for some same day, side by side testing. I thought it seemed a bit big of a jump for 15* as well, hence my concern for hunt week.. Hoping cooler weather comes in without rain so I can run them both <60*f and then compare numbers on the "hot" batch..

Thanks for the continued info folks!!

[pdq5oh]

Don't know if this will be of any help but, I shot factory 123 AMAXs yesterday in 85* weather. I didn't chrono them, but used the same drop data as for my reloaded 123 SSTs that average 2,470. I was dead on at 200 from a 100 yd zero. 20" barrel.

[lamrith]

Got to the range today for more testing. Had cycling issue previously that I was trying to troubleshoot. I added a H3 buffer as well as oring mod to ejector. Seems to have worked as I had no cycling/eject issues.

Got to run both batches of ammo side by side a few minutes apart.


Was nice to see that they ran pretty close. no worries on drop regardless of what match I am shooting. Just need to figure out how they handle 80* heat somehow.