Powder temp sensitivity

[muntz]

Looking for a source that rates powders temperature sensitivity in regards to common powders used in .223/5.56.

[30Cal]

Basically, ball powders vary a lot with temperature. Extruded powders don't. There is no chart, but Hodgden has published some data on their website.

[ar15barrels]

Quickload takes temperature into effect and will calculate differences in pressure and velocity based on temperature change.
I don't know how to get the factors out of the powder data file though.

[rksimple]

Hodgdon advertises their "extreme" powders as being very temperature stable. When I called hodgdon, they said Varget was the most stable, and as you deviated from that burn rate, it became less temp stable. Some IMR powders, while extruded, still have some temperature sensitivity. But as a rule, the ball powders are the worst when it comes to stability.

[6079Winston]

I have found alot of info on temperature, velocity and pressure on 6mmbr.com. From the small fraction that I remember: 1. Extruded is supposed to be better than ball, however some U.S. military ammo loaded with ball powder is less temperature sensitive than some ammo using extruded powder. This makes some sense, since contract ammo has to perform well at extreme high and low temperatures. 2.The temperature sensetivity of powder is related to it's burning rate which is also affected by the size and shape of the case it is in. While Varget is very insensitive in .308, it apparently is less so in .223. I also remember seeing somewhere that H4350 was very insensitive in .30-06. This whole tmeperature sensitivity thing is really most useful for long range target shooters and hunters, service rifle shooters and those who work up maximum loads in winter and shoot them in summer.

[ar15barrels]

Quickload Predictions:

308 Winchester
168gr Matchking
45gr Varget

temperature: pressure:velocity
10:55380:2726
30:57223:2750
50:59124:2774
70:61073:2796
90:63061:2817
110:65089:2837

308 Winchester
168gr Matchking
46gr BL-C2

temperature: pressure:velocity
10:51834:2716
30:53803:2742
50:55828:2766
70:57907:2790
90:60040:2812
110:62225:2833

308 Winchester
168gr Matchking
45gr 748

temperature: pressure:velocity
10:51088:2727
30:53091:2753
50:55191:2777
70:57328:2799
90:59505:2820
110:61734:2840

[bruce_ventura]

Varget has the lowest sensitivity to temperature, but is a bit slower and dirtier than Reloader 15. Many service rifle shooters still prefer it over Reloader 15, though.

[SVRider]

Quickload Predictions:

308 Winchester........

Randall,

I was looking for a single powder to span 223 and 308. I was mostly looking at 3 (Varget, BL-C2 and TAC). Would you be willing willing to run the numbers for 69gr 223's and 168gr 308 adding TAC to the mix?

Thx.

[ivanimal]

Tac and Hogdon 335 or 748 would all be extreme powders and good for either cartridge.

[ar15barrels]

Would you be willing willing to run the numbers for 69gr 223's and 168gr 308 adding TAC to the mix?

Bump this thread sunday evening after about 5pm and I'll have more time to do quickload sims for you.

[Alanski56]

I've used BL-C2 for .223 and .308 for a few years now and it works very well for me. I use 55 grain Hornady V-Max and 69 grain Sierra Matchkings in .223 and 168 grain Sierra Matchkings in .308. I purchase 8 lbs. at a time from Midway USA when, number one I need it and number two, they send me a coupon. I use the coupon to offset the Haz-Mat.

Have a nice evening.

[Franksremote]

Ahh, load with Viht, anything from a place that cold can't be temperature sensitive

[SVRider]

Thank you for the offer kind sir....here is the bump you requested.

Bump this thread sunday evening after about 5pm and I'll have more time to do quickload sims for you.

[ar15barrels]

Would you be willing willing to run the numbers for 69gr 223's and 168gr 308 adding TAC to the mix?

223 Remington
20" barrel
69gr SMK
25.2gr Ramshot TAC

temp/pressure/velocity
10/49,324/2801
30/51,107/2832
50/52,939/2862
70/54,817/2892
90/56,741/2921
110/58,728/2948

308 Winchester
26" barrel
168gr SMK
44.8gr Ramshot TAC

temp/pressure/velocity
10/52,837/2712
30/54,687/2736
50/56,582/2759
70/58,210/2777
90/60,191/2798
110/62,214/2817

[SVRider]

Thank you very much sir for taking the time.....

223 Remington
20" barrel
69gr SMK
25.2gr Ramshot TAC

temp/pressure/velocity
10/49,324/2801
30/51,107/2832
50/52,939/2862
70/54,817/2892
90/56,741/2921
110/58,728/2948

308 Winchester
26" barrel
168gr SMK
44.8gr Ramshot TAC

temp/pressure/velocity
10/52,837/2712
30/54,687/2736
50/56,582/2759
70/58,210/2777
90/60,191/2798
110/62,214/2817