N570 temp variations

[TradLife406]

Hoping someone can save me a lot of reading on similar threads.

Setting up 4DoF and Shooter, what's a good number to put in for temp variation when using 570?

Thanks fam

 

[Rjk300]

I just adjust my velocity with the temp im shooting in but if I were to use a factor it would be .5 fps per degree. My experience is in the Terminator and rum cases and the velocity change is faster from 80* to around 40* then it slows down from 40* to 15*. 15* is the coldest I’ve chrono in and upper 80*s and higher velocity starts to climb fast so I don’t shoot these when it gets past 80*.

 

[Chase16]

Here is a sample (albeit limited) of what I have recorded so far with N570 out of a 7PRC:

50deg - 2995
65 deg - 3000
98 deg*** - 3030

I would lean much more towards the difference between 50 and 65 when figuring a standard factor to use. This is why I am a fan of apps that use temp tables instead of a single factor, many powders behave nonlinearly as you get really warm as you can see here. These are all captured off of 10+ rounds. I don't have a lot of different temp data points yet but a good number of rounds at each point.

* on 98 becasue i am assuming as the temp was low 90's and I tried to keep the ammo out of the sun but it was getting a little bit of direct sunlight.

 

[TradLife406]

Here is a sample (albeit limited) of what I have recorded so far with N570 out of a 7PRC:

50deg - 2995
65 deg - 3000
98 deg*** - 3030

I would lean much more towards the difference between 50 and 65 when figuring a standard factor to use. This is why I am a fan of apps that use temp tables instead of a single factor, many powders behave nonlinearly as you get really warm as you can see here. These are all captured off of 10+ rounds. I don't have a lot of different temp data points yet but a good number of rounds at each point.

* on 98 becasue i am assuming as the temp was low 90's and I tried to keep the ammo out of the sun but it was getting a little bit of direct sunlight.

Yeah not sure why Hornady has such a small library of powders. Why I was thinking of using the varget data and calling it good.

Is there an app that has n570 that works good?

I know 4DoF isn't that popular on here. But I basically have been using it in learning how to shoot better over the past four years or so. So between it and shooter there's a reason that app is on my home page of apps and shooter is a couple swipes over.

 

[wind gypsy]

I dont think powder temp sensitivity is a standard thing. I think it varies by cartridge and pressure and likely other factors as well so you get generalizations.

 

[ACHILLES]

Ive run .2 in shooter and AB for awhile now with a lot of different cartridges.

 

[Libtard McSocalist]

I think having one form factor is really dumbing it down. I imagine it changes a lot across different calibers and especially pressures and different temperature ranges. In my experience with multiple 28nosler barrels and n570 it was pretty stable at all in my application. Never shot it when it was super hot out but 70s to 30s I didn’t lose much. I think my form factor for lost velocity was around .5. It’s not rl23 or varget but it’s pretty good

 

[TradLife406]

Probably just need to go out when it's super cold out like in November and see how it compares to now when it's 70-80's.

 

[wapitibob]

I've been using N570 for a cpl years now and don't really worry about temps. I went out a few mornings ago and double checked my marks from 200 to 800 and the temp was comparable to what I'll see in early October. In the summer, 80 deg at the range, I might move it a click. Longest animal shot so far is 450, I don't think it matters too much.

 

[ACHILLES]

I’ve tested n570 in a few larger cartridges from 20-100* difference is usually less than 30fps. Between 30-90 is usually less 20fps. Shooting 3-5shots at each temperature. I’m not to worried about shooting in summer anyway. I’ll constantly be shooting steel at all ranges right up until season opens anyways so my drops and AB are fined tuned in hunting temps regardless. But from summer to winter my drops out to 750 don’t change when shooting at first or last light. I think if you start trying to put in larger velocity/temp variation values it could possibly hurt more than help on longer shots. That’s one of the reasons n570 is so popular its temp stable to minimize those variations. On the flip side using a powders like us869 or Ramshot LRT with huge 150* temp swings from winter to summer then yes it’s probably an ideal time to use the velocity/temp variation input.