Strelok beginner question

[Oldmauser]

Where do the assumptions in Strelok Pro come from? I choose a bullet and I get already preloaded data on velocity etc. So the indication Strelok gives on the number of clicks at certain distance is based on that preloaded data. How can I make the calculations in Strelok more precise? I guess I could measure the fps value at the muzzle and put it into Strelok.Tthat would make the calculations more precise. What is your method to get maximum precision out of Strelok?

 

[6.5SH]

The default values if adding a new rifle are based on a sample .308 with 168gr @ 2563 fps. You have to replace it with your own data or choose the cartridge not bullet library. This will again not be 100% accurate but whatever the manufacturer provided which is usually close enough to get you onto a 6x6 target frame. All of these come from the JBM ballistics library.

If you do not own a chronograph but have a good 100 yard zero and access to further known distance targets you can measure the drop then adjust the velocity in Strelok until the table lines up with your results. This should be reasonably correct to about 600 yards.

Read the threads on weaponized math for further info on truing your calculator to match what your gun does.

 

[Simonsza1]

Use,buy or borrow a magnetospeed.

 

[PJT]

search on the Web for StrelokPro, the address is "borisov.mobi" this site provides information about how to use, setup and Tune the software as well as gives utube pages for guidance.

 

[Oldmauser]

I don't quite understand the recommendation of Borisov to switch off the temperature of powder if you are a beginner. Why should I do that?
I am shooting tomorrow a match and there will be 2 degrees Celsius outside. Should I calculate the clicks with the switched off temperature of powder or put manually 2 degrees Celsius?

 

[Deleted member 113831]

I don't quite understand the recommendation of Borisov to switch off the temperature of powder if you are a beginner. Why should I do that?
I am shooting tomorrow a match and there will be 2 degrees Celsius outside. Should I calculate the clicks with the switched off temperature of powder or put manually 2 degrees Celsius?

If you are just getting started you have no idea how the change in temp will affect your powder burn rate, and therefore your speed. That is why he says that.

If you are going to shoot a match without any actual dope...you are probably fucked.

Good luck!

 

[Oldmauser]

Very polite answer, indeed. Thank you.

 

[6.5SH]

Unless you have chronographed your load in different recorded temperatures you won't have valid info to enter for it.

 

[Lowlight]

Just because an App has a feature, doesn't mean you should use the feature,

 

[PJT]

I tend to collect information that I think may be of help, I've not had time to test this statement out and can't remember where I read /copied this from but, If you know the temperature you zeroed your rifle and have dope for that temperature it may give you a guideline it may be a long shot, but ignore the strelok temp feature and try this

"Effects of temperature
Temperature affects the firer, ammunition, and air density. When ammunition sits in direct sunlight, the burn rate of powder is increased, resulting in greater muzzle velocity and a higher point of impact. A general rule; note the air temperature when you zero your rifle, a 20 degree increase in temperature at any time after your zero will raise the point of impact by 1 MOA. A 20 degree decrease at any time after your zero will drop the bullet 1 MOA. A major key to consistency in your shooting is keeping aware of your environment and knowing how it's changes effect your shots."


I'm sure there are members on the forum who could offer better advice, but if all you are wanting to do is take part this may help,

Good Luck.

 

[Lowlight]

Where does a 20-degree temp change move my impact 1 MOA?

100,

200

300

400

800

1000 +

 

[Diver160651]

Where does a 20-degree temp change move my impact 1 MOA?

100,

200

300

400

800

1000 +

Ha, everyone gets wrapped around the axel on this. You'll see people checking their Kestrels over and over during the day even on a 600-yard target were other than rounding error they will not even see a .1mil change even with 2x that temp swing with most slippery cartriges.

"Effects of temperature
Temperature affects the firer, ammunition, and air density. When ammunition sits in direct sunlight, the burn rate of powder is increased, resulting in greater muzzle velocity and a higher point of impact. A general rule; note the air temperature when you zero your rifle, a 20 degree increase in temperature at any time after your zero will raise the point of impact by 1 MOA. A 20 degree decrease at any time after your zero will drop the bullet 1 MOA. A major key to consistency in your shooting is keeping aware of your environment and knowing how it's changes effect your shots."
.

Oh boy, this is just about as bad as any information I have seen offered.

 

[Deleted member 113831]

A general rule; note the air temperature when you zero your rifle, a 20 degree increase in temperature at any time after your zero will raise the point of impact by 1 MOA. A 20 degree decrease at any time after your zero will drop the bullet 1 MOA. A major key to consistency in your shooting is keeping aware of your environment and knowing how it's changes effect your shots."

Misunderstood, regurgitated shit, that was misappropriated into the sniper manuals and was wrong from the beginning.

That comes from the shooting teams shooting IMR4064 and/or IMR4895 at 600 yards...and even at 600 yards, it wasn't totally true even then.

But, to provide something somewhat useful to the OP... between 40*F and about 80*F you can expect an average change of 0.75fps per degree ambient. Some smaller cases like 223 shooting Varget might be closer to 0.25fps and something like a 300Win or 338 will be closer to 1fps per degree ambient.

 

[PJT]

Thanks for the constructive comment Skookum, the passage was regurgitated from an old online manual, which those not in the know would have expected to be valid.

 

[Diver160651]

Misunderstood, regurgitated shit, that was misappropriated into the sniper manuals and was wrong from the beginning.

That comes from the shooting teams shooting IMR4064 and/or IMR4895 at 600 yards...and even at 600 yards, it wasn't totally true even then.

But, to provide something somewhat useful to the OP... between 40*F and about 80*F you can expect an average change of 0.75fps per degree ambient. Some smaller cases like 223 shooting Varget might be closer to 0.25fps and something like a 300Win or 338 will be closer to 1fps per degree ambient.

I don’t know how accurate the .75fps or 1fps per degree really is.

A few years ago (maybe 8) I set 308 & magnum rounds in the freezer over night and then in the cooler in a frozen slurry, other rounds where kept at 105 and some at ambient 67-

Using Varget/H1000; rounds were shot intermixed round out the barrel’s bore expanding and creating differences-

I didn’t keep my log, but remember that the FPS variation was so small it was hidden in the noise of the SD’s -

Thats not the same as my test with some powders like Re22.

For Varget snd H1000 I personally am not filling out the temp variable on the programs

 

[Lowlight]

When I did use it, once, my 260 i think was .6 might have been a 260 or 308 but it was that small, .58 was another number i remember from others it’s probably still floating around

 

[Deleted member 113831]

I don’t know how accurate the .75fps or 1fps per degree really is.

A few years ago (maybe 8) I set 308 & magnum rounds in the freezer over night and then in the cooler in a frozen slurry, other rounds where kept at 105 and some at ambient 67-

Using Varget/H1000; rounds were shot intermixed round out the barrel’s bore expanding and creating differences-

I didn’t keep my log, but remember that the FPS variation was so small it was hidden in the noise of the SD’s -

Thats not the same as my test with some powders like Re22.

For Varget snd H1000 I personally am not filling out the temp variable on the programs

I was taking all powders into account having no idea what load the OP might be using.

For me, 0.7fps per 1 degree is good for 30-06 w/IMR4350, 0.5fps per for 308 w/H4895, IMR4895 is 0.6fps. My 300win works out to about 0.9fps w/RS Magnum.

I don't do the cooler trick. I shoot cold guns w/cold ammo by leaving both out in the garage over night before shooting in the morning.