Savage Mark ii

[farmboy]

Remington yellow jackets five shot speeds. Low 1316,high1390,average1352, deveavtion73.48.

CCI stingers five shot speeds.low1545,high1658,average1614,deveation112.8

CCI mini mag low1303,high1337,average1325,deveation34.29

Winchester 555. Low1216, high1260,average 1244,deveation44.2

[farmboy]

The large spreads don't look to good for the hyper velocity loads!

[gitano]

Interesting program that is calculating your "deviation". The numbers I see are just the max spread with two-place decimal.

I've had CF ammo that had fairly large Standard Deviations of say, greater than 30 f/s that shot well, say MoA, and ones with relatively low SDs that shot worse than MoA. How did those four kinds of ammo shoot?

Paul

[farmboy]

I will reread the instructions and what the abbreviations mean I very well could have called it the wrong thing! I think that I am right but thinking that and being wrong has happened more than once in the past! Lol. I think the abbreviation was SD which I took to mean standard deviation.

[farmboy]

You certainly can tell there is lots more snap in the stingers. I shot a group of 37 grain Winchester shells they were making really high speed over one hundred fps above advertised. I will re shoot them the stats ended up mixed into the load before and I had to go to town so when I get back I will try and group of loads then shoot them at paper to see where we are at.

[gitano]

There are SEVERAL Chronograph manufacturers that calculate the standard deviation wrong. There is truly NO EXCUSE for that. NONE. ZERO. ZIP. The equation is non-trivial, but once written into firmware it's "done". In this day and age, there simply is NO EXCUSE for erroneous mathematical calculations by machines. Did I mention NONE?

That said... about 99 and 44/100s (the purity of Dove soap), of the shooters "out there" couldn't care less about the standard deviation of the MV figures they get out of their chronos. I would venture to say that most of them simply take one reading, or take the highest reading, or take the average reading of 5 shots, and call it "good". The SD is of no value to them. They're fooling themselves about their rifle/ammo's performance, but who's gonna 'prove' it. For that matter, who cares enough to try to prove it. Most of those few that do actually look at the SD figure, don't have a clue whether the calculator on their chrony is calculating the value correctly or not. Most of them assume JUST LIKE THEY DO ABOUT BULLET DESIGN, that "somebody" MUST HAVE checked and did the "research". That is a very, VERY shaky assumption about ANYTHING associated with firearms and especially ballistics.

And THAT SAID... The SD doesn't matter too much to group size in my opinion. As a general rule, the smaller the SD the smaller the groups, but sometimes as I said in the previous post, that isn't true. I use standard deviation to get some idea about the consistency of my handloads. If there is a large SD in MV, then there might be something I should look at in the reloading process like case capacity, case length, neck ID and OD, etc. I don't let large SDs bother me if the ammo is shooting small (enough for me) groups.

Paul