im reloading 50gr hornady vmax with 24.3g of h335 with cci magnum small rifle primers got hole in hole accuracy at 50yds today and was wondering i might be able to get my hands on a chrono to see what the fps of the load is according to the lee manual if i loaded 24.0g it would be 3166 so my question is how many shots do i need to take and do i add all the velocitities together divide it by the number of rounds shot
- Thread starter sniper81
- Start date
Hodgdon's 2012 magazine:
24" barrel
Win case, Win SRP, 2.210", 50gr Speer SP
H335:
Min: 24.0grs...3166 fps...43k CUP
Max: 26.0grs...3393 fps...51.7k CUP
Knock off perhaps 25 fps for every inch of barrel loss, under 24".
Most chronos will give you a high and low reading, an average reading of the string, up to 99 shots, the extreme spread between the high and low velocities in that string of X number of shots, your standard deviation and in some cases, an average deviation.
I'm no stats guy but I think that a population of 31 is statistically valid for N, or N+1, but I have had others tell me that closeer to 20 in the population, is statistically relevant.
The more the merrier, however.
Chris
24" barrel
Win case, Win SRP, 2.210", 50gr Speer SP
H335:
Min: 24.0grs...3166 fps...43k CUP
Max: 26.0grs...3393 fps...51.7k CUP
Knock off perhaps 25 fps for every inch of barrel loss, under 24".
Most chronos will give you a high and low reading, an average reading of the string, up to 99 shots, the extreme spread between the high and low velocities in that string of X number of shots, your standard deviation and in some cases, an average deviation.
I'm no stats guy but I think that a population of 31 is statistically valid for N, or N+1, but I have had others tell me that closeer to 20 in the population, is statistically relevant.
The more the merrier, however.
Chris
25 grains of H335 gave me a little over 3100 in a 20 inch barrel AR with 52 Grain SMK's.
I read this in one of the gun magazines years ago.
The author was referencing typical three shot FUDD groups and the story went on to talk about what 'tells you more' and the conclusion was that a single seven shot string told you more statistically than a few three shot groups, a five shot group, or even two, five shot groups, IIRC.
This was for 'on paper' measurements and not chrono data, however.
I load boxes of fifty, usually, so ten, five shot groups is how I usually do it.
Anyhow, that seven shot string seemed to be the most 'efficient' in terms of valuable data vs. shots fired, or something like that.
Chris
If that's what a gun writer wrote, then it must be true.
No need to be cynical, I was just confirming, through my personal readings, what the other guy had mentioned.
No-body's saying it's a truism, or an absolute fact.
I think that there's some valid statistical analysis behind the theory, but I'm not a 'stats' guy.
Feel free to do some research and confirm/deny.
Chris
Was it on the internet? Than it must be true.
I'm not being cynical - if it won't shoot with three, why shoot seven?
Sorry, that's not what "hot" means here. Hot means a heavy load generating high pressures and usually, but not always, high velocity. You need to do some thinking about your methods.
First of all, you doubted what somebody wrote here because it was taken (referenced) from a gun magazine, as if everything written in gun magazines is patently false. That's the reason I called you "cynical".
You then created a red herring fallacy about validating a recipe's merit based only on three shots, because if it 'won't shoot in three, why would I want to waste 4, 5, 6 and 7?', which wasn't what I was referencing in the first place--the statistical superiority of a 7 shot group, over a trio of 3s, or a pair of 5s.
I can think of a lot of reasons why a sample size of three might be statistically insignificant and not a bona fide 'tell all', or a valid indicator, which is kind what the other guy and I are talking about.
I mean, if you're such a great shot shooting only three rounds, why bother with five, or ten, right?
Just come here and post your three shot groups and see how much Frank approves, lol.
Anyway, the statements were referencing a statistical theory, more than having to do with shooting, or chronographing this, or that.
Like I said to you two 'doubting Thomases', you can probably research it on a 'statistics' site, if you're curious.
Chris
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You need to do some thinking about your methods.[/QUOTE]
i dont need to do any thinking about my methods i know what a hot round is, i was just stating that the barrel wasnt as warm as the factory loads i sighted in with, this is why i really hate posting things on this website cause jerk offs take what u type and warp it around so it makes it look like you dont know what ur talking about, not to mention how rude some of them are, just to be clear i have been reloading for about 3 years now with this caliber and the only reason i posted anything on here is i have never used magnum primers before
i dont need to do any thinking about my methods i know what a hot round is, i was just stating that the barrel wasnt as warm as the factory loads i sighted in with, this is why i really hate posting things on this website cause jerk offs take what u type and warp it around so it makes it look like you dont know what ur talking about, not to mention how rude some of them are, just to be clear i have been reloading for about 3 years now with this caliber and the only reason i posted anything on here is i have never used magnum primers before
