doubloon said:

I was just trying to figure out a comparison to what end if it's not to figure out if one is more accurate.

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Just within the limited scope of that particular preliminary comparison - a test only conducted to determine validity of experimental design, I've already presented here multiple aspects of comparison, as well as demonstration of relative behavior.

Many folks have asked, during the secondary phase of crowd-sourced aspects of comparison, simply for determination or validation of relative performance between these units. "Which one should I buy? And why?" seem pertinent questions for folks with money in hand and all 3 of these options in front of them on the computer screen. Folks are questioning whether the Athlon at the lower price will perform as well as the Garmin and LabRadar units - which have longer market provenance of performance than does the Athlon. Above, I presented a data set showing, at least in this ONE instance, 100 rounds, the consistency between multiple Garmin units is defensibly better than the consistency between the other two brands. The comparison above also presented strong evidence that each brand measures notably faster or slower relative to the others - which, considering the reality of this particular data set, could be considered that the Garmin falling in the middle as the moderate choice, and the above sensitivity analysis, would suggest choosing the Garmin might offer the most moderate risk profile. But... Again, when we really digest the sensitivity analysis, either all of them are right or none are.

Certainly through this particular test, I've also witnessed that frequency/channel hopping or manual assignability is a relatively important consideration for buyers who would be on busy firing lines, AND that the acoustic or recoil trigger options will only HIDE interference, but not actually prevent it. A lot of folks may be mislead by youtube videos of athlons caught in "analysis loops" and think the LX or even the VelociRadar are a better option - but once they fire, both have the same risk of interference, the Athlon is simply more honest about it.

For a great book on Acid Gambit,read Six Minutes to Freedom from about 10 years ago. Superb book! Kurt Muse was the guy that was rescued.

The flying by the 160th guys was incredible!!

Hell if a ballsy mission.

Sirhr

Any one know if FW Arms is going to open up for orders again?
Another site said they sold
Some product lines to Dillon.
Tried several times today to order a new S1050 shell plate and their checkout is not working.
I have called and emailed and no response.

$1400

kbiss said:

Just tried to install my vudoo 360 action with 1.2 kriegar barrel and had slop in action with mpa action bolts supplied. Any answers? Thanks

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Slop as in side to side or up and down?

So, realistically, how would this sound?



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Cool project!

Great design!

Sirhr

$2250 buys the AR
$800 buys the Leupold scope and mount

Williwaw said:

Possibly more relevant, what are Mr. Lott's aspirations/expectations? Not being a smart adze but given your experience, how low can we go?

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My goal is to get a repeater in the teens .1999 or 10.7mm for 10 shots at the Lapua test center (I think we are there but the ammo is not). Best 10 shot group has been a .22, with a bunch of .23,.24,.25s we have had a few .75 for 20 shots at 100 yards. We have shot sub 1" 5 shot groups many times at 200 but again I think ammo is still the culprit with good wind conditions. I was just curious what customers have come to expect.

Sold

That's pretty much how Optimal Charge Weight method works.

Pics would be beneficial.

doubloon said:

Right, the data points are there but which data points are more accurate than the others?

How to identify and weed out the bad data points?

One unit may record lower ES or SD than the other but which one is correct?

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The spread between all 6 units for 80% of the shots was less than 4.2fps. A 4.2fps error in a ballistic engine for my 6 creed load would be a MAXIMUM potential of 0.84" at 1k and with a simple RSS assessment on a rifle shooting .5moa at 100yrds shows it would only account for less than .1" at 1,000yrds. Equally, realize, the average displayed by all 6 units were only 2.7fps spread from fastest to slowest, so HALF of that potential difference at 1,000yrds. Within this dataset, ALL of the singular results were incorrect, because the variability of the ammo itself, but for each data point, the potential error from one unit to the other was very tight. So as I mentioned above, either ALL of them are good enough, or none of them are. A 99% confidence interval for this particular dataset, however, shows any given one of these units would only be potentially within ~9fps of the true average - even after 100rnds - so this dataset isn't seeking truth, it's seeking comparison. When we're only an average of 3.5fps spread among the 6 units with a set which only held +/-9fps for a 99% confidence interval, eh, nah, they're either all telling the truth, or none are. Even if I only took ONE shot, the odds of being "wrong" have nothing to do with the unit being used to measure the velocity, and everything to do with the consistency of the ammunition and the relative insensitivity of our trajectory to such small variations in velocity.

doubloon said:

Vertical spread is a half decent litmus test for validating recorded speeds and figuring out which unit is lying. Barrel whip not-withstanding.

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I'll readily admit, I'm not sufficiently skilled as a shooter to be able to tell the difference of 0.06" at 1,000 yards in my groups to determine truth between two chronographs showing 4fps spread among them. Certainly, my subsequent testing using a better performing centerfire load instead of this cheap and shitty 22LR ammo will improve ability to determine validity of result, but again, I'd have to be able to hold less than 1/10th of an inch difference at 1,000yrds to be able to tell the difference.

Anecdotally, I've used my Garmin velocity over the last 2 seasons to hit 1.5moa targets with 1st round impacts as far as 2200yrds. This is with a load which typically displays 5-9fps SD's for 10 shot strings, and 7-10 SD's for 60 shot SD's. A 99% Confidence interval for this load would be +/-3.2fps. That potential 6.4fps variability in the 1% uncertainty describes a difference of 19.16mils vs. 19.25mils at 2200yrds... One click in my scope, on a target about 5 clicks tall - and I'll be honest, I just don't shoot well enough to hold my shots within 1 click on the turret at 2200yrds.

So I struggle a little to conceive of any application where I REALLY have the ability to differentiate with live fire between any results as close together as the above dataset describes. I generally have control at 2000-2200 where my waterline is within ~0.3mils using velocity obtained via my Garmin, so to think I'd dial off 0.02mil less if I were using the LabRadar or dial on 0.03mil more if I were using the Athlon, eh, I'm pretty sure I can't shoot the difference between the 3 brands.

I do, however, have a MacDonald TwoBox acoustic chronograph unit which claims to be true within +/-1-2fps, which is tighter than the potential +/-0.1% of these radar units. Set up is a massive pain in the ass, requiring level and straight installation across 15ft span, so if this works as described, this would be my most accurate opportunity for "true" velocity within subsequent testing out of the 8 different chronograph units I have on hand. Data for this forthcoming with sunny weather. But reminding, as we see here, we have high confidence that the "truth" is somewhere between the min and max of these 6 units, and despite being the minority result, any of the 6 units each demonstrated the highest, lowest, and median results throughout this dataset.

Episode One of three that come to mind.

I was elk hunting during late cow season in the fall of 1973 with a high school buddy. We were driving up a little two track road along North Fork Creek, in Snowy Range west of Laramie Wyoming, at first light in my dad's 1969 Bronco. There is a series of beautiful grass meadows along the stream. I remember telling Ernie (my hunting partner) that it would be nice if we could catch a herd of elk out in one of the meadows. You guessed it, we spotted a herd of about 50 elk, most were feeding but some were bedded down. We did a short sneak and got about 150 yards from the elk. The plan was for me to get first whack, then Ernie would fling some lead.

I got a good solid rest over a downed tree, and gently squeezed the trigger on my Remington 721 30-06 as I peered through my old Weaver K4 scope. The rifle shot shattered the quietness of the brisk morning air, followed by a thunderous thump as splinters flew in every direction from a tree stump about three yards in front of me. The entire herd hauled ass in the opposite direction, which is really strange because they typically would exhibit enough confusion for me to get another shot.

Meanwhile Ernie is poised to launch a round offhand at the running elk from his old Montgomery Wards Western Field rifle as the elk ran into the timber on the far side of the meadow hundreds of yards away. He (Ernie) proudly announced, "I got the bitch". I recall replying something to the effect of, "Bullshit, the lens caps are still on your fucking scope". We then trudged across the meadow and there laid a portly dry cow elk, with a bullet hole right behind the ear.

The leupold rimfire scopes have fixed parallax at 60 yards. Is GTG up to 100 yards no problem