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Discussion Starter #1 (Edited)
I just got some ballistics data from a couple of rounds in the SCAR 17s using my new Magnetospeed barrel mounted chronograph. I'm very pleased with the price and performance of this chrono and prior research revealed it is within a few tenths of a percent accuracy compared to a high end Oehler system under carefully controlled tests by the prestigious Southwest Research Institute. I did 10 rounds ea. consecutively, using a slow to medium pace, perhaps 10-20 seconds between shots. It was cold bore beginning with the 168 gr then moving right to the 155 gr. I also meant to test some FGGM and American Eagle but didn't want to stay out until the range closed. Had to get some dinner as well...

(all data in ft/s)

Hornady 168 gr TAP A-MAX
average: 2472 (corrected typo from 2463)
min: 2463
max: 2483
standard deviation: 7
(I was particularly impressed by this SD figure, it was better than any round in the SCAR and better than both rounds in my bolt action Remington 700)

Hornady 155 gr TAP A-MAX
average: 2596
min: 2558
max: 2649
standard deviation: 30

Both rounds exhibited about 100 ft/s advantage in the 20" Remington barrel (1:10 twist) or right about 25 ft/s/in.

I've been able to obtain sub 1 MOA (0.8 MOA) performance at 100 yards prior with this 168 gr round in the SCAR. Not consistently, but that's me not the rifle...
 

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I love that chrono. Might have to get myself a festivus present....
 

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Discussion Starter #4
Looks good. Wonder how it works with a handgun.

Thats some nice SD on that Hornady.
Would be difficult to get it too work with a semi-auto - would obviously require full custom mounting solution mounting it to the frame. It would work perfect on a revolver. Of course it begs the question, why chrono a handgun?
 

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Would be difficult to get it too work with a semi-auto - would obviously require full custom mounting solution mounting it to the frame. It would work perfect on a revolver. Of course it begs the question, why chrono a handgun?

Yes, I know they are not made for handguns without a work around. I was being a WA. :roll: Lots of money for a chrono when it can only be used on a rifle but the specs do look good.

I chrono all my loads that I build from scratch, regardless of whether they are rifle or handgun......prevents them from blowing up.
 

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Hornady 168 gr TAP A-MAX
average: 2463
min: 2463
max: 2483
standard deviation: 7
(I was particularly impressed by this SD figure, it was better than any round in the SCAR and better than both rounds in my bolt action Remington 700)
That ammo is the most accurate I have used in my 17. Just curious... please look on the bottom of your brass. Do you see the word "match" on it? The 168 nickel plated TAP ammo came in two different loadings from what I could tell, exact same part number except for the brass head stamp. One just had "308 Win" on it, the other was marked "match". The match stuff literally shot one big hole out of my 17 for five shots, hovering at 1/2 MOA.
 

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Discussion Starter #7
That ammo is the most accurate I have used in my 17. Just curious... please look on the bottom of your brass. Do you see the word "match" on it? The 168 nickel plated TAP ammo came in two different loadings from what I could tell, exact same part number except for the brass head stamp. One just had "308 Win" on it, the other was marked "match". The match stuff literally shot one big hole out of my 17 for five shots, hovering at 1/2 MOA.
Me too, although I've only shot 4 types of ammo from my 17S

"MATCH" is on both the 168 gr and 155 gr brass

It may be the difference between TAP FPD, TAP and TAP A-MAX. They are not all the same this is red box, "LE only" TAP A-MAX.
 

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Question for ya, Swamp:

Is the average velocity for the 168gr TAP a typo? I'm trying to figure out how the average is the same number as the minimum velocity?

I'm not doubting the results, but I would assume the average is somewhere in between the min and max. The SD of only 7 ft/s is awesome though!
 

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Also wanted to add that for a 16-17 inch barrel in 7.62x51 I've found that the 168 gr is consistently the top performer. Seems like just the right weight for most applications.
 

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Discussion Starter #14
Question for ya, Swamp:

Is the average velocity for the 168gr TAP a typo? I'm trying to figure out how the average is the same number as the minimum velocity?

I'm not doubting the results, but I would assume the average is somewhere in between the min and max. The SD of only 7 ft/s is awesome though!
Thanks, typo corrected and documented.
 
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