SCAR Velocity Testing (16"/13") M118LR, MK316, M80

[BooneGA]

On the old forum someone asked if I could do some velocity testing on the 16" and 13" MK17s with the different ammunition we have available here. Below is the data from our Magnetospeed.

16" MK17

M118LR

AVG – 2504
SD – 22.1
Max – 2531
Min – 2476

MK316

AVG – 2532
SD – 13.8
Max – 2552
Min – 2518

M80 Ball

AVG – 2606
SD – 27.3
Max – 2651
Min - 2583


13" MK17

M118LR

AVG – 2424
SD – 8.6
Max – 2432
Min – 2410

MK316

AVG – 2442
SD – 6.3
Max – 2449
Min – 2434

M80 Ball

AVG – 2527
SD – 16.7
Max – 2549
Min - 2512

Thats an average of 83 FPS loss across the ammunition types from a 3" shorter barrel. I don't remember who was asking for it, but hopefully someone finds this useful.

Rick

 

[JSTARSZ]

That follows the common known pattern of the loss of 25-30 fps per inch of barrel reduction . How many rounds were you firing per string? I was wondering because of the SD reduction with the same ammo but with the loss of barrel length. I wonder if anyone has a theory why the SD would tighten up on the shorter barrel?

 

[BooneGA]

They were 5 shot strings all shot within a 5 minute window. Unknown as to why the SD would vary so much between the two barrel lengths - maybe a difference in mounting could cause that?

Rick

 

[RickyRodney]

Its a small sample size, unless he shot 1,000 rounds for each test. The laws of probability are at work here.

 

[MSTN]

Great info! Thanks much.

 

[Gasgun]

Thanks for sharing this.
I've been back and forth over whether to SBR my 17 or not.
I was expecting a little more of a velocity loss.
​​​​​​​This has me leaning more towards SBR.