Muzzle velocity: SR25 EM vs Noveske N6

AR/M4 Beyond 5.56/.223
1

Looking at the KAC and Noveske websites, I came up with the following figures:

12.5" barrel Noveske N6 Leonidas:
175gr M118LR
High - 2,417 fps
Low - 2,365 fps

16" barrel KAC SR25 EM
175gr M118LR
2,317 fps (as advertised on Knightarmco.com)

When I called Noveske, I was advised that the numbers on their site for the 12.5" N6 are correct and that they were using Lake City M118LR. I assume the SR25 EM numbers would have been with Lake City as well as it is designed for use with milspec 7.62 NATO loads.

I haven’t had a chance to contact KAC yet to ask if the numbers on their site are dated or correct.

Maybe someone here could chime in? KevinB? I’m curious as to how the 12.5" barrel N6 could exhibit higher MV than a 16" barrel SR25 EM? I would wager to guess that maybe the numbers on the KAC site are off, but I could be wrong.

Any info would be much appreciated.

Tspeis

EDIT to add: MV for the 12.5" HK417 is advertised as being 709 m/s (2,326 fps) with M118LR.

2

short answer,
polygonal rifling increases velocities…

3

I think KACs number is low

This is what I got

Session 1:

Chrono was done on blackhills 175gr and PVRI 175gr using 9 rounds of each.

Atmospheric data at time of chrono: Temp 66, Pressure 30.00, Humidity 38%.

Black hills 175: Average 2560fps
PVRI 175: Average 2559fps

Session 2:

Rounds shot: 60 BH 175: chrono: 2548fps average
20 Fed 168 chrono: 2527fps average

4

I do not know who or how they came up the the velocities on our website but they are not correct at all.

Polygonal Rifling can give more velocity, but my 11.5" Noveske was only about 25 fps from the KAC 11.5" barrel, which is close to the sampling error.

5

Thank you for the info gents.

Tspeis

6

Here is a third source

Repr
per combat arms p 28 2010 by guns and ammo list

Lake City 175gr smk

12in 2257 fps
16in 2441 fps +200fps from 12in
20in 2497 fps + 50fps from 16in

I believe that Noveske appears rather high for 12in
hell someone on here posted
168 tap in a 16in repr under 2400

Now as a very wise being by the name of Jamie Foxx once said

I ain’t saying she’s a gold digger, but she ain’t messing with no broke black person
be advised words in red have been edited from original quote