MK318mod0 chronograph check

[MisterHelix]

**DISREGARD : ammo type was misrepresented.**

I just rebarrelled one of my Noveskes with a 12.5" CHF barrel, and put a few rounds over the Chrono. The velocities I'm seeing from the MK318mod0 seem kinda high.

The stuff is obviously pretty hot, with light to moderate ejector marks on the brass.

I thought I'd post the Chrono results and see if anyone familiar with this ammo thinks my Chrono is full of crap. I see that Molon's post on the MK318 shows 2,900fps from a colt 14.5" barrel, so 3060fps from a 12.5" seems dubious.


MK318mod0
Created: 10/19/17 12:05 PM
Description: 12.5 GPR Noveske
Notes 1: w/Specwar762
Distance to Chrono(FT): 15.00
Ballistic Coefficient: 0.304 (?)
Bullet Weight(gr): 62.00
Temp: 76F

# FPS FT-LBS PF
4 3044 1275.84 188.73
3 3063 1291.82 189.91
2 3039 1271.65 188.42
1 3051 1281.72 189.16
Average: 3049.2 FPS
SD: 10.4 FPS
Min: 3039 FPS
Max: 3063 FPS
Spread: 24 FPS
True MV: 3061 FPS

My 77 grain handloads seem about right, though.

Nosler77cc/Benchmark @22.5/cci450/LC brass/COL=2.245"

Created: 10/19/17 12:07 PM
Description: 12.5 GPR Noveske
Notes 1: w/Specwar762
Distance to Chrono(FT): 15.00
Ballistic Coefficient: 0.340
Bullet Weight(gr): 77.00
Temp: 76F

# FPS FT-LBS PF
4 2407 990.74 185.34
3 2374 963.76 182.80
2 2385 972.71 183.65
1 2384 971.89 183.57
Average: 2387.5 FPS
SD: 13.9 FPS
Min: 2374 FPS
Max: 2407 FPS
Spread: 33 FPS
True MV: 2396 FPS

[TomMcC]

I wouldn't say your chronoing is full of crap.....it is consistent. 3060 fps out of a 12.5" is pretty smokin' though. Got anymore 318 you could try? Maybe a different lot.

[MisterHelix]

I wouldn't say your chronoing is full of crap.....it is consistent. 3060 fps out of a 12.5" is pretty smokin' though. Got anymore 318 you could try? Maybe a different lot.

All the MK318 I have looks to be the same lot. I think I'll put some LC M855 over the chronograph to try to get a baseline. I hardly ever shoot factory ammo, but m855 oughta be predicable.

[MisterHelix]

image.jpgI set up the Chrono again in the shade to eliminate "shine", and tested it again, still using the Noveske 12.5" CHF barrel.

I "calibrated" my chronograph with 5 rounds of M855 (2005).

The velocity (5 shot average) was 2,800 fps, which seems about right.

The MK318 (5 shot average) was 3,070 fps, with one round over 3,100fps.

Even if my Chrono is reading "fast", this lot of m318 is really hot.

Unless I'm missing something. Unfortunately, I got this MK318 from a guy I know, so I don't have a lot number. The headstamp reads "FC 12 5.56x45", with greenish sealant mouth and purple sealant on the primer.

Created: 10/20/17 01:02 PM
Description: m855 '05
Notes 1:
Notes 2:
Distance to Chrono(FT): 15.00
Ballistic Coefficient: 0.304
Bullet Weight(gr): 62.00
Temp: N/A °F
BP: N/A inHg
# FPS FT-LBS PF
5 2775 1060.31 172.05
4 2761 1049.64 171.18
3 2801 1080.27 173.66
2 2805 1083.36 173.91
1 2809 1086.45 174.16
Average: 2790.2 FPS
SD: 21.1 FPS
Min: 2761 FPS
Max: 2809 FPS
Spread: 48 FPS
Shot/sec: 0.5
True MV: 2801 FPS
Group Size (in): 0.00

-------

Created: 10/20/17 01:03 PM
Description: mk318mod0 '12
Notes 1:
Notes 2:
Distance to Chrono(FT): 15.00
Ballistic Coefficient: 0.304
Bullet Weight(gr): 62.00
Temp: N/A °F
BP: N/A inHg
# FPS FT-LBS PF
5 3065 1293.50 190.03
4 3119 1339.49 193.38
3 2994 1234.27 185.63
2 3060 1289.29 189.72
1 3062 1290.97 189.84
Average: 3060.0 FPS
SD: 44.3 FPS
Min: 2994 FPS
Max: 3119 FPS
Spread: 125 FPS
Shot/sec: 0.4
True MV: 3072 FPS
Group Size (in): 0.00

[ABNAK]

Holy Shiite Batman! Is this the Federal T556TNB1 load? I have about 1100rds of the stuff. It is NOT factory seconds (or at least isn't marked as such).

[MisterHelix]

Disregard. . I pulled one apart and it's a 51.6 grain hollow point flat base.

[TomMcC]

Disregard. . I pulled one apart and it's a 51.6 grain hollow point flat base.

Bummer dude.......got hosed. How much did you buy? Not too much I hope.

[MisterHelix]

I've got about 1,000 rounds. I'd just like to know what the hell it is at this point. image.jpg

51.6 (52?) grain hollow point flat base w/cannelure
Sealed mouth and primer
Federal 5.56x45 brass
Silver colored primer
Annealed case neck.
Crimped primer (circular crimp)
3000+ fps from a 12.5" barrel.

[TomMcC]

Did you get it from a dealer with a good rep? If so, give them a call......see what's what.

[MisterHelix]

image.jpgNo, I got it in trade from a guy. Good guy, he thought it was mk318. He's willing to "make it right". I'm just trying to solve the mystery.