Ammo testing SK mag out of my 455 with IBI

[fljp2002]

Spent a couple hours shooting 5 rounds group this evening. The goal was to compare groups and chrono data of weight sorted ammo versus random.

With unsorted SK Mag over 3 x 5 rounds group, I achieved an avg group size of 12.99mm ( just over 1 MOA) with best group at 7.82mm

Sorted SK mag over 9 x 5 rounds group I averaged 14.88mm with a best group of 7.57mm

In summary:

1. Sorting ammo may help.
2. Not all variables are as accurate as others so you would need to only use what your rifle likes.
3. My sample was small so larger sample may change the result
4. MV are fairly stable accross all variants, SD varied more.

My summary, since SK Flatnose unsorted is giving me sub MOA performance , don’t think I will weight and a measure my ammo. At this point, my rifle and ammo combo are still outshooting me. once again I missed the my rifle shoots sub MOA all day prove it by one set.

Here are the result by group at 50 yards out of CZ 455 with IBI 20 inch.

group 1 and 2: SK magazine random, Avg MV 1032, SD 24.4, spread 84, group size 1 x 19.25mm 2 x 11.91mm group 2 is sub MOA

Group 3: SK magazine 51.5 grain, Avg MV 1033, SD 25.9, spread 49 group size 24.27 mm

Group 4: SK magazine 51.6 grain, Avg MV 1040, SD 14, spread 36, group size 13.41mm

Group 5: SK magazine 51.7 grain, Avg MV 1049, SD 8 spread 21, group size 8.32mm (Sub MOA)

Group 6: SK magazine 51.8 grain, Avg MV 1052 SD 5.9 spread 16 group size 10.98mm (Sub MOA)

Group 7: SK magazine 51.9 grain, Avg MV 1053, SD 14, spread 34 group size 19.67

Group 8: SK magazine 52 grain, Avg MV 1065, SD 14, spread 39 group size 13.98

Group 9 SK magazine random Avg MV 1072 SD 27 spread 60:group size 7.82mm (Sub MOA)

Group 10 SK magazine thin rim, Avg MV 1060 SD 20 spread 51 group size 26.02 mm

Group 11 SK magazine largest rim, Avg MV 1055 SD 14, spread 34 group size 9.72mm (Sub MOA)

Group 12 SK magazine med rim, Avg MV 1054 SD 26.7 spread 63 group size 7.57 (Sub MOA)

Group 13 to 17 SK Flatnose unsorted, Avg MV 1070, SD 10.6 spread 39, avg of the 5 group is 11.21 mm (3 of the 5 are sub MOA with best (group 13) at 6.53mm)

Finally the 5 set target is again SK Flatnose unsorted avg MV 1080 SD 8 spread of 40, avg of the 5 group is 12.114mm (4 of the 5 are Sub MOA)

B0843526-E391-45DA-816A-5A13D3E55F63 by fljp, on Flickr

Best group:

394E145C-6B8E-4794-8580-99322B1691AD by fljp, on Flickr

My setup

679C3C91-5764-4A13-89A6-FAA23C42E61B by fljp, on Flickr

 

[SigWig]

How does cci standard vel compare in your barrel?

 

[fljp2002]

How does cci standard vel compare in your barrel?

Haven’t shot cci sv yet,,,will let you know

 

[grauhanen]

Thanks for sharing the information, fljp2002.

In general, SK Magazine, the lowest grade of SK ammo, is often quite capricious. It will usually have more rounds that will behave like "individuals," doing their own thing, than other SK varieties. Ammo that has a great deal of inconsistency in its performance has a significant number of combinations and permutations in what's produced on target.

Small sample sizes are notoriously unreliable. Relative to more consistently performing ammo, there will be a few small groups, a few really large groups, and a lot in between. Which ones are representative? They all are.

The information posted shows that ES and SD numbers will fluctuate wildly especially when small numbers of a larger group of relatively inconsistent ammo is used.

As a final observation, and not a criticism, while Canada is "officially" metric, some shooters familiar with European and testing facility results may take measurements given in Canada in milimeters as outside measurements because in Europe and at testing facilities they are.

 

[emerson]

My experience with SK Magazine is that it is very inconsistent. Will not buy again.