Small Rifle Primer Rankings & 0.5 MOA at 600m From .204 Sako 85 Varmint
I am just working on .204 Ruger loads and I need some help working up some loads. I would like to get some of your opinions on your load data as well. Figured more than just I will use it too.
40 gr Hornady V-Max
27.5 gr H4895
2.295" OAL.
Hornady Brass
Winchester Primers
Need to Chrono them still since the last one I had has issues with small fast rounds.
If it was possible to share powders with my .308 that would be great but it isn't a problem so I am not focused on that.
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G'day POA = POI,
Although a couple of years behind the play, in late afternoon, cool (no mirage), still conditions, using our .204R stainless fluted Sako 85 varmint with set-trigger, laminated stock, Harris bi-pod, rear sandbag (on the bench) and a 5-25x56 S&B PMII SFP Illum. P4 Fein, we recently fired the following 204R hand loads, using FL resized, new Hornady brass that had been primed with Winchester No. WSR primers and set to a .010" jam seated OAL:
32gn Nossler Ballistic Tip Boat Tail (26.8gn of AR2219 gave 3,530fps)
40gn Hornady V-Max Boat Tail (24.0gn of AR2219 gave 3,307fps)
45gn Hornady SP Flat Base (23.0gn of AR2219 gave 3,136fps)
These loads were hand-fed, zeroed and CED chrony'd at 100m, then checked for dispersion at 600m, with Hornady's 32gn Factory ammo used as the baseline performance reference.
Surprisingly, the best group at 600m was 0.5 MOA from Hornady's 32gn Factory ammo, followed by 0.7 MOA at 600m from the 40gn V-Max. As anticipated, no further long-range work will be done with Hornady's 45gn SP Flat Base.
Warning - potential grassfire info to follow!
For wider reader interest, the best Small Rifle Primer performance, i.e., largest relative energetic output with smallest spread from my purpose-built, thermostatically controlled .22 Cal. primer kinetic energy test rig, came from Winchester's No. WSR primer with a relative energetic output (0.5 x m x v^2) of 9.33 Joules and an SD of 2.52m/s (averaged over 10 sequential shots).
Surprisingly, the worst Small Rifle primer performance came from the CCI BR-4 primer with a relative energetic output of just 5.73 Joules, but more importantly, an SD of 6.69m/s.
If I simply rank Small Rifle primer performance based on my observed, quantitative energetic outputs, the order looks like this:
Remington No. 7½ 10.52 Joules / SD 4.31m/s
Winchester No. WSR 9.33 Joules / SD 2.52m/s
CCI 450 7.93 Joules / SD 6.12m/s
Federal GM205M 7.30 Joules / SD 3.17m/s
Federal No. 205 7.18 Joules / SD 3.52m/s
CCI 400 6.34 Joules / SD 5.08m/s
CCI BR4 5.73 Joules / SD 6.69m/s
TulAmmo KVB-223 5.71 Joules / SD 4.00m/s
Fiocchi 4.92 Joules / SD 5.24m/s
However, in terms of uniform Small Rifle primer performance, the order now looks like this:
Winchester No. WSR 9.33 Joules / SD 2.52m/s
Federal GM205M 7.30 Joules / SD 3.17m/s
Federal No. 205 7.18 Joules / SD 3.52m/s
TulAmmo KVB-223 5.71 Joules / SD 4.00m/s
Remington No. 7½ 10.52 Joules / SD 4.31m/s (This Primer Lit Up Like An F-16 Jet Engine In Afterburner Mode)
CCI 400 6.34 Joules / SD 5.08m/s
Fiocchi 4.92 Joules / SD 5.24m/s
CCI 450 7.93 Joules / SD 6.12m/s
CCI BR4 5.73 Joules / SD 6.69m/s
Based on these 'no expense spared' experimental results, Winchester's No. WSR primer at 9.33 Joules and SD 2.52m/s is the all round best performer, with Federal's GM205M a more than respectable second.
Note: from my related research into Small Pistol primer performance, from which Remington's No. 5 1/2 was the best with an energetic output of 10.49 Joules and SD of 2.06m/s, the minimum impact energy to function these different primer types can be expected to range between 0.050 Joules and 0.080 Joules.
Primer manufacturers who have undertaken competitor product analyses on their own primer impact test rigs will find no surprises here.
Cheers from the Great Land Down Under.
Ideas/ feedback/ practical results of your own are welcomed- share your recipes!
