Re: Advice on primer choice
Here is the results of several groups in a Savage 26" 9 twist heavey barrel .223 at 100 yards. The results here only work for this rifle. A different rifle I did prefered the Winchester primer.
The powder charge of 27.5 grains usually produced velocities in the low 3200s. The primers used are as follows: Federal 205 and 205 M, Remington 7 1/2 Bench Rests, CCI BR 4 and 450 magnum and Winchester WSR. All groups used five shots at 100 yards.
Federal's 205 made <span style="font-weight: bold">three</span> groups. They measured .519" @ 3220 fps, .962" @ 3224 and 1.216" @ 3210". The 1.216" group had a couple of fliers. They averaged .899" @ 3218 fps.
The 205 M from Federal is a match primer. There are records for <span style="font-weight: bold">four</span> groups. They show groups of .709" @ 3224 fps, .726" @ 3224 fps, .644" @ 3224 fps, .757" @ 3227 fps. Their four group average was .709" @ 3225 fps. This primer produced the most consistent velocities that I have seen in any fire arm. Consistent velocities did not translate into the best accuracy.
The <span style="font-weight: bold">four</span> Remington 7 1/2 Bench Rest primer's groups measured .744" @ 3211 fps, .682" @ 3211 fps, .676" @ 3224 fps and .682" 3223 fps and averaged .696" @ 3217 fps.
Winchester's WSR primers worked as follows: .582" @ 3220 fps, .399" @ 3249 fps, .830" @ 3219 fps and .812" @ 3219 fps.
The average for WSR is .656" @ 3227 fps. All of the WSR primers were pierced by the firing pin.
The next primer is from CCI and is the CCI 450 magnum with <span style="font-weight: bold">six</span> groups. It produced .684" @ 3200 fps, .546" @ 3207 fps, .711" @ 3234 fps, .544" @ 3219 fps, .806" @ 3191 fps and .525" @ 3218 fps. The average for the magnum primer was .636" @ 3211 fps.
The last <span style="font-weight: bold">five</span> groups tried were another bench rest primer. It is the BR 4. We saved the best for last. The groups measured .492" @ 3245 fps, .477" @ 3250 fps, .441" @ 3245 fps, .452" @ 3232 and .460" @ 3229 fps. Its phenomenal five groups average is .464" @ 3240 fps. It also produced the highest velocities.