Last updated on April 4th, 2018 at 12:17 pm
A New Match Rifle: Report #1
Many of you may recall my oft stated position that “real men” shoot iron sights on their match rifles. However we are now well into the 21st century and I have always prided myself on keeping up with technology. Although I still think WINDOWS XP was the best thus far. So a while back I began asking myself what is the latest technology in match rifles. As it turns out the current technology in match rifles is not all that new being the AR15 platform. What is new, is the 22 Nosler cartridge. Thus I determined my immediate need for a 22 Nosler match upper for use with optics. It was just my luck that Compass Lake Engineering happened to have one in stock with a 26” 7.7 twist Krieger. What a lucky break!
After some discussion with Frank, we agreed that an adjustable gas block was in order – the reason being that there is no need for barrel burning bullet speeds at 200 yards (assuming good accuracy with reduced loads). Two twenty three speed would be fine with 69-70 grain bullets saving the 77-80 grain high speed bullets for 3 and 600 yards.
While waiting for the upper to arrive I started to do some research on 22 Nosler loads. I first called Sierra to see if they had any 22 Nosler data. The way the Sierra guy reacted to my question one would have thought Al Franken had asked for a date with his daughter. So my guess is that the green bullet box guys are not interested in any promotion of the red bullet box guys. I next checked the Nosler and Hodgdon web site to check their data. That was pretty eye opening! Most of the literature on the 22 Nosler brags about velocities of up to 300 FPS faster than the same bullet in the 223. Here is the data for 2 loads directly from the Hodgdon web site using Varget.
223 Rem with 69 grain Sierra26.0 grain Varget 3010 FPS 24” bbl
22 Nos with 70 grain Hornady 27.6 grain Varget 3014 FPS 24” bb 1.6 grain more for 4 FPS more speed
223 Rem with 80 grain Sierra 25.0 grain Varget 2869 FPS 24” bbl
22 Nos with 80 grain Sierra 26.5 grain Varget 2854 FPS 24” bbl 1.5 grain more for 15 FPS SLOWER!
When the upper arrived on a 32 deg November day with sunshine and no wind it was time to compare my loads with some Hornady data. But right away I noticed that CLE sent the upper with a fixed gas block. Upon calling CLE before T day Frank apologized for the mix up and a new adjustable gas block would be sent right after the holiday.
Meantime I decided to shoot break in and do some preliminary chronograph and group testing with the fixed gas block. I started off with the Hodgdon load of 26.5 grain Varget with the 80 grain Sierra in a 26” bbl. That load made 2823 FPS and one would expect a bullet in a 26” bbl to be faster than the Hodgdon load. Five rounds were fired with Moly bullets to foul the bore with Moly then 77 grain Sierra testing began. IMR 4320 shows up at almost exactly the same burn rate as Varget and I have a lot of 4320 so testing began with that. Testing started with 26.6 grain IMR 4320 with 4 shots each load at 100 yards with a 16X scope. Those results were as follows:
26.6 grain IMR 4320 2786 FPS. As this was WAY to slow the load was increased to 28.2 grain
28.2 grain IMR 4320 2983 FPS. 28.6 grain was skipped as 2983 was still slow & no pressure signs @ 26.2
29.0 grain IMR 4320 3077 FPS no primer pressure signs but case head showed some gouging.
29.5 grain IMR 4320 3121 FPS no pressure signs on primer but case head had more gouging. Time to stop!
The upper functioned perfectly with the 26.5 Varget load thru the 29.5 IMR 4320 load. This leads me to believe there was too much gas pressure with the heavier loads which was hard on the case head. At this point I decided to stop testing till I got the adjustable gas block installed.
Thus far the rifle shot ½” groups consistently with all loads tested, including 69 Sierra with 29.0 Varget @ 3071 FPS. However, all the loads tested had extreme spreads of 40 FPS at best to as much as 70 FPS, and these were just 4 shot groups! So, the ½” inch at 100 yards might not be acceptable at 600 yards with spreads that big. If the current Global Warming attack continues into early December. I’ll do more testing with the adjustable gas block and some XBR8208 and reshoot the 4320.
Stay tuned for part 2, but it may be Spring!
CLICK HERE to read Report #2 of “A New Match Rifle”.