Last updated on April 15th, 2018 at 11:56 am
A New Match Rifle: Report #2
When we last talked winter was rapidly approaching and I was waiting for my new adjustable gas block from Compass Lake. The block arrived a few days after report #1 was submitted, but Winter was upon us so further testing ended. The adjustable gas block was installed and about 10 rounds were fired out the back door to find the minimum gas opening to ensure good function. At this time the Vikings were headed for a swell season and there were many other games to watch so the bbl was cleaned and put away till Spring.
You may recall in the first report a comparison between 223 and 22 Nosler loads with 69-70 and 80 gr bullets. If you missed that report, the bottom line is that there is very little advantage for the 22 Nosler over the 223 based on Nosler reloading data. So now all winter long I’m wondering if I had spent $1000.00 for another 223 that uses really expensive brass and has half the barrel life?
Of more concern was the serious damage to the expensive 22 Nosler case head with loads that surpassed 223 velocities. There were big gouges in the case head from the extractor digging in and serious ejector marks normally associated with hot loads. The velocity was 2900 FPS and there were none of the normal pressure signs on the primers.
Extractor and ejector damage at 2900 FPS
In late Winter I started seeing YOU TUBE videos of 22 Nosler testing and others were seeing the same damage to case heads and having accuracy issues. Some speculated it was a brass quality problem with Nosler brass and unfortunately Nosler is the only source. With a couple 45 degree days in Late March It was time to chronograph some more loads with the adjustable gas block.
When seating bullets I noticed the bullets seated fairly easily. They were tight enough they couldn’t be pulled or turned by hand but I thought perhaps more bullet tension might help with extreme spreads. All the brass for Spring testing was run thru a Redding neck bushing die to squeeze them down another .002 before seating bullets. BINGO! There were no gouges, dings or pressure signs at 3040 FPS with 80 gr Sierra and extreme spreads were 30 or under with 5 loads tested. The moly coated 77 gr Sierra seated to magazine length clocked 3083 FPS and a 4 shot group measured ¼”. The adjustable gas block and more neck tension lead me to believe the gouges and big spreads are not a brass issue. It’s a gas pressure and neck tension issue.
Four shot group with 29.0. gr IMR 4320 @ 3083 FPS seated magazine length.
It’s now a waiting game to get into North Star and get zeros at all yard lines and shoot it at the first OTC match.
One more item to consider is ammo boxes for your 22 Nosler. The Nosler case is to fat to fit most 223 plastic ammo boxes, especially after firing. Even if they will fit your 22 boxes the lid will not close on anything seated longer than magazine length. Therefore it seems 308 boxes are the only choice for now.
As always all loads mentioned were safe in my rifle but your mileage may vary, and I accept no responsibility for your equipment and loads.
CLICK HERE to read Report #1 of "A New Match Rifle".