Small Groups

Shooting home

The Quest for Small Groups

The following target scans are for small or interesting groups. Unless otherwise indicated all groups are 5 rounds. The rifle is an AR-15 with a Bushmaster V-Match flattop upper with a 26" Krieger heavy stainless steel barrel. A Tasco World Class Plus 8-32x44mm target scope was used on the highest magnification. The lower was assembled by the author and includes AR-15A2 furniture and a Jewell 2-stage trigger with both stages set as light as functioning allowed. The bore has been moly coated according to the procedure documented elsewhere on this website. The groups were shot from benchrest free-recoil using a Bald Eagle front rest and rear rabbit-earred bag.

Unless otherwise noted all loads had the following case preparation. Lake City once fired military cases were weight sorted to a 0.5 grain range. Brass was sized to -0.002", with flash hole and primer pocket reamed, and case mouth chamfered inside and outside. No neck turning was employed. Handloads were assembled on a Forster Co-Ax single stage press with Redding dies. Bullet seating was 1.890" as measured on a Stoney Point gauge. This was about 0.015" off the rifling.

Note the excessive muzzle velocity spreads and standard deviation. These are all hand-weighed loads. Something is causing this excessive MV variation. Neck tension? Case volume? Runout? Freebore? My guess is neck tension and I'm taking measures to uniform it.

	Date: 01 March 2002 Temp: 35 F Powder: 26.0 grains Hodgdon Varget Bullet: 52 grain Sierra Matchking HPBT, moly'd by the author Primer: Federal GM205M match Muzzle Velocity (FPS) Average: 3050 Minimum: 2983 Maximum: 3093 Spread : 110 Std.Dev: 28.9 The 0.404" group shows a 0.203" four round sub-group.
	Date: 01 March 2002 Temp: 35 F Powder: 26.0 grains Hodgdon Varget Bullet: 52 grain Sierra Matchking HPBT, moly'd by the author Primer: Federal GM205M match Muzzle Velocity (FPS) Average: 3050 Minimum: 2983 Maximum: 3093 Spread : 110 Std.Dev: 28.9
	Date: 15 March 2002 Temp: 50 F Powder: 26.5 grains Hodgdon Varget Bullet: 52 grain Sierra Matchking HPBT, moly'd by the author Primer: Federal GM205M match Muzzle Velocity (FPS) Average: 3148.3 Minimum: 3103.0 Maximum: 3212 Spread : 109 Std.Dev: 24.1
	Here we have comic relief. The wind was blowing, mostly from the right. I was trying to shoot in-between conditions. Obviously, I was unsuccessful. Date: 15 March 2002 Temp: 50 F Powder: 22.8 grains Accurate AA2200 Bullet: 52 grain Sierra Matchking HPBT, moly'd by the author Primer: Federal GM205M match Muzzle Velocity (FPS) Average: 3144.0 Minimum: 3070 Maximum: 3228 Spread : 157 Std.Dev: 44.3

Accurate AA2200 Powder Performance in .223