Some info on the 6mm CM, makes a great prone rifle for 600 or 1000 yards.
6CM LOADING NOTES FOR REFERENCE ONLY
Reamer used was the 6CM LR a version of a 243 Winchester improved.
Action: BAT single shot model B
Bench rest mode with a Night Force BR 12 – 42X scope. The rifle weight is 17.25 #.
Winchester 243 Brass was prepped and sorted into lots by weights. Neck diameter new and sized is 0.269”, loaded is 0.271” and fired is 0.273”. Sierra 115-grain bullets touch the lands with an OAL of 2.915”. Berger 115-grain bullets touch the lands with an OAL of 2.972”.
NOV 10, 2006
New barrel installed, Krieger 1:7.5 length is 28”
Load test at 100 yards on 11-10-2006 at Sacramento temp was 40 degrees.
Powder = H1000, Primers = CCI-BR2, Case = Winchester, OAL = 2.900” jumping 0.020”, Sierra 115 grain bullets.
Chronograph numbers are questionable with the dim light.
47.0 grains MV=2956 Group = 0.426” five shots
47.5 grains MV=3010 Group = 0.331” five shots
48.0 grains MV=3066 Group = 0.375” five shots
48.5 grains MV=3089 Group = 0.397” TEN shots ---- Round count thru barrel = 65
First Match ----- three 600 yard prone matches, iron sights 11-11-2006
Conditions at Sacramento 40 degrees, light rain, dim light, heavy wet wind flags that could not show the changes.
Match Winner with a 598-30X
First -- 600 using the 47.5 gr. Load = 200-09X
Second 600 using the 48.0 gr. Load = 198-09X
Third -- 600 using the 48.5 gr. Load = 200-11X
The 48.5-grain load did shoot the best; all three loads shot very good elevation.
Round count thru barrel = 131
6CM LOADING NOTES FOR REFERENCE ONLY
Reamer used was the 6CM LR a version of a 243 Winchester improved.
Action: BAT single shot model B
Bench rest mode with a Night Force BR 12 – 42X scope. The rifle weight is 17.25 #.
Winchester 243 Brass was prepped and sorted into lots by weights. Neck diameter new and sized is 0.269”, loaded is 0.271” and fired is 0.273”. Sierra 115-grain bullets touch the lands with an OAL of 2.915”. Berger 115-grain bullets touch the lands with an OAL of 2.972”.
NOV 10, 2006
New barrel installed, Krieger 1:7.5 length is 28”
Load test at 100 yards on 11-10-2006 at Sacramento temp was 40 degrees.
Powder = H1000, Primers = CCI-BR2, Case = Winchester, OAL = 2.900” jumping 0.020”, Sierra 115 grain bullets.
Chronograph numbers are questionable with the dim light.
47.0 grains MV=2956 Group = 0.426” five shots
47.5 grains MV=3010 Group = 0.331” five shots
48.0 grains MV=3066 Group = 0.375” five shots
48.5 grains MV=3089 Group = 0.397” TEN shots ---- Round count thru barrel = 65
First Match ----- three 600 yard prone matches, iron sights 11-11-2006
Conditions at Sacramento 40 degrees, light rain, dim light, heavy wet wind flags that could not show the changes.
Match Winner with a 598-30X
First -- 600 using the 47.5 gr. Load = 200-09X
Second 600 using the 48.0 gr. Load = 198-09X
Third -- 600 using the 48.5 gr. Load = 200-11X
The 48.5-grain load did shoot the best; all three loads shot very good elevation.
Round count thru barrel = 131
