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300 Whisper Loads
I just got an AR-15 type of upper made by model1sales. 16" barrel. 1-8 twist.
No modification done to gas block.
The loads & fps is worked up in this barrel, with a silencer.
Bullet: Sierra 220gr matchking(#2240)
Case : 221 Fireball(remington). If you use 223 brass internal volum may vary,
and pressure & fps will not be the same.
Case overall length: 34.6mm/1.362"
Primer: Winchester small rifle(WSR)
Cartridge overall length(C.O.L): 57.6mm/2.267", because of magazine length.
Max c.o.l. in "my chamber" is 59.3mm/2.335".
WARNING: Some bullets(ex. remington 180gr spitzer will touch the rifling
before you reach max magazine length!
Measure to be sure. You may do as follow:
Close the bolt.Take your cleaning rod(not the threaded open end, but flat end) and insert it from muzzle end until it touch the bolt. Mark rod at muzzel. Remove bolt assy. Insert bullet of your choise in chamber. Hold bullet against rifling with a pencil. Insert rod. Mark at muzzle. Difference between marks is c.o.l.
Vihtavuori powder(V-N)
Norma Powder(N-N/R)
V-N110
9.0gr @ 893fps
9.5gr @ 980fps
10.0gr @ 1036fps
10.5gr @ 1143fps
11.0gr @ 1189fps
11.5gr @ 1232fps (pressure sign)
N-R123
9.0gr @ 849fps
10.0gr @ 1092fps
11.0gr @ 1152fps (pressure sign)
THESE 2 loads will not cycle the action. I.e. hold bolt open on empty mag.
ALL other loads posted will!!!
V-N120
10.0gr @ 814fps
11.5gr @ 1016fps
12.0gr @ 1099fps
V-N130
13.0gr @ 1026fps
13.5gr @ 1112fps
V-N133
13.0gr @ 931fps
14.0gr @ 1077fps
V-N530
13.0gr @ 878fps
14.0gr @ 1035fps
14.5gr @ 1099fps
N-N200
13.0gr @ 1088fps
N-N201
15.0gr @ 1089fps
Around 1000/1040fps there will be no bullet noise. Above this it gets louder until you reach appr 1300fps where the sonic crack comes into play.
When working with subsonic load and different powder combo. Make sure the bullet leave the muzzle!!! It may be stuck in there, & you will be very sorry next time you pull the trigger. At lowest load, look into barrel to be sure.
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