I have a few of the little Whisper guns. The latest being built by forum member Spook. This is the second 300 Whisper upper he has built for me.
I had this built with only shooting 125 Sierra Matchkings, 125 Speer TNTs and 125 Nosler Ballistic Tips supersonic in mind, no subs. Spook used a 14 twist Mike Rock barrel with a carbine length gas system. The gas block is a PRI adjustable. The upper is a rifle length VLTOR mono upper. The scope is a Schmidt & Bender 1-4 Short Dot in LaRue rings with a 3gunstuff cat-tail. The lower is an STI with a JP trigger (my only lower without a Geissele 2 stage) and Magpul UBR stock.
The brake is a Sure Fire, as is the can. Even with the can it is still pretty light.
I took it to the range and using Lake City brass, AA1680 and N-110 and 125 Sierras going the speed of heat, I was able to shoot several 5 shot groups under .5 inches at 100 yards. Even with this stout load, recoil was very mild. With the can the POI shift was very repeatable and recoil was still mild. The difference in hitting a steel plate at 300 yards compared to a 223 with any bullet weight was night and day.
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