The .300 Whisper ia a great round that comes from its versatility.
It actually has better downrange ballistics than the .30-30 due to it ability to shoot spitzer bullets whereas the .30-30 is limited to bluntnose designns, unless you are shooting it in the Contender... :lol:
The things to watch for is the rifling twist. A 1-10 twist will only stablize the lighter bullets, much over 180 grainers will be tumbling after a short range.
Heavier bullets need a 1-8. There is a tradeoff there, it may not be the best for the extremely light bulllets.
The .300 became popular because it was the most efficent .30 caliber cartridge at the time that was suppressed...that could be fit into exisiting AR magazines and use the same AR bolt.
It used a heavy bullet,(220) with an exellent BC that allowed it to hit harder than anything else and it allowed it to do it with a small powder charge that wasnt near as sensitve to postion in the case as other calibers that suffered from erratic ignition.
Its a good round in the supersonic range in the fact its not so loud, it gets the job done and in an AR you have mutiple shots.
I never personally have killed a deer with mine, I havent had the chance yet. A friend of mine that has the same AR platform killed two with his last season. One with a 220 suppressed round and one with a supersonic 150 grain Nosler Ballistic Tip. He zeroed his scope for the 150 NBT and had his iron sights zeroed for the suppressed 220.
We were hunting together. He whacked a medium sized doe with the suppressed round. He was a couple hundred yards away and I never heard the shot. The round entered right behind the shoulder just above the heart and exited. The deer was recovered about 115 yards from where it was shot. Not much different than any other cartridge.
About a week later he shot a 6 point buck with the supersonic round. He hit it in the heart. That one was recovered about 70 yards away. After inspection, it did more damage than the suppressed round did which only made a nice clean hole and did not expand at all.
Both deer were killed. This was with a 16 inch barrelled AR-15.
I wish I could tell you about the 10 incher but thats all I've got on the .300 Whisper.
Since my Contender is stainless, Id like to get the Whisper in stainless to match the rest of my barrels. Where did you get it?