7mm Whisper

[yulie22]

Howdy all, I'm a handgun silhouette competitor. I'm thinking of building a new pistol. Can someone give me any info on 7mm whisper? Can you buy dies? Has anyone used it on centerfire silhouette targets? What's it like? Cheers.

[LouBoyd]

I presume the 7mm Whisper you're referring to is the 7mm/221 fireball. Basicly the 300 whisper necked down to 7mm. The obvious disadvantage is your limited to 175-180 grain bullets (perhaps some round nose 195s) simply from what's manufactured and you'll need a custom chamber (and barrel twist if you want to shoot near mach 1).

Maybe JDJ has dies and reamers, but I've not seen either on the market.
I expect they would build a pisol (maybe just a barrel) for you. I don't think they rent reamers. Reamer companies will make anything you send them a drawing of. Call it what you want. JDJ owns the "Whisper" name.

Advantage over a 300/221? There are slightly higher BC 7mm bullets available from Berger and JLK than in 30 cal. From an AR-15 it should give a bit longer range than the 300 whisper and slightly less bullet noise. Subsonic it would have less energy and momentum at any reasonable distance which would be the main reason it's not popular.

I presume you talking IMHSA 1/2 size "hunter" class silhoutte targets. I can't imagine it knocking down the full size 40+ pound rams reliably even with maximum supersonic loads. The larger 7mm TCU won't. I doubt a 300 Whisper would either though it would have a better chance with heavier bullets. My pistol for shooting the full size critters was a TC in 44 magnum with 300 grain bullets. That wasn't excessive and occasionl left rams standing with poorly centered hits.

From the quickload database the 7mm whisper has a case length of 1.397" and a capacity of 24 grains versus 1.390 for the 300 whisper and 24.95 grains.

I haven't used a 7mm Whisper. It didn't exist when I was shooting silhouette regularly. I have a TC contender barrel in 7mm TCU which is a 223 necked up to 7mm and has 33 grains capacity. I've used it for hunter silhoiuette but I prefer a 30 carbine barrel for that class. The 30 carbine has only 21 grains case capacity. Bullet momentum knocks down targets. Energy just spatters bullets. (MV versus MV^2). Of course you get more of both with higher bullet weight or higer velocity. it's just the ratio of momentum to energy whcih can be adjusted. Slow heavy bullets work well for silhouette but they still need reasonably high BCs to perform well in windy conditions. For the same momentum the 30 Carbine gives similar recoil to the 7mm TCU but noticably less muzzle blast. That should be true versus the 7mm whisper too.

I just don't see an advantage of the 7mm's over a 30 carbine or 32-20. The 32-20 Win is an old cartridge with 22 grains capacity and is used with .308 bullets. It's advanatge in a TC is its a rimed cartridge making them easier to handle and extract. It was popular when I was active in silhouette some years ago though brass was bit hard to find even then.

Hope that helps. I no longer live near a range which shoots silhouette so
I haven't kept up with what's the latest vogue. You might get better info from current shooters.

[yulie22]

Lou, thanks for your reply. It has answered all the questions I needed. Seems 300 Whisper will be the better choice for what I want, and all the bits will be easier to source. Cheers, Yulie.