"Other" caliber opinions

[ray1970]

Thinking about doing a build in something other than 5.56 just for kicks. Thought I would pick everyone's brains for their thoughts or opinions or experiences. Thinking about maybe the 300 Blackout but I am not opposed to other options. I could also go with the 6.8 SPC. If anyone has any information on the 6.5 Grendel or maybe the 6mm PPC that would be great too. Thanks.

By the way, this build is going to be an 18" barrel if that makes any difference. Just going to use it at the range to punch holes in paper out to about 200 yards. The more accurate the better.

[TrapperJohn]

One that I am interested in is the 300 blackout and from what I understand it is like the 7.62x39(AK round) and is supposed to be open for any company to use. It also is supposed to work in 5.56 mags. If anyone here has tried this round I would also like to hear your opinion.

[ray1970]

One that I am interested in is the 300 blackout and from what I understand it is like the 7.62x39(AK round) and is supposed to be open for any company to use. It also is supposed to work in 5.56 mags. If anyone here has tried this round I would also like to hear your opinion.

Most of the 30 caliber rounds seem to be quite similar... hopefully someone will come along and explain to me the big difference between the 300 AAC Blackout, the 300 Whisper, and for that matter the 7.62x40 WT.

[rammit]

Im pretty sure 300blk is the commercialized version of the 300 whisper.

[Hoser]

I would vote for the 300 Whisper family. Very easy to reload, uses AR mags and bolts. Using surplus bullets it is also relatively cheap to shoot.

I have a bolt gun and a 9 inch AR. Lots of fun and accurate. Very easy to suppress.

hopefully someone will come along and explain to me the big difference between the 300 AAC Blackout, the 300 Whisper, and for that matter the 7.62x40 WT.

Chamber wise there is almost no difference between the three. The difference is in the throat length. The Blackout has a very long throat, the 7.62x40 (Wilson Combats version of the Whisper) throat is longer than the JD Jones version, but shorter than the Blackout. The 300 Whisper is all over the map as it was never standardized.

I made the brass for Wilson Combat for a while until he got spooled up to make it himself.

[Colorado Osprey]

The PPC has feeding issues due to the shoulder.

7.62x39 reliable mags are still hard to find.

I chose the 6x45. A necked up 223 to 6mm with 30% more energy with the same weight bullet when comparing 223 and 6x45. The bonus to the 6x45 is just barrel swap. All standard AR parts work including bolt and mag.

Another one that really intrigues me is the 6.5 PCC
It is a necked up 223 as well as a shoulder move and a trim.
Here's a link to the progress on that cartridge in the AR: http://www.ar15armory.com/forums/65m...ar-t95187.html
It has the muzzle energy of the 7.62x39 with better ballistics than the 223. Down range energy it has more energy at 200 yards than the 223 has at the muzzle.

I don't like the Grendel... FWIW
The 6.8SPC excels in a short barrel.

If paper punching is just your goal... the 17 Remington, 204 Ruger, 20 Practical and 20 Tactical come to mind. They are all lasers compared to the 223 out to 200 yards.

[SA Friday]

300 Whisper all the way, then suppress it. Most of the others like grendle and 6.8 are made to optimize longer distance shooting.

[SAnd]

The 300 Blackout has been registered with SAAMI so the dimension information is available publicly. The 300 Whisper has been kept proprietary by SSK so other than SSK endorsed products no one has the official dimensions. Because of this the anyone can make 300 Blackout stuff. That makes everything cheaper.

[ray1970]

Thank you all for the opinions! Still not sure which one I want to go with. Might be a month or two before I am ready to buy the barrel anyways. Guess that gives me time to do more research.

[Troublco]

I like the 6.5 Grendel. Nothing wrong with the 6.8, but it's a 400 yard cartridge and the 6.5 will go past 1k with the right load.