"Other" caliber opinions

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. [Awesom]

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.

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Originally Posted by 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.

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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.

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

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.

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Originally Posted by ray1970

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.

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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.

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.

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

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.

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.

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.

The 6.5 Grendel is looking rather appealing. Originally I thought I wanted to go with one of the 30 caliber cartridges but now I am not so sure. Once again, thank you all for your replies.

The Grendel calibers are cool till you price brass.

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Originally Posted by Hoser

The Grendel calibers are cool till you price brass.

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That's why I seek information here. Always get good advice. Makes the 300 Blackout look more appealing since it is based on the 5.56 case.

Not having played with the calibers listed I will give one piece of advice. If you are going to build a different one make the change a substantial one.

I only say this because a small change from what you have now may leave you wanting. When Fal kits were cheap many built them in everything from 9mm lugar to 8MM mauser. the cost of the components to load or heaven forbid one has to buy ammo will put a damper on some choices.

Taking a .308 and making a .243 out of it was boring. Taking a 9lb .308 rifle and making a 6lb 7.62X25 carbine was fun.

As far as distance goes with an AR how many shoot past 600? I know a few that do with 80's but in all reality just because it can how many times are people that have an AR going to shoot at 1000 yards vs 300-600?

Just a thought. :)

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Originally Posted by jerrymrc

As far as distance goes with an AR how many shoot past 600? I know a few that do with 80's but in all reality just because it can how many times are people that have an AR going to shoot at 1000 yards vs 300-600?

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Although my range has a nice 1000 yard range I really have no plans to shoot past 200 yards. Every AR I have owned has been either .223 or 5.56 caliber and I just thought it would be nice to have something in a different caliber since there seems to be plenty of components available nowadays to make building a different caliber very easy and affordable. Just another toy to play with. [Awesom]

OK. I made up my mind. I am going to build something in 300 AAC Blackout. Might be a little while before I start rounding up parts.... hopefully I don't change my mind in that time.

I wish a few more barrel profiles would show up in .300 blackout. I know exactly what I want but can only get it in 5.56 and 6.8 :(

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Originally Posted by splogan

I wish a few more barrel profiles would show up in .300 blackout. I know exactly what I want but can only get it in 5.56 and 6.8 :(

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Get in touch with a custom AR manuacturer instead of just build houses and they will cut you what ever barrel profile you want.
My suggestion would be Mike Milli one of the experts and pioneers of alt cal AR's.
www.dtechsuperstore.com
He also has a accuracy guarantee. He is currently using Shilen blanks.