I have always been a fan of military style firearms, especially the Evil Black™ ones.
I have, occasionally, thought that 5.56x45mm NATO was inadequate; but mostly I think it's a decent round.
My first rifle was a Ruger Mini-14. There's a lot to like about the Mini, it's simple and has a decent trigger. It's light and handy in stock form, but I didn't leave it that way. I added a folding stock and a combo flash-hider bayonet lug. I made a 9.5 lb. rifle out of a 7.5 lb. rifle and ruined the balance in the mean time. It looked cool though. I added an Aimpoint 1000 and B-Square mount for another 3/4 pound too.
There were two big problems with the Mini. The first, and largest, was the wandering zero. The point of impact would move up to 5" at 50 yards between range sessions, it got tiresome. The second problem was once the Assault Weapon Ban (AWB) hit good magazines for it dried up.
Before the AWB hit I dabbled in 7.62x51mm. I had a Chinese M-14S for a while and as the ban loomed I built a British L1A1 from a parts kit. Poor financial decisions on my part required me to sell the .308 guns (thankfully the AWB had made them worth more than I paid.)
The sale of the battle rifles had gotten me caught up on my bills and left enough left over to replace the Mini-14. I was considering an AR-15 just because magazines were all over the place at the gun shows and still reasonably priced. At this point one of the gun rags did a review of Korea's new assault rifle, the K2; nice but the AWB only allowed a few semi-auto versions in and they were more than I had. A letter a couple of issues later pointed out that neutered versions without the bayonet lug and with a thumb-hole stock were being imported as the DR200. So I borrowed my room-mate's credit card and ordered one from an ad in Shotgun News. Two weeks later I picked up my gun from the local gun store. As a bonus, I sold the Mini to a friend who was getting interested in firearms.
The DR was a nice rifle, much lighter than my Mini had ended up and while not as accurate because of the wide front sight, the zero stayed put between trips to the range.
What soured me on the DR was the importer failed to dot a tee or cross an eye or something and coupled with the executive order banning further importation there would be no parts support should something break. It began to matter a lot less when the AWB expired in 2004.
Which got me thinking of AR's again after a friend of mine demonstrated how easy it was to make one from parts. Much easier than an FAL! And gobs cheaper than buying a complete rifle.
The AR has been a love/hate thing for me for a long time. Thanks to the Army, I didn't understand how they really worked and how to properly clean one. The ergonomics have always been "just right" for me.
So, I bought a parts kit and a lower receiver and some tools and built myself a 16" carbine. I also used my tools to put together two rifle kits that friends had bought. I love learning! The very first thing I learned about my new AR was that the Army had never issued me proper cleaning materials. Commercial solvents were much better than Break-Free CLP® at removing carbon. The second thing I learned was really something I'd known all along, bearing surfaces should be lubricated.
The next thing I learned was how wonderfully modular the AR family is. There were so many interesting configurations and patterns to choose from. I made several.
Eventually, the looming specter of "5.56 inadequacy" showed up. Since I was covered for the Zombie Apocalypse with several guns that used standard 5.56, I felt I could afford to make one in a non-standard caliber. My choices at the time were 6.5 Grendel, 6.8x43mm SPC, 7.62x39mm and .300 Whisper.
7.62x39mm was my initial choice. It appeared to offer stopping power advantages over 5.56 and the lack of range seemed to not matter since any place where it would matter it would be illegal to take the shot. The main problem with it in an AR is the magazines. The round wants a constant curve that doesn't fit into the straight magazine well the AR is designed with.
.300 Whisper became my favorite when I found loadings that emulated 7.62x39. It was handy in that the only part that was different from a normal AR was the barrel. Unlike all the other alternate calibers it used the 5.56 bolt and magazine. .300 Whisper is proprietary, but identical to .300-221 or .300 Fireball. The real problems were finding a barrel without an excessive wait and there's no factory loaded ammo. I am not ready to trust myself reloading yet.
6.5 Grendel should have won. It's a pretty impressive long range round that still fits in a standard AR's magazine envelope. Three huge problems asserted themselves rather quickly while I was doing research. First was the long wait times. Second was Bill Alexander (owner of the proprietary round) making an ass of himself. Third was the 6.5 fan club, they simply omit any data that undermines their predetermined conclusion; drowning out the reasonable people who have valid reasons to share about why this round is excellent. Reliable magazines are a problem from what I have read since the case is based on the severely tapered 7.62x39, but good ones are out there.
6.8x43mm SPC should not have won. The specs that got me interested weren't the same specs that were achieved in the real world because the chamber dimensions were messed up in the SAAMI application and the ammunition sent to Afghanistan was not properly specced for how it would be treated. Luckily for me, there was a dedicated fan base who worked hard to get the round to realize its potential. What they had at the end was a round that fit in a standard AR envelop that hit harder than 5.56x45mm and farther than 7.62x39mm.
Dottie has been a sweetheart.
AAC has introduced a new take on the .300 Whisper; .300 AAC Blackout. This will have all the advantages of .300 Whisper, but will have factory loaded ammo and short wait times for barrels. Should I convert Kaylee or just get a spare upper in the new caliber?