New AR owner

[bj139]

I took the plunge and bought an AR 80% polymer lower, stock, lower parts kit, 5.56 upper and carry handle sight. The receiver is milled out and seems to function fine. I haven't shot it yet but I am already looking for another upper to use for deer. I am considering 6.5 Grendel, 300 Blackout or 458 SOCOM. AR collecting can be addicting.

[VASCAR2]

Welcome to the forum bj139! There are many members here who have several AR-15's. I did my own research in 2009 comparing the AR-10 7.62X51 and varient cartridges for the AR-10. I considered all the AR-15 cartridges and decided to add a 6.5 Grendel to my 223/5.56 AR-15's. I did not want the expense or size of the AR-10 platform. The 6.5 Grendel met my performance criteria.

I think I made the right choice for me but you need to decide which cartridge best serves your needs.

[Red Dawn]

Congrats on getting your first AR. Good thing is there are plenty of options for what caliber to build bad thing is all the different calibers you gotta keep stored. I've gone through a few different ones and narrowed it down to 556 and 6.5G however I'm thinking the 762x39 could be a project in the future. Good luck on your next one.

[just_john]

bj139, welcome to the greatest group on the net! Presumably, most of us have gone thru the same emotional forest - what AR do I want first, then which, then which, .......... I have done most of 'em but then logistics and costs start intruding into the logic of it all. Arguably, the 5.56 is rapidly becoming the next .22, so you will end up with several of them. But, beyond that, the Grendel is the most useful, most versatile round in the AR world. Having played with the Beowulf, 6.8's, 300's and others, I can't help but evangelize the Grendel as the top of the heap. Before this past Christmas, I was the ammo SME at Cabela's here in N. TX and was amazed at how many, very loyal Grendel owners there are around here.

[LRRPF52]

Welcome aboard.

I wouldn't shoot .458 SOCOM with a polymer lower.

6.5 Grendel has more retained energy at 200yds than .50 Beowulf, .458 SOCOM, and .450 Bushmaster.

Hit probability is much higher due to low recoil, flat trajectory, and minimal wind drift.

[bj139]

Thanks for the replies. I guess what I would really like is a 6.5 blackout. That should only mean a custom barrel, I think. I could give up a few hundred fps to get brass availability and magazine compatibility. I used to wonder why the US military did not go to 6.5 after buying a Swedish Mauser in the 80's. I used to try to shoot groups with the Swede and with a stock rifle and a cheap Bushnell 4-12 scope shot a 1-1/16" group with 4 shots in 3/4". Total cost of rifle and scope ~ $150. I will probably get the Grendel upper since I still have several hundred 85gr and 120gr 6.5mm bullets. The 85's shred groundhogs like nobody's business.

Why wouldn't 6.5 blackout be a good idea?

[VASCAR2]

There is a 6.5 PCC which is a 6.5 bullet in a necked down 5.56/223 case (6.5X45). The biggest disadvantage of the 6.5 X45 is limited case capacity compared to a 6.5 Grendel plus 100 grain bullets are about the limit because longer heavier bullets take up to much powder space. If you necked down a 300 Blackout case you'd have very limited case capacity compared to Grendel. I never heard of anyone necking down a 300 Blackout case to 6.5/264. Not saying it hasn't been done or if it is worth while. Even with 31-32 grains of powder people are still seeking more speed out of the 6.5 Grendel.

[bj139]

I took my AR to the range today and shot it at 50 yds. I shot 15 rounds and got three 3 shot groups. The best was 1.25". This was with the carry handle peep sight. I have to give more thought about my next upper but the Grendel is what I am thinking.

I did find some information about the 6.5 MPC but availability of ammo and dies makes this not such a good choice.