Caliber options for a .223 lower??

[Truck10]

I bought a Seekins lower on the group buy with the idea of putting it on one of my current 223's, but now i'm thinking of a new build, but the caliber is the trouble i'm having. The 300 Blackout caught my eye but i wasnt sure if the cartridge would work with the 223 lower.

Just lookin for ideas for something different and fun, i have 4 Ar's and there all .223's...

 

[Force_Multiplier]

Re: Caliber options for a .223 lower??

300blk works w/ 223 everything...except the barrel... that's one of it's best qualities

 

[cb4017]

Re: Caliber options for a .223 lower??

300 Blackout works ok. I had a 16" upper that shot well. I was able to get 125 grain bullets to 2300 fps. I sold it because I wanted something to reach a little further.

I'm now waiting for the parts to finish a 6x45 upper. I plan on working on a load around an 87-90 grain bullet to 2800 fps.

 

[country888]

Re: Caliber options for a .223 lower??

300 blkout, 6.5 grendel, 6.8 spc, 204 ruger & a number of 6mm rounds. If you can think it, its out there for a AR lower. I do love my grendel & blkout though.

 

[dmpowder]

Re: Caliber options for a .223 lower??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 10Truck</div><div class="ubbcode-body">I bought a Seekins lower on the group buy with the idea of putting it on one of my current 223's, but now i'm thinking of a new build, but the caliber is the trouble i'm having. The 300 Blackout caught my eye but i wasnt sure if the cartridge would work with the 223 lower.

Just lookin for ideas for something different and fun, i have 4 Ar's and there all .223's... </div></div>

The only thing that makes it a ".223" lower is the numbers stamped on the side.

My vote goes to either 6.5Gren/264LBC, 6WOA, 243LBC, well just about any 6 or 6.5 cartridge that they make so far.

 

[Jaytrigger]

Re: Caliber options for a .223 lower??

just bought a Seekins upper and lower with a Bar rail. Im building a 458 SOCOM when I get back from current deployment. I will be buying another set shortly to build a 6.8 as well.

 

[cutamerc]

Re: Caliber options for a .223 lower??

458 Socom would be a hoot.

 

[ORD]

Re: Caliber options for a .223 lower??

Caliber options for a .223/5.56 lower are NUMEROUS to put it mildly (dozens and dozens...especially if you count the wildcat cartridges and "one-offs"), but the "big" few are roughly 5.45x39, .223/5.56x45, 6.5 Grendel, 6.8SPC, .300 Blackout (or 7.62x35), .458 SOCOM, and .50 Beowulf to name a few. The .300 Blackout is an excellent choice for many applications but depending on your wants/needs, may not be the best for you.

Also, don't forget the venerable conversions for .22LR and the multitude of pistol caliber options, especially the 9mm/9x19. Both of these options are nice given the EXTREME cheap cost of running a .22LR with 9mm still coming in considerably cheaper than most bulk-pack .223/5.56 ammo.

Let your particular needs/wants dictate what would be the best caliber for you. If you have anything in mind in terms of what you'd like from a new caliber, by all means post 'em up and maybe we can collectively help you narrow the field somewhat.

 

[BIPMaster]

Re: Caliber options for a .223 lower??

The downside to 6.5G is the ammo choices/cost if you don't reload. What are you wanting to do with a different caliber? If just for general shooting fun then go with the .300BLK. Long range, any of the 6mm or 6.5G. I built a 6.5G upper for longer range precision, and it is a blast to shoot.

 

[longrange223]

Re: Caliber options for a .223 lower??

i've got both platforms & am trying to narrow it down between the grendel & the .260

 

[country888]

Re: Caliber options for a .223 lower??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longrange223</div><div class="ubbcode-body">i've got both platforms & am trying to narrow it down between the grendel & the .260 </div></div>

A 260 will not work with the AR 15 platform. You will have to step up to AR10 to handle the 260. Grendel will work fine with the AR15.

 

[mjh30]

Re: Caliber options for a .223 lower??

10Truck, you have four AR's and they are all 223, lord sell two of them, you don't know what you are missing in the world with either a 6.5G or a 300BLK. Love my 264lbc, the rifle plains shoots far and I mean far, and by all accounts the 300blk covers lots of bases from hunting to shooting.

 

[Truck10]

Re: Caliber options for a .223 lower??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mjh</div><div class="ubbcode-body">10Truck, you have four AR's and they are all 223, lord sell two of them, you don't know what you are missing in the world with either a 6.5G or a 300BLK. Love my 264lbc, the rifle plains shoots far and I mean far, and by all accounts the 300blk covers lots of bases from hunting to shooting. </div></div>

I think i'm going with the 300, mainly because i dont shoot much past 300yds. Any recommendations on barrels makers??

 

[country888]

Re: Caliber options for a .223 lower??

10Truck, I would go with ACC or a Noveske. It seems they have done alittle more homework and shoot and functions great.

 

[244]

Re: Caliber options for a .223 lower??

Wilson Combat now has the 7.62 x 40 cartridge. It has a bit longer of a case than the .300 BO and does well with supersonic loads.

You could make the TCU family of cartridges, 6.5 and 7 mm. They use 5.56 brass necked up. The 6.5 Patriot is similar.

The 7mm ARK is the Grendel/.264 LBC necked up.

.204 Practical is 5.56 necked down to .20 caliber.

Alternate chamberings with factory ammo: .204 Ruger, 5.45 x 39 Russian, 6.5 Grendel/.264 LBC, 6.8 SPC, .300 BO, 7.62 x 40 WT, .450 Bushmaster, .458 SOCOM, .50 Beowolf and probably a couple others I forgot.

 

[country888]

Re: Caliber options for a .223 lower??

204 ruger is a 222 rem mag necked down to a .20cal. 5.56 and or .223 is a smaller case. Just sayn

 

[mjh30]

Re: Caliber options for a .223 lower??

10Truck good choice, AAC or Noveske are excellent choices.