Preferred setup on 308/6.5CM large frame?

[hlee]

I didn't read most of the post above. But, I will let it stand on its own merit as a testament to the adage "read more, post less." I need a drink...

 

[Skunkworx]

Buddly reincarnated?

 

[bobke]

A certain measure of intelligence can be being smart enough to know what you don’t know. Apparently, that is not the case here.

 

[Huskydriver]

Which is the flawed post this time? and i read a lot, and i ask a lot of questions, nobody know everything and nobody can do everything well, but anyone can be their own best and exceptional at anything they set out to do, here's an example, i needed both knees replaced, and roughly 30% are worse off then before, crippled up, in pain, and so on. reason? the didn't post their asses off asking questions. and those that did got the shit comments people on here like. I posted, researched, i even called the manufacturer to spec the knees i needed and then told the doctor what he was going to do, so like you know all this stuff i have the same in my realm so have surgery and components come loose cripple me and require a do over, most can't handle one let alone four, so respect the new set with cement and stabilizing spike, discuss post op recovery and told probably limited from the trauma, and pain, tell him hes wrong, then spend half hour discussing drugs and dosages i want if he wants to do the surgery and off we go. wake up go home do my own therapy because i know that better too, 7 weeks later i go from crippled to one of less than 800 patients to not only recover, but recover with range of real knee in and fully heal in 5 months while the rest suffer for a year and end up with legs that bend 80 degrees to my 153. Its because i spent endless hours of study, i can do drug dose calculations in my head, I'm where I'm at now because it was required. this is no different , its just knew and i'll master it as needed and in the end at worst be consistent. and it might take longer, because when someone reads what you consider rants on knee forums, the ask me a million questions so they can be their best, and i'm happy to help them get to the goal, so they can be their best. when you're really good at something the cost of that experience is sharing it with others. and nobody thats truly ever god at something ever uses it to belittle like this fucking place. So just like the knees, i'm master this with or without help and then thank myself and hopefully outshoot some of the mouths on here.

Uh with?

 

[GreenGO Juan]

Reading this it seems an 11.5” .308 (2200fps)is being compared to a 20” 5.56 shooting 77(2750fps). Cut that 77grain 5.56 down to 11.5 and the mv drops to around 23-2400. If you compare the two at the same barrel length the 308 has around 2x as much power, period!

The og topic was .308 vs 6.5, as mentioned they are dang similar, given equal barrel length until you start stretching the distance past 600 or so yards. Where the 6.5 has slightly better performance, given comparable bullet selection. 308 wins in logistics while the 6.5 creed has the edge in performance.

Back to the set up, depends on the intended use.

Imo these are the main considerations.

-If you are need mobility shorter barrel.
-If its a bench gun, go longer.
-If rapid fire is needed heavier contour
-If slow shooting a thin light barrel will do just fine.

All of these will be a balance of gains and losses.

Personally IMO for an Ar-10/ Ar308 the idea is a mobile weapon that is a manageable semi auto while on the move/on your feet and high rate of fire with the ability to put more energy down range if need from a rested position. Something that has the ability to fight close quarters and also build a position and put effective fire with more energy on target than offered in an Ar-15 platform.

For me thats why I go with 16” medium barrel, with a high magnification main optic and 45 offset non magnified optic for close in. That is manageable in tight areas and still has enough gas to be consistent on the long end. That for me is a good compromise. Of weight, size, power and range.

What really matters in setup is what your intended use is. How you intended to use it.

 

[drewthebrave]

For my light & midweight rifles I stick to AR15s. When I built my large frame AR, my goal initially was to keep it relatively light, but realized it was kind of redundant after comparing the planned big boy build to my 18" 6.5 Grendel at ~9 lbs. I'd have to make a lot of compromises in my components (pencil barrel, expensive lightweight components, etc) to get the performance I wanted while keeping the rifle below ~10 lbs (including optics & magazine) . Since the Grendel was going to be my walkabout gun, I figured the large frame build should be more of a bench & tripod gun.

I could have gone with a bolt action to keep things simple, but living in CA I decided to build a semi-auto while I still can. After some patient research, I found a deal on a heavy Criterion 18" 6.5 Creedmoor barrel from Craddock and built a rig that comes in around 13 lbs loaded with a Bushnell DMR II scope. The extra weight makes it super stable on a tripod or bipod, and the recoil impulse isn't far off from the ~4lb lighter Grendel. With lead-free hunting ammo, the same 18" barrel length in 6.5 Creedmoor gives an extra 250-300 yards of effective expansion range compared to the Grendel.

Define your goals for the rifle and build it to fit your intended role. If you want a 16" lightweight gun (around 8 lbs), you can definitely do it - but you'll need to be very patient & particular about your components to get there without breaking the bank. If your budget is unlimited, you can do whatever the hell you want!