AR platform for hunting mule deer.

[Old Stony]

I've used the AR-10 platforms in 6.5 Creedmore and .308 and while they both performed just fine, I think I would have to consider the 6.5 Grendel for your needs. It will give you nice performance in a lighter package.
I have considered one for myself, although I don't know why..other than it's a great cartridge in a light platform.

[mehavey]

This son is in to the AR platform. ... Idaho... Muleys...
... coyotes ....Remember light weight is a huge +

6.5 Grendel, hands down.
Standard military 2-pt sling across the chest/muzzle down.

...under $3,000

Combine a standard 5.56 lower with Bill Alexanders best upper... about ½-⅔ that -- including scope.

.

[CarJunkieLS1]

Originally Posted by rodwhaincamo

Wow! Haven't heard of this cartridge. Seems it's equivalent to a 7mm-08, though I'm not sure how with a much smaller case capacity.

The #'s you see quoted online are actual numbers from real users barrels. Efficient case design and careful component selection is how it does well against factory loaded 7-08.

As an owner of the 7mm Valkyrie I can 100% that what you see is what you get. By far my favorite rifle.

[rodwhaincamo]

Phenomenal! Comparing that to the 6.5mm Grendel or 6.8mm SPC shows a big step up in power and range, and with the great bullet selection and high BC's of the 7mm I'd have to say that's the greatest round available for this task and compared to the AR-10's options still better if for no other reason but weight.

[ms6852]

Something light is what you asked for as well and I would highly recommend a Tikka T3 lite in 7mm08. Under 7 lbs, good for hiking and has an adjustable trigger pull. My Tikka in 30-06 is sub-moa at 200 yards. If not Tikka, a Savage in 11/111 or 14/114 models. The Kimber Montana rifles are nice too, since you have the budget but models mentioned above get the job done for hundreds less.

[CalmerThanYou]

The bolt gun and 6.5 suggestions are all excellent. However the author stated his son wants a AR platform. I get that want, It may not be perfect for hunting all game, but the ammo is cheaper, and I would think range time is important.
The POF is light and 308 is inexpensive, versatile and plentiful.
I bet down the road he will learn the beauty of a well put together bolt action gun. Having both will likely happen in time.

[sixgunnin]

I'd like to keep it under $3000

WOW!!! Take it easy. You won't have to spend half that for the highest end AR rifles. I personally own Rock Rivers, Me and everyone I have talked to truly believe they are by-far the best deal in the AR world. At around $1,000 You will have an AR that is capable of poking less than a half inch hole at 100 yards. Topped with a quality scope (Nikon personally) I am confidently making head shots on game at 250 yards with 5.56 when conditions are opptimal. I personally like head shots as you have ZERO meat damage and is the most humane death possible (as long as you are good enough to consistently hit the brain or spine)

[rodwhaincamo]

Not to start an issue as I know it's a touchy subject for many, but I prefer a neck shot as the head often moves abruptly and quickly. The first third of the neck by the shoulder just doesn't move enough to be a big deal breaker unless spooked or some such. Drops them right there, and once picked a for up and flipped her head over heels (.270 Win). But that was a unique situation in which it was the evening of my last hunt and getting dark. Slowly using the scope to pick out the biggest doe from 75 yds away I was apparently spotted or otherwise alerted and she was lifting her hoof to stomp so I put the bullet in her throat from a forward facing position.

[Sure Shot Mc Gee]

308.
No quicker {dispatcher} in a AR platform than the 308.
Such Regal animals as Mule deer are. Truly deserve a quick humane ending of life. Any other way is unacceptable.
Speculating what will do isn't appropriate. 308 has the reputation all the other current cartridges try to measure too.

[rodwhaincamo]

The 7x57mm Mauser was known to take all manner of game on earth. The .308 Win does more than that, but the .284 cal bullets are superior when comparing them by sectional density, which is how I feel is the way to compare apples to apples to say. I'd certainly open to hearing another way to make an appropriate comparison if you or anyone else sees it from a different perspective.

For instance the Nosler Ballistic Tip in 7mm at 140 grns has a SD of .248 and a BC of .485 whereas the .308 at 150 grns also has a SD of .248 but a BC of .435.

The 6.5mm is also well known for having high BC's.

The 7mm-08 Rem, to me, has always been the ultimate cartridge, even more so Ackley Improved. If I could have but one...

That's not to say I don't like or appreciate the .308 Win or caliber. I also liked the idea of the 30-30 Win AI in a T/C Contender, though I still believe the 7mm Waters AI being a bit better...

The .308 Win has that reputation because it's been around longer than many of the cartridges it's compared to. And it didn't hurt that, before the better bullet options we have now, that it is a larger caliber. However a properly placed bullet is a huge part of the equation along with design/construction and velocity/energy to work properly.

The way I understand it is we have a young fellow likely in his early teens who is interested in the AR platform. An AR-10 that can handle the .308 cartridge is a bit much for the average youngster to hike up and down hills looking for an animal that likely weighs over 200 lbs. Granted I haven't a clue as to his size or condition. My 8 yr old daughter goes backpacking and hiking with us and carries 12 lbs of her gear which is the upper end of the % for her size/weight. She is fairly tough for a little girl and has camped in the freezing temps in the winter. Park rangers are often dumbfounded that we take her to primitive camping sites, but then she's been doing her own walking once her legs weren't so wobbly like a baby giraffe. And then they may well have an ATV to drive the miles back to camp/truck or plenty of backs to place the meat for carrying. 10 lbs of rifle along with a day pack and a deer would be daunting for many of us even in fair condition.

Were we talking about large game I'd not be so approving of any of these rounds excluding the 7mm Valkyrie even though the 6.5mm Grendel has been shown to be effective on elk just beyond 400 yds. Mule deer less than half that size? Certainly. And that's not to say I feel it's superior. Quite frankly I feel a .260 Rem, 6.5x55mm, 6.5mm Creedmoor, 7x57mm, 7mm-08 Rem, .308 Win, etc. in a light compact rifle would be much better.

[Scorch]

My apprentice just finished building a "lightweight" AR-15 in 6.5 Grendel. It weighs in at 7.5 lbs with a scope on it. Not to sound negative, but a cartridge with the ballistics of a 25-35 and the weight of a full-sized bolt action does not interest me. If light weight is what you are looking for, a bolt action is in your future. The Kimber 84M in 308 weighs under 5 lbs, by the time you have a scope on it it may be pushing 6 lbs. Nothing wrong with an AR, but lightweight they are not.

[Double Naught Spy]

I am a Grendel hunter. I would suggest 6.5 Grendel or 6.8 SPC. I would definitely NOT suggest going with wildcat rounds for your son's rifle, otherwise you are going to be doing a lot of specialty reloading/fabrication just so he can practice with it, much less to hunt with it.

Of the OP's option, I would go with the 300 BO if the shots are going to be under 100 yards.