Ask TTAG: What Caliber for my Short AR Platform Hunting Rifle?

Today’s question comes to us from reader ‘London 35’ who asks . . .

I am interested in building a short barreled rifle out of the AR platform. I recently read your article about short barreled .308s and was wondering what your input on the matter would be. The goal is a small, lightweight, and maneuverable hunting rife to be used on deer and hogs at a max of 200 yards. The calibers I’m considering so far are the 300 ham’r, .308, and 6.8 spc. What caliber do you think would be best suited for this application, barrel length around 12-13in. Thank you for your time.

To get right to the point, there are already many, many options out there for that category of arms. A custom build isn’t really necessary, but would be fun to do. Off-the-shelf options exist currently that fit this category.

I wrote that .308 article almost a decade ago now and it’s been very popular, far more than I ever thought it would be. I don’t know how much it’s actually influenced anyone, but I am glad to have been asked about it so much.

The thing is, a decade ago we didn’t have a lot of the information we have now, and while my original numbers were great at the time, a lot has changed. There are newer and better rounds out there that meet or exceed what I did back then, but with a substantial savings in weight and greater ballistic efficiency.

Alas, this is not about those rounds, but maybe I will do an updated article on today’s products.

In a recent Ask Josh, there was an effort to sh*tcan me for expressing my views on why it isn’t a great idea for an inexperienced/trigger happy hunter to start buying magnum-class semi-autos to make up for poor bolt gun results. I’m not a Fudd, I’ve just been around enough bad hunters to know that it’s a dangerous situation.

Despite the expected amount of flak I received in response to that piece, I think people missed my point that there are so few of products in that category because they appeal to a very limited audience. And that the people who they appeal to are sometimes misguided as to the functional value of those rifles.

The same goes for this answer in that I want London 35 to understand the limits on what is being asked and, while SBR-length barrels are relatively common, they are, again, useful for a much narrower band of individuals.

London 35 lays out a very specific set of criteria, which is great. I’m seeing it here as short-barreled rifle. I am not sure if this is an NFA SBR or something that would be pinned and welded out to a legal 16” length.

There is, of course the pistol route, and among these options in the 13” range, there is little ballistic difference given that it’s more of a legal classification issue than a performance one.

In addition to a 13”-ish barrel, the desired game is deer and hogs at 200 yards and in. This is helpful and I can recommend going with any of these rounds, but with a preference for .308 Win.

A 13.5” .308 can be pinned and welded out to 16” pretty easily and there are companies that make brakes or flash hiders that do just that, but you’ll want to be sure of those measurements. If we’re talking about a NFA SBR as opposed to just a short rifle, then you don’t need to worry about the pin-and-weld, just the long NFA wait time.

The main thing we’re now looking at is the difference between what you get in platform size and weight in this category. The .308 size/AR10 will always be a bit heavier and larger than an AR-15 in 300 HAMR or 6.8 SPC, but the difference is not as apparent when the overall size will be quite similar and almost as compact.

Parts choice is big here and there are plenty of ten-pound SBRs I’ve seen and shot. It’s easy to get heavy, so London should avoid big scopes and extra gizmos if keeping the rifle light is the order of the day.

My general recommendation would be to go with the .308 size and expect to be firing a 168gr bullet at about 2400 fps from a 12″ to 13” barrel. You can also do a 175gr at about the same speed, give or take a bit. A 130gr bullet can go pretty fast in this setup, at about 2600 or more if you push it.

This is more powerful than a .30-30 and is really not that much different from a full-length barrel at the 200-yard range. Can you do it with a 6.8 or the new(ish) 300 HAMR? Sure you can, and those rounds may be a bit more efficient in a smaller envelope, but they aren’t as commonly available as .308 today and enjoy fewer options for ammunition. That can always change, but I would only invest in something harder to find if I had a ready supply of ammo available to me.

Since we’re talking game at 200 yards and in, there is a wide selection of .30 caliber bullets that perform well in the shorty .308. I haven’t found one that absolutely sucks at those ranges, but I haven’t tried them all. I would say that pretty much any good 150 grain hunting load will work well.

Now, about those limits I mentioned earlier. The short rifle is very handy and easy to use. It can be extremely accurate and, as I proved in my original .308 article all those years ago, it can be just as precise as a longer barrel mechanically.

I think accuracy is a non-issue in short rifles, especially at 200 yards and less. If you approach the short hunting rifle realistically, you won’t be disappointed. If you come at it from a ‘but its only good for X distance what if an animal comes out further’ or ‘but it can’t pierce armor in some imagined battle’, you haven’t understood the concepts. There is a narrow band of individuals who like to work with short rifles who understand their limits and don’t push them.

Wind drift issues can arise with shorties at longer ranges, but that won’t really impact London 35 because at 200 yards, there isn’t usually enough wind to have a significant impact on bullet drift. Shorter barrels do suffer in regard to velocity, but this can be overcome at a given range with a dedicated load. In this case at 200 yards, I don’t see the need for special ammunition for cutting the wind.

Overall, even if London goes with something in 6.8 or 300 HAMR, it will work just fine at 200 yards. I recommend .308 because I know it well, and I have seen what it can do in a short barrel. There are some ergonomic issues like recoil and blast that may need to be addressed, but the .308 isn’t a beast like some people think.

Another idea that London may like is the bolt action route, as there are a growing number of bolt action pistols coming out and they are looking like they may be the next hot thing. TTAG’s Jeremy S. will probably be able to help with something related to Black Collar Arms.

If you want something very slick and super-light that will turn heads, order The Fix from Q, which is just about as light and compact as you can get. I’d love to SBR one of those for a truly micro setup. I know the order of the day is semi-auto for London, but I do think a mini bolt action would be sweet in this role as well. Hell, buy both if you can.

Some Post-Analysis Fudd Time 

In the case of London 35, I appreciate that a rifle is being built for a specific distance for hunting that should reasonably allow the ethical taking of game. I wish more people would think this way and I applaud London 35 for doing so. The resulting rifle will be perfectly suited for that 200-yard distance.

‘BuT WhAT iF I hAvE To sNIpe iN a wAr?’ Look, I get it that some people are all amped up for SHTF scenarios and everyone thinks they’re a sniper, but you’re mixing your cards with another deck. There is nothing functionally wrong with a short .308 for hunting. I know this from personal experience.

What I really don’t get is the idea that everything has to be about fighting or a coming ‘Red Dawn’ situation. In that other recent Ask Josh, I was surprised the comments being so militant and that I was was lecturing people on what to buy.

Buy what you want, but I don’t think you should be buying deer rifles for their ability to shoot through vehicles at a mile any more than you should be buying a bow for its ability to launch grenade-tipped arrows or some other Hawkeye sh*t.

Maybe it makes me a Fudd for saying that people shouldn’t buy guns they can’t shoot well or master easily. It’s almost like I’m encouraging them to practice and make ethical shots.

Hunting with a short rifle shouldn’t be discouraged and I really do recommend it because it puts a realistic and intentional limit on the distance at which you shoot game. I agree that there are some cases where a long shot is necessary, but it should generally be avoided and used as a last resort.

I set up many of my guns for a maximum distance or the effective range for my given cartridge. I have dropped countless deer with a bolt action 14” .450 Bushmaster (with a pinned brake) and have never had an issue at 200 yards, which I believe is the true max for the round.

I also have several 6.5 Creedmoor rifles optimized for 500 yards and in, and others set up for 500 yards and beyond. For hunting with any of these, I’m never really looking past 300 yards, with 500 being an absolute limit given flight time and possibility for error.

London has it right, and I’m very happy to see this mindset becoming more prevalent in the hunting community. Too many people have 1000-yard guns for 70-yard shots and its just not necessary. And the temptation to take longer range risks increases with your imagined effective range. Shorter shots are always better and if that means a shorter rifle, so be it.