So you want to buy an AR-15?

First off, this is just my general advice, and I recommend to everyone -> get the advice of many people before you purchase...my experience is limited to my DTI AR-15 (which was highly recommended by my local gunshop), and my reading and observations of other brands. I'm just another voice in the crowd, and by no means a supreme authority.


Whenever friends get a chance to shoot the AR, they are hooked and want to pick one up....because it's just fun to shoot! I have a few pieces of advice to keep in mind when you start shopping.

What you want is a mil-spec AR-15, and they are made by many manufacturers. Wheather it's from DTI (Delton), Bushmaster, Colt, DPMS, Stag, Smith & Wesson, or coutless others...the general form of an AR-15 is the same....and if they are built to mil-spec, then the parts are compatible with each other (for the most part). I can take the upper receiver of my friends AR-15, and attach it to the lower receiver from my DTI, and the gun will function perfectly!

First, get your AR-15 chambered for 5.56 NATO. If it's chambered 5.56 you can shoot .223 Remington in it, but you can not go the other way around!

Determine what style you desire for your application, this will point you towards a long rifle, or a shorter carbine, as well as the weight of barrel you need. Aside from quality of manufacture, I see this as the only major consideration...as every part of the rifle is upgradeable...if you don't like the grip....change it.....trigger blows...change it (a friend has a Timney trigger and loves it).....want that quad rail up front....add it later....it's no big deal. Even the front sight/gas block can be changed down the road if you want to mount a scope to the rail, and get the front sight out of the way.

This leads to the next consideration...upper receiver type, and in my opinion anyone buying today should get a picatinny rail upper reciever...if you like the carry handle look of the AR, then you can add one....but if it's an integral part of the reciever, your stuck with it.

Beyond this, I feel the choices start to become highly personal. I like the AR 'all black', though I know people who have the OD Green grips, and it looks nice...but it's just not me. I also like the looks of the collapseable stock carbines (though mine looks adjustable, it is fixed, NY feels a collapseable stock is 'evil'), the other major option is the classic rifle stock...along with many aftermarket stocks. The AR becomes a very personal weapon as you build it up.
As far as sights go...I feel you definatly have to have iron sights...even if it isn't your primary tool, you should have backup iron sights...and you should know how to use them effectively.

Accuracy

A lot of people ask 'how accurate are you'...I'm a beginner, and I get better every time I go out to practice. With my Savage 17HMR, I am doing sub 1 MOA using a front sandbag rest. With the AR-15...I'm running sub 4 MOA...at 50 yards using a front rest, I managed a 10 shot group of 1.7". Acceptable, but I wouldn't call it 'good'. But like I said, everything improves with practice.

Keep in mind with this picture, at 50 yards my AR is shooting about 1.1" low, so it is the tightness of the group that is of interest here, not the bulls eye.
And in my opinion, you should judge your accuracy based on 10 rounds, and not 3....anyone can get lucky....but 10 times in a row starts to show what your made of.

Excellent reading on the history of the AR-15

I highly recommend this book to anyone interested in the history and development of the AR-15 platform.

The Complete AR-15/M16 Sourcebook: What Every Shooter Needs To Know by: Duncan Long
http://www.amazon.com/Complete-AR-15-M16-Sourcebook-Shooter/dp/0873646878

Scope DOPE

Knowing your DOPE, or Data On Personal Equipment is important when it comes to shooting your rifle accurately. Since the bullet travels in an arc, the point of impact compared to your point of aim will vary with distance. As a side note...the bullet initially travels upwards before it starts heading down...this isn't due to 'aerodynamic lift' it is due to the fact that bullets are fired in a slight upward angle.

I like to use the Nikon scope calculator (located here http://www.nikonhunting.com/SpotOnRegistration/ ) to generate my STARTING ballistic curves. These values serve as starting points, and will need to be fine tuned with live fire at your shooting range.

I write these values onto a chart which i then cover with clear packing tape (to help waterproof it), and then adhere it to the inside of my scope cap, that way it's always on hand when your using your rifle.

I sight in my scope at 225 yards which keeps me within -3.65" at close range (the distance of my muzzle to scope center) and a maximum of 1.2" at 155 yards....which will keep me well within the 'vitals' for self defensive use. With my setup, the bullet passes the sight line at 80 and 225 yards.

AR-15 with Karsten Cheek Rest

As a first post to my 'AR-15 Shooter' blog, installation of my new Karsten Cheek Rest (available from http://karstenskydexcheekrest.com/ ) seems like a good place to start!

Using the carry handle mounted scope on my AR-15 didn't allow for a good cheek weld, and was adversly affecting my aim. In searching for a solution on the net, I came across the Karsten Cheek Rest, and ordered one up. I'm very happy with the design and build quality of the piece, and the price was right!

Installing the rest on my AR-15 carbine did present one challenge....with the buffer tube running down the center of the stock, I had to drill the holes pretty low on the stock, and this location did now allow the riser to compress and grip the stock. My solution was to use nylon spacers available from Lowes to fill in the space and provide centering to the riser. They did not have 3/4" spacers so I superglued a 1/4" and 1/2" spacer together to do the job.

I then drilled two 1/4" holes in my stock, one that widened the existing 'strap slot', and a new hole towards the front. Be sure to drill the hole low enough so the spacer will sit flush against the stock.

The setup works great, and gives me an extra 8/10" of rise above the existing stock, exactly what I needed!

I also glued on a piece of leather to the top of the rest using 3M Hi-Strength 90 Spray Adhesive (lay the leather face down and spray on the adhesive directly to the back, then stick the leather to the cheek riser). I found the leather at Jo-Anns Fabrics, and trimmed it down to fit...it's a much nicer feel than cold plastic on your cheek.