It’s been a while since I upgraded or purchased a stock or any other parts for a full-size AR-15 rifle. In recent years, all my builds and upgrades have evolved around AR-15 pistols. A shorter weapon is ideal for many reasons, and they have great accuracy unless you are trying to shoot way out there. In 2012, the ATF declared AR-15 pistols with stabilizing braces legal and not an SBR (short barrel rifle). But no one told the ATF there were no takesies-backsies and they recently took it back. They changed their minds and declared their previous opinion wrong. Now stabilizing braces on AR-15 pistols are considered SBRs.
The Magpul CTR Adjustable Stock
There are two primary styles of stocks dominating the market right now. The first is the Mission First Tactical Battlelink Minimalist stock. This polymer stock is durable and lightweight because there isn’t a lower section to the brace. I have a few of these and they are great stocks, but I prefer the A-frame ones over the L-frame ones. The CTR has QD attachments on both sides of the stock, so the sling works on either side. There are other stocks that work better for specific purposes, but this one is great for a multi-purpose AR-15.
What I Like About the Magpul CTR Stock
The AR-15 was originally built and designed for a full-size fixed stock. It was several years later that adjustable stocks were being used for special purposes in the military. But once they came out, they continued to grow in popularity. When selecting a rifle stock, I want something solid, and adjustable, with a QD attachment, and a rubber butt pad. I use QD attachment slings, but others may want something different if they use another type of sling. The CTR meets all of those needs for me.
How To Install a Magpul CTR Stock
If your pistol brace was already on a mil-spec tube, you can switch it out for this one in five seconds. The lever on adjustable stocks moves up towards the top of the stock to adjust it. At the point where the adjustment lever pivots, pull down on the lever. This pulls the pin clear of the back of the buffer tube and allows it to come off. The CTR has a small lever directly under the adjustment lever that does the same thing. Pull the lever down to install the stock on the buffer tube.
Once the stock slides onto the buffer tube, use the lever to adjust the stock to the desired setting. If you don’t have a mil-spec tube, you will need to install one before you can add a brace to the rifle. The AR-15 that I am working on was a pistol that I am converting back to a rifle. I have already changed out the barrel and handguard but still need to change the brace. The rifle had a maxim defense brace when it was a pistol. I will be removing this and adding a standard mil-spec tube.
Installing a mil-spec buffer tube for the CTR stock
To change the stock, first remove the upper receiver from the lower. I use a Real Avid AR-15 block to hold up my lower while I’m doing this. Push down on the buffer tube retainer and the buffer and spring will come out. Next, use an armorer’s wrench to loosen the castle nut on the back of the lower receiver. Be careful not to turn it too fast because there is a pivot detent spring under the end plate. With the castle nut unscrewed all the way, pull straight back on the end plate and remove the detent spring on the lower right side. Then place your thumb over the buffer retainer and unscrew the buffer tube. When the buffer tube clears the buffer retainer pin, pull it and the spring out. The tube can now be unscrewed the rest of the way and removed.

Need a new stock?
Selecting the right stock is not easy, but it shouldn’t be hard either. If you are building a long-range rife then you may want to look at some of the stocks that have adjustable cheek rests. If you’re going light and as small as possible, you can go with a butt pad that connects to the end of the buffer tube. But if you want a great stock for a multi-purpose rifle, the Magpul CRT is the best one I have seen at a reasonable price. The shape is perfect for bracing on your shoulder, and it works well with a QD two-point sling. If you’re shopping for an AR-15 stock, check out the Magpul CTR adjustable stock.