Given the availability of high quality upper and lower receivers at excellent prices, it’s understandable that more and more potential AR buyers are turning away from the “build it yourself” route. Whereas I used to build nearly every one of my ARs from individual components, in recent months, I have gone to almost all factory ARs. Frankly, since BCM started selling uppers again in 2008, I’ve been tinkering with fewer and fewer uppers – prior to that, I just couldn’t get all the features I wanted at what I thought was an easily affordable price. Now, I don’t have that problem.
In that time, I’ve used primarily one upper receiver action block – a plastic one sold by Model 1 Sales. I have no idea exactly how many uppers have been assembled and disassembled using that block, but it’s been starting to show cracks and definite signs of wear for quite a while. In addition, when I attempted to disassemble an upper which had been “loctited” together by someone else, the amount of flex allowed by the polymer block didn’t help my cause – eventually, though, I did “win.” However, I’m sure that these extreme stresses were a major factor in the current state of that action block.
That said, I’m perfectly happy with its performance, especially for the $25 that I paid, and it would serve the vast majority of “home tinkerers” well.
When Tom at Spike’s Tactical told me about the action blocks he made to assemble the Spike’s uppers, though, I knew I wanted one. Similar in design, but not identical to, the DPMS Panther Claw, their blocks are machined from 6061 aluminum, tumbled, and then anodized in a type III hardcoat. The end result is a block that doesn’t allow nearly as much flex and enables more consistent torquing of the barrel nut. In addition, it’s more compatible with a variety of uppers that don’t follow either the A2 or M4 pattern which my other action block was designed for.
If it looks like the block isn’t brand new, well, I started using it about 30 seconds after I pulled it out of the box, and only stopped to take pictures about a dozen assembly/disassembly cycles later.
The block has come in especially handy with the Noveske cutaway receiver, upon which I am careful to not over-torque a barrel nut. As you can see, I’m using a scrap barrel nut that doesn’t require indexing with the gas tube. I keep torque below 20 ft-lbs with this upper, as it rarely sees more than ten shots before it’s torn down and reassembled with another barrel.
So, should you buy this action block? Well, I have no idea what it’ll cost (probably a good bit more than the $50 DPMS Panther Claw made of polymer) or when it’ll be available (hopefully soon). I can’t say that people building ARs in their garage absolutely need one of these, but it’s definitely a welcome addition to my AR tool collection, and one that’ll see a lot of use. The lack of flex has already allowed me to disassemble an upper that I found nearly impossible to disassemble with my old action block. In terms of aggravation avoided, it was worth its weight in some rare earth metal.
It’s my understanding that this and some other high quality AR tools will be available from Spike’s at some point in the future. If you’re the type of guy who wants the best tools, regardless of cost, keep an eye out; you’re not likely to be disappointed with what they have to offer.