Spike’s Tactical ST-15 Lower Receiver Assembly

Last month, I wrote about the excellent, and affordable, Spike’s Tactical M4 LE upper receiver assembly. I was so impressed with it that I decided to pick up a stripped Spike’s Tactical ST-15 lower receiver. Now, I have two requirements for lower receivers: the magwell must be sized properly to drop free Magpul PMags, and all of the holes must be drilled in the right place. Anything else, such as a pretty finish, is nice, but unnecessary. I was pleasantly surprised to find that the $105 ST-15 receiver met not only my criteria, but it also had a good, even finish.

Only a few days later, though, I was contacted by Spike’s Tactical to do a T&E of their new enhanced lower receiver parts kits. Among other things, the “enhanced” kits have nickel boron plated fire control groups. Nickel boron is a coating used by FailZero on bolt carrier groups and is purported to reduce lubrication requirements – eliminate them, actually, but I’ll stop lubricating my weapons when the owners of FailZero plate the internal components of their cars’ engines with nickel boron and stop using oil in them (I do realize that there are other considerations with engine oil- just go with me on this). Now, don’t get me wrong – it definitely does have a “slick” feel, and the FCG is devoid of any grittiness whatsoever. I would just continue to lubricate any critical part that was plated with nickel boron, such as a bolt or bolt carrier.

Along with the nickel boron fire control group, though, was a lower receiver! This one was of a slightly different design than my other ST-15 lower. It also came with quite a few additional goodies, as you can see here.

Love it or hate it, the Spike’s Tactical logo adorns this lower. Although I’m generally freaked out by spiders, I actually like the logo.

Though I don’t use a magwell grip, for those that do, the front of the receiver has been machined to provide additional grip.

KNS pins and a billet enhanced trigger guard are also options.

The receiver is of the “low shelf” design and will accommodate a registered drop in auto sear. The trigger, hammer, and disconnector have all been plated with nickel boron. Also note, on the extreme right, the staked receiver endplate (Magpul ASAP).

I highly recommend the Spike’s ST-T2 buffer in all carbine gas system AR-15s. This lower comes standard with one, which resides in a six-position mil-spec diameter receiver extension tube.

The Spike’s Tactical ST-15 lower assembly is pictured here with another excellent quality lower receiver assembly, the Bravo Company BCM4.

An ambi safety, Magpul CTR stock, Magpul MOE grip, and Magpul ASAP sling plate are also available.

The ST-15 lower receiver fits the M4 LE upper receiver assembly perfectly.

It’s interesting to note that even with all the extra features and attention to detail of the Spike’s Tactical upper and lower assemblies, they’re still cheaper to acquire than the average Bushmaster or Rock River found at a local gun store or even online. I’ll be putting the lower to good use at the range this weekend and will update this post accordingly.



Filed under Firearm Components

4 responses to “Spike’s Tactical ST-15 Lower Receiver Assembly

  1. RJ Rivero

    I have been using Spike’s Lowers for the last 3 years. I haven’t had one yet that had any “issues” with them.

    I’m interested in these Coated Lower Kits and am interested in hearing what you think of them.

    Is there any “grittiness” or excessive “creep”? Is the trigger break nice and crisp? How would you compare them to other triggers you’ve used?

  2. Andrew (Vuurwapen Admin)

    It is a very crisp break. It’s not a match trigger, but it’s incredibly smooth compared to “standard” GI type triggers.

    There is practically no discernable movement in the trigger prior to firing. You simply put pressure on the trigger until it fires. No grit whatsoever.

    This is very impressive considering that the trigger has yet to wear in or “break in”.

  3. Frank Nowakowski

    I recently bought two of their lowers. After mating them to a couple of 5.45×39 uppers I can say I was VERY pleasantly surprised.

    Everything fell together fine, no issues at all.

    Nice finish, and all the Spikes supplied pieces/parts appeared first rate as well.

    Fn in MT

  4. Dave

    I recently met the crew at Spikes. Very nice people and you can’t go wrong with a lower at that price. I’m pleased to hear that you’ve seen good results with yours.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s