Building Out Your TAC-9 Receiver (blog entry for FAQ and build data)
This lower is very tight on some standard Aero precision uppers I have, has a ambi magazine release which I like, wouldn’t accept a strike industries anti walk pin set but this lower is very tight and should work great once it’s broken in.
Only time will tell but so far this lower has functioned exactly as I hoped. Putting it together was just as easy as using an aluminum lower. Fit and function has been good so far. Plan on attempting a 308 very soon.
The lower seems to be very durable, however the extractor was too tall by about 3mm (this could have been tolerance stacking however) on top of this though, there was too much material at the forward end of the threads for the buffer tube resulting in the lower rubbing on the bolt carrier. I was able to fix my issues with a dremmel.
However this lower took about 3.5 weeks to ship to me.
This receiver looks great and is really light. I installed an Unbranded AR ELG LPK and Strike Industries Anti Walk/Rotation pins with no issues. I used a buffer tube with the anti tilt retaining ears as suggested. I do not believe a tube without the retaining ears would have worked at all for my build due to the placement of the buffer retainer hole. I finished out the build with a Zaviar Complete Upper from 22Mods4All. This upper required major adjustments at the pin holes and buffer tower. It took me a couple hours sanding and filing little by little to get a fit that was just right. Things are still a little tight, but it will break in and loosen up with time. I chose an FM9 BCG for the build which also required major fitment. The ejector was sitting much too high and required much more to be filed away than was implied in the TNArms instructions post. After filing the ejector and checking clearance repeatedly, I finally got to an acceptable clearance. Test firing the rifle went great overall. The receiver held up well and functioned as expected. My final feedback is on magwell clearance. The magwell allows enough slop on Glock mags that if the gun is not held completely flat then the mags cant left or right just enough to cause the bcg to smack the back of the mag. Both of my metal lined Glock mags got damaged and required filing to repair. I did find that Magpul GL9 mags fit much tighter in the magwell, which reduces the slop and prevents the mags from canting far enough to be damaged by the BCG. I will be using Magpul mags exclusively in this lower going forward.
Overall the receiver works well and is very functional for the price. If you pick this up then be prepared to put in the time and patience needed to make it a perfect fit. Regardless of the issues I had, this lower is still a very solid option for a lightweight and/or budget build.
So far tight but good. Use lube and will have more info when upper ships. Seems very solid.
Went together easy, but it fit very tightly had had to use a lot of lube. Also after a breakdown to clean the front pin hole broke. The pins fit so tight I don’t see it being a problem but it’s annoying.
Lpk went in without issue, everything is to spec.
Has a sweet built in ambidextrous magazine release.
Now whether or not it will survive a years worth of shooting we will see, I'll update this review if possible if it survives a couple thousand or breaks.
Works great. All holes to spec.
The receiver had a month delay before shipping which was a bummer but not a deal breaker. The receiver itself fit much like the standard receivers, but with a few key differences that lost it 2 stars.
1. The fitment of the take down pins: The rear detail from the upper receiver would not this lower without significant modification. These are molded for a tight fit and some minor touchup, but much more material was required to be removed from this lower than any I've bought thus far (over 10).
2. Magazine fitment: The lower itself had a flaw such that magazines placed into this lower lock, but have a certain amount of front to back movement. The magazine itself will fit and feed correctly as placed into the lower, but can rock into a position that will force the magazine out of position and result in a significant number of jams.
The magazine well is slightly over sized resulting in the condition described. The 9mm round tilts nose up, jams against the barrel face and bolt carrier. 5 hard jams in 4 mags, Glock Pmags and KCI mags were tested.