Do Sharps Bros lowers fit TacFire uppers?
Sharps Bros lower + TacFire upper: yes, they fit
Yes. Sharps Bros AR-15 lowers fit TacFire AR-15 uppers. Both are AR-15 size receivers. A real mil-spec keeps AR-15 receivers from different makers close, though not exact, and fit problems show up most when the upper and lower come from different makers. We checked them with the rules the AR builder runs.
One exception: Sharps Bros AR-15 lowers are a smaller frame and do not fit TacFire AR-10 (.308) uppers.
Fit comes from the same rules the AR builder runs on every part you add. Build data only ranks the setups; it never decides fit. Checked October 31, 2026.
Our take
Most built setup: the Sharps Bros Showdown Stripped lower with the TacFire 7in Upper 5.56x45mm 1:8.
TacFire is one of the most picked upper brands on Sharps Bros lowers.
Sharps Bros makes billet receivers with bold styling like the Livewire, plus AK receivers and pistol grip modules.
Founded 2012
TacFire is a dealer only wholesaler, so you'll find its stripped uppers, lower parts kits and AR kits at online retailers, not on its own site.
Sharps Bros lowers and TacFire uppers by platform
Each row is checked on the most built part of that platform from each brand.
| Platform | Fit |
|---|---|
| AR-15 | Yes, they fit |
| AR-15 lower + AR-10 (.308) upper | No, they do not fit |
AR-15: yes, they fit
Both are AR-15 size receivers. An AR-15 lower takes the upper's 5.56 NATO.
Checked on this Sharps Bros lower
Sharps Bros Showdown Stripped Lower Receiver$284.95and this TacFire upper
Tacfire 7" Upper 5.56x45mm 1:8$258.99AR-15 lower + AR-10 (.308) upper: no, they do not fit
The lower receiver (AR-15) cannot support a AR-10/.308 build.
Checked on this Sharps Bros lower
Sharps Bros Showdown Stripped Lower Receiver$284.95and this TacFire upper
Tacfire 20" Upper .308 Win 1:10$391.44Most built Sharps Bros lowers and TacFire uppers setups
Ranked by how often builders pick the exact pair. Only pairs our rules pass are listed.
#1Yes, they fit49% of these buildsCheck fit
#2Yes, they fit8% of these buildsCheck fit
#3Yes, they fit5% of these buildsCheck fit
#4Yes, they fit4% of these buildsCheck fit
#5Yes, they fit4% of these buildsCheck fit
#6Yes, they fit1% of these buildsCheck fit
#7Yes, they fit1% of these buildsCheck fit
#8They fit, with a catch1% of these buildsCheck fit
Watch the frame size. Builders also pair parts our rules say do not fit, like these two: Lower Receiver (AR-15) cannot support an AR-10/.308 build.
What Sharps Bros and TacFire say
Sharps Bros: Sharps Bros AK receivers have an integrated AR buffer extension, a feature it patented in 2014, so you can run AR stocks.
Sharps Bros: The Sharps Bros Showdown lower works with all mil-spec internal parts and other aftermarket mil-spec upper receivers.
Sharps Bros: The Sharps Bros Gen 2 Hellbreaker, Warthog and Jack lowers take any standard AR-15 lower parts kit and mate with any standard AR-15 upper.
Sharps Bros: The Sharps Bros Showdown takes PMAGs, Hex mags and other standard capacity AR mags, and it uses a threaded bolt catch pin.
TacFire: The UP01C stripped upper is 7075-T6 aluminum with a black hardcoat anodized finish and M4 feed ramps.
TacFire: TacFire's 18 inch .308 complete upper is designed for the AR-10 style platform and sold with a bolt carrier group.
TacFire: TacFire's UP01C stripped upper comes with the dust cover and forward assist installed. It still needs a barrel, BCG, charging handle, handguard, gas block, gas tube and muzzle device.
Fit is judged from the specs retailers list, which can be missing or wrong. Confirm with the manufacturer before you buy, and have a qualified gunsmith check any build before you fire it.
Other uppers builders put on Sharps Bros lowers
- Sharps Bros lowers + BCM uppersMost picked
- Sharps Bros lowers + PSA uppersThird most picked
Other lowers under TacFire uppers
- PSA lowers + TacFire uppersMost picked
- Smith & Wesson lowers + TacFire uppersSecond most picked
- Wilson Combat lowers + TacFire uppersThird most picked
- Aero lowers + TacFire uppersFifth most picked
Sharps Bros lowers and TacFire uppers: questions builders ask
Will a TacFire upper fit a Sharps Bros lower?
Yes. Sharps Bros AR-15 lowers fit TacFire AR-15 uppers. Both are AR-15 size receivers.
Do I need a matched upper and lower?
A real mil-spec keeps AR-15 receivers from different makers close, though not exact, and fit problems show up most when the upper and lower come from different makers.
Does a TacFire AR-10 upper fit a Sharps Bros lower?
Sharps Bros AR-15 lowers are a smaller frame and do not fit TacFire AR-10 (.308) uppers.
Why might a TacFire upper feel loose or tight on a Sharps Bros lower?
Some play between an AR-15 upper and lower is common, but it can get excessive when the two come from different makers, and a tension screw or an Accu-Wedge takes it up.