KelTook
When what's mine is mine and what's yours is also mine
Note:
The KP50 is also know as/has been known as the P50, so that’s what it is called in this article.
Stuff and Things inc. is abbreviated STINC
Keltec Recently released an updated version of the P50 called the MP50
The main change from the P50 is the removal of the fold open to load setup the original design had.
This was seen at release as “a little silly but you have 50 rounds”. Similar to something Stuff and Things made the PP Bizon clone.
A major Idea behind it’s development was to make reloading during any potential engagement less likely.
The P50 was released to limited excitement and fanfare. From my memory, it was adored by the usual oddball gun fetishists like myself. Seen as impractical but cool. Especially if you already had a p90 and the mags to match.
TheP50s were released at about 1200-1500$, Way too much money for most people and quickly dropped, Blems were selling shortly after release for 499$, once these became cheap, many people began to tinker with them, We can assume that’s when someone from Stuff and Things INC picked one up.
We are going to skip over a lot, but here is a basic timeline.
In around May of last year, STINC began shipping their lowers…
Trip kits for followed in October.
Just from my personal observation, Once these kits hit, anyone who had a P50 bought one and was using one, it changed the gun from something destine for the forgotten pile to pretty compelling replacement for an AR57 or other 5.7 sub guns.
Where Things Get Seedy
It is very hard to argue that these are independent designs. Especially when the official instagram account for keltec has posted the ST50, and did so early in 2025.
Ok? It’s their gun why should we care?
In my opinion it’s fair to not want to care, but let me try to convince you to…
Hoffman Tactical Invented the super safety, and immediately made it free and open source, It has objectively been the biggest development in the 2A space in decades. It is 100% free, and anyone can make and sell them
He had his design stolen (in a much worse way than what’s going on here) and is now being sued for patent infringement on his own design.
Please donate money to his legal defense fund if you can.
s3igu2 took Hoffmans open source design and came up with the Leber V2. If you wanted a full fun MP5 (it also works in some models with similar lowers), he’s the reason you can afford it now.
For some reason, A random boomer took his design, added a logo and started saying
“After extensive testing and refinement, it’s finally ready for prime time.”
(What’s even funnier is s3igu2 is creating a more accurate HK style lower for the leber.)
Beside the blatant misrepresentation of who actually developed and tested this, misrepresenting designs like this can be dangerous*.
In both these examples, major developers and the beta testers who helped get their work off the ground completely lose credit and have no motivation to continue sharing their open source designs. All they asked for on release is to help future development work and sometimes they just want credit, if that. What the developers have received in return in Hoffman’s case is going to probably be a multi year legal battle, and in s3igu2’s case is a (relatively) minor annoyance that discourages future development and sharing.
Lets Refocus back on STINC,
Keltec produced the P50 → STINC takes the design and does a lot of work to make it work with an AR FCG→ Keltec takes the STINC design and features it at trade posts and on their social media, reviving interest in the P50 → while this is happening STINC releases a trip kit so it works with FRTs. → Keltec out of the blue Releases their own version, with a rename, while also copying the mag couplers.
How is Keltecs different than the STINCy version:
Metal
From what we can tell a non-AR FCG
What motivation does STINC have now to develop any more designs if a larger company can just swoop in and take credit? They are a large reason there is ANY interest at all in the P50. They are probably the sole reason Keltec is creating the MP50 model as well. Is the industry better when people like STINC don’t release their guns/kits.
Keltec’s original design
STINC’s new lower.
Could you please let me know where you can get a Groza before STINC came out with one?
Could you also let me know where to pick up a Bizon before STINC made it happen?
The Gepard? These things were super common place beforehand. /s
Oh wow, it’s not like any real companies collaborate with people that small anyway! Your asking for too much from the big guys!
While still a early prototype, because the geniuses at STINC were able to get Helical mags working, BnT is prototyping with their magazines. They didn’t just buy a few and then copy their design. They are working with a smaller company to make interesting things happen.
What can Keltec do to fix this mess?
Honesty, I would have just wanted them to credit STINC with the design. Even better if they get STINC to OEM some of their parts. There are good reasons to release a model officially under the brand and not as a kit. Most owners don’t want to tinker.
Now that the cat is out of the bag, I’m not sure what they can do to make it right. I’m also not sure what STINC wants and what they would have preferred happen. It almost certainly isn’t this.
Bringing it home…
Do you like weird shit? Support developers.
Do you like cool shit? Support developers.
Do you like interesting designs? Support developers.
Do you want the firearms industry to get better year after year? Support developers.
Do you like the little guy? Support developers.
Do you want New guns and not just more AR15 clones? Support developers.
Supplementals
KelTec KP50 & MP50: New 5.7x28mm Carbine at EnforceTac 2026
*
*A new design for a MPA/MAC FRT , many people have already started selling it, with no design changes, even though the current design has major problems with “consistent OOB Detonations”. 9mm out of battery detonation are not super dangerous, but can injure or even in a worst case blind you. The fact that many sellers aren’t advertising it’s deficiencies is troubling to say the least.
I will be reaching out to parties for comment and will include them if received