There are a few obscure guns that have managed to hold my interest over the years. For example, I still find some of the last 1911 variants used by the USMC intriguing, particularly the MEU(SOC) 1911s that were rebuilt and rebuilt and rebuilt over the years by Precision Weapons Section at Quantico. What I found most interesting about the MEU(SOC) guns was that they used a recipe that mixed parts from nearly every major custom 1911 maker - Ed Brown safety and beavertail, Wilson magazines, Caspian slide and magazine release, Bar-sto barrel, Cylinder & Slide trigger and hammer, the list goes on. Interestingly, the USMC couldn't build enough of these pistols to meet demand, and so at varying times added a mix of Kimber, Springfield Professional, and Springfield Custom Shop pistols to the force. Later, these pistols would be succeeded by the short-lived (and less interesting to me) Colt M45A1.
Among long arms I've long had an interest in some of the more obscure Russian assault rifles, particularly the AN-94 and AEK-971. I've posted about some of these less well known rifles before (though perhaps the AEK-971 and AEK-973 will gain more notice after this recent news). I thought Larry Vickers' video series in Russia where he shot the AN-94, AEK-971, AK-12, and AK-400 was terrific.
And, of course I still think the HK G11 is super cool (as well as the other ACR Rifles). The ACR competition kicked off in my youth, and I scoured the gun magazines of the day for as much information as possible on these rifles. These are very much the rifles of the future that never came to pass.
What obscure firearms and variants still hold your interest?