No agency ever dropped the weapon because it got too hot for training, and a small group of people used to compete in even IPSC with long barrel P7M13s. It may not fit the current training paradigm of shooting a large volume at a very close target, but the gun worked incredibly well for what pistols are used for.
Ah, so it fell from favor because of the 'spray and pray' crowd, and not because there was a single flaw with the product; gotcha. Everyone was just too stupid or something to continue buying & using the guns, or anything remotely similar.
The basic idea of the R51 design is to use a hesitation lock to allow a fixed barrel 9mm pistol to be made less expensively than other designs.
I'm afraid you are
badly mistaken. Remington never promised, nor even suggested, this design would undercut budget recoil-operated 9mm's by some virtue of its design. On the contrary, it really surprised (and greatly worried) most people following its development when the sub-400$ price point was announced. They especially did not make this economy the primary selling feature, which was odd given its objectively low price point. No, instead they claimed their product would;
-Have a lower bore axis than the competition
-Less felt recoil than the competition while being able to shoot +P ammo
-Have a weaker recoil spring than the competition for easier manipulation
-Easily mounted suppressor (the AAC silencer equipped version was a constant companion to the plain model from the get go)
-Be more ergonomic & carry friendly than the competition, also better looking to those not stuck in the dystopian 80's (curves not blocks)
-Bring back a mostly forgotten but beloved operating system/pistol name as a unique flagship to their more mundane RM380s, the Glock clone they'll be offering soon, as well as the 1911s
What's funny, is that absent the reliability & trigger feel issues that directly resulted from a damning lack of quality control, they essentially delivered on all but the silencers. The above are why so many people were so excited about the gun prior to its debut, by the way; had the quality been anything but contemptible it would have been a smashing success...which is why the conclusion that ultimately came about is so frustrating. My guess is that Remington's experience with Para 1911s convinced them that consumers simply won't pay more than 400$ for a handgun for any reason in quantity, and they modified their business plan accordingly. They clearly failed to realize the unique attributes of this gun warranted a more luxury product, at least initially.
The Gen2 is closer to working correctly than Gen1, but neither seem to work as reliably as the .45 M53 the Marines tested 100 years ago.
God, if only someone could have impressed this upon the Remington VPs prior to the initial rollout (or the second gen rollout), that substantially similar guns had been made previously and would obviously be compared to the new model, and that therefore they had better do this new version right, at least initially. Sadly, the Remington of 100 years ago scarcely resembles the one of today. Still, even in those days of expensive manufacturing done manually, the Model 51 was notably well made among its peers, and fairly expensive compared to its blowback competition. Since a more pedestrian variant was never made (the Model 53 is externally, but I doubt anyone really knows much about its innards anymore), it's hard to say if this level of quality was crucial to its success, or merely bolstered a solid design's reputation further. I suspect it is somewhere in the middle like all other designs, since the crummy R51s still generally run despite all their fabrication issues.
That could be because chamber pressures for 9mm are so much higher than either .380 or .45, or it could just be the manufacturing and materials.
Once again, with short-chambered barrels with the texture of sandpaper and rough tool marks & debris all over the operating parts,
no pistol will function well. Now that the Gen 2's are being made not quite so horribly, but still to objectively low standards, performance is much better but not great or consistent. Who'da thunk it?
The R51 is a gun with a short trigger pull and no safety, which seems crazy. The barrel is "fixed" for accuracy, but I can't tell how tightly the barrel fits. Ideally, the barrel would be pressed into the frame for accuracy, not just held by the slide stop pin. Like a PPK, Mak, B-76 or P7.
The gun has a manual safety actuated by the palm instead of the thumb. It's hardly unnoticeable like a 1911's spongy grip safety, nor insignificantly light like Glock's, it's a very distinct 'snap' not unlike the P7's only about 8-10lbs and not fifteen or whatever the cocking mechanism clocked in at. Once depressed, less force is needed to hold it down (again, like the P7 which doesn't force a death grip throughout the trigger pull). The feed ramp boss on the barrel is shaped to fit into slots in the frame which largely constrain its motion in all directions but along the barrel, which is fixed by the insertion of the pin. The slide nose is about as close a fit as any common recoil operated semi-auto, and when fully forward tightly controls the barrel's heading (they are not independent of each other, though they technically could be with a tight frame slot fit). Since the guns are quite accurate as-is even given their humble manufacture, I don't see how a more rigid connection would improve upon this, but assuming it would, I suppose it would be an improvement; it would also make servicing the gun far more difficult. Not to mention that it would probably impact reliability and accuracy of the actual guns negatively, given that the slide is somewhat loose on its rails vertically (somewhat necessary due to the aluminum/steel interface, but mostly due to Remington not polishing the rails in any manner & seeking to reduce wear from these nitrided tool marks on the soft anodized aluminum)
The aluminum frame is a good thing - polymer fixed barrel guns are not going to be rigid enough for great accuracy, and frame rail wear is less of an issue with this sort of action. However, the shoulder that stops the breech block should probably be a steel insert, like how a Sig P220 has a steel locking block in its aluminum frame.
The steel insert bit is probably true were the gun being designed for a long life (spoiler; it wasn't). But to Remington's engineer's credit, it doesn't appear that anything but abrasive wear is occurring on these surfaces --which you have to admit is a bit surprising since the locking surface is about 1/3rd as strong in direct bearing as your average 1911 which also has about twice as much surface contact. There's something interesting happening very quickly before the bolt locks in the R51, because you shouldn't be able to hammer on 7075 like that and not see peening or rounding after even single shot. My gun, at about 500 rounds, only ever showed peening where the disconnector slide over the soft MIM bolt body (the bur in turn carved a shallow groove in the aluminum frame, but did not deform it) and it was self limiting. My only guess is that pressure has dropped a lot by the time the bolt locks, and the lug doesn't arrest the entire momentum of slide & bolt (just the bolt), effectively transferring a good portion of the cartridge energy in to the free-moving slide as opposed to the locking surface.
I think this pistol is hampered from being what it could be by the attempt to ape a cocked and locked design from a century ago while competing with Glock type triggers. Remington missed the chance to bring something new to the scene by trying to make something old.
Glock type triggers.. what? Remington was making something old yet aping modern Glocks? I'm kind of surprised you didn't think the frame was also polymer like so many folks out there*. Apart from some significant changes (improvements in my eyes) to the bolt/slide interface, practically every part in the gun looks just about identical to the original. I guess the vestigial slide safety was removed, but it was never used in practice anyway. The R51 is literally a scaled up Model 51 (or scaled down Model 53) that had more robust cam surfaces designed for it to prevent the cracking issues which killed many of the originals. The gun is hammer fired single action, but it is shrouded. There are two pivoting sears adjacent to eachother on the front side of the hammer pivot; the first lifts when the trigger is pulled partially and would otherwise stop the trigger at half-cock, the second lifts from the primary sear surface to release the hammer. Neither can move until the safety is depressed (which can actually screw with the function if you intentionally release the safety without releasing the trigger then cycle the slide)
For such a strong condemnation of the whole R51 concept in the face of 'what it could be,' your suggested improvement on that front is oddly absent. FWIW, I wholeheartedly agree; a nice polished blued finish (and polished/anodized/painted frame), steel insert or frame, a means to lock the barrel to the slide for disassembly, a superlative quality of internal parts, along with spare magazines & threaded barrels from the get-go, would have made the R51 a success for the ages. We'd be seeing them in spy movies by now.
TCB
*for whatever reason, there is a HUGE amount of misinformation about very basic aspects of the gun. Hammer fired, single action, aluminum frame, manual grip safety, 9mm. And yet you wouldn't believe how often you see someone claiming the gun has some combination of; double action, no safety, trigger safety (it technically does but is not the primary), striker fired, 45acp (maybe one day), and polymer frame. Really weird seeing mistakes like this from otherwise gun-knowledgeable people on a gun with so much documentation, but there it is. The Strike One is another that throws people for a loop, but it's a got a number of unique features and is still quite a bit more obscure in America.
