Remington R51

[1SOW]

- Snug roll pins or conversion to pin-screws (threaded pins with a slot head)
- Extended mag floorplate
- Machined grip panels (probably micarta or something similarly cheap/easy)
- Sight dovetail adapter or dovetail truing (to normal dovetail dimensions)
- Stippled/ridged/checkered grip safety (shimmed/centered in the frame)
- Replacement trigger stirrups

SAY AMEN to that list!

A fix for the rear sight due it's design, would be two allen set screws through the already flat plate on the rear sight. This would be an easy DIY permanent fix.

A more rigid grip safety with a smoother engagement would also be a great improvement.

Remington got mine back last Wednesday according to the UPS tracking info (using their overnight air package). I'd like to get some feedback from 'them', but somehow don't think that's going to happen.

I have missed all the details on the issues of the bullets hitting the leade/rifling, but that's not "UN"usual for a SAAMI Compliant pistol. CZ and even XD are both eastern European pistols with tight chambers, primarily cut for NATO RN bullets/ammo.
CZs in particular are finicky about some FN and/or JHPs that WILL hit the leade. Especially the conical nose bullets can be problematic. A simple 'plunk' test gives a go-no-go for those bullets loaded at that oal.

In my short test series, I used 124 gr Speer GDs, 124 gr Hornady XTPs and a long oal 124gr plated RN. They all fed smoothly without contacting the leade. On the other hand, I have no doubt the chamber needs 'smoothing/polishing' to improve the feed reliabilty.

In a perfect world, they'd send me a much later model that had actually been thoroughly QC'd----yeah, right.

I would PAY for a real trigger that actually fits and travels smoothly!

 

[cfullgraf]

Actually at this point, it is the bolt that is driving the slide.The chamber pressure drives the bolt backward and the bolt drives the slide. The bolt is angled downward out of the slide and is stopped by the locking ledge on the frame which locks the breech to allow chamber pressure to drop. The slide continues and recontacts the bolt at the lug on top, camming the bolt front down and raising the rear of the bolt over the locking ledge. Then both bolt and slide continue to the rear.

The main point of impact between frame and slide seems to be in front of the forward rails, as on the 1911.

Right.

But, based on my experience with other aluminum frame pistols and what I am seeing in the R51, I am more concerned with the wear at the step the lock the bolt.

While the bolt is not heavy, it is moving at about probably the highest velocity of the slide movement when it strikes the stop and then the bolt get raked over the step as the slide retracts it.

It is quite possible that the slide will peen over the front of the rails during repeated hits under recoil. The rails are tapered such at it will be a while before any peening will affect operation of the pistol. Of course, the reduction of the area due to this taper where the slide contacts the frame will increase the load/square area that the frame experiences.

For both, time will tell.

 

[JRH6856]

It is quite possible that the slide will peen over the front of the rails during repeated hits under recoil. The rails are tapered such at it will be a while before any peening will affect operation of the pistol. Of course, the reduction of the area due to this taper where the slide contacts the frame will increase the load/square area that the frame experiences.

For both, time will tell.

Yes, it bears watching. I don't recall seeing Pedersen address this in the patent notes. Since I'm pretty sure he expected steel on steel, that isn't surprising. I'll have to look through the patent again (the copy I have is 122 scanned pages and is not searchable).

 

[barnbwt]

Strangely, I see the least wear on the front of the locking step on the frame as anywhere. The rail issue is simply because the slide is very rough, and extremely hard. It's like sandpaper, and riding directly on aluminum. I don't know yet, but mine at least appears to wear rapidly if the rails aren't lubed, and I scarcely expect the slide to ever polish smooth as hard as it is. I could be wrong. As far as slide impact, I thought it bottomed out on the spring bushing (hence why it is needed) and the barrel pin catches the impulse, though I haven't really looked hard at the question.

TCB

 

[JRH6856]

The bearing surfaces of the rails can be polished. Have to get through the nitride, though and it will change the dimensions slightly so the slide will be just a bit looser.

I see wear and maybe some peening on the front of the frame below the rails. Whether from the slide or the bushing, or both, I haven't looked at closely enought to tell. (pic attached)

As to the front face of the locking block, impact force will deform it faster than non impact pressure. I'm kind of getting the idea from reading Pedersen's patent* that most of the impact force is carried by the slide and the breech-block is guided rather than slammed in and out of lock. That would mean there are some very close and precise tolerances between the breech-block and slide and breech-block and frame and a lot would depend on how closely Remington followed the original design in the R51.

* …a breech-block located within said chamber of the slide, and arranged for a relatively short recipracatory movement longitudinally therein for said firing-pin bearing, and coacting stop faces in the slide and block in position for liniting said reciprocatory block movement, and block-end lifting means including inclined faces in position and arranged for lifting one end of the breech-block at a time during the retraction of the breech action" (p53 ln. 120-p54, ln.5)​

 

[barnbwt]

"That would mean there are some very close and precise tolerances between the breech-block and slide and breech-block and frame and a lot would depend on how closely Remington followed the original design in the R51."

Something inside tells me, "not on this gun" . All the slide going into battery does is push down/forward simultaneously on the bolt, which eventually pushes it down and forward until it stops. The reverse is true, but the simultaneously back/up forces are due to slide momentum, rather than tremendous bolt thrust, so I doubt they could gall the locking block anytime soon. I do think the gun probably doesn't have the service life of a Browning, but that's just because a tilt-barrel really doesn't have any sliding surfaces (the barrel cam maybe on a Hi Power/Glock, but there can be tons on play in that geometry without really harming function). I think it's the nature of the beast (and a svelte beast it is ), as is the much softer shooting dynamics.

Lots of folks seem to think any alternative or even improvement over older designs has to be better in every way to even justify investigation, when that is simply not the truth of how innovation works. The Pedersen system seems to deliver much softer shooting at the expense of strength (essentially), which is why they chambered it in a 'reasonable' cartridge without tons of bolt thrust, put it in small, lightweight, ergonomic, and intuitive CCW package. If you want a truly rigid-locked breach that allows extremely high pressures and has tons of locking surface area to allow for enormous bolt thrust, a Browning tilt-barrel, rotating bolt, or single shot falling block are better choices. They will all kick harder than an action whose momentum fights itself, though.

TCB

 

[kefefs]

Reading these range reports...

All I can say is I'm glad I wasn't the Guinea pig for Big Green!

Same here! I lost a lot of trust in Remington after the whole ACR thing. I just got around to trusting them again and was really looking forward to the R51.

That'll learn me.

 

[cfullgraf]

I put another 90 rounds through my R51, total 390 rounds.

Only one hiccup, it spit a live round out again. This was again with an FMJRN set to 1.105 COL. I had forgotten to tap the back of the magazine to seat the cartridges to the back of the magazine.

I have not spritz some dry lubricant into the magazine as suggested by JRH6856. The follower may be sticking a little and not pushing up on the rounds evenly.

I've never experienced this with cartridges set to 1.13 COL (290 rounds).

It is definitely getting smoother and better with use.

 

[barnbwt]

This evening, I broke my gun in the name of science. Behold!, the attached file below:

TCB

PS; I'm starting a new thread to break down each component groups' function and apparent issues (hint, the disconnector design does in fact thoroughly suck )

 

[cfullgraf]

Interesting picture.