DPris

The .357 version uses stainless steel instead of aluminum, which should resist stretching longer.

Frame stretch can & does occur in some steel-framed revolvers over time with heavy use of magnum loads, but it's typically more vulnerable in small framed guns with less material to resist possible stretch.

Denis

Waveform

ChrisLCR - No, I'm not the guy in the YouTube video. But it only took 15 rounds to do the damage I had. Maybe it was the ammo....we'll never really know.

I didn't have to get Ruger CS involved since this was a Davidson's gun. Davidson's had a new one in my hands in 24 hours. I didn't have to send the old in first or jump through any hoops. My LGS took care of me - I walked in and showed them and they made one phone call and next day I had my brand new LCR. I'm sure Ruger CS would have taken care of me too but I would have to have sent in the old for evaluation, etc.. Kudos to Davidson's on this one.

I have shot some Hornady Critical Defense +P, 110 gr. with the new LCR and have had no problems. And I can shoot regular .38 spec. all day long with no issues and that's what I shoot almost all the time anyway.

Wave

Waveform

Denis - Do you suppose this Remington HD +P was hot enough a load that the frame stretched at ignition by a few thousandths but contracted immediately after? So it's not a stretched frame that stays stretched but enough elasticity in the polymer frame to allow a slight stretch that in turn allowed the flame to cut the top strap? I did measure the BC gap with a feeler gauge before the old LCR left the shop and the measurement was within industry standards, I think 5 or 6 thousandths. (I'm no gunsmith so my measurements are suspect!)

I noticed S&W puts a little piece of steel in that spot on the frames of their AirLite. Perhaps for a good reason.....

DPris

There are different formulations of metals used across the brands, the stainless that S&W uses, for example, may not be the same formulation that Ruger uses in a comparable part. Same with aluminum, and even with polymer/plastic parts. Ruger uses a different version of plastic in their frames than Glock, for instance.

Materials composition can & does determine the capabilities of a given part in a given application, Ruger's alloy frame in the LCR is not precisely the same as Smith's in their alloy revolvers.
Ruger hasn't seen a need for a blast shield in the LCRs, S&W does with some of their alloy revolvers.

Caliber & intensity of the blast through the barrel/cylinder gap (pressures & gas velocities) are additional factors that can either create or accellerate flame cutting in the frame.
The type of particulate matter in the gas itself from the powder used as it burns can be another factor.

I've done some limited testing on ported guns to check for particulate ejectae & found it can vary with the gun & the ammunition.

Barrel/cylinder gap can be another factor.
So can an improperly cut forcing cone that may be shaving bullets as they jump the gap.
Ran into that with the early 4-inch SP101s in .22 LR last year, and I have a converted Nagant revolver that shaves bullets & creates ejectae that impacts the frame around the cone.

So, if you had a combination of the above factors it could add up to the results experienced.

The materials used in the gun can have elastic properties to a degree, in allowing some minor temporary stretch (as brass cases do in chambers on ignition), but it varies between materials.
Steel frames CAN stretch & stay stretched over time & high-volume use.

It wouldn't be stretch in the polymer sub-frame that'd affect B/C gap, it'd be stretch in the alloy frame that houses the barrel & cylinder.

I'm not a metallurgist, but aluminum has less stretch & springback capability than steel (as a GENERAL statement), and I can't see the alloy LCR frame stretching enough at ignition to widen the B/C gap enough to contribute significantly to the problem and then returning to original form.
There have been sporadic reports of flamecutting in the .38 LCRs, but the vast majority seem to be holding up, and Ruger's selling a bundle of them.

When it does happen, could be a bad run of frames, could be a combination of that & some of the above factors.
Denis

Waveform

Thanks Denis - I appreciate the expert's input on this. You mentioned an improperly cut forcing cone and the presence of "particulate ejectae" and that caused a little light bulb to go off in my head. When I had the damage occur to the old LCR I was at the range with a friend who wasn't shooting but standing close behind my right shoulder. He commented that there was "stuff" spraying out when I shot - apparently a few bits had bounced off the divider between range lanes and hit him. That may have indicated there was an issue with the forcing cone, no?

Wave

DPris

Could easily have been.

You'll always get gas escaping in a 360-degree circle between the the forcing cone & cylinder in a standard revolver type, but if "hard" material in the form of particulates large enough to bounce off a divider & noticeably be felt by somebody behind you is occuring, something's wrong with the cone, the gap, or the chamber/cone alignment.

If the particulates are that large & that substantial, you'd be getting the equivalent of highly concentrated high-temp sandblasting on the frame directly above the gap, since that's the nearest point of metallic contact to the gap.

Again- the powder type in the rounds fired could have contributed. I wouldn't hazard a definitive statement that the problem was entirely the ammo, or entirely the gun.
Denis

pizzapablo

I have not heard ANYTHING from Ruger. I reckon I'll have to contact them, again.

I went to the range, last week and the same thing happened. Only when shooting +P ammo, left handed, from retention, did the cylinder come un latched. It did not fall, but opened just enough to disengage, but unlatched it was.