Just Right Carbine (JRC) in 40 S&W---anyone shooting cast boolits

[brown bass hunter]

I have been looking at the Just Right Carbine in 40 s&w for a while now. I want to shoot cast boolits in it and just wandering if anyone here in the cast world has any experience with this. Thanks

[Reverend Al]

Well, I can't advise you on the .40 S&W version, but last year I was offered a screaming deal on a nearly new JRC in .45 ACP and I absolutely love this little carbine. The accuracy is amazing and even offhand at 15 to 20 yards it's not too tough to throw them all into one big ragged hole. This thing shoots! The funny thing is that the company recommends only using jacketed bullets and mine isn't at all reliable with factory round nosed hardball (I tested some WW and Federal factory 230 RN hardball in mine initially) and it jams and stovepipes at least one round per magazine. With some cast 200 SWC (COWW) that we had with us it was equally as accurate but functioned 100%. Go figure ...
I'd highly recommend the gun though and I'm sure with very little "tweaking" of the loads and adjusting the COL I'll find the "sweet spot" for mine.
PS: I just ordered 3 extended length Glock mags to use in mine (pinned to 10 rounds capacity to be Canadian legal of course!) as the standard length factory 10 shot Glock 21 magazine that came with the gun is a little bit awkward to change with my big fat "meathooks". Just sayin' ...

[brown bass hunter]

Thanks for your input Reverend Al. I have considered the 45 acp also. It is good to hear you found a cast load that will cycle in the JRC. I have been checking on the high cap Glock mags and they seem to be fairly easy to get now. Good luck and keep shoot in the high north.

[Dthunter]

I use cast for my 45ACP as well.
I have loaded the ammo to match pistol velocities in the carbine length barrel. The rifle be omes very reliable once the 750-800 fps (pressure range) is reached.

If I shoot my 200grain RN cast, or jacketed much past 800fps, the stove pipe issue starts to reoccur.

[Forgetful]

I get stove pipes and FTF with 180gr american eagle in my JRC40. Am looking at RN molds to hopefully solve the FTF's. Did any of you have any luck with cast boolits in this carbine?

[Tackleberry41]

I have a mechtech upper in 40. Havent had any issues with FMJ or cast thru it. Be it whatever random store bought, 170gr cast out of a lee mold, or heavy 200gr XTP, it doesnt seem to care what you put in the mag.

Not seen a RN 40 mold, everything I have seen is flat nosed to fit in the case and magazine. I looked, couldn't get a 40cal 1911 to not jam, RN would have helped alot.

[Prospector Howard]

The JRC 9mm we're shooting has a pretty steep feed ramp. Round nose boolits are the only type that feed well in it. I've had better luck with my reloads than factory rounds as far as feeding and jams, also.

[Tackleberry41]

Makes you wonder how much testing they do when designing something like the JRC. You would think getting the feedramp right so it would feed a wide variety of ammo would be a consideration. I dont keep something like a 9mm thats picky about ammo.

[Forgetful]

Makes you wonder how much testing they do when designing something like the JRC. You would think getting the feedramp right so it would feed a wide variety of ammo would be a consideration. I dont keep something like a 9mm thats picky about ammo.

There are problems with unsupported headspace in the 40S&W, limiting ramp depth. I briefly thought about adjusting the ramp and after a bit of research I just wanted to get rid of it or find RN bullets.

[Deadpool]

They fixed those issues with a heavier buffer, new ramp on magwell, and new ramp on the barrel. I reload the 40S&W JRC (cast) and it's awesome. Zero jams! I had similar problems as described above, and after the replacement parts came in (free of charge from JR) factory ammo performs flawless and brass comes out clean. It was biting the brass and folding it and crimping it on ejection, but that all changed. Now I use longshot (I get 1450-1500fps with 180gr on my 18" barrel with that) and am trying similar speed powders.

[Tackleberry41]

There are problems with unsupported headspace in the 40S&W, limiting ramp depth. I briefly thought about adjusting the ramp and after a bit of research I just wanted to get rid of it or find RN bullets.

Guess thats a difference in the mechtech, they supply a little feed ramp that drops in the frame to guide from the mag into the chamber, not much need for a feed ramp in the barrel that way. So no unsupported case. Like I said one would think if someone was going to design a gun from scratch something so obvious would be a consideration. I looked for a RN 40 cal mold, only way I have seen would be something custom.