Extractor failure in XCR-L pistol

[captain92]

Whole Bunches, very interesting post. Thanks for the info!

[Sean K.]

Thank you for the post regarding uneven chrome lining. Time after time people say its uneven without giving any proof, in which case I felt from the words in their posts they were simply parroting old info. Here and there someone would say the state of the art in chrome lining has improved over the years. It is reminiscent of the fable about the blind men coming across an elephant for the first time and each describing what they feel the elephant looks like from each touching a different part...we are each reporting from our individual experience. I have sometimes wondered if the military way of gaging the throat to determine bbl serviceability is at least partially based upon the ease in which it can be done at even the smallest unit.

I'm retired Navy, but did spend 2 tours with the Marines, the last of which I was made an alternate armorer and took the Marine course in inspection and repair of firearms. Besides the inspection points/criteria of various wear parts, the Marines also had a standard of how many rounds could be fired before the weapon was turned in for what they called 4th Echelon Maintenance (4th Echelon units replaced barrels for example) (my medical unit armory was 1st Echelon...basically we could tighten grips screws and inspect and that was all), regardless of whether the firearm appeared to be in working order. IIRC 50,000 for the M16 and 24,000 for the M14. Based upon my bbl wear measuring of M16 and M14 barrels, there is no way they could go that long.

Now that I think about it...it may not have been that they were "uneven"....but then, it probably depends on what one means when one uses that term.

A few of my XCR bbl chambers were too tight. To me, that means the chrome plating process wasn't correct, resulting in either high spots or a uniformly too small chamber which caused extraction issues. Granted, that was now somewhere around 9 years ago. I don't know if the process has been significantly improved in the last decade or not....

[Whole Bunches]

Took the 7.5" 5.56 bbl pistol out today. Fired it with and without the linear comp and 55gr ball ammo and 50gr frangible ammo. Functioned 100% with and without comp with the normal gas setting for each type of ammo.. I did not expect that. Maybe it's well broken in now. Set gas to "0" and fired 55gr ammo. BCG would not lock back on the empty mag, but did eject the empty. Only loaded 1 round in the mag at a time, so I don't know if it would have chambered another round, but suspect it would have.

[fmunk]

.556

LOL. How's the recoil? Like a blow dart?

[Whole Bunches]

Our Robinson team shooters wear barrels out between 10 and 15k rounds. Those are stainless barrels running .556

When the team's barrels are worn out, what went bad? Accuracy no longer good enough? Throat visibly worn out? Velocity dropped? Gas hole in the bbl enlarged/elongated?

Thanks

[Sean K.]

That's the thing really....RA is not at all competitive on bbl costs. You can get a really good quality CHF bbl for an AR for around $300. It just sucks that RA's are $400+ for the -L (M's are more) and they aren't even really that accurate (though one could argue that's a result of the design, not the bbl per se).

[navalbeaver]

That's the thing really....RA is not at all competitive on bbl costs. You can get a really good quality CHF bbl for an AR for around $300. It just sucks that RA's are $400+ for the -L (M's are more) and they aren't even really that accurate (though one could argue that's a result of the design, not the bbl per se).

I agree, but at the same time you're getting an adjustable gas block(see below) along with the barrel. I love my XCRs but the cost makes it hard when everything AR is half or less.

Took the 7.5" 5.56 bbl pistol out today. Fired it with and without the linear comp and 55gr ball ammo and 50gr frangible ammo. Functioned 100% with and without comp with the normal gas setting for each type of ammo.. I did not expect that. Maybe it's well broken in now. Set gas to "0" and fired 55gr ammo. BCG would not lock back on the empty mag, but did eject the empty. Only loaded 1 round in the mag at a time, so I don't know if it would have chambered another round, but suspect it would have.

If you can shoot on setting zero(0) and have it cycle.... The dials aren't setup right ..... Unless you're running some really high pressure ammo. The adjustable gas block isn't adjustable at that point. What are the other 6 settings above "1" for? "Extremely fouled"?

In a perfect world, I'd say zero(0) is off (no cycling)and seven is running wolf in a dirty rifle. Have the higher end for weaker, unsuppressed ammo with the lower end for suppressed without launching the casing 60'

[Whole Bunches]

In regards to the gas dials, within a given cartridge, are the gas dials the same regardless of bbl length or do they vary by bbl length? I believe the lowest settings in my 5.56 dial on the 7.5" bbl seemed real small openings. It is my understanding that the gas pressure is higher the closer to the chamber you get (that is the gas port pressure gets lower the longer the bbl and the farther away from the chamber the gas port is). If they are the same dial per caliber, it would make sense that larger openings/settings would be used on longer barrels. In any case "0" should be off, that would make sense to me.

I run unsuppressed. I don't have a suppressor that is rated for a 7.5" 5.56 bbl. I would say my loads are not high pressure.

[navalbeaver]

In regards to the gas dials, within a given cartridge, are the gas dials the same regardless of bbl length or do they vary by bbl length? I believe the lowest settings in my 5.56 dial on the 7.5" bbl seemed real small openings. It is my understanding that the gas pressure is higher the closer to the chamber you get (that is the gas port pressure gets lower the longer the bbl and the farther away from the chamber the gas port is). If they are the same dial per caliber, it would make sense that larger openings/settings would be used on longer barrels. In any case "0" should be off, that would make sense to me.

I run unsuppressed. I don't have a suppressor that is rated for a 7.5" 5.56 bbl. I would say my loads are not high pressure.

I can't speak with authority on the sizes of the ports in the dials vs caliber and or gas system length, which also gets into gas port size as well as the opening in the gas block. The 300 dial does have larger holes and Sean posted data about specs for type 1 gas dials a long while back. I ordered the 3 different sizes of gas dials that were offered for the type 1 but had a hard time distinguishing them from each other and I don't know if that's because the sizes are so close or possibly got the wrong part (it's happened before). The info Sean posted was good to know but doesn't mean that it was followed when the rifles were assembled and sent out. I've got no clue on what the process is at RA but if there's test firing done, an over gassed rifle is going to pass muster unless they're looking for function beyond just "did it go bang".

Short version, if there are specs, I'm not sure they're being adhered to.

I've seen plenty of variations in the type 3 (dial and block). I'm willing to bet your zero setting isn't drilled out in the dial but clearly there's enough blow by to cycle the action. With the introduction of the type 3, Alex had mentioned that they could regulate the gas better with the type 3 (vs the type 1 which had a lot of blow by) to the point that they wouldn't have to weld up the gas port on gen 1 rifles that always ran on "s" (which I think you experienced).

The type 3 has been better than the type 1. But it seems like they've been lazy (or changed spec for the worse) with the port sizing lately. Early type 3s actually stopped cycling on zero, even with a can on.

As an aside, the type 2, in my limited trigger time, was modestly gassed. I may have to shoot that setup some more.

[owtlaw]

When the team's barrels are worn out, what went bad? Accuracy no longer good enough? Throat visibly worn out? Velocity dropped? Gas hole in the bbl enlarged/elongated?

Thanks

Usually when we wear out a barrel it will start shooting 6" groups. Our 2 junior shooters wear them out 2 or 3 times a year. They shoot upwards of 50k rounds per year.