FMJ vs Non-jacketed

[fido4x]

While I'll admit to being new to the AR platform (Colt M4 Dec '12) I did do some serious reading on what ammo to use. From my reading I don't shoot steel in this rifle and to note, if I remember correctly (old timer's disease ya know) due to the expansion differences between brass and steel inside the chamber. I use steel (wolf primarily) for my SKS, it was made for that crap but I only do brass casings in the Colt.

As for the jacket, I believe I've only used FMJ and some Lake City and PMC green tip. I have not had any issues with this rifle.

[jet66]

I'm talking CASE, you are talking JACKET.

I'm pretty sure that (MCBT) is in reference to the bullet itself. At any rate, in the case of XM193, I know it is a brass case and I've yet to possess any 'black box' AE .223 that was non-reloadable steel case.

[RtWing]

I'm pretty sure that (MCBT) is in reference to the bullet itself. At any rate, in the case of XM193, I know it is a brass case and I've yet to possess any 'black box' AE .223 that was non-reloadable steel case.

Cool. Thank you for the info. I just assumed that where it's called "metal case" ammo it was actually talking about THE CASE. Hahahaha. FMJ speaks to the jacket, so why wouldn't it be called MJBT (instead if MCBT) if it were actually referencing the jacket? I don't really expect you to be able to answer that question - that's really a question for the manufacturer. It doesn't make sense to have inconsistent naming nomenclature.

[jet66]

Yeah, I was scratching my head over it as well, and couldn't find anything (even on this forum) about what it meant exactly. I didn't see it mentioned on the Federal/American eagle site, either.

[Magelk]

That is absolutely, utterly untrue, and has been confirmed as such many times on these forums.

It will be a cold day in hell when we finally stop hearing it.

[Whytep38]

That is absolutely, utterly untrue, and has been confirmed as such many times on these forums.

It's true, but only if you're shooting left-hand ammo from a right-hand gun and vice-versa. (Reverse it if shooting below the equator.)

For all of you ambidextrous shooters out there ... well, you're hosed unless you reload.

Actually, I've shot my share of steel-cased ammo, and I do believe it's true that steel cases don't expand as much as brass, thus leaving room for crud to get in. I've never had a problem shooting steel after brass. But when I shot brass after steel (once), the brass came out with clumps of crud stuck to it. I even read a post by someone who claimed he always shot a round or two of brass after steel to help clean the chamber. Regardless, it makes me wonder whether it's the crud, not the lacquer or polymer, that builds up and causes problems.

[Vash1023]

I'm really doubting the guy's story here. If you had a bullet lodged in the barrel, regardless of why it was stuck there, and fired another live round, I'd be more worried about having to replace other stuff than the barrel: The bolt, carrier, upper receiver, and possibly parts of your face and hands. I can't imagine that NOT causing a catastrophic 'kaboom!'

As for the rest, I think he is talking about 'bi-metal' jackets, where there is a very thin layer of copper (and not paint) over a steel bullet. I've not personally heard of this supposed barrel-clogging problem, other than the usual steel case debate and how exactly it fouls the chamber, when it comes to such ammo use. (and that indoor ranges don't allow steel-core or bi-metal rounds, too damaging to the back stops.) As far as I know, most bi-metal bullets are from companies like Wolf, Tula, Brown Bear, and the like. The AE 'black box' stuff is good, I've never heard of it being bi-metal, if that was in question. As far as the more technical details of 'steel case pros and cons,' do a search here on 'steel case ammo' and you will find pretty much everything you could ask about it. Personally, I've not had a problem shooting a ton of Wolf ammo through my rifles when it's all I've got, but I always do a good cleaning afterwards.

i will say that this has happened to me personally, but only on a 22 semi auto rifle...

the first round lodged about halfway down the barrel, the second round joined it, and the third round expanded the barrel enough to allow all rounds to exit, not to mention that they were probably fragments by that time.

[weggy]

I think that he must have dreamed this, and then believed it really happened. Sounds like BS to me.

[Magelk]

It's true, but only if you're shooting left-hand ammo from a right-hand gun and vice-versa. (Reverse it if shooting below the equator.)

For all of you ambidextrous shooters out there ... well, you're hosed unless you reload.

Actually, I've shot my share of steel-cased ammo, and I do believe it's true that steel cases don't expand as much as brass, thus leaving room for crud to get in. I've never had a problem shooting steel after brass. But when I shot brass after steel (once), the brass came out with clumps of crud stuck to it. I even read a post by someone who claimed he always shot a round or two of brass after steel to help clean the chamber. Regardless, it makes me wonder whether it's the crud, not the lacquer or polymer, that builds up and causes problems.

It is the crud.

[Magelk]

i will say that this has happened to me personally, but only on a 22 semi auto rifle...

the first round lodged about halfway down the barrel, the second round joined it, and the third round expanded the barrel enough to allow all rounds to exit, not to mention that they were probably fragments by that time.

How did you come to the conclusion that this was happening?