so... another question

[benw315]

Hey all!

I have yet another question to ask. How many of you have shot both a lightweight and a standard barrel AR hard? Particularly, BCM. I'm curious as to the performance of a lightweight barrel compared to the standard one after a long, hard day of shooting at something like a class. I'm not sure how much the groups will open up and how soon after sustained semi-auto fire and I want something I can run hard and not worry about. Thanks again!

Ben

[random clever name]

You will run out of money before you put enough ammo through it to cause the barrel to have immediate issues. Too much rapid fire will erode the throat and cause degraded accuracy over time. I haven't run BCMs hard, but I have run Colt pencil barrel guns hard, including full auto, with no issues. The gun will get too hot for you to hold before you start to cause the barrel to fail. On the flip side I've also run crappy bushmasters on full auto and not been able to cause them to fall apart. All of this was done with GOV weapons and ammo so it was free and if it messed them up it was still free. The courses of fire you will encounter in good training will heat the weapon up, but not enough to cause either barrel type to have problems. Also the heavier barrels resist heating up a little better, but the thinner barrels shed the heat a little quicker so it's a trade off.

Either way if you abuse the barrel you will degrade the accuracy.

[C-grunt]

I had a Colt pencil barrel. After lots of shooting it would string up and to the left a little but was still plenty accurate.

Even though they heat up pretty quickly they also cool down really quickly.

It really shouldnt really even be noticeable in a class unless you are doing lots of rapid long distance shooting.

[benw315]

Thanks for the replies! I was just wondering how a pencil barrel would perform after a steady dumping of three mags or so... accuracy wise at around 100 yards and beyond.

[Littlelebowski]

Thanks for the replies! I was just wondering how a pencil barrel would perform after a steady dumping of three mags or so... accuracy wise at around 100 yards and beyond.

You worried about group size on 3 consecutive mags dumps at 100 yards? It's not going to matter with that methodology which barrel you use. Now if you were proposing something somewhat sane like "shoot one mag as quickly as you can acquire the target at 100 yards," it might be interesting. Otherwise it's just silly.

[bkb0000]

fortunately, we're talking about MOA differences, not MOM. CQB=lots of rounds, not much need for "accuracy." distance=not much shooting, need for accuracy. since lots of rounds decreases accuracy, it's good that that happens when it's not needed.

non issue, holms. if you find yourself in a situation where you're dumping magazines, then engaging at distance, you're probably not gonna make it anyway, 'cause they have motorolas and lots and lots of friends.

[300WM]

You will run out of money before you put enough ammo through it to cause the barrel to have immediate issues. Too much rapid fire will erode the throat and cause degraded accuracy over time. I haven't run BCMs hard, but I have run Colt pencil barrel guns hard, including full auto, with no issues. The gun will get too hot for you to hold before you start to cause the barrel to fail. On the flip side I've also run crappy bushmasters on full auto and not been able to cause them to fall apart. All of this was done with GOV weapons and ammo so it was free and if it messed them up it was still free. The courses of fire you will encounter in good training will heat the weapon up, but not enough to cause either barrel type to have problems. Also the heavier barrels resist heating up a little better, but the thinner barrels shed the heat a little quicker so it's a trade off. either way if you abuse the barrel you will degrade the accuracy.

Crap, I own a crappy Bushmaster that will shoot 1/2 moa at 100 off a rest all day and I can't get it to fall apart, either.

[Armati]

Throat erosion is the big killer of AR accuracy over time. Really there is not much you can do about this but you will be well into 20,000 rounds (depending on how hard you run the gun) before you have to think about it.

Keep in mind, distance = time. The further the target is, the less of a threat it is, the target is smaller but you have more time to engage it. The closer the target, the more of a threat it is, but the target is bigger and you really only need to worry about 'practical accuracy.' If your hot gun opens up from sub-MOA to 2 MOA, this really won't make a difference at normal combat distances.

Mag dumps may impress the poorly trained and uneducated but they really don't accomplish very much. In combat, the guy standing in one spot laying down silly amounts of suppressive fire will become a fixed target and bullet magnet - shoot, move, communicate. This never changes.

Check out this shoot out vid. This guy is a discharged Marine with actual combat experience using an SKS to effectively engage at least 3 LEO's. Good tactics are essential:

http://www.youtube.com/watch?v=IUYgr...has_verified=1

http://www.youtube.com/watch?v=pgBEv...eature=related

By the way, he dies in the end, because you can't out run a radio! Remember, shoot, move, communicate.

[benw315]

good deal... I'm obviously a noob with this stuff and do not know what a carbine class consisits of... I'm assuming a pencil barrel is still able to make hits at around 150 to 200 yards on an 8 inch steel plate after a long, hard drill (if they do this in classes, im sure they do).

[Littlelebowski]

Throat erosion is the big killer of AR accuracy over time. Really there is not much you can do about this but you will be well into 20,000 rounds (depending on how hard you run the gun) before you have to think about it.

Keep in mind, distance = time. The further the target is, the less of a threat it is, the target is smaller but you have more time to engage it. The closer the target, the more of a threat it is, but the target is bigger and you really only need to worry about 'practical accuracy.' If your hot gun opens up from sub-MOA to 2 MOA, this really won't make a difference at normal combat distances.

Mag dumps may impress the poorly trained and uneducated but they really don't accomplish very much. In combat, the guy standing in one spot laying down silly amounts of suppressive fire will become a fixed target and bullet magnet - shoot, move, communicate. This never changes.

Check out this shoot out vid. This guy is a discharged Marine with actual combat experience using an SKS to effectively engage at least 3 LEO's. Good tactics are essential:

http://www.youtube.com/watch?v=IUYgr...has_verified=1

http://www.youtube.com/watch?v=pgBEv...eature=related

By the way, he dies in the end, because you can't out run a radio! Remember, shoot, move, communicate.

He didn't have actual combat experience. Motor Transport guy who never left the wire.