I have a RRA with their chrome lined 4140 barrel, which is quite accurate.

If I do 2 or 3 consecutive mag dumps am I going to ruin the barrel?

no –– the DEA chose RRA over everyone else a few years ago for a reason

you are fine in semi auto

I woulddnt get worried over the 4140 vs 4150

You'll do more damage to your bank account, than your rifle.

Uhhhhh, why dump a mag?
Moon

He swings, and he misses.

I like to do a mag dump when I build a new upper and im testing function 1 mag controlled shots 3 4 seconds apart then a mag 1 second in between...make sure things will run no matter how hard your running the rifle of course if you really want to run a rifle hard take a carbine class.To answer the OP in semi-auto chromelined its not gonna matter between the 2 steels.

Think of it this way.

If you did, you really don't want that barrel in the first place.

Are you being serious???

Thats the RRA Add


RRA makes quality AR15`s

Back in '04/'05 RRA was the rifle to have.

RRA rifles are still quite good- I have an 04 entry tac I bought right after the ban expired.

The rifle runs like a top I have had one malfunction it was caused by running two mags very quickly through it at an informal 3 gun match then leaving it sit for about two hours with a round in the chamber on safe in 32 degree weather.  That round went off but the case ripped in two the next round would not seat but when I preformed SPORTS the seperated case head was stuck on the next bullet it then ran fine.

It may have been the bullet- a black hills reload, it may have been the cooling of the rifle- most likely- it may have been the wylde chamber- but the rifle still runs great.

My only complaint about RRA is there are no light weight barrels for everyday offer.

Everyone knows if you didn't spend at least $2k on your rifle it won't fire.

Bad/worn out brass, no fault of the gun.

Wow, I did not spend that much money on my rifle. And though it has been working great, I'm throwing it away this morning, just in case it stops working so well.

Depends on what kind of accuracy you want after you finish.

If the barrel is chrome lined like you said then 4140 vs 4150 is a moot point with a semi auto firearm. I would just shoot the piss out of it.

Also RRA does (or did) offer a LW barrel cause I have one. I have a chrome lined LW middy A2 that came from RRA. It is a very nice upper and the fit, finish, and accuracy surpasses my BCM.

Do you do this every time you shoot it, or you just want to try a function test? Sustained rapid fire will erode the throat and increase the rifles headspace if regularly done. Metal becomes more malleable when hot and the jack hammer action combined with high heat will wear your barrel out before it's time.

New barrels, of excellent quality are availble from $200 to $500 and are easily installed bt anyone. Unknown quality barrels are cheaper still. If you enjoy this sort of thing just buy another barrel when this when belly ups. Unless you are shooting at pretty long range, you're likely to never see any reduction in accuarcy.

I have a 1981 AR-15 SP1 barrel that has seen better days. It still shoots quite well and is totally reliable. The throat is so rough I can hardly push a cleaning patch through it. The rest of the barrel looks fine. I've put several crates of ammo through it, some of it was hot Porteguese ball and abused it in every fashion imagineable other than neglecting to keep it cleaned and lubed. I use it at informal carbine classes that my club runs because I don't care about "saving" that barrel and it only has to hit things inside 100 yards there. It's utterly reliable and that is why I haven't replaced the barrel.