I bought a DPMS M4 last week.  It is the LEO 14.5" version.  At my local gun store the guy told me a police officer had dropped it off because he needed some quick cash (probably true).  He also told me that the guy never shot it.  Yeah, i'm sure he probably had a car to sell that had only been to the grocery store and back too!!he
1. DPMS barrel not chrome lined.  At what point would most of you guys change out the barrel?  I already have a chrome lined bushmaster M4 barrel on hand, but not going to install it until I wear this barrel out.

2. The bolt catch on this gun has a small dent/ gouge/ scratch (really not sure how to describe it)on it.  Doesn't look like it would affect its function, but would you guys use it or go on and replace it (they are only like 9 bucks).

I have a 13 year old well used bolt catch on my beater rifle.It was a bushmaster part off one of my buddies rifles.The barrel will need to be replaced when groups start opening up.Chrome lined is harder than unlined and will last 2x as long but depending on how fast you shoot,Heat the elements you use it in are all a factor on wear.You could get a gauge for chamber throat erosion wich is probably more important to keep an eye on.They are go,no go gauges that you can get from brownells.For any serious field rifle I would have chrome lined.I would suggest puting that chrome lined barrel on a different upper and use the unlined for pracxtice aand training and chrome lined for serious work.Or do like I would and build a new rifle around the new barrel

Thanks. That's basically what I thought.  I didn't know if anyone had a rough average for number of rounds through an unlined barrel.

The accurate life of a barrel depends on how you treat it. If you do full mag dumps in 30 to 60 seconds the throat will quickly erode and the acuuracy will drop off after a few thousand rounds or so. If you keep the barrel clean and shoot 1 round every 30 to 60 seconds (never let it get hot) it will have a much longer usefull accuracy life. Take care of it and it will take care of you. Semper Fi. Charles the Gunsmith.

just shoot it and when you feel that its not accurate anymore replace it ( might be a long time though)


the bolt catch is good to go unless its broke.





now you say its a 14.5? hope there is a long flash hider of some sort permanently attatched to the end of it making it over 16" or you had to fill out a lot more papers than usual, pay taxes and wait a lot longer than usual.

the 14.5 is not legal length in the u.s. unless its a registered sbr, on a pistol lower, or has a perm. attatched muzzle device making it oal of 16"

I think with flash hider it clocks in right at 16"

Scratch that.  16.5 with flash hider.

Paperwork from gun store says 16.5" barrel.  DPMS label on box lists 14.5" barrel.  Flash hider is exactly 2 inches.  

Gun is a DPMS  RFA2-14R (RFA2-AP4)

I spoke to the Tech folks at Bushmaster about this. The guy said that you should expect to get around 20,000 rounds out of a 20" heavy barrel. I didn't ask about an M4 barrel.

The next point is that you should keep track of how many rounds you are putting through your rifle. Unlike a deer rifle in which you might shoot 200-300 rounds over 10 or 15 years, most of us like to shoot a lot of ammo through an AR. I keep a log of all the ammo I put through my guns. Think of it as an odometer for your AR. The Sniper Data Book has a log in the back or you can just make up your own form. Anyway, it is easy to do once you start. Good luck.

eklikwhoa,

You got me worried for a minute.  I didn't realize that civilians couldn't own 14.5.  Checked it out and it appears that flash hider has been permanently attached with 2 washers behind it to bring the length to 16.5.