DPMS AR Not firing... Bought from board

[RDWheeler]

I bought a DPMS AR-15 Sportical from the for sale section here. The guy was very nice, and had alot of guns for sale. Anyways, took it to the range yesterday after buying 500 rounds of PMC 55gr brass rounds. Loaded it all up and click, click, the firing pin is not hitting the primer hard enough to ignite it, I had my buddy pull it all apart and everything looks perfectly fine in it. I changed the firing pin with his AR's and still nothing. I am wondering if there is some sort of adjustement that can set the firinig pin out just a hair further? Or if I need to just take it in. thanks

[JoeH]

PMC primers are very hard. Are you seeing any marks on the primers at all, even light strikes? You may need a stronger hammer spring.

[RDWheeler]

Yeah, theres definately a mark, but not quite enough... I even ran some of my ammo through my buddies and it shot fine. Could the gun still be very stiff from less then 30 rounds through it? I know they are tough to get goin in the first hundred rounds or so, but damn how frustrating lol!

[GekoIQ]

Sounds like a trigger issue. ARs will mark the primer just by chambering a round because of the floating firing pin. Sounds like the hammer is not making contact with the firing pin for some reason, or its not hitting hard enough of course.

[JoeH]

Have you tried any other ammo?

This should be an easy fix once we know the problem.

[gyrfalcon]

Does it have the stock trigger in it? Could be you just need to replace the hammer spring like JoeH mentioned.

If you take it apart how hard/fast does the hammer come up?

Also have you tried a carbon scraper to get rid of any buildup in the firing pin channel? One thing you might want to do it just switch uppers with your buddy and see if the problem goes away. That way you can completely narrow it down to being an issue with the lower receiver.

[FJ540]

I'd swap the complete bolt carrier before I swapped uppers - there's no need to remove the front takedown pin to check the firing pin.

And since when are AR's problematic at first? There's nothing in them that should need any kind of break in other than the barrel for the first few round.

[RDWheeler]

We did switch the bolt carrier, and then it shot 2 rounds, then started doing the same thing again.... We took it all apart and everything looks just fine, but there was quite a bit of build up, so its all cleaned out now, and we will see what happens hopefully tomorrow.

[RDWheeler]

and yeah it has the stock trigger.

[Gecko, Extra Crispy]

Is this the one that I sold? if so PM me and I will make it right.

[tacticalninja32]

I had somewhat of the same problem with my dpms but when I switch to american eagle the problem went away, now I can chamber any ammo without a hiccup, and ohyeah cleaning it more thoroughly in the chamber helps too,

[Pat]

You need some new springs. Not a big deal to change out, and all should be hunky dory. Order from http://www.dpmsinc.com.

[Geezer43]

Never hurts to install a new hammer spring, or to have one as a spare.
However, before installing a new spring -- check to make sure that the old one has been correctly installed.
They can be installed "backwards". If that was/is the case it will not work properly.
When installing a new one make sure that it is correctly installed.

[RDWheeler]

Do you know if any place ,locally stocks the spring?

[tacticalninja32]

Try DKmag in shoreview