Registered a while back, first post...

[OMCHamlin]

Howdy. It looks like I registered a year + ago, which might line up with about when I blundered into my local pawn shop and decided I "needed" an older DPMS 308 AP4 Carbine. Honestly, I thought it was good raw material to piddle with, and at around $500, I figured it was "okay". I still think so, because it's a decent shooter and responded well to the look I was trying to achieve. Heavy though. 

Here it is, though that RR rear sight might get turned into a KAC 300/600 BUIS that I have tucked away. For LPVO clearance.

Anyhow, the gun was dirty and literally loose. I found, while taking it apart, that things like the flat top gas block screws were loose, the barrel nut wasn't "in spec" tight, buffer tube, etc... Well, okay, I'm in there now, swap what I want to swap, check what I need to check and work my way back out. Even had that ugly curved DPMS M4 curved buttstock.

During the course of events, I changed out the buffer tube (receiver extension) for an older matte anodized 6 position one that, coincidentally, measured 7.75" long. I put the original DPMS spring and 2.5" stock buffer (3.8 oz, I think) and while shooting it alongside my Spanish FR8 bolt gun, I noticed the thing was kicking harder then the 308 bolt gun! It also ejected out at ~1:30-2:00, 3-4' away.

I happened to have a stash of 308 AR parts from a guy on another forum, including a Sprinco Orange (seriously looks Red to me?) spring in a tube labeled ".308 CARBINE DPMS PATTERN EXTRA POWER BUFFER SPRING", plus, I figure, now that I know I have an A5 length tube on there (7.75"), I can use a carbine H3 buffer at 3.25" long and see between the two (Sprinco and H3), if I've improved the recoil and maybe tweaked that ejection pattern some towards that beloved 3:00-4:00 pattern. 

I feel like the Sprinco and H3 were good on felt recoil and ejected okay, but when I subbed in the Sprinco and an H2 I perceived the felt recoil was still okay, but it ejected closer to ideal at about 2:30-3:00 with I had laying around to test (M80 ball & some Perfecta 308). I also have some commercial hunting stuff and some M118 LR and M852 to test. Of the ammo listed, which do you guys figure would be most likely to give cycling challenges? The gun's not fancy, but it's accurate enough, BUT, it needs to be reliable above all.

All throughout this little tuning session the bolt locked open on the last round as it should.

Should I stop, leave the Sprinco and the H2 or H3 in the gun and just go shoot it?

 

Oh, and since this is the intro section, we relocated from Virginia a few years ago to Tennessee. With VA's current political climate, I have no cause to second guess that decision, although I hope it's only temporary! I'm retired Navy, wife only did four, gave it up to marry me. Bad call on her part...

And, we have a dog.

 

 

[98Z5V]

LASSIE!!!   

Welcome aboard, man, literally.  Nice work on the gun.  Keep the Sprinco Orange, or run a Sprinco Red, and put the H3 back in it.  The Red with the H3 in the longer extension is pretty much the Armalite AR-10 carbine spec from the factory - if only you could find the Armalite EA-1095 recoil spring.  Doesn't matter, The Red is an identical performing spring.  Orange works just fine, it's just made for the shorter AR15 carbine extension and the short 2.750" buffers.  

If it's running, let it run.  I don't think any of the ammo you listed will give you any cycling issues...  

[shooterrex]

Welcome from Ky. Sounds like ya got it running.

[OMCHamlin]

Good morning, going to check it out today, hopefully!

[Armed Eye Doc]

Welcome from Texas. 

Give a report on how it goes.