PSA AR10

[jimbob86]

Smaller buck taken 2 days later from the same blind .... just a tad further out (did not range). Perfect behind the shoulder lung shot ....

[stagpanther]

Not trying to revive a dead horse here--but really trying to correct a mistake I made, and publicly fess up and have a slice of humble pie.

This PSA 10 project has vexed me since the beginning, mostly because my shooting has ben very inconsistent. Even when I found a load that shot OK--the next time out wit hthe same load could spray all over.

The core problem IMHO is that PSA has simply over-gassed this configuration--using a mid-length gas system on an 18" 308 barrel is inviting trouble IMO. While the gun works and runs with everything--I could tell it was bashing the gun part's (as well as me) with each shot. I estimate the distance from the gas port to muzzle to be at least 8.5"--so that's increasing the dwell time and likely causing the bolt to try to unlock too soon.

My brain fart came when I assumed "reduced power" buffer spring meant that the spring reduced the power of the recoiling BCG--so that's why I grabbed the yellow sprinco spring and put it in. After reading the spring description ratings on Sprinco's site I realized I should have done the opposite and used the orange extra power spring--which I immediately swapped out.

We're in the middle of yet another snow storm with 30+ mph winds--but the what the heck, right?

Imagine my great surprise when shooting-- standing up with the gun resting on the tailgate and using budget ammo that was previously grouping 2.5"-- that all 5 shots from the magazine were touching --though in a string.

Once again I screwed up--sorry to have mislead anyone--though I still think the stock PSA carbine is over-gased, though this seems to be a quick and easy solution.



Now I'm going to have to retest the hundreds of loads I wasted.

[HankC1]

carbine gas system on an 18" barrel

It is mid-length.

[stagpanther]

It is mid-length.

Right you are--my mistake (again)--but the port remains pretty far from the muzzle and is still over-gassed.

[Big Shrek]

I'm loving the Updates on this thread...was about to Hit the Button on the AR10 set last November,
when I walked into a local shop and ended up with a S&W Sport II in 5.56/.223 for $379...
good reason to blow the budget

But I'm patient when it comes to guns I want, so more than willing to relax and wait for more reviews!
Especially since I'm just getting used to the AR platform again, having not touched one of its kind
since around 1995 when I got outta the Army (Yeah, I know, slightly different animal is the M16A2).

[stagpanther]

Don't get me wrong--I still think for under $500 this PSA 308 carbine is an excellent deal--just needed some tuning in the upper and lower I bought. I've seen their free-float railed version for about $50 more--I'd probably opt for that instead--especially if it comes with a better barrel and gas system (not sure which it has)The lower in particular, which comes matched with the EPT and magpul stock is a great deal IMO. To top it off, it's actually pretty light weight--probably need to spend another 2K to take a pound or two off it's weight. I've done some standing free-hand shooting with it that would be difficult with my long-barreled and heavier xx308 builds. If we ever stop getting pounded by winter storms I'll try to re-test some of the loads I did earlier.

[Mobuck]

Still haven't shot mine yet. Having shoulder problems that I don't want to aggravate.
Maybe you've seen those commercials using the line " I saw it and said "just gotta have it", well that's where I'm at right now.

[stagpanther]

Still haven't shot mine yet. Having shoulder problems that I don't want to aggravate.
Maybe you've seen those commercials using the line " I saw it and said "just gotta have it", well that's where I'm at right now.

In my case the dwell time is too much relative to the gas "hit" to the carrier--so the recoil was very snappy and the parts were hitting themselves hard when cycling--I could easily see signs on the rim faces of the bolt struggling to unlock and extract. An extra power spring--and maybe a heavier buffer too slows things down enough that mine behaves better now--and accuracy has significantly improved.

[bfoosh006]

Stagpanther....Try an adjustable gas key.

( If you want to keep the front sight )

And IMHO, you are dead on correct about the gas... the shear volume of the .308 gas is overwhelming the system.

And IMHO... after an adjustable gas system... I'd remove the Sprinco.

I found the added strength from the spring sent the BCG ( etc ) forward fast enough to cause muzzle dip.

I suggest you try the Tubbs Flatwire .308 spring.

Here are some spring weight measurements from David Tubbs... just food for thought.

A2 (old) - 7.6lb closed, 14.5lb open
A2 (new) - 9.1lb closed, 16.7lb open
Tubb Flatwire - 10.5lb closed, 16.3lb open
Tubb .308 Flatwire - 13lb closed, 16.7lb open
SpringCo White ? (standard) - 8.3lb closed, 16.3lb open
SpringCo Red (extra) - 10.5lb closed, 18.4lb open
SpringCo Orange (increased) - 13.9lb closed, 24.8lb open


IMHO, an extra power spring isn't needed , nor wanted.

I tried both the "Red" and "Orange" ... both caused needless muzzle dip, and were slamming the BCG really hard into the breach face.


The Tubbs .308 adds the extra power on the closed breach.. with normal cycle weight.

[stagpanther]

bfoosh--I see the power difference--are these assumed open/close for a 7" carbine buffer tube?

The sprinco orange extra power was especially made for 308 carbine set-up--and I have to say it's been a vast improvement it performs as well as I could expect--how would that cause a muzzle dip?? I'm just curious. I looked at the adjustable key carriers but they seem to be reduced mass set-ups in general. I even thought about looking for a gas tube that has a bit of extra length--like a pistol pigtail--that retards the gas hit to the carrier a bit.

Thanks for the linked info--I will look into that.

[stagpanther]

Very interesting--I can see exactly what bfoosh means when I drop the bolt from the catch--it definitely hits hard enough to cause a dip--oddly enough--when firing the weapon I don't notice this--it's almost as if it's cancelling the muzzle flip to some degree? I did look around for adjustable key carriers but they seem to be sold out.

[stagpanther]

Went ahead and ordered a few Tubb's springs direct--pretty stiff shipping though--$25 for basic UPS ground!

Also--found Taccom3g--didn't know you could order the keys seperate (why not I guess) Although looking at the system I'm thinking all it is is a drilled and tapped hole with a couple of set screws?? I'm wondering if over the long haul these can loose their seals--I know adjustable blocks can

[bfoosh006]

https://www.youtube.com/watch?v=8fMVZbrnvu8

David Tubbs video on it.

[stagpanther]

Interesting video--thanks for that.