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PA10 Nitrated 18", NB BCG, Gen 2 observations...


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1st photo ..... MEN 2016 Ball

2nd photo .....MEN 2016 ball again

3rd photo.../ Aus. Outback 168gr SMK

4th photo.....Hornady TAP "AR" .... this is the Heavy Buffer group that shifted after "one more click of gas "....first 6 , top right, added click, bottom left 5.... ( Rifles are fussy !! )

 

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Edited by bfoosh006
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57 minutes ago, jtallen83 said:

Really some nice groups, all are acceptable, the FGMM is real nice. How much of a pause did you use versus the rapid stuff? I'm more of a pull the trigger as fast as I can get back on target guy myself. 

I am with you, I kind of dream of being fast and accurate.... Lol

2-3 slow breathes. ( spelling )

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1 hour ago, Sisco said:

Good write up bfoosh. It looks like some remedial work is going to help the PSA 308 out. It will be interesting if it correlates with the experience of other PSA 308 owners.

Thank you, I am also curious if others have similar issues.

I am tempted to order up a complete 20" upper to look at.. ( and for spare parts )

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On 7/29/2017 at 5:44 PM, bfoosh006 said:

Where to start.... Adjustable gas block, what a difference !  I whole heartedly recommend the SLR adjustable gas block, it truly transformed the abrupt cycling PA10 into a smooth cycling .308 rifle. Ended up using the 5 clicks from fully closed setting, 10 more clicks ( opening the gas flow more ) were available.

I used the standard weight AR15 rifle buffer for the accuracy and function testing first  Are you using the Armalite AR 10 Buffer system ?

4 clicks failed to cycle 2 of 20 rounds of FGMM .308 168gr, and 5 of 40rds of ZQI, 2 of 20 Horn. TAP "AR"  (  ... 5 clicks performed 100% with the FGMM, ZQI ) The  Hornady TAP "AR" needed 6 clicks to cycle with the KAK 9.3oz heavy rifle buffer.

Interestingly, at one point while firing the Horn. TAP AR round , I adjusted the gas block one additional click wider, and the point of impact for the next 10rds shifted 2 inches down and 2 1/2 inches left ?! .... It is just as possible that I "shifted" as well... but 10rds makes it hard for me to think it was just me. Depends on if it was sighted in with the Tap Ammo or are you saying g it changed after the Gas system adj. .

ZQI also performed miserably accuracy wise ... again.

At 5 clicks and the rifle fired approx. 300rds trouble free. ( Except the later heavy buffer tested 2 Horn. rds. , with the standard rifle buffer it was fine ) As above if incorrect Buffer components used .

The brass caseheads no longer show smear marks from the ejector, which is directly attributable to the "slower" ( milliseconds slower ) speed of the action. Pressure levels have dropped more prior to extraction because of this... so the case has a moment more to time to lose the chamber gripping PSI. 

Doughtful Chamber pressure changed by small adj. to redirected propellant gas through Barrels Gas Port , Chamber pressure has already dropped by the time the Bullet passes the Gas Port . Action may be loosening up from round count , breaking in , more or less .

The new replaced by me ..firing pin retaining cotter key is not bent ( I forgot to mention this earlier, the OEM PSA cotter key was getting bent from the violent cycling !?!? , I had a replacement on hand so changed it out )  Sounds like FP over travel , could be a Machining issue , out of spec Bolt . The FP retaining pin is only to hold it in place , don't think it should touch it , the FP has stop flange for that purpose & it should stop correctly by the machined surface or flange inside the Bolt .

The rifle now feels like a 7.62x39 AR.... so it is a pleasure to shoot !!

I haven't compared group measurements yet ( from the OEM configuration compared to the current configuration ) ... but I did see improvement, for the most part across the board.

I will add.... the GEN 3 Magpul PRS's recoil pad.. while "softer" then the old models, needs the sharp edges radiused more..... by rd 300, it was biting into the shoulder more then needed... I will fix that !

Later on I will post the various ammos groups.

 

For now, and on a completely different subject / caliber.... if any of you were lucky enough to get some RUAG 5.56 SS109 HC, it really shoots very well ....9rds 100yds, benched scoped bagged...

Next photo ... 10rds ADI M855, same benched..

Last .223 /5.56 group.. 20rds Fed. Tipped Varmint 50gr, rapid fire, same BSB'd

 

 

 

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Edited by survivalshop
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Survialshop...

"Are you using the Armalite AR 10 Buffer system ? "

This one from PSA....http://palmettostatearmory.com/psa-pa10-a2-rifle-buffer-tube-kit.html

"Depends on if it was sighted in with the Tap Ammo or are you saying g it changed after the Gas system adj. . "

POI changed after adjusting one click more open.

"Doughtful Chamber pressure changed by small adj. to redirected propellant gas through Barrels Gas Port , Chamber pressure has already dropped by the time the Buulet passes the Gas Port . Action may be loosening up from round count , breaking in , more or less . "

Agreed about chamber pressure... I should have said less gas being used to yank the case from the chamber while the chambered round is still at high pressure... so the "slower" cyclic action of the BCG is "allowing" the case more time ( milliseconds ) before extracting.

"Sounds like FP over travel , could be a Machining issue , out of spec Bolt . The FP retaining pin is only to hold it in place , don't think it should touch it , the FP has stop flange for that purpose & it should stop correctly by the machined surface or flange inside the Bolt . "

Interesting... I will have to look into this more.  FWIW, No primers appeared pierced, and for the most part looked "normal". ... I will say the Hirt. cases had pretty "deep" firing pin strikes.

 

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On 7/8/2017 at 5:14 PM, washguy said:

Good for you !   Thats what we wanna hear !   Hint hint  orange spring  best 20 bills you will spend   :thumbup:  Wash

Bad info, wash.  Not gonna work right in his rifle recoil system, brother. 

On 7/8/2017 at 5:19 PM, bfoosh006 said:

I've got a large assortment of buffer springs and buffers from my 9mm blowback follies ... so I might try the Orange in the PRS stock.

 

Washguy , Thank you for the suggestion... I will try it.

Using the Orange Sprinco spring in a rifle recoil system would be a mistake. You need to research the reason the Orange spring was developed in the first place - hint, it's not for a rifle recoil system, in any way, shape or form.  Don't do it.

On 7/9/2017 at 8:00 PM, bfoosh006 said:

I realize most people say upper to lower fit doesn't matter... but that makes no sense to me.... IMHO that is like saying a loose stock to action doesn't matter.

Upper to lower fit does NOT affect your accuracy, in the least - as long as they mate together and function. Your "accuracy" components are all contained in the upper - barrel to receiver, BCG to locking lugs.  The only contact between the upper and lower when firing it the hammer to firing pin, not counting the two pins that hold the rifle together.  Your hammer doesn't care if there is a little bit of slop in the mating of the receivers, when it contacts the end of that firing pin...

On 7/10/2017 at 4:58 AM, survivalshop said:

   Well , the AR type rifles are made different & some tolerances are there for a reason , its not the same as a loose stock . Too tight & you can actually decrease accuracy & accelerate component wear .

^^^  Truth.  If you're chasing receiver fitment, you're chasing a ghost, as far as accuracy goes.

On 7/29/2017 at 2:44 PM, bfoosh006 said:

I used the standard weight AR15 rifle buffer for the accuracy and function testing first

You can't do that in a .308 AR.  AR15 Rifle buffers are 5.900" long, and 308AR rifle buffers are 5.200" long.  That shiit just doesn't work.

This is honestly the first time I've read your whole thread all the way through - because you're dealing with PSA stuff.  It's my own fault, because I was tired of hearing about PSA problems and issues.  I ignore it. What you have/had planned, in what I quoted, won't work.  Don't to the Sprinco Orange spring, don't use an AR15 rifle buffer, etc...

 

Take that for what it's worth...  Listen, or don't listen...

Edited by 98Z5V
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  As said above , no AR 15 Buffer components in a 308 . Armalite AR 10 Carbine systems are different , then DPMS based systems .

  What was this ? Did you change Buffers ? 

On 7/29/2017 at 5:44 PM, bfoosh006 said:

I used the standard weight AR15 rifle buffer for the accuracy and function testing first

Edited by survivalshop
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On ‎7‎/‎9‎/‎2017 at 7:39 PM, bfoosh006 said:

BTW... this is what it looks like now. Current weight... 12 1/4lbs as pictured.

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Geeez   put that thing on weightwatchers !     most all of my DPMS/Mega come in at  9 + pounds with optics and empty mag....ive got 2 that are 8 pounds with optics and empty mag but they are a hybrid. I think I might have a heavy one ,but its so far back in the bunker it hasn't seen the light of day in years  I wouldn't even worry about recoil,,,crap just getting it out of the truck would be my task for the day     :banana:  Wash

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Whoa Foo       When did you go from car stock to rifle stock? Or I missed the rifle stock from the get go prolly? All this time im giving you springs and buffers for car stocks....none of the car stuff works in rifle stocks cept the Tubbs spring...where did I miss the riflestock deal?      Listen to 98Z    I missed the riflestock deal completely no $hit !     :embarrassed:   Wash

 

 

 

Edited by washguy
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Just an FYI.... Apparently Magpul makes a different MIAD Gen 1.1 Type 2 hand grip with taller backstraps for the PA10.... I have ordered one up, as well as some of the Brownells $10 AR10 metal mags to try out.

"* NOTE: This TYPE 2 Kit uses taller backstraps for optimized fit with certain 7.62x51 receivers such as the Armalite AR-10A/B/T, DPMS LR308, KAC SR25, LaRue OBR, LMT .308 MWS, Palmetto PA10, and S&W M&P10."

https://www.magpul.com/products/miad-gen-1-1-grip-kit-type-2

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This.... at this point I would not buy more Brownells 20rd mags at even $5 a mag.... even if a little filing at the latch helps.

I just received mine, unloaded, ....width 1.0645..... snug fit in magwell.....with bolt closed, locks in well , .... does remove freely ( not quite drops free ).

Loaded 20rds easily..... loaded width 1.099... tight fit in magwell.... have to VERY FIRMLY smack the bottom to get it to lock in ( even after filling some of the OAL of the leg off of both the front and back of the follower..... and it will not drop free, ( while fully loaded.. period. )

I will try to lightly file the mags latch area, in order to make insertion easier.... but, I think the ultimate problem is the feedlip spread, since unloaded it snapped into place easily.

Function was 100% hand cycled.
 
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Ok... while I am happy with the rifles performance, eventually I will want better accuracy. Criterion, Krieger, Bartlein barrels or such..... 18" 1n10 twist or a 20" maybe.

What barrel spec's ( DPMS ? ) should I keep an eye out for ? .... and will the PA10 Bolt work with what barrels ?

For that matter, I would like a spare BCG or bolt in general... PSA is almost always out of stock, so what other ones are compatible ?

I wish PSA wasn't so "secretive" about the various parts and such....

 

Thanks ahead of time !

Edited by bfoosh006
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On ‎8‎/‎9‎/‎2017 at 7:49 PM, Boot_Scraper said:

Alright alright... where's that damn credit card...

Exactly !! Honestly, I have wanted a truck gun ( preferably the nitrated upper ) and while the accuracy is good... I really want better "general" accuracy.

So which ever upper is the lesser will be the parts donor for the better barrel.

My M21 and My Krieger barreled AR15 will shoot most all ammo "better" ( those barrels have made me an addict to accuracy ) ... they both have ammo they hate, but for the most part there is a general improvement in overall accuracy ... that is what I'd like with a better quality barrel.

The issue with the M21 is it only holds great accuracy for about 150rds before the groups open up ( seems to be related to the gas piston and fouling )... a good cleaning will restore the accuracy, but the Krieger AR15 doesn't do that.... I am hoping the AR platform in .308 ( with a decent barrel and a little finessing.. trueing the receiver face and a properly headspaced bolt ) will yield the results I would like. 

 

At this point, I am strongly considering a 18" or 20"Criterion rifle length gas. The price is good and the reputation is very good.

Edited by bfoosh006
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