Can we get a thread or steer me in the direction of some PCC race guns pictures?    Is this a dead trend?

for pictures it is a good idea to look at the cover of the Front Sight magazine, and take a look a Zack's set up, for a written suggestion...

I'm now shooting Steel Challeng with rimfire due to the primer shortage, but don't think it is a dead end... I shot PCC for about 5 years prior to Covid... bottom line is that it allows you to shoot your AR style rifle on a limited depth range typically pistol range, and on steel that the 9mm won't damage

for high end guns... some sort of delayed bolt, not that the JP with the silent adjustable buffer system is a slouch... MPX with a gas system... MP5, Angstadt, roller delayed...CMMG radial delayed (my PCC)....

for optics, I've become a Holosun fan boy with a H510c (I like the green circle dot reticle, but have a couple of red ones), with roll over point blank, not necessarily optic so you don't have to adjust for sight height above bore for close, precision head shots

carbon fiber, or aluminum shrouded barrels to help increase speed of transitions

good muzzle device, and hydraulic or tunable buffer system

ergometric fitting butt stock... I like a SOCOM cheek rest

high end trigger .. Geissele, Fast Fire  etc

on the other hand ..., regular blow back, mid price trigger (I use a LaRue MBT) , good comp like a modified Miculek, hydraulic buffer like an Enidine, H510cg dot will allow you to tune your ammo, and get into the game, and let experiences lead you in what direction you like... regards Les   L747

What is it about the delayed where it has an advantage over the blow back.  The Aero is blow back correct? Why does the Aero platform not have a great rating?  I have also seen things about hotter ammo for the 16 inch barrel for reliability.

AR9s have more "felt" recoil than a 5.56... what you need to control is the amount of dot "shake" or front sight movement...most blow back AR9 bolts + buffers weigh close to 22 or so ounces, and when they reach the end of recoil (recoil spring is fully collapsed) impart residual energy to your shoulder... the different techniques of reducing the initial bolt movement, ( momentarily delaying its opening)  allows the bullet to leave the barrel, and reduce gas pressure, which lessens the speed of the bolt, so a lighter bolt and buffer can be used.. at one point I was going to machine an annular ring in the chamber of my blow back but never finished the project... an annular ring or ditch in the chamber allows the soft ordnance brass cartridge case to deform into under pressure, and the ejection force is reduced as the case is re-sized as it leaves the chamber, like the Seecamp .32

my RDB upper is an Aero Precison, and plain ole AR15 upper.... I was shooting a G34 for competition and 3 gun, so I went with a dedicated New Frontier Armory billet AR9 lower in Glock format... there are typically two different formats... the Colt magazine is double stack double feed where cartridges alternately feed from either side of the magazine so the bolt needs to be wide enough at the bottom to do so.... the Colt magazine was designed for a last round bolt hold open that worked off the rear of the follower like the AR... the Glock magazine was designed as double stack single feed, so most AR9 bolts are "hybrid" so they can strip narrow feed lip Glock mags without hitting the narrower feed lips, and wide enough to work alternately with the Colt format... the Glock lower typically are slanted and the Colt more upright...since the Glock magazine is designed for a pistol, the front of the magazine follower activates the slide lock, so a linkage is needed to make a Glock format lower work LRBHO... I don't need one for USPSA PCC, only to manually lock the bolt back to show clear...

Aero Reliability... both of my AR9s  use Aero uppers, but I don't have complete gun or lower... I've not had a problem... for grins I ran a mill around the edge of the ejection port, but had no real reason to do so...I limited the length of the bolt's travel so the bolt just clears the bolt hold open catch to help preclude a piece of fired brass from getting into the rear of the action

about hotter cartridge... most PCC shooters do just the opposite, and produce a power factor (bullet weight in grains x velocity in feet per second) that just safely makes the minimum for scoring 125,000... I shoot a 130 grain polymer coated LRN with enough Win Super Field powder to make 1000fps...you adjust your buffer weight and spring diameter to do this... a muzzle brake helps control dot shake from muzzle movement, and I use a hydraulic buffer...

So are there some 9mm bolts to stay away from if you know that you use Glock mags?    Do you have a link to which buffer and spring you use?

my AR9 evolved over a couple of years... the early bolts, used rather small pistol style extractors... most now are much better AR15 style claw extractors...I use a heavy duty extractor spring from Bravo Company as I had some reliability issues at about one year of competition...I don't really have a  preference for blow back bolts... my USPSA PCC uses a CMMG radially delayed bolt and barrel, on a New Frontier Armory billet Glock lower... the buffer is an Enidine hydraulic that I had used in my 3 gun 5.56 rifle, with a VietNam era A1 stock and a standard rifle spring... I use a Miculek style muzzle brake, but open up the back wiper to minimum thread diameter for 1/2x28, and thread the entire boss of the comp,. I used my back up lower, a Palmetto State Armory branded billet originally built by NFA as an AR9 pistol... 8" barrel with an AR rifle length buffer tube and rifle buffer, no blade or brace, just a rubber end cap.... it was a proof of concept when I was looking at a "truck gun" project. I typically use the slightly shorter KAK 8 1/2 buffer tube with carbine buffer and springs for my 5.56 AR pistols

a simple blow  back bolt and one of the tunable recoil systems like the JP silent system can give you a better than entry carbine for a reasonable price... you really need to hand load ammunition if you want to make a competition carbine...if you are going to shoot commercial ammo, you probably won't notice the difference...I give up a little bit of recoil for control of the dot movement... I'm a fan of the Holosun 510c, currently shooting a green reticle for rimfire Steel Challeng

my responses have been for the AR9 platform... since I've quit shooting PCC division (Covid), several roller delayed bolt systems have been introduced (though considerably more money) as well as purpose designed blow back platforms like the Beretta carbine, and Ruger PCC Charger that use a recoil system not requiring a buffer tube and a proprietary bolt... the Ruger has a tungsten mass IIRC... I'm just more familiar with the AR style furniture... I use a registered SBR for rimfire steel challenge, and 10/22 in a PMACA chassis that uses AR stock and grip...

@lasnyder what does this mean?
with roll over point blank, not necessarily optic so you don't have to adjust for sight height above bore for close, precision head shots

I’m about to dip into PCC. I’m waiting for a JP competition to come back in stock and am trying to pick a good optic. I’m not sure what you’re talking about. Is that. Type of mount or something the 510 goes on?

the roll over sighting system I was referring to was with a 5.56  3 gun AR not an AR9 PCC... for larger matches like the Ft Benning 3 gun matches, targets range from head shot with hostage targets at 5 meters to 10" MGM flash targets at  418 meters...for the Ft Benning matches from 2005-2010 I shot a fixed 4 power TA01 4x32 ACOG and until 2016  a red chevron TA31F ACOG.

the center line of the optic's lens height above bore for the ACOG was about  2 3/4"..so at close distances the bullet's travel was that much lower than the aiming point....  for a head shot (6x6) at point blank range I had to hold the chevron or dot at the top of the target... I did not normally shoot matches with close in targets, so while I knew this need for hold over, it was not intuitive, so I added a set of fixed iron sight that offset to the right of the rifle at a 45degree offset... these sights were zeroed for close in point blank ranges... to use the sights all you do is roll the rifle counter clockwise, and use the iron sights  .... at the time only one optic was allowed on the rifle.... I believe now, that a 1x non magnified dot is allowed...for an intro AR9 this roll over optic is not necessary, and adds expense....  I think you have the correct optic choice with the Holosun 510c...I use one on a Ruger MK iV .22 pistol, and use the entire clamp mount

https://www.youtube.com/watch?v=ZTT9Q6EMq5c

I used a much cheaper alternative on my 3 gun rifle, but that technology is at least 15 years old now... I started shooting the PCC around2014 till Covid and did not use a roll over sight

https://www.amazon.com/dp/B017KYJB0I?tag=arfcom00-20

Ahhhh. Shit I gotcha now. I guess I wasn’t getting what you were putting down. Optic offset. Very familiar. With an ACOG too. I guess I was having a word brain fart and hadn’t heard what you called it. It’s different for me going into PCC from AR’s. It looks to be fun. I ordered a JP Monday. So here goes nothing I suppose 🤣

if you plan on shooting enough to be seriously competitive, think about getting into reloading your own ammo,  small pistol primers seems to be available, though still pricey ... and if you can decide on a load prior to tuning your recoil system in the PCC that would be better... I don't remember if you already shoot pistol, and what caliber, but if you shoot a 9mm, using a single load data cartridge for both pistol and PCC is an option... I shoot either a 130 grain Bayou polymer coated bullet or Precision Delta 124 jacketed bullet with Winchester Super Field propellant that gives a 127 power factor with the pistol... good luck... I've met a lot of good people in the last 40 years of USPSA... Les