ajn1963

I finally got my vise block and wrench and I removed the 16" barrel, an put on the 10" barrel with a thread protector and left the A2 Hybrid compensator muzzle device off. I printed a clover leaf group at 25' using a Spitfire II prism scope, then I was able to hit 4x6" and 6x10" plates at 100y. Now I did not try the 16" barrel, I think I am going buy another stripped upper and build a second complete upper with it, but I am just going to put a thread protector on that as well. The A2 muzzle device came installed on the complete 10" upper I purchased from PSA. While I never recalled printing a clover leaf with it before I switched to a 16" barel, I was able to consistently hit steel at 100y with it. With it off, the group now touches. When I have a chance I will hang a target at 100y to see how it prints. But I recall before with the 10" and A2 bird cage installed I got about a consistent 4-5" group at 100y and consistently hit steel at 100y with it. I would say at 25y I was getting a 2-3" group. It must be the A2.

Thank I think going forward I am just going to go with a thread protector. That A2 Birdcage worked perfect on the 10" barrel. It think you, @IVC and @Joe4d might have solved this problem for me. I pretty much us the A2 birdcages on all my ARs from 5.56 to 7.62 and never had accuracy issues. I know 9mm is not great in ballistics. Going forward, I will have all the tools to be able to take off and change out parts. i.e. vise block, 1 1/8" barrel nut wrench, ect. Thank you all. I am having hand surgery next month, might get the barrel/muzzle device off and changed before then, but might be quite a while before I am able to try it. When I do, I will update.

@IVC stated the same about the muzzle device. I unfortunately not at liberty to remove the muzzle device and test. But the A2 bird cage with the solid bottom is exactly what came on the 10"upper which again was a complete upper from PSA. I had no issues with the 10" barrel. It was transferred over onto the the 16" barrel. I have a vise block on order, once I get that I can get the muzzle device off. And try it. Thanks, that is very good to know. If I may ask what muzzled device did you put on your barrel or do you just use a suppressor?

I tried selling the gun and parting it, nobody interested. If I could I would have gotten a CZ Scorp or another PCC.

Again, thank you, I hear exactly what you are saying. I can only do so much in the way of stripping parts as I don't have a vise block or wrench, taking a day off work and going to club hoping nobody is there so I can setup my Chrony, changing barrels ect. I cannot do this on the fly. However I went over my firearm and what I did in entirety with John at Spikes and he feels it is the barrel. So I don't know. I asked him if the muzzle, buffer, ammo, anything and he said no. He says he had gotten a bad barrel at times and best way to tell is to swap it out. In the meanst I am in the process of ordering a vise block, and if the 10" has no issues, that is what I am going to live with. At some point I may get back to the 16". I liked the 10" better and I never missed the steel at 100y stage of ARC with it. Just jammed like hell. My ARC peer who build his AR9 from parts with a 16" barrel and uses an H3 buffer on a 556 lower with a 9mm glock magwell, has no issue and shot the same Federal ammo as me. No feed or accuracy issues. When I shot it from the bench, I loaded, shot, looked through my scope, shot again, looked through my scope, ect. Rapid fire is not allowed on my range, so loading one by one I don't see the point, if it was bolt bounce or the bolt not fully closing I would not see it firing as such, and I checked the spents for case bulge, detonations and the cases were all normal, I even reloaded some of them and shot fine in my Sig or Glock. As for the muzzle device it was the same standard A2 bird cage that was on the 10". Now when I get my vise blocks I can take the BCA muzzle off my 7.62x39 AR and swap it. I prefer the A2 bird cage as A2 is what I was issued in the Navy and E2 when I was in the NG. The previous barrels came from another source and machined the bolt. I went around and round with him and he refunded my money and told me to go elsewhere, but in addition to having no accuracy the spent case would not eject and stove pipe on those barrel. When I inspected the bolt found the bottom lug was machined off and the bolt could not hold the spent case to extract the round and never reached the extractor. Those barrels shot with no accuracy. Now I shot Federal, AE, Blaze ammo along with my hand loads and no change, others used the same ammo in their 16" as we all get ammo from Rural King when it goes on sale and they had no issues with any ammo. I can't see it being a bolt, buffer or muzzle device problem, I think you are making a good bet it is ammo, but I can't prove that overnight. My details to Spikes they feel it is the barrel. I can't make that determination. Recently I bought a CZ 457 LUX 24" barrel and my buddy got a CZ 457 Jaguar 28" barrel and setup the Chrony to see how much more the 28" pushed CCI StdV and we got exactly 1070 on my 24" and his 28" we were expecting a higher velocity and did not. My handloads in the 10" shot extremely well, to help feed issues I was advised to set the COAL to SAAMI max of 1.17 and see if it plunks and did, which i did got more reliable feeding and they shot the same. The book says use 1.15" Federal, Blazer all shot the same in 115 124. Spikes wants the barrel back, and I got a return shipper for it. No I started with just a plain Spike's Tactical lower, orders the remaining parts from KAK, SB Tactical for the brace, and had a standard AR buffer, that I upgraded to a KAK extend 8oz buffer. The upper was a 10" PSA complete upper. Then I ordered the 16" barrels. The only difference from the 10" to the 16" is the 10" PSA was a complete upper installed at PSA, and the 16" were install by gunsmith and/or someone at my club who has the stuff to swap barrels, and successfully does so for other people who shoot up at the NM at Camp Perry with barrels he installed, he is not a licensed gunsmith but know how to rebarrel. Like I said I am going back to 10", if the accuracy returns, that is what I am going to stay with. I put too much time and money and ammo into this. It is time to cut and run. Thanks I appreciate all the advice.

I talked to the barrel maker Spike's Tactical in depth today. They open and willingly feel it is the barrel, and going to send me a replacement. I am going to put it on myself this time. I just ordered a vise block from Opticsplanet. I just need to find an armorer's wrench that has a 1 1/8 barrel nut slot. I found a guy on ebay who laser cuts them, but would rather have a good armorers wrench if anyone can recommend one?

Thank you and understood.

Thank you, I think you are right it is something bolt/buffer related and timing. I don't have a vise, ect to remove barrel/parts. I don't want to put any more into this. For a build that should have been under $750 I am well over $1400 on it now. I am just going to go back to the 10" barrel which I like better and wanted, and got better accuracy, and love the balance and ergo feel. I would have never taken it off if it were not for the brace ban, and I am not spreading for the ATF under any circumstances, not even for a silencer. I chronograph ed my loads out of my Sig and Glock and got consist 1100fps with a very small SD. One of my ARC peers has a similar build and uses a H3 buffer and has no issues other than a stovepipe about every 30 or so rds. I have a KAK heavy 9mm extended buffer around 7.7oz. I used my 124/147 hand loads and Federal/AE 115, 124 grain and I got the same results across the board. My handloads are HS6, CFE Pistol and Bullseye all around 1100fps per Hornady published data. I am a dipstick for not following that ATF ban injunction closely, I like the 10" better, but if the 16" was accurate, I would buy another upper, barrel nut and mlok rail and would have a complete spare upper as I have a spare bolt. I had a been a little more patient I could have gotten a CZ 9 months later, instead of buying that lower and building, and if I was even a little more patient, I could have left the AR9 as is and waited out the ban, which I knew was going to fail, but thought that would take years. When you compete it always become a gear race, and trial and error getting the perfect firearm for competition and have to have it now. While the ARC and SC matches I shoot are unsanctioned and we add embellishments into the stages and courses, you can still get overzealous getting that perfect firearm. In my case it did not work in my favor. My father-in-law who was a CMP ranked High Master in Long Range told me if you get a gun or gear that just does not fit you, just sell or scrap it and get what works instead trying to get use to it or make it work. Unfortunately I can't sell off the parts. if I do it will be for pennies on the dollar, I rather it sit my safe than give it away. And I been way too stubborn trying to make this work for me. If I get that 10" back on now, and it shoot straight and does not jam, it will work for ARC matches and PCC class in SC. On the whole I would have rather had the Sig MPX PCC, or CZ.

I tried to sell it, no takers. I would not even get close to what I paid for it anyhow. I tried to give spare parts away and nobody wanted them. I went through three barrels, three bolts, two buffers watched every AR9 youtube video, and had two different gunsmiths attach the barrels. It just won't group at 25y, and the shots are scattered out 24" beyond 25y. I am going to put that 10" back on and live with whatever comes of it. Including of disassembly the firearm, and locking the lower up in my safe.

Thanks, sorry for all the confusion and thanks for the advice. I am going back to the 10" barrel. I did not know there was an injunction placed on the braces. I know I look like a dipstick, I had my labrums repaired in my hips October/November and with surgery and recovery I did not follow nor did I hear of any mention the brace ban was enjoined. I was waiting for a wider coverage news announcement. However in the future if I do go back to the 16" at least I know there will be a starting point, pain, and remediation to do so. If they ban the braces again, and does not look likely they will unless my state of PA does, I am just going to scrap this gun. My advice is to buy a PCC and not build one. I met very few that had a perfectly running firearm. Overall if I go back to the 10" barrel, and seemed to have corrected the last round not feeding with bending the LRBHO wire I should have a pretty reliable firearm.

I did not know this as I did not follow this closely and did not see any news articles on this, but I am understanding that the pistol brace ban has been injunctioned, making it legal to use a brace and < 16" barrel. So I am going to for the 4th time swap the barrel out and hopefully go about with a normal shooting rifle as they 10" barrel was pretty accurate for a short barrel and 9mm at 100yds. Thanks for all the advice. Being NRA ARC and Outlaw SC end in October, I have not seen or talked to anyone or followed the ban. I thought it was still pending and gave up trying to understand all the legal pros on youtube. It there is any more difficulty with this firearm or they ban braces again, I will scrap it. Thanks again. I put too much thought and effort into trying to make this work, I lost track of everything else.

Mine is basically the same build but I removed the 10" PSA barrel and replaced it with a Spike's Tactical 16" barrel. I have a KAK 9MM Carbine Buffer Extended 8 oz and just a standard carbine spring. I did not use a spacer, but I am going to print one and see if that helps. My suspicion is the buffer might be too light, and I been googling "ar9 buffer accuracy" and from what I read it fixes reliability and FTE problems but few claims stated that it improved accuracy with the assumption the before accuracy was still at an acceptable grouping. At 25 yrds I get about a 6-7" group and best zero I could make from that group. At 100 yards, I came up 5 clicks on my Spitfire and put on a bipod, the first shot was at 11 o'clock 21" from center, second shot 7 o'clock 5" from center, third shot 4 o'clock 18" from center. That was with a 124gr JRN with 5.1g of CFE Pistol ≈ 1100 fps per Hornady Handbook of Reloading. I don't have the targets/groups from before, but this last attempt I put up target backer and kept everything for analysis, before my groups were random anywhere upto 24" from the target at 100 yds, at 50 same thing but 8-14" from the target center. I am reluctant at this point to spend anymore money on this gun, and I may have said this before when there are problems it seems to be some common problem nobody has a clear cut answer to fix. I suspect maybe buying the KAK K-SPEC Enhanced AR15 PCC 9.5 oz Buffer with Flatwire spring, might be the solution. But I know peers with similar configs and same or less buffers that shoot perfectly well.

I chrono'd the load in the past from my Sig M17 it matches what the Hornady book states for 5.1g of CFE Pistol and a 124g JRN at 1100fps The Hornady manual only goes up to 1200fps for those projectiles. I shoot different Factory ammo and get the same results. I cannot tell if the jackets separate, I am not able to retrieve them. The holes in the target are round and no keyholes. From researching this online, I find that there is one school of thought that if there is not enough propellant in the ammo it will not clear the longer barrel and the other thought is a longer barrel is going to produce higher velocity which I know is true from loading rifle ammo. I have not had a chance to setup the Chrony, but my peers with AR9s shoot Factory ammo and have no issues out to hundred yards. They don't group great but they get 5-6" group and can hit the steel at 100yds. This is a Spikes Tactical barrel. And is the third 16" barrel I put on the gun with no change in results. I went through two barrels from an independent that did the same thing, I return those barrels as he machined the BCG to where it would not extract. He did say that when he tested those barrel they printed a 2" group at 50, and I can get some semblance of a group at 25 but beyond that there is nothing. I had two different gunsmith capable people install the barrels, no change. The one told me the most torque he could put on was just over 60 using a bar extension and could go any further. The other told me that they tightened the barrel as tight as they could get it. I am going to call Spikes Tactical next week and see what they can offer. Other than that with the availability of S&W Response's or FPC, I am probably going to scrap this gun and just go with one of those, probably the Response being it take AR parts and I can use a spare Geissele trigger I got laying around. I searched around and seems others have the same feed problems and accuracy issues but nobody had any solutions. Hopefully this pistol brace ban gets thrown out and I can go back to the 10" barrel.

I have a Chrony F1. Going over my load data from Hornady manual my loads are going out at 1100fps. I used my own reloads, Blazer, American Eagle, Federal, I don't think it is the ammo. I think I am going to print a buffer spacer and try that. There are a few on Thingiverse and I can easily print one. I have a standard ar carbine buffer spring and a KAK Industries 8oz AR9 buffer. I don't want to gamble another $60 and try their 10oz buffer yet unless I know that is the exact solution. I never messed with buffer spacers, my impression is that shorter buffer space would make the buffer constantly slam into the back of the buffer.

Thank you all for the replies. So I will try to respond and address all the advice. I have a Vortex Spitfire red dot, and I also swapped out for a cheap Aimsports 4x compact scope. No difference. I typically use HS-6, CFE Pistol or Bullseye for my 9mm loads. I would say my loads are typically 1100-1200 fps. I have not chrono'd them through this gun. I am tempted not to do that as I don't want to shoot my Chrony if things are that off. I have a standard A2 birdcage for a flash hider. I don't see any build up, I hardly have any residue and fired less than 200 rds through this barrel. And just recently cleaned it. I put my Magpul bipod on yesterday tried some completely different ammo I made with 147 grains/CFE Pistol and 124gr/Bullseye. No groups all random scattered holes on the target at 50yds. As for the feed problem I fixed that by bending the LRBHO wire up and taking tension off the follower. Gun always fired fine until the last round in the mag which got pushed straight into the chamber face smashing the round. I used this gun in unsanctioned NRA ARC matches for both rifle and 2 gun variants we run which I use my G19 and liked having same cartridge and mags. Two stages there is steel out a 100 yds which I rang perfectly with the 10" barrel, but sighing beyond 25 yards is not possible with the 16" barrel. I have not used the gun with this new barrel in a competition yet but I know on the practice range that after sighting in best I could at 25 then using Strelok Pro to calc the come up to 100yds, I could not ring the steel plate and on paper the group size was scatter over 24". So I am going to ladder out some 9mm, I have No.2 Titegroup and Unique I have not tried yet. The bullets I use are 124gr Hornady seconds I get from MidwayUSA, in my Glock 19 and Sig M17 from a rest I easily put a three rd group in the X ring constently. My Glock 19 is my ECW and I use it for Outlaw Steel Challenge and NRA ARC 2 gun competition along with my M17. I know these bullets despite being seconds are dead on from my Glock and Sig that have respectively Trijicon and Leupold Delta Point Pro dots. I bought some Berry's 115 RN to try also. I have 124 Berry FP which do not feed at all in this gun to try. I use the Audette method to ladder my Highpower match loads for 69g, 77g and 80g 5.56 loads which I live and die by at Camp Perry, so I can try to ladder out some new loads and see if that makes a difference. The two barrels I sent back the vendor stated after receiving the barrel back he put five rounds under 2" at 50 yards, however he machined a lug off the BCG and the gun would not extract, after fighting with him he returned all my monies and sent me an unmachined replacement BCG. I had two different people put the barrels on the upper, and I tried three different BCGs and no improvement in accuracy. If there is no other solution, my only hope is that the pistol brace ban gets killed and I go back to the 10" barrel which I liked better anyhow. I spent way too much money on this gun that I tried to keep under $800 in total and sorry to keep repeating myself, could have bought the Sig MPX PCC, which I would have but was not available back in 2021 when I need a PCC for comp. Seems like feed and accuracy problems are common and inherent is AR9 builds, and no clear cut answers or solutions. I tried to sell this gun at our Flea Market at the club and absolutely no interest with a price to sell.