bluesman2a

What about the 3D printed ones that Taccom has listed here? https://taccom3g.com/taccom-3d-print-downloads/

I dimly remember reading somewhere that these use 1911 recoil springs. Haven't checked validity, but you could compare. You might look look at something like this and compare color codes. http://nictaylor00.blogspot.com/2014/08/1911-recoil-springs.html?m=1

What are your thoughts on the Nerd comp? Did it really help?

So I had a chance to take out Carbine#1 today. It worked flawlessly. Zero jams over 200+ rounds. The setup for today was: Carbine #1: 16" Kaw Valley Precision barrel on a CMMG/colt dedicated lower with a Spinta Precision slickside 9mm upper. Ran the KVP bolt and the Heavy Buffers 9Q buffer. I also tried the KVP 7.5oz buffer and the Spikes ST-9X buffer which is 8.0oz. There was more recoil as the lighter buffers were used. I did NOT get to try my extra power spring, as I unintentionally left on my bench in the shop. Recoil wasn't bad but still lots of dot-bounce. I want to try the JP SCS on this setup, but I didn't have the JP bolt with me either. My next step is to try the HB9Q buffer with a 308 spring, and also run a Spinta upper on the QC-10 lower for troubleshooting. In the way of new purchases, I've ordered a Holosun HS510C https://www.amazon.com/gp/product/B01IIQ5YAI/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 I'm also looking at what muzzle device. I was thinking the JP or the MBX. Any thoughts here? From the left to the right: Spikes ST-9X 8oz. KVP 7.5 oz Heavy Buffers 9Q 9oz (notice the taller collar on the bottom. JP Silent capture spring in the back. Springs -- Compare normal Carbine Buffer Spring to Extra power spring, the longer is the extra power obviously.

I think I'm rapidly coming to the same conclusion. Would you mind sharing what you ultimately wound up with as your final build? also odd question, on your QC10 lower, does the ejector move around st all?

Initial range report: The Pistol was running the KVP buffer and bolt. It ran like a top without a single failure through 5 full magazines. I *WILL* be SBR'ing this, it's just too fun not to. LOTS of felt recoil. Too much for what this is. I want to try th heavier buffer in this and see if it makes a difference. Will also throw the 308 spring in as well. I was surprised the magwell block solution ran as well as it did. Reliable LRBHO performance. I also want to try a comp on this, currently it is running the KVP XL Linear comp, I bought it more as a thread protector than anything. I am unimpressed with it's performance. I will try an MBX, and am open to suggestions on others I should try. Carbine#2 Ran OK. I had several jams with this, currently unsure why or what is causing it. Probably 4-5 out of 5 full mags. Mostly it was with a single mag and once it happened I would get several more strung right together. Empty casings were still in the chamber area along with a new/live round, and to clear them I would have to drop the mag, pull the bolt all the way back and let everything drop out the bottom. Bullets that went through this would have a slight BEND in them where they were partially in the chamber when the bolt closed on them. This is somewhat annoying and I'm hoping I can solve it with a good bolt/buffer/spring combination. The carbine shot MUCH smoother than the pistol. I like the SCS, but I want to make sure it is not the root of my issue before committing to another one. I will also compare this to performance with the HeavyBuffers going forward. Again, I am open to suggestions on other bolt/buffer/spring/comps and tuning tricks that have worked for others. Muzzle device comparison. Despite the size, the larger one is actually lighter.

I wanted to share some information/testing on Colt-pattern mag solutions, I didn't want to step over the excellent build thread that @Aircooled6racer has going so here's what I've got: I'm currently working with three builds and components I will be switching back and forth. They are as follows: Platforms: Carbine #1: 16" Kaw Valley Precision barrel on a CMMG/colt dedicated lower with a Spinta Precision slickside 9mm upper. Carbine #2: 16" KVP barrel on a QC-10/colt dedicated lower with a Gibbz Arms side-charging 9mm upper. Pistol: 4.5" KVP Barrel on mil-spec lower using a Rock River magwell block with a Spinta Precision slickside 9mm upper. Buffers: JP Enterprises GenII 9mm Silent Capture Spring. KVP 7.5oz buffer -- http://www.joeboboutfitters.com/KVP_Solid_Stainless_Steel_Blowback_Buffer_7_5oz_p/kvp-buffer-7.5-9mm-ss.htm Heavy Buffers 9Q --http://www.heavybuffers.com/9q.html Triggers -- I'm running 2 different drop-in trigger systems. Both seem to work fine with the bolts listed. No reset issues. POF -- flat 2.5# flat. Velocity -- 2.5# curved. Bolts: JP Enterprises KVP Faxon ?? This may be a future purchase. I have a 3rd bolt/buffer system I want to buy, but I want to see how these components work before jumping into something new. Magazines: Palmetto State/Metalform/Colt mags -- I have a good supply of these and the LRBHO seems to work well so far. Modified Uzi Mags -- Once I have some established reliability metrics, I'll throw these into the mix. I have a ton of them, but they do NOT have an LRBHO. Ammo: This will mostly be using LAX Ammo 115Gr, because it's cheap and I shoot a lot of it. If this is problematic, I can look at changing, but I would prefer to be able to run ONE ammo in everything.

I had the same question and even ORDERED their special cam pin in case I needed it later. In answer, yes, the Gibbz IS 9mm specific and yes it does grab it by the nub that is the gas key.

Inhave one of the Taccom couplers, is there any reason I could not use/start with that? I've looked at a couple solutions and that was the first I tried.

Thanks for the kind words all. I haven't been able to do more than shoot a couple of test rounds, and play with the controls in dry-fire sims, but it's a little different. I can see where it would be nice for clearing jams in that you just tip it far right and rack. In practical application, I haven't run it enough to have an opinion yet. As for matches, I'm still focusing on steel matches at this point. I'd like to look at more action shooting at some point. With PCC, is there just a requirement for a sling and holding your mags, or is there other gear necessary to shoot a match?

Eric, I just got done putting my QC10 Colt build together last night, I opted for a Gibbz side-charging upper with a KVP 16" barrel and JP bolt/SCS. Thanks for all the great info here! Odd question here: on your lower is/was your mag release sticky? In looking at mine there seems to be some binding on the side that has the flat release plate. I tried some polishing and sanding to knock down any rough edges, but it seems to still be an issue. I didn't play with it too long before I had to stop. I haven't shot it yet, but I can see this will drive me nuts. I also polished the mag release bump that rides inside the magwell, it's better now, but still not great. Going to try another mag-catch later, but thought I'd ask.. .

remove, please

I got a notification that Joe bobs got these in on thursday. They still have the matrix uppers in stock now.

Awesome! Thanks for the heads up! I had heard of them but always just for barrels. Never thought about bolts and other goodies. Snagged a couple of those uppers this morning!

What is up with 9mm parts these days? Can NOT find a side charging upper in stock ANYWHERE, so decided to fall back to a slick-side 9mm upper. Still not a lotta joy. I get that most of these places have the same material "suppliers" but there doesn't seem to be anything in the pipeline. Any ideas where I should look? Tried the usual suspects listed above. JSE Surplus has a Yankee Hill in stock, but I haven't read much about them.

Wow! Considering what the Tactical 5.0 and the like are running for, they are certainly quite proud of them!

Just saw some of the new DVC models coming out of Shot... Anybody have ideas on actual release dates/pricing for the DVC Tactical and/or the Host?

Good point, currently they are MUCH cheaper than they had been when I built my stash of uzi mags. Back in the day, the colt mags were running in the $40-50 range and nothing else ran well.

I'm interested in the solution here as well. I had intended to build a side charging upper that would be using Colt mags. Another side-bar as well, is anybody running modified Uzi mags? I'm running a couple of PCC uppers I've had built for years and the uzi mags work fairly well. The only downside is they don't operate the BHO, but for $7 a piece it's kind of nice to just have a pile of them around. Modding them is pretty simple if you have access to a mill.

Has anybody seen any details on this? I saw "light, around 1#" but not much more.

I heard some buzz around new PCC's coming out at shot that would take 2011 mags. Does anybody know more about these? I know that Nordic has put out their offering that allows for changing the magwell, and they have hinted that 2011's are to come, but is there anybody else out there I should be looking at?

Yep... I learned a lot building a 6" gun. I actually passed this one on to my builder at the time. Also note that fusion carries stuff for 7" slides too, but have never seen one of those.

Actually I have the same setup on an all stainless gun. You can get the guiderod and the plug to use the 5" springs at Fusion Firearms: http://www.fusionfirearms.com/parts/slide-parts/guide-rod-system/guide-rod-2-piece-6-inch-with-end-cap

Thanks for all the replies! I get that there's not a simple answer.. And that's why I came here, I knew you guys would steer me correctly. So I ordered mags today, a couple more Dawson's, a wilson, a Tripp, and a metalform. I know the dawsons run well in what I have, but it'll be nice to have the others on hand for troubleshooting purposes as I finish my current and future builds.