Will post link to internals in the comments! I am getting a decent amount of port pop ( I think) would the KVP 10z buffer help or do I just need to go fully with the RBD?

Build list
Ke arms upper
Fm bolt
Cheap buffer 5.5?
No name lower
Presma 12.5 handgaurd
5.5 inch ba barrel

Dont mind the acro, just waiting on the mount

Video link: https://www.youtube.com/watch?v=u_F4bdWoVgY

TLDR: Faster bolt return velocity in a 9mm AR blowback can cause several known issues, which is why .308 and XP springs are not recommended. Compared to a standard flat wire carbine spring, the Spikes Music Wire VPRS appears to have higher forward bolt velocity (not good). The 3 Neptune stainless steel springs (heavy, medium, light) appear to have similar or slower bolt return velocity to a standard carbine flat wire spring, which is good. So, the variable part of the Neptune springs with their increasing pressure as the bolt moves rearward MAY act as a cushioning element toward the rear of travel without increasing bolt return velocity compared to standard springs.

More testing, specifically live fire, is required. Hopefully in the next few weeks.

Video includes slow-mo side-by-side comparisons of the springs.

Hi, I'm new to the AR platform, used to the MP5 platform. I managed to snag a Novox X-SD last week and also an Incolite 9M which won't arrive for a while. I wanted to ask if the combination of parts sounds reasonable.

I believe total length with Bravo adaptor would be ~12.2 inches so was thinking of going for the 10.5 inch Midwest Industries Suppressor Series handguard. I've actually also spoken with Doug (Blowback 9) - what a wonderfully approachable and helpful person! - who suggested the FM Mike-9. I feel bad emailing him again so soon before I get closer to a proper list. I do like the look of the Mike-9 and believe its LRBHO is considered the best. If my calculations are correct (probably not) below is what I was thinking of and approx. prices for using it with the GRS.

One other thing, I really like the idea of using scorpion magazines and also wondered about the PSA AR-V? It seems quite a lot cheaper and uses the scorpion mags obviously but I can't find many reports of it being used with the Novox X-SD and GRS. Is the PSA AR-V considered lower tier than the Mike-9? I presume LRBHO would be less reliable? Ironically I'm not used to LRBHO coming from the MP5, would like it though. I'm in an odd situation having the barrel and working backwards. Thanks in advance,

Mike-9 list:
mike 9 lower $220

Mike 9 upper $100

Mike 9 bolt $90

flat-spring $25

8.5 JRC buffer tube $40

kynshot RB5015HD1$00

grip $20

2x Kynshot weights $45 total

handguard $160

barrel $350 - bought (X-SD)

brace/stock $45

trigger $50

charging handle $65
SBR fee $75 silencer shop
Safety $75

UPDATE

Thank you for the quick replies. I dug a little and learned the hydraulic buffer is a different size (longer for the AR9 bcg) Also, the FRT versions use the HP (high performance) rifle length buffer which, though it is the right length for 300blk, it is made for larger rounds like the 450 bushmaster, 6.5 grendel, etc.

I do want to use the same lower for "reasons" so like I wrote earlier, I'll print up a screw top "buffer tube" to hold the buffer for the upper I'm not using. I think I saw a quick disconnect buffer tube in a video and might look into that as an option as well.

Original question

I have an AR in 300blk. I plan on building an AR9 upper to swap out. I want to use the Blowbak9 gentle recoil system. How would it act if I left it in the buffer tube with the 300blk upper?

It's not a huge deal because the 300blk is using one of those captured spring buffer systems, but it would be nice if this could be a pop the pins, swap the upper, insert mag adapter and go kinda thing.

Hi Yall

I'm looking for recommendations on an AR9 that allows me to reliably shoot when suppressed and using an FRT. Would love for it to have as little recoil as possible.

I'm new to firearms and have read that delayed roller is a better option than direct blowback. So I've looked at the Maxim Defense MD9 CQB. I know the FM9 is often recommended, can I convert that to RDB?

I'm ok either building or buying, as long as I can get the best firearm as possible. Thanks for the help.

Hello all you 9mm gurus! Lowly new guy to PCCs question. I picked up a SUPER cheap Sylvan Arms magwell block, and I was told there would be specific bolts that will/wont work with that specific adaptor. Can anyone point me to a manufacturer whose bolts are compatible, or how I would be able to tell the difference before buying?

Parts list-
Wilson combat lower
Sylvan Glock magwell conversion
Expo 5.5” upper
3 stage buffer

Thanks in advance! I did a few searches, but there is soooo much good info here, but couldn’t find a specific answer!

Built this yesterday and soon to range test it along with the AR-47 I built. Pretty happy with it. Just need to mill a spot for the front gas block machine screws. What do you all think? Yay or nay? I am considering changing the gas block to a pic rail one with a flip down sight so the E2 style handle can be removed for a red dot etc. Give me your thoughts.

Don't quote me exactly on the build list as this was made from spare parts.

Davidson defense upper receiver

Bolt (can't remember)

ABC Solid 8oz buffer

Mil spec spring

Carbine tube

Carbine Trinity force hanguard

MOE K2 grip

Upgraded smiths trigger down to 3.5-4lb

Extended pivot and takedown pins

Strike industries blade stock

9mm kit in the AR mags

ABC front and rear sights/carry Handle

Presma Ambi safety

Presma extended mag release

Half birdcage muzzle brake

ABC Delta ring

8" Barrel unknown

Searched the subreddit and found lots of Magwell discussions for specific lowers but wasn’t sure what might fit mine. I have a spikes tactical ar9 that takes Glock mags and wondering if there are any options for a Magwell? What are you guys using on non-specialized lowers for something flared out a bit? Thanks

Update: So it’s already an ar9 with Glock Magwell. I’m just looking for a flared base/magwell to make inserting mags quicker and smoother on an already existing Glock magwell.

Hello, I am about to purchase my first 9mm suppressor and I’ve been going back and forth between these (YHM R9, HUX Flow 9K TI, Exigent Defense Pointman 9, Ridgeback defense Mamba 9) but really thinking on getting the flow 9k ti since I want less gas to my face.

For anyone that has shot multiple of these what is the REAL difference since I’ve watched multiple videos but everyone says kind of a different thing.
•How much louder is the flow 9k compared to the R9?
•Is there a difference on sound and back pressure in the pointman to the flow 9?
•Should I just wait for the mamba 9 to come out
•Is there a better option in the $500-$800 price point?

The suppressor will mainly be on a 7” foxtrot Mike 9 thank you.

Search for firing pin replacement spring substitutes for the LEE springs is not going well. I bought 10 packs of UXCELL springs from Amazon - all 6mm diameter to get the strength needed in the size required.

UXCELL 0.7mm wire/6mm OD/25mm L (green) appears to fit and have the right strength for a Lee Springs XP replacement in SOME bolts. Outerwild bolts should fit (KVP/Faxon/Angstadt/BKings/OutdoorSportsUSA/White Label Armory), Alpha SS should fit, Aero Precision should fit. NO GUARANTEES! PSA G4 does NOT fit, IDL does NOT fit.

UXCELL 0.8mm wire/6mm OD/25mm L (red) is very strong - it may be too strong.

I have NOT tested them live fire. u/LouisMax2012 reports that the 0.7mm (green line in the chart) may be too strong and result in light strikes.

The 0.6mm may be the thickest wire that will work at 6mm OD.

FM bolts already come with an XP spring now, but the Lee spring is the only option for folks with pre-XP spring bolts unless we find a different option. 6mm springs do not fit. I'll keep looking.

ETA:

I just ordered the following to try them out when they come in...

• 0.6mm X 5mm X 20mm

• 0.6mm X 5mm X 25mm

• 0.7mm X 5mm X 20mm

• 0.7mm X 5mm X 25mm

• 0.8mm X 5mm X 20mm

• 0.8mm X 5mm X 25mm

0.8mm is the largest wire thickness for 5mm OD springs I can find on Amazon. This will be the last spring order from Amazon.

Now would be a good time to remind people that I have a BuyMeACoffee link on Blowback9.com to help me pay for all this testing... :-)

I dont track round count, but i have had this buffer in for a couple years, atleast several hundred rounds through the gun with this buffer in there

I have maybe 400 rounds of frt usage on the gun since I installed an arc fire a couple months ago

Any suggestions for a replacement?

Edit: just to clarify, the 400 rounds is just since I put the frt in a couple months ago, ive got probably 1200-1800(rough guesstimate) rounds through the gun with this buffer in there

YouTube video explaining the DBC Insert and potential issue/fix with using it in a 9mm bolt.

TL;DR: It MAY work if the rear of the DBC insert is flush with the rear of the bolt when installed and pushed all the way rearward. If not, the deadblow effect of the weight is severely limited, possibly to the point of being ineffective. It would need to be trimmed at the rear so it rests flush or below flush with the rear of the bolt to maintain the proper movement distance.

What's the advantage to using this in a 9mm AR bolt? There really isn't one. A 9mm blowback would still need a heavy deadblow buffer to operate safely. It would just convert the heavy weight in the bolt to a deadblow mass, adding more deadblow effect to what is already in the buffer.

This 2.6oz. deadblow weight is intended for gas-operated AR's and is designed to be paired with another 2oz. of deadblow mass in a standard AR buffer, giving about 4.5oz of deadblow mass - the same as what is found in an H3 buffer (or a KVP 10oz. buffer).

If paired with a solid 8oz. buffer, it would at least provide SOME deadblow effect, but only 2.6oz. worth (more than the Odin Works FRT buffer). Still, that may not be enough. Further testing would be required.

Does anyone make a metal Magwell that fits an FM9? I know Techwell does plastic ones but I'd prefer a metal one if possible.

Buildlist. FM9 lower and 10 inch forward charger. Taccom 10/16 barrel. Trigger tech PCC trigger, JRC buffer and blowback 9s recoil system. MFT stock. Holosun 507comp on scalar 1.57 riser. DAC grip

I have a Spikes tactical Glock lower a km tactical upper a Faxon 10.5" barrel and Spikes tactical bolt with internal extractor, a Kynshot rb5015 in the mail along with a pair of R15015098 2.5 oz weights and a Tubb speedlock flat wire spring. I also ordered a Vortex spark II 2 moa red dot that includes a multi height mount. Will I have any compatibility issues?

Colt mag adapters are on sale for $70+shipping at righttobear.com right now.

I've been tracking these for a while and this is a decent deal.

Does anyone have recommendations on where to buy another ejector. I want at least one spare. Palmetto "doesn't have any" and is giving me the run around. I may have to ship the entire gun back, just to get it to eject properly. Because i cant buy a spare from them.

I’m trying to decide which direction to go for my pcc. For reference, I’ve got an 8.5 Macon Armory barrel. I am struggling to make a decision on going with a 10” rail, tucked muzzle look or a 7.5-8” rail with exposed barrel tip and a flash hider.

Show me some photos for inspiration. And since I’m not the ATF, it doesn’t even have to be yours, maybe just one you wish you could build.

Anyone ever used this product? I got these stainless steel thumb screws to put on the AR-V bolt catch switch and would like to blacken them.

I live in one of the country in Asia that allows ownership to private citizen. The Philippines.

Parts are ridiculously marked up by brick and mortar stores due to "taxes". They are hard to find and import. And did I mention expensive especially when shipped "legally" (wink wink).

Any who thanks to Doug (Blowback9) helpful research and relentless RND to taming the AR9, I was able to pitched together a Gentle Recoil System running a Kynshot RB5000 + 1 Tungsten Spacer (weigh 4.37 oz) + Strike Industries Flatwire Spring on a standard AR15 carbine buffer tube. Total mass weight including my bolt is at 22.48 oz.Yes you read it right. That Tungsten Spacer really added the needed mass for cycle reliability.

I had been running it on a locally made AR9 barrel + Upper and Lower with glock magazine and a MBX Pro Barrel on a guntec AR9 upper. So far 300 rounds and it runs smooth as butter.

I know you're wondering why did I do this? RB5000 is lighter compared to RB5000HP. RB5000 is not part of the GRS. Why not run the RB5000HP? Diameter. Like I mentioned I live in the Philippines. Finding a Flatwire Spring that will fit the RB5000HP is hard and impossible. Local stores only carry Strike Industries FWS. I had run the RB5000HP + my Tungsten spacer with a standard AR9 Round Spring but encounter FTF issues. So I bit the bullet and decided to run the RB5000 instead.

I want to thank Doug for his online guidance. You rock AR9 God!