I have a 10.5" 5.56 SBR upper and enjoy it quite a bit. The 10.5" barrel still gives you good velocity and that plus flash cone makes it no more a nuisance to shoot than a 16" barrel (at least IMO). I'm thinking about getting a 9mm upper and magwell conversion as well. This will most likely be a range toy so the magwell conversion will be for Glock mags since I already have an abundance of them. I'm looking for opinions on barrel length and manufacturer. I have seen videos of people shooting 4" barrels with a 6" handguard and it looks super fun. PSA seems to put these together for a good price. Also, can I run a stock buffer setup? Thanks!
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9mm AR SBR Build
- Thread starter Shawnyc
- Start date
Lot of questions there. The Glock conversions haven't typically been as reliable (purely allegorical feedback), 9mm doesn't need much more than a 6" bbl (powder is mostly burnt at 6"; mine are all 8" CMMG bbls), I'm not a PSA fan though they exist, you can start w/ a stock buffer but will likely need something around 8oz. (JP makes a very nice captured buffer system), since the AR9mm system does not have a locking bolt that makes OOB detonations more likely/possible so I tend to stick with high quality mfg's (which rules out PSA). Other will disagree, I only have 3 AR9mm uppers on four different lowers.
SJan
NES Member
Have you researched a glock magwell conversion? What one do you plan to use?
For the buffer setup - you will at least need a dedicated 9mm buffer. They are 5.5oz up to 10 oz, and I recommend one that is also longer than a standard carbine buffer. That will reduce the un-needed travel of the bolt. A stock carbine spring will do, but you may want to experiment with something stronger, like a AR10 spring.
For the buffer setup - you will at least need a dedicated 9mm buffer. They are 5.5oz up to 10 oz, and I recommend one that is also longer than a standard carbine buffer. That will reduce the un-needed travel of the bolt. A stock carbine spring will do, but you may want to experiment with something stronger, like a AR10 spring.
I don't know about barrel length but I've seen reports of Stern conversion kits being pretty reliable. That's the kit i was going to try out if i were to do a 9mm build. They don't ship to mass but I'm sure you just need to get creative to get one. If you try it, I'd be interested in seeing how you make out with it.
Products
Products
Military Arms Channel reviewed this one and it looks pretty good: MAG-AD9
These kits look decent and I was considering their magwell adapter. Do you know where you have seen the reviews?
You don't actually NEED a 9mm buffer. Start with a carbine buffer and tune from there. As for the length, a simple chunk of nylon works perfectly fine. Some guys even use quarters taped together as there isn't anything special about being a spacer.
SJan
NES Member
It is a small investment for a dedicated 9mm buffer, with the correct weight and length to almost guarantee proper function. I have fired dozens of 9mm carbines, built by people who have experimented extensivly with buffer weights and spring combinations, and ALL of them run a buffer that is 6oz or heavier
The problem with a stack of quarters is you are shortening the effective length of the buffer tube, in regards to the buffer spring. (And you are adding preload to the spring, but that may actually be a benefit) While with a longer buffer, you still have all of the space for the spring to not bind.
After all of my own testing, I settled on a viltor A5 tube (longer than regular carbine tube). In it I have a 3 stage recoil system.
Aaaand back to my original point: Don’t gaf what all of your friends run or what they experimented with. Still not necessary. Might run “better” and it might not; the buffer system needs to match the gun, the loads, and the purpose. You don’t need a heavy buffer to make a budget AR9mm run.
Ftr, lengthening of the buffer vs shortening the tube still give the spring the same amount of space to compact in. The Tacom stuff is overkill for a guy looking at PSA uppers.
Ftr, lengthening of the buffer vs shortening the tube still give the spring the same amount of space to compact in. The Tacom stuff is overkill for a guy looking at PSA uppers.
SJan
NES Member
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I have just completed a non-SBR 9x19 EBR conversion from 5.56 and very recently received notice from the DOJ that my application to convert one of my ARs into a 9x10 SBR has been approved and I will get the stamp shortly.
I decided to forgo Glock mag lowers since true pre-pan 33 round magazines are on the shelf right behind the hens teeth. Legit, for real, pre-94, 32 round UZI mags are available from www.robertrtg.com for $12.95 - less if you buy in bulk or get lower grade ones with surface rust. They are available for only a little bit more at GFA arms in Natick. +10 extensions are available from Taylor Freelance taylorfreelance.com (long springs an extra $10 or so). The Rock River Arms www.rockriverarms.com conversion block for $175 is excellent, and converts a regular lower to a Colt/Uzi mag lower for $175 with no modification or damage to the lower.
The UZI mags are built like a tank and will take far more abuse than a Glock mag.
The limitation is that the Uzi mags must have a new notch cut, and they also do not provide last round hold open. I recommend using a milling machine to cut the notches (the Japanese Nissin CNC unit does a great job), but SJan did it with a dremmel and the roughness of his notches will not prevent him from easily whomping me at a match since I've never seen his jam on the field of honor.
As to uppers - JPs occupy the pointy part of the cool/quality pyramid, as does their captive buffer unit.
I decided to forgo Glock mag lowers since true pre-pan 33 round magazines are on the shelf right behind the hens teeth. Legit, for real, pre-94, 32 round UZI mags are available from www.robertrtg.com for $12.95 - less if you buy in bulk or get lower grade ones with surface rust. They are available for only a little bit more at GFA arms in Natick. +10 extensions are available from Taylor Freelance taylorfreelance.com (long springs an extra $10 or so). The Rock River Arms www.rockriverarms.com conversion block for $175 is excellent, and converts a regular lower to a Colt/Uzi mag lower for $175 with no modification or damage to the lower.
The UZI mags are built like a tank and will take far more abuse than a Glock mag.
The limitation is that the Uzi mags must have a new notch cut, and they also do not provide last round hold open. I recommend using a milling machine to cut the notches (the Japanese Nissin CNC unit does a great job), but SJan did it with a dremmel and the roughness of his notches will not prevent him from easily whomping me at a match since I've never seen his jam on the field of honor.
As to uppers - JPs occupy the pointy part of the cool/quality pyramid, as does their captive buffer unit.
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I had a friend do my mag conversion on a $300K Japanese 5 axis milling machine, but that is overkill.
I expect GFA/Natick would be able to do it, provided you exercised good manners and bought the mags from him (he has them in stock). You'll pay a couple more $$ each than mail order, plus sales tax, but it will be worth it if you have him notch them. You would have to buy enough to make it worth Greg's time to move all the stuff he has piled on his Bridgeport. He also has original pre-ban Colt 32 rounders in stock for just under a c-note each. This is less that the asking price in the NES classifieds. Both options are considerably less than trying to track down pre-ban (single notch) Glock 9x19 33s.
Our local PCC (pistol caliber caribine) USPSA Grand Master did his with a dremel. They look ugly, but work flawlessly.
SJan
NES Member
Who you callin' ugly?
Ok, the first few were failed attempts to get the height of the notch correct, I later perfectet the process.... It helps that I got those mags when they were about $8 a piece.
boilermaker
NES Member
Yeah, upper left.....you have to admit that is ugly.
The rest look good enough and who cares as long as they function. Nice job!
The rest look good enough and who cares as long as they function. Nice job!
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I hate to disagree with big blue but the shorter unsupressed 9mm sbr are far more finicky.. as far as ballistics or velocity for a range toy it doesnt matter...also dor hunting...im pretty sure itll be deadly at close range (1-300 yards)
For mags.. id just go colt ove some hackjob, unless you got the mags to be hacked for free
I also have like 8 different 9mm buffers..what works for a buddy or you read online may not work for you...I recommend experimenting with different stack of quarters as a spacer
For mags.. id just go colt ove some hackjob, unless you got the mags to be hacked for free
I also have like 8 different 9mm buffers..what works for a buddy or you read online may not work for you...I recommend experimenting with different stack of quarters as a spacer
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Colt mags can be had for well under a hundred if you can wait and or you buy in bulk. I gobbled mine up for $25 (after waiting 2 years)
If you get them for under 50 its a good investment...
Its very similar to the true ceiner 32 rd .22 LR mags.. they go for over 100 all the time.. but can be had for $30 from somone who just doesnt know the value.
Preban Glock mags seem to always be more than any orher option
If you get them for under 50 its a good investment...
Its very similar to the true ceiner 32 rd .22 LR mags.. they go for over 100 all the time.. but can be had for $30 from somone who just doesnt know the value.
Preban Glock mags seem to always be more than any orher option
