Will a standard rifle buffer (5.56mm Bushmaster) and spring work with an Olympic upper? Or do I need to buy a 9mm buffer?

(I will be using an A1 stock from Cav Arms, with a full length buffer tube and spring.)

I'm pretty sure you need a 9mm buffer since the 9mm bolt is a different size/weight than the .223 bolts.

Originally Posted By Lapp_Dance: Will a standard rifle buffer (5.56mm Bushmaster) and spring work with an Olympic upper? Or do I need to buy a 9mm buffer? (I will be using an A1 stock from Cav Arms, with a full length buffer tube and spring.)

Standard buffers will typically work.  Occasionally some people have problems with "bolt bounce" and need to use the heavier 9mm buffer, but 97% of the time your standard .223 buffer and spring will work.

Originally Posted By Lapp_Dance: Will a standard rifle buffer (5.56mm Bushmaster) and spring work with an Olympic upper? Or do I need to buy a 9mm buffer? (I will be using an A1 stock from Cav Arms, with a full length buffer tube and spring.)

The 9mm buffer will be too short, unless you use a spacer.


If you find that you need to increase the mass of your rifle buffer, shoot me an email and I'll tell you how to proceed.

FYI if you need a muzzle brake for your 9mm AR if you live in a state with a ban, try Brownells.

Question for Oly 9mm Glock... Any info on it, I heard that Oly uses a magwell that only uses glock mags and has no factory mod. Is this true? If so, can one use ANY 9mm upper with this lower? I have a Glock 17 with 32rd mags and could use them in this system, and my overall objective would be to SBR it and add a can, I like the Gemtech complete upper and wonder if that would work with the Oly glock lower, as this is made for Colt 9mm AR15...  Thanks

Originally Posted By fdawg: Question for Oly 9mm Glock... Any info on it, I heard that Oly uses a magwell that only uses glock mags and has no factory mod. Is this true? If so, can one use ANY 9mm upper with this lower? I have a Glock 17 with 32rd mags and could use them in this system, and my overall objective would be to SBR it and add a can, I like the Gemtech complete upper and wonder if that would work with the Oly glock lower, as this is made for Colt 9mm AR15...  Thanks

I am pretty sure you can only use an Oly upper with their dedicated Glock mag lower.  the feed position on the Oly and Colt systems is different.  I am not syaing that it couldn't be made to work, but it probably would require some WECSOGing to get to operate.

Thanks I was afraid of that....

Will a 5.56 hammer work in a 9mm?

Will a 5.56 hammer work in a 9mm?

If it's an Oly upper:  yes.
If it's a Colt-style upper:  maybe.

If the 5.56 hammer has the notch at the top front like most then it won't work unless the bolt is ramped.  If the hammer does not have the notch, like DPMS and maybe some newer ones from other brands, then it'll work.

Originally Posted By David_Hineline: If it were me and I wanted to use the Glock lower I would buy a complete rifle from Oly, install a free float tube , cut the barrel short, and put a 3lug adapter onto the barrel, then use a 3lug silencer of quality and put it into the free float handguard.

What about the same thing with a 5" barrel threaded to 1/2 28 and a FIRSH carbine length and an Evolution-9 with the spacer sleeve?

Great thread for those of us who only have experience on the ".223" side.  Keep the posts coming - I'm learning something new every day and looking to build my 9mm lower within the next two weeks and buy a complete upper in the next 2 months.  I have two RRA stripped lowers that have been "collecting dust" for over a year now and I need to build something!!!

Thanks to all for the great advice.

Great info. I'm doing a 9mm build and have figured out from this post that I've got a little more research to do. Would love to find a 9mm bolt notched for a LL.

Originally Posted By Quarterbore: Thanks Again SBR7_11! I looked at my Jewell and it does have the same funky notch in the front side of the hammer.  I would like to keep my 2-stage trigger in my lower if I can so I guess I need to look for an M-16 style 9mm carrier, plan on modifying a semi 9mm carrier to work, or perhaps modify the jewell 2-stage trigger group's hammer. Thanks for helping a understand the 9mm system! FWIW:  I have a Colt 9mm Upper that I just bought with the JRW 2-pc block and a few modified UZI mags.  I just do not have the bolt/carrier group so I can actually use it.

 I realize that Im late to the conversation, but I have a Jewell trigger in my lower and my Colt style upper runs perfect.  Matter of fact, it bumps like a mother.

okay, looking over the FAQ, I was wondering... if you have a lower with a collapsable stock (M4, etc) and you swap the upper out with an Oly 9mm (or .45)  Upper, do you have to swap out the buffer? Or is there a buffer you can put in that is usable with both rifle and pistol calibers?

Seeing as the A2 buffer can be used with either.

No Expert

Got a 9mm AR question:

I've shot one in the past. I plan on getting one. However I've never taken one apart. So I don't quite fully understand the inner workings of a 9mm AR vs. a .223 AR.

Is there a line drawing diagram of a 9mm AR?

- The bolt and carrier are all (more or less) one piece with in a 9mm system in comparison to the way the .223 bolt and carrier work, correct?
- Does the receiver extension tube serve the same purpose that it does in a .223 AR? What I mean is on "blowback" does the bolt carrier group still enter into the RET?
- Is the buffer and buffer spring for a 9mm AR the same or is it better to have one specifically made for 9mm AR's?
- In a 9mm AR is the receiver extension tube just empty... basically just there to attach some type of stock onto?
Do you have to install something into the receiver extension tube to avoid the "bolt/carrier" from going as far into it as a .223 AR bolt carrier would?

I think some of thise stuff can be answered through pictures on quarterbore's page, but I kind of need it dumbed down and explained a little more... I'm stupid like that.

- The bolt and carrier are all (more or less) one piece with in a 9mm system in comparison to the way the .223 bolt and carrier work, correct?

Yes.  The bolt does not "lock up" like a .223 bolt.

- Does the receiver extension tube serve the same purpose that it does in a .223 AR? What I mean is on "blowback" does the bolt carrier group still enter into the RET?

Yes.  Bolt goes back into the tube just like a .223 AR.  "Blowback" means that the bolt isn't locked up and only its weight/inertia keeps it closed while the bullet is in the barrel.

- Is the buffer and buffer spring for a 9mm AR the same or is it better to have one specifically made for 9mm AR's?

If you have a rifle-length tube you can use the standard rifle buffer.  If you have a short CAR-length tube you should use a buffer heavier than the standard CAR buffer.  All of the "9mm" buffers are CAR-length and heavier.  Spring is the same as a .223 AR.

- In a 9mm AR is the receiver extension tube just empty... basically just there to attach some type of stock onto?

No.  It has a spring and buffer in it.  

Do you have to install something into the receiver extension tube to avoid the "bolt/carrier" from going as far into it as a .223 AR bolt carrier would?

No.  Unless you want to use a heavier "9mm" buffer in a rifle length tube, in which case you'd have to block for the short buffer in a long tube.  I did see something in a thread on bolt catches that if you're using the BHO feature you might want to install a block to minimize overtravel of the bolt to reduce abuse on the catch, but it's not necessary for functioning.

Originally Posted By Mike_L: Do you have to install something into the receiver extension tube to avoid the "bolt/carrier" from going as far into it as a .223 AR bolt carrier would? No.  Unless you want to use a heavier "9mm" buffer in a rifle length tube, in which case you'd have to block for the short buffer in a long tube.

Do not ever try to use a CAR buffer in a rifle tube, If you forget the spacer, accident waiting to happen.  The CAR 9mm buffer is nothing you or the rifle will ever notice, so just leave the std rifle buffer in place if using a rifle stock.  

IF you decide you want more weight in a rifle buffer, you can step up to 7oz by dumping the guts out of the rifle buffer and replacing with a machined brass dowel to fit inside, that is what I run for 9mm and 223 with an A2 stock, or remove some from the diameter of the dowel body in the middle area to tailor the weight to what you want.  

The added weight is good for me because I run a suppressor in 9mm, and that slows the debris from the eject port.  Another approach is to machine a rifle  buffer from stock, here is a 12.8oz stainless I use in my slowfire MAC.

So if I'm planning on putting an Ace Ltd. M4 SOCOM (collapsing stock) on a 9mm AR I should get a CAR buffer system?

Originally Posted By pathfinder74: So if I'm planning on putting an Ace Ltd. M4 SOCOM (collapsing stock) on a 9mm AR I should get a CAR buffer system?

You should get the 9mm buffer that's much heavier than the CAR buffer.  Spring is the standard CAR-length spring.  

hey look! here is page 4.

Originally Posted By ZW17: hey look! here is page 4.

No it's not.  It's still on page 3.

Now that i'm totally confused....I have a new stripped DPMS lower which i'm going to document and build as a pistol lower. I'm going with a 10.5" upper which i haven't purchased as of yet. I trying to decide what all i need to get the results i'm looking for. I'll lay it out, i'd like a 9mm which i can push the take down pins out, remove the mag block and put on a 5.56 upper when i feel like something different. I also need to know what lower parts i need so there's no changing hammers or whatever. Another member said he had this setup and he got his info at this forum. So i came here and starting reading Colt style, OLy style i've yet to figure out the difference. Can you not take a Colt lower and put a SOCOM Mfg block in it and shoot 9mm or pin a Colt mag block in an Oly lower. I'm must be missing something somewhere, lost in translation so to speak. Any help or clarification will be greatly appreciated. Any dumdass remarks will be respected.

As i read in one posting, does the Colt style / Oly style all boil down to the mfg's feed position?

[email protected]

Build the lower in the std fashion, it doesnt know what is up top..  Here is my my all purpose multi top swapping SBR.   Mine is of the "COLT" pattern for the 9mm.

Use a M16 hammer with the "offending" lug removed.  You can buy hammer like this from a few vendors with the lug already removed, I bought mine at the funshow some 10yr ago.



Run what you got, you want pistol, lose the stock -



Push the pins, swap the top,  lose the magwell adapter, and install a mag full of 556, and shoot -

Colt style, OLy style i've yet to figure out the difference. Can you not take a Colt lower and put a SOCOM Mfg block in it and shoot 9mm or pin a Colt mag block in an Oly lower.... As i read in one posting, does the Colt style / Oly style all boil down to the mfg's feed position?

"Colt" and "Oly" here refers to which of the two designs it uses.  It is indeed possible to put an Oly-style upper on a Colt-brand lower and vice versa, provided you use mag blocks to match the upper.  (An Oly-style upper on a Colt lower with Colt-style mag blocks won't work, and vice versa.)  RRA's uppers are clones of the Colt style.

The two designs differ primarily in the magzine type.  Colt uses a double-stack, double-feed magazine where the top round alternates sides like the .223 AR mags.  Oly uses the double-stack, single-feed Sten magazine which looks more like the double-stack pistol mags at the top.  The Colt style are a lot easier to load but the Stens are really cheap.   Oly welds a piece onto the back of the Sten mags so they don't need a mag block, but most everybody buys a mag block so they can use unmodified Sten mags.  Colt has their own mag and and can also use modified Uzi mags.

AFAIK all Oly-style mag blocks use a paddle mag release at the back of the block and not the normal AR mag release (which will drop the whole block out).  I don't think the bolt hold-open works with the Oly-style either.

At least some (all?) Colt-style blocks use the regular AR mag release and some will work with the bolt hold-open if you use the right mags.  

Colt-style requires a hammer without the notch at the front.  Colt has a special "9mm" hammer, but most people use one like SBR7_11 pictured, available from DPMS and others.  It works just fine with .223 uppers so no need to swtich back and forth.  I believe the Oly-style uppers work with the regular notched hammer.

Swapping to .223 simply requires swapping uppers and removing the mag blocks.   Removing the mag block involves varying degrees of difficulty depending on which block you use.  Oly-style drop right out by pushing the AR mag release unless they're pinned in.  Some Colt-style drop out easily like the Hahn bottom-load blocks.  Some require removing and/or changing the bolt catch like the Hahn semi-dedicated top load blocks.  If you want the bolt hold-open to work you'll probably have to take the bolt catch out when swapping, either to change from the "9mm" one to the regular one, or to get the Hahn blocks out.  

Thanks Mike_L that's cleared up a lot of questions i also had. What had me confused was the fact that i pretty much knew that all the .223 lowers where the same as far as machining specs . The same holds true for pretty much the uppers to. So the designation Colt style and Oly style actually refers to the type mag being used in the 9mm caliber and the type block needed to attach that mag.Thanks again.

David

I hope I got all that right.  I don't have a 9mm AR, but keep toying with the idea so I've been trying to keep up on the discussion of them here.   The actual shape of the bolt and barrel face is different between the two styles too, not just the mag-related parts, but the different mags is the key.  I believe some people have made the Sten mags work with a Colt upper too.

I forgot to mention that the 9mms require a heavier buffer.  The rifle buffer weighs about 5 oz. and is OK with .223 or 9mm.  The shorter CAR buffers are about 3 oz. and are too light for 9mm.  "H" buffers are heavier and "9mm" are heavier still.  They might function with the lighter buffers (and Oly says you don't need to change it) but at the very least it'll beat the gun up.  As far as I know the heavier buffers work with .223 as well so you wouldn't have to change back and forth.  The main side-effect to the heavier buffer for .223 is a slower cycle time, which is a non-issue with semi-auto anyway.

There's also the issue of ramping the bolt on Colt-style uppers.  This involves adding an angle to the back of the bolt so it cocks the hammer more smoothly, reducing wear and tear on the hammer pin.  I thought I read somewhere that a ramped bolt will work with a regular notched hammer, but I'm not sure about that.

I've read where DPMS, i think it was, has a hammer which will work with the 9mm and 223 uppers. Do you know if this is the hammer that comes in their std kit LPK-1 or is it an all together different creature.Thanks.

I believe the hammer they're talking about is the standard hammer from DPMS.  M-16 hammers have a rounded front and a hook at the back for the auto-sear.  Most AR-15 hammers have the hook cut off and a notch at the front.  The DPMS one has the hook cut off, but doesn't have the notch.  

Anyone hear in the grapevine if any other AR manufacturer is planning on doing a 9mm AR that accepts Glock magazines... or is it still just Oly?

I think i made a wrong turn. After reading a kazillion threads i thought i had it figured out until i went back and read them again. Double check my answers. ( 1 ) I've got a new DPMS lower which i'm building as a pistol lower, no problem here? ( 2 ) I've purchased a RRA 16" complete upper which i'm going to have cut down to 10.5", i hope i'm still alright ? ( 3 ) I purchased a SOCOM style mag block to use the Sten mags, will this work or do i need a Colt style mag block? I was under the assumption that you could use the Colt style upper and Sten mags as long as i used an OLY style mag block, or will i have to change my mag block? . If someone could clarify this i'd appreciate it. ( 4 ) I'm going to be be using a short pistol style buffer tube and i'm wondering what type of buffer i'll need to use to shoot both 9mm and 5.56 without changing it. Any help will be appreciated..

Thanks, David

[email protected]

Originally Posted By AllCn1: I think i made a wrong turn. After reading a kazillion threads i thought i had it figured out until i went back and read them again. Double check my answers. ( 1 ) I've got a new DPMS lower which i'm building as a pistol lower, no problem here? Not that I see, as long as it was purchased bare, fill in the 4473 to document "bare" or "pistol".. ( 2 ) I've purchased a RRA 16" complete upper which i'm going to have cut down to 10.5", i hope i'm still alright ? Cut is as short as you desire ( 3 ) I purchased a SOCOM style mag block to use the Sten mags, will this work or do i need a Colt style mag block? You bought a COLT pattern upper (barrel)....  the SOCOM Mfg block is for Sten mags, but this particular combo is used to feed the OLY system I was under the assumption that you could use the Colt style upper and Sten mags as long as i used an OLY style mag block, or will i have to change my mag block? If you desire to use STEN mags in the COLT system, you will neeed to cut up a COLT pattern block into 2 pieces and machine/alter it to accept STEN mags in the COLT position...  Look for a topic authored by "Brushdog" in regard to his 40 set-up, he is using modified COLT block set, or carefully breeze through the "sten mag in Colt system" topic tacked here, though it is rather beat up/fallen apart with the couple board re-dos', and pics being 'red X ".... . If someone could clarify this i'd appreciate it. ( 4 ) I'm going to be be using a short pistol style buffer tube and i'm wondering what type of buffer i'll need to use to shoot both 9mm and 5.56 without changing it. Any help will be appreciated.. Thanks, David [email protected]

Thanks again SBR7_11... I think i'll just sell the block i've got and get a drop in Colt style, i gave $45.00 for it shipped so that's what i'll sell it for.

David

[email protected]

tag

Originally Posted By fdawg:
Question for Oly 9mm Glock... Any info on it, I heard that Oly uses a magwell that only uses glock mags and has no factory mod. Is this true? If so, can one use ANY 9mm upper with this lower? I have a Glock 17 with 32rd mags and could use them in this system

Thinking of purchasing such a setup from Oly, however I get conflicting reports from this forum, so is oly the only manufacturer that makes a lower that can accept glock magazines? Someone else asked that question already and I don't really thing it was answered, is there any modification required in the glock 32rd mags for use in the oly lower? what about these magazine blocks I hear about, do they need to be used?  What manufacturers make upper assemblies that will work with the oly setup w/glock lower (bushmaster, RRA? or are these all the colt system?) I would purchase the entire rifle from oly, but I hear not so good things about them from the forums, plus their upper assembly doesn't come with a cromed barrel.

Does anyone have a oly using a glock lower in 9mm?  Have yet to see any reviews on it.

SWAT magazine ran an article on the Oly Glock AR (and .30 Carbine) sometime in the last year or so.  

As far as I know Oly is the only place making ARs that take Glock mags, and last I heard they won't sell just the lower.  IIRC from the SWAT article the mags are un-modified and the lower is one-piece, no mag blocks or anything.  I believe the upper is the same 9mm upper as they use in their Sten-mag version, but I'm not 100% sure of that.  The mag release was a teeter-totter sort of thing--push in where the normal AR release is and it pivots so that the other end swings out to disengage from the standard Glock notch.  

All of the other 9mm uppers (BM, RRA, etc) are Colt system, which feeds completely differently and wouldn't work with a Glock magzine.

Originally Posted By Mike_L: SWAT magazine ran an article on the Oly Glock AR (and .30 Carbine) sometime in the last year or so.   As far as I know Oly is the only place making ARs that take Glock mags, and last I heard they won't sell just the lower.  IIRC from the SWAT article the mags are un-modified and the lower is one-piece, no mag blocks or anything.  I believe the upper is the same 9mm upper as they use in their Sten-mag version, but I'm not 100% sure of that.  The mag release was a teeter-totter sort of thing--push in where the normal AR release is and it pivots so that the other end swings out to disengage from the standard Glock notch.   All of the other 9mm uppers (BM, RRA, etc) are Colt system, which feeds completely differently and wouldn't work with a Glock magzine.

Great info, anyone know which issue of SWAT that article was in so I can find it.  I think it might have been the August 2004 issue, but that was not last year?  SWAT's online archives only show you the preview of the article from what I can tell.  However it says they reviewed a PCR-9?  Oly's website has the glock lower reciever rifles listed as a K9-GL, are these the same thing?

Good to hear there is no mag blocks definate plus...I will have to check about their uppers, but since they are the only company that would make a compatible one I guess I'll have to deal w/ oly, perhaps I could get them to chrome the barrel for me, but their online catalog has it listed as a non chromed bore.  I can always go the cheap route if I want a rifle to shoot glock mags and go for a kel-tec sub 2000

I'm pretty sure the article in the August 2004 issue is the one I was thinking of.  Guess it was longer ago than I thought.  The rifle they reviewed was definitely the Glock mag lower, so Oly must have changed the name, or they got the designation wrong in the article.  

I wouldn't worry too much about the chrome barrel.  9mm doesn't burn them up like the .223s.

Great info Mike_L sounds like a winner, and I need to find a copy of that article

My situation:

I have my SBR lower registered in 9mm/.223.  It is currently set up for .223.  I want to use the Colt/RRA 9mm system so I permanently need:

DPMS M-16 hammer (after I shave the "nub")-  This will work w/both 9mm/.223 so I dont have to change the hammer back/forth??



Then to temporarily convert to 9mm:

9mm buffer- 20.00?
VM Hy-Tech mag block 126.00ish/Brownells
+ the 9mm upper and ramped bolt/carrier? (I would have needed this anyway)

I was going to have a dedicated 9mm lower but in rethinking it, it was going to run 350.00 for the complete lower + the 200.00 tax/transfer.  The above way is one lower w/minimal changes and 150.00(ish) vs. 550.00.

What else am I missing????

Originally Posted By scottMO: My situation: I have my SBR lower registered in 9mm/.223.  It is currently set up for .223.  I want to use the Colt/RRA 9mm system so I permanently need: DPMS M-16 hammer (after I shave the "nub")-  This will work w/both 9mm/.223 so I dont have to change the hammer back/forth?? DPMS sells the hammer without the offending sear lug also... Then to temporarily convert to 9mm: 9mm buffer- 20.00? What stock do you plan to run ?  If rifle, run what you have...  If CAR length tube, then the "9mm" or something of more weight will be fine.   If you run a suppressor, then you should plan on something like 7oz+.  Mine is set up with a 7oz rifle length buffer in a rifle stock VM Hy-Tech mag block 126.00ish/Brownells Install it, and use plain 25 round Uzi mags... those with the seam down the rear. + the 9mm upper and ramped bolt/carrier? (I would have needed this anyway) Need upper with a 9mm barrel, and a bolt, ramping is advised I was going to have a dedicated 9mm lower but in rethinking it, it was going to run 350.00 for the complete lower + the 200.00 tax/transfer.  The above way is one lower w/minimal changes and 150.00(ish) vs. 550.00. All the lower does is hold the upper in place, trigger group, and magazine in position... stick the block in to allow the smaller 9mm mag to fit. What else am I missing????

SBR,

Many thanks!!  This just keeps getting better!!

This will be in a CAR stock so looks like the 9mm buffer will be needed.  Looks like Brownells has the complete  9mm Carbine stock assembly for 31.69/24.90(dealer).

Mfr: COLT

FITS: AR-15 Carbine, 9mm; AR-15 Match Target Lightweight, 9mm
Catalog page 382

  Stock Number / Desc
  160-307-101
Buffer Assembly, Sliding Butt Stock   $31.69
$24.90

www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=4872&title=BUFFER+ASSEMBLY%2c+SLIDING+BUTT+STOCK


After re-examining my hammer in my SBR, it looks like I already have the hammer needed.  I assembled my lower from a DPMS LPK from Brownells.  Mine looks like the hammer #2 (in the middle of the pic of the 3 hammers on page 1).  

I plan on getting a dedicated SBR RRA 9mm upper and the bolt ramping.  This would have been done from the start.  Somehow I thought that there was not a universal hammer to use w/both the 9mm and .223 and figured the 2nd lower may be the only option (or a lot of hammer changes).    


scottMO

Does anyone out there have the latest info on where to get the SOCOM Oly 9mm mag block? Looks like SOCOM's last known website (www.socommfg.com) is coming up empty.

Also, I seemed to have lost the great thread done by a US Army Lt Col a few years back on sighting in a 9mm AR. Anyone have an idea on the new link? You can send me an email.

Thanks,
capt.john
phoenix27

Does anyone know of anybody making a mag block to use Colt type polymer mags in a Oly upper and lower?

I just got an email from Olympic Arms that states that their regular 9mm uppers will not work on their Glock type lower.

Has anybody tried this?

I just purchased a RRA 9mm. It uses modified uzi mags with no bolt hold open feature.I'm told that ProMag polymer mags will work in this application and also have the bolt hold open. Anyone know for sure.Thanks

Hey, I am looking to get a 9mm upper for my bushmaster xm-15 lower. I am curious as to which style mag block would work best? I looked in the FAQ  post on page 1 but only saw the Colt, RRA, and DPMS lowers mentioned. Which Is comparable to the bushmaster lower? (sorry if i overlooked any bushmaster info on page 1)

Thanks in advance! crossDawg

Originally Posted By crossDAWG: Hey, I am looking to get a 9mm upper for my bushmaster xm-15 lower. I am curious as to which style mag block would work best? I looked in the FAQ  post on page 1 but only saw the Colt, RRA, and DPMS lowers mentioned. Which Is comparable to the bushmaster lower? (sorry if i overlooked any bushmaster info on page 1) Thanks in advance! crossDawg

From what I've been reading here, it depends on which style upper you get. The lowers work with all the uppers, but the mag blocks are dedicated to what style upper you get.

Cazio

Has anyone used the Timney Trigger System on a 9mm?