Any Modern Sporters been built in 9mm?

jiffx2781

jiffx2781

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Curious if anyone has (or knows of anyone who has) put a MS together in 9mm? If so what components were used?

Bolt carrier group? I already have a Spikes Tactical (Glock and Colt compatible) which should be fine?

Magwell adapters that worked with the MS? Glock or Colt pattern? Pros or cons of either type? What brand of adapter? I already have both Glock and Colt mags so either type doesn't matter as far as mags go. More concerned about the magwell adapters fitment and functionality.

Buffer and spring? Regular carbine buffer spring? What buffer weight? Not much for 9mm buffers sitting anywhere right now but I do have an Odin Works AR15 Adjustable Heavy buffer which can go up to 5.8 oz. I would have to use a spacer in the rear of the receiver extension so the bcg doesn't travel as far back with the regular AR15 lenght buffer no? Is a 5.8 oz buffer heavy enough combined with the bcg which weighs ~15 oz?

NR length barrel. Got it covered if I go through with it.

And before anyone says anything, this will be built for my buddy Mike.

Thanks for any info that will help him out.
 
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For adaptors the Stern Defense works well, but the caveat is you need to retrain your brain to use the push magazine adapter button. Some times I had mistakenly pushed the AR mag release with some issues during PCC matches. A positive is it is well made and solid with no slop and has last round bolt hold open built in.

Back in the day before I sold the MS I used the ODIN 9 mm buffer and 5 quarters for the spacer in my Mil Spec Carbine extension. The quarters allow you to play with the bolt cycle distance before cutting a solid piece of plastic or using the item that comes with the JP Silent capture kit.


If you do not prefer an adapter these also work.


Faxon bolt and barrel.
 
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Sqr said:
For adaptors the Stern Defense works well, but the caveat is you need to retrain your brain to use the push magazine adapter button. Some times I had mistakenly pushed the AR mag release with some issues during PCC matches. A positive is it is well made and solid with no slop and has last round bolt hold open built in.

Back in the day before I sold the MS I used the ODIN 9 mm buffer and 5 quarters for the spacer in my Mil Spec Carbine extension. The quarters allow you to play with the bolt cycle distance before cutting a solid piece of plastic or using the item that comes with the JP Silent capture kit.

IMG-0640.jpg


IMG-0641.jpg


IMG-0646.jpg


IMG-0648.jpg


If you do not prefer an adapter these also work.

IMG-0645.jpg


Faxon bolt and barrel.

IMG-0644.jpg
Click to expand...

Thanks for the info and pictures.

Using the quarters as spacers to gauge what lenght of spacer you need to cut is a great idea.

Also am I on the right track in thinking that the P-Mag conversion kits would need blocked to 5 rounds? Cool idea and a cleaner build without the need for a magwell adapter but I think only 5 rounds?
 
jiffx2781 said:
Thanks for the info and pictures.

Using the quarters as spacers to gauge what lenght of spacer you need to cut is a great idea.

Also am I on the right track in thinking that the P-Mag conversion kits would need blocked to 5 rounds? Cool idea and a cleaner build without the need for a magwell adapter but I think only 5 rounds?
Click to expand...

Yes five rounds with the rivet down near the base plate if you do not cut the spine spacer. They come setup for 10 rounds and can bet set in plus five increments by trimming the spacer.

It's surprising how much force the quarters take which is enough to deform them.
 
This is a good thread. I was just thinking about this concept. That Stern adapter gets great reviews, but the mag release relocation bothers me. After 20 years of training and shooting ar15s I’ve got a lot of muscle memory built up...
 
Some general knowledge of the important stuff I learned while I was still building one, before May:

I used the CNA colt mag adaptor from TNA, On my rifle (ser# first 200) it fit perfectly in the lower; the upper however was a different story. At the front of the receiver behind the front pivot pin lug there is that flat area of metal and it extends into the magwell area by a few thou (literally, you can see clearly through the pivot pin pin hole but there is the tiniest sliver of metal, so you can see that it is too far forward for the pin). So if you you buy a TNA and maybe others of the same colt drop in style, you may have to sand a few thou off a 3/4" rectangle front face of the adapter from the top.

After building up the receiver into something else; I finally tried the other version of this receiver (that are made in the UK) and I can report that upper and lower fit together fine with the same conversion block, but because of the tight magwell I had to sand the sides of the adaptor a few fractions of an inch (and got it stuck inside the magwell when I became impatient, no matter, it is was planned to be permanently 9mm anyway). If you are looking for the easiest way to go with the colt style adaptor, I heartily recommend the ATRS set for being WAAAAAY less sanding.

Just remember on the buffer too. It needs to be 9mm (or A5) length (unless you want to eat bolt catches every few hundred rounds) and at a minimum 5.6oz (what is in my colt AR) weight but have heard of guys going to almost 10oz. Before finding an A5 length I was planning on making a small spacer in the rear of the receiver extension with a cut down buffer tube+plastic end piece to get the right size, but I’ve heard of guys using aluminum dowels and even stacks of quarters in the states.

Also, I had looked at using a silent (or captured) buffer system, but if you do, you will need a bolt with the weight pinned INSIDE the bolt NOT the ones that have it pinned in to the back of the bolt (like New Frontier Armoury or the ones currently sold at TNA) as they will be too short and probably bust up your lower and upper.


As for functioning, everything seems to function fine(mags drop and retain, bolt catch functions, everything fits together) on Colt/USGI style parts but without a barrel, I can’t tell you 100%

Anyway my gun (before May of course) WAS only missing a barrel so if you get a run done, let me know.
 
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MACH said:
Some general knowledge of the important stuff I learned while I was still building one, before May:

I used the CNA colt mag adaptor from TNA, On my rifle (ser# first 200) it fit perfectly in the lower; the upper however was a different story. At the front of the receiver behind the front pivot pin lug there is that flat area of metal and it extends into the magwell area by a few thou (literally, you can see clearly through the pivot pin pin hole but there is the tiniest sliver of metal, so you can see that it is too far forward for the pin). So if you you buy a TNA and maybe others of the same colt drop in style, you may have to sand a few thou off a 3/4" rectangle front face of the adapter from the top.

After building up the receiver into something else; I finally tried the other version of this receiver (that are made in the UK) and I can report that upper and lower fit together fine with the same conversion block, but because of the tight magwell I had to sand the sides of the adaptor a few fractions of an inch (and got it stuck inside the magwell when I became impatient, no matter, it is was planned to be permanently 9mm anyway). If you are looking for the easiest way to go with the colt style adaptor, I heartily recommend the ATRS set for being WAAAAAY less sanding.

Just remember on the buffer too. It needs to be 9mm (or A5) length (unless you want to eat bolt catches every few hundred rounds) and at a minimum 5.6oz (what is in my colt AR) weight but have heard of guys going to almost 10oz. Before finding an A5 length I was planning on making a small spacer in the rear of the receiver extension with a cut down buffer tube+plastic end piece to get the right size, but I’ve heard of guys using aluminum dowels and even stacks of quarters in the states.

Also, I had looked at using a silent (or captured) buffer system, but if you do, you will need a bolt with the weight pinned INSIDE the bolt NOT the ones that have it pinned in to the back of the bolt (like New Frontier Armoury or the ones currently sold at TNA) as they will be too short and probably bust up your lower and upper.


As for functioning, everything seems to function fine(mags drop and retain, bolt catch functions, everything fits together) on Colt/USGI style parts but without a barrel, I can’t tell you 100%

Anyway my gun (before May of course) WAS only missing a barrel so if you get a run done, let me know.
Click to expand...

Lots of good info. Thank you.
 
Also, some minor, but important 9mm specific quirks that I had forgotten to add:

Use stainless steel trigger pins (very important according to Colt engineering/demonstration-type Chris Bartocci; a man who worked on the 9mm ARs) as the increased bolt thrust causes A LOT of stress on the FCG and Bartocci states it’s not a matter of “if” but “when” they break so go stainless to extend their life and maybe keep a few extra.

Also, be careful of aftermarket triggers, many have hammer designs that have issues with 9mm bolts, and with the numerous makes of triggers+bolts, unless you or someone has tried it, there is no guarantee that particular bolt works with that particular trigger

If you do use USGI style parts, make SURE your hammer is a full face, NOT one of the ones that has the notch cut out at the top where it strikes the firing pin. Full face USGI style hammers are the safest option IMO.


And to clarify, the reason TNA/New Frontier style bolts don’t work with captured (or Armaspec SMB) buffers is because to accommodate the guide rod on the buffer assembly, the weight that is pinned in or to the back of 9mm bolts must be removed and this removal would leave the TNA/NF bolts too short (or maybe a hole could be drilled in the weight and the buffer end chamfered, but this requires someone who is much more adventurous and has access to more professional tools as well as willingness to risk breaking a few eggs/buffers/bolts or even receivers than I to make sure it is functional).

As a free bonus (seems obvious, but many overlook it) - make sure to “time” (aka bend) the ejector on your conversion block (if of the colt style, YMMV on others like the Stern as I’ve never played with one) so it rides juuuuust not quite touching your bolt (some even say a liiiiitle bit of contact is okay), but the amount of inwards bending is ultimately tied to as much as needed to get reliable ejection. Forgetting to time the ejector on brand new parts is the #1 reason people have failures to eject on these 9mm platforms.

Oh and buy an Uplula no matter which way you go, because using your hands when loading glock mags is annoying but doable, Colt SMG mags are downright painful on the other hand.

Hope all your 9mm projects are successful. I know my (rest in prohibition) Colt 9mm was my favourite gun. It was a ton of fun and cheap to shoot.
 
MACH said:
Also, some minor, but important 9mm specific quirks that I had forgotten to add:

Use stainless steel trigger pins (very important according to Colt engineering/demonstration-type Chris Bartocci; a man who worked on the 9mm ARs) as the increased bolt thrust causes A LOT of stress on the FCG and Bartocci states it’s not a matter of “if” but “when” they break so go stainless to extend their life and maybe keep a few extra.

Also, be careful of aftermarket triggers, many have hammer designs that have issues with 9mm bolts, and with the numerous makes of triggers+bolts, unless you or someone has tried it, there is no guarantee that particular bolt works with that particular trigger

If you do use USGI style parts, make SURE your hammer is a full face, NOT one of the ones that has the notch cut out at the top where it strikes the firing pin. Full face USGI style hammers are the safest option IMO.


And to clarify, the reason TNA/New Frontier style bolts don’t work with captured (or Armaspec SMB) buffers is because to accommodate the guide rod on the buffer assembly, the weight that is pinned in or to the back of 9mm bolts must be removed and this removal would leave the TNA/NF bolts too short (or maybe a hole could be drilled in the weight and the buffer end chamfered, but this requires someone who is much more adventurous and has access to more professional tools as well as willingness to risk breaking a few eggs/buffers/bolts or even receivers than I to make sure it is functional).

As a free bonus (seems obvious, but many overlook it) - make sure to “time” (aka bend) the ejector on your conversion block (if of the colt style, YMMV on others like the Stern as I’ve never played with one) so it rides juuuuust not quite touching your bolt (some even say a liiiiitle bit of contact is okay), but the amount of inwards bending is ultimately tied to as much as needed to get reliable ejection. Forgetting to time the ejector on brand new parts is the #1 reason people have failures to eject on these 9mm platforms.

Oh and buy an Uplula no matter which way you go, because using your hands when loading glock mags is annoying but doable, Colt SMG mags are downright painful on the other hand.

Hope all your 9mm projects are successful. I know my (rest in prohibition) Colt 9mm was my favourite gun. It was a ton of fun and cheap to shoot.
Click to expand...

The CMMG delayed blowback design was specifically engineered to minimize the bolt thrust.
 
Sqr said:
The CMMG delayed blowback design was specifically engineered to minimize the bolt thrust.
Click to expand...

Which is the system I originally was interested in using. Lots of good information out there leading me to believe it's a better system than the standard blowback. And it allows you to get away with using less operating mass. Lighter firearm, smoother recoil impulse etc...

But the usual US ordering sources have left me empty handed. A couple of them are out of stock and the one that does have it won't ship a bcg anymore without an additional export permit $$$ :(

Oh well, doesn't matter now that all I'm possibly needing for parts is a heavier buffer.
 
jiffx2781 said:
Which is the system I originally was interested in using. Lots of good information out there leading me to believe it's a better system than the standard blowback. And it allows you to get away with using less operating mass. Lighter firearm, smoother recoil impulse etc...

But the usual US ordering sources have left me empty handed. A couple of them are out of stock and the one that does have it won't ship a bcg anymore without an additional export permit $$$ :(

Oh well, doesn't matter now that all I'm possibly needing for parts is a heavier buffer.
Click to expand...

I am not sure if you know but the CMMG is not just the bolt carrier group as the barrel extension is also different so an entire kit is required.
 
Sqr said:
I am not sure if you know but the CMMG is not just the bolt carrier group as the barrel extension is also different so an entire kit is required.
Click to expand...

Yes but I was thinking that a good gunsmith should be able to salvage the CMMG barrel extension. Then a barrel could be made to the appropriate length.

Either way it's not really the most cost effective way to go about it.
 
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