Dedicated lower or conversion

[chenault]

I feel like an idiot asking these questions sometimes, but I haven't found an answer in any of my searches.  I'm looking to get into PCC, and was wondering if I can use a reg ar lower with a mag conversion and have a magwell for 9mm, or is it just better to get a dedicated lower?

 

Edited December 19, 2018 by chenault

[Darqusoull13]

10 minutes ago, chenault said:

I feel like an idiot asking these questions sometimes, but I haven't found an answer in any of my searches.  I'm looking to get into PCC, and was wondering if I can use a reg ar lower with a mag conversion and have a magwell for 9mm, or is it just better to get a dedicated lower?

 

Get the dedicated lower. You will just end up keeping a conversion in the lower all the time eventually and from what I understand you're forced to used Colt pattern mags. My match experience is that the conversions are more prone to malfunctions. 

With the dedicated lower like a GMR-15 you have a super reliable system, awesome mags (GLOCK-brand-GLOCK), unreal aftermarket support and an unreal amount of options to personalize and optimize your gun for you. 

[brix]

I feel like an idiot asking these questions sometimes, but I haven't found an answer in any of my searches.  I'm looking to get into PCC, and was wondering if I can use a reg ar lower with a mag conversion and have a magwell for 9mm, or is it just better to get a dedicated lower?
 

It's not a dumb question. I've been running a dedicated qc10 but was intrigued by the Stern defense conversation so I got one. Other than the mag release, its not a bad deal just going with a conversation. Taccom has tested their buffers with this setup witb success if you wanted to get a dedicated buffer although Stern recommends that a standard AR buffer be used.
An adapter is not a bad way to go, especially if your in a restricted state or your lgs doesn't carry dedicated lowers. I'm finishing building a second pcc on a Stern defense with a spare lower and it's been great so far.

Sent from my moto g(6) using Tapatalk

[chenault]

I ask because I have a spare lower with a stamp which could be dedicated towards 9mm, but I wouldn't have to worry about the whole weld to 16" business 

[Darqusoull13]

1 minute ago, chenault said:

I ask because I have a spare lower with a stamp which could be dedicated towards 9mm, but I wouldn't have to worry about the whole weld to 16" business 

Electronic Form 1's are between 11 and 15 days. Because of that I just put in paperwork for a couple more stamps. I actually ordered a spare GMR-15 lower just to SBR it. Yes, it's annoying and taxation is still theft. But I want my shorties just like you. 

[MoRivera]

Living in CT, we can buy 'other' AR formats, but they have to have an arm brace, which will officially exclude them for use as PCC in many competitions.  So I went with a pre-ban AR lower for a dedicated PCC (as it was the only way to legally put a stock on) and use a Stern Defense magwell converter for 9mm Glock mags.  The relocated eject button takes a little getting used to, but for me it became very intuitive.  The Stern has last-round-bolt-hold-open, which I find useful because I live in a state that bans 'high-capacity' magazines, and some IDPA matches that I shoot PCC in have stages with mandatory reloads after six shots or what have you.

 

My only complaint about the Stern adapter was that the magwell opening was rather tight and it would be nice to have it more funneled for mag changes.  But now Stern also sells an attachable delrin magwell funnel, and that helps tremendously.

 

Altogether it was a lot to spend.  If I lived in a free state, I would most definitely have started with a dedicated lower. or just have gotten a Sig MPX or CMMG Guard.

[bwikel]

1 hour ago, chenault said:

I ask because I have a spare lower with a stamp which could be dedicated towards 9mm, but I wouldn't have to worry about the whole weld to 16" business 

I stated this way with a 10.5 in upper and a colt conversion block. It served me well but the conversion blocks can be finicky and be unreliable if not set up just right. I have since moved to a dedicated lower since I wanted to use my stamped lower for the original purpose and pulling the block in and out drives most of the reliability issues for the 9mm set-up. 

 

Another option would be use endomags on the stamped lower with no conversion block. This is a good option if you aren't interested in competitive matches like USPSA or UML. If you are planning on using the PCC in matches just go ahead and get the dedicated lower, you will end up there eventually. 

 

 

[Tampa-XD45]

You can use your current lower with a mag conversion block.  Unfortunately a good mag block like the Hahn is going to be around $200

Stern Defense & Sylvan Arms make Glock mag blocks for $120 - $180.  I haven't tried them.  I have used Spikes Tactical & Hahn mag blocks.

 

You can get a complete PSA Glock style lower for about the same cost as a good mag block.

I run Colt mags with a mag block only because I use a registered SBR lower and I can remove the mag block and use a 556 upper.  I built mine 5 years ago before any of the current AR9 options existed.

 

If I were getting into the AR9 platform today, I would buy a dedicated Glock style AR9 lower or complete gun.  Your budget will dictate the brand.

[Aircooled6racer]

Hello: I have used the Hahn block that inserts from the bottom with Colt style magazines. It worked 100% with Metalform magazines. If you have a SBR lower and want a SBR 9mm  I would do the magazine insert. If you want a dedicated AR9 I would get a QC10 lower and build on that with a 16" barrel. I have both a Glock and Colt QC10 lowers and they have been great. Currently working on a 40 S&W upper for the Glock lower. The Glock lower gives more options for what ammo you want to shoot with different magazines. QC10 also make a large magazine lower for Glock magazines. Lots of cool stuff out there for PCC even a Sig MPX, Guard and Mech Tech. Thanks, Eric

[chenault]

Hmm sounds like a dedicated lower would be the best way to go.  

[chenault]

I'll look at the cq10 lowers.  Anyone try the cmt lower?  Their ar lowers are excellent

[Matt1911]

I have both, and although they are both reliable, I choose the dedicated lower for competition because the mag changes are much easier on the Glock lower. 

The Colt lower with Hahn mag block requires a really hard slap to make sure the mag seats.

[MemphisMechanic]

7 hours ago, chenault said:

I'll look at the cq10 lowers.  Anyone try the cmt lower?  Their ar lowers are excellent

 

QC10 not cq  

 

I have a QC10 Colt mag lower with a giant @bmiller magwell on it that I’ll be looking to sell here in the classifieds after the first of the year.

 

I’ll probably have to re-cerakote it though. It doesn’t match anything.  

 

[tha1000]

21 hours ago, chenault said:

I ask because I have a spare lower with a stamp which could be dedicated towards 9mm, but I wouldn't have to worry about the whole weld to 16" business 

 

My main gat  has a dedicated lower and 14.7" upper with a welded comp, but I have had a colt 6450, which is a 556 lower with a 9mm mag block, for decades that has never once given me any issue.  I also have an unbuilt 556 stamped lower and as time and money permit, i am going to build me an 8~" sbr for in state matches.  I don't see why a 556 magwell wouldn't help on a 9mm with a block, the block kind of acts like a magwell at the front and back anyway, but I haven't messed with it.

 

If you do go with a dedicated lower, I would let magwell availability dictate which lower I bought.

Edited December 20, 2018 by tha1000

[chenault]

45 minutes ago, tha1000 said:

 

My main gat  has a dedicated lower and 14.7" upper with a welded comp, but I have had a colt 6450, which is a 556 lower with a 9mm mag block, for decades that has never once given me any issue.  I also have an unbuilt 556 stamped lower and as time and money permit, i am going to build me an 8~" sbr for in state matches.  I don't see why a 556 magwell wouldn't help on a 9mm with a block, the block kind of acts like a magwell at the front and back anyway, but I haven't messed with it.

 

If you do go with a dedicated lower, I would let magwell availability dictate which lower I bought.

This is good to know.  There is a lot to consider.  I just read through a lot of buffer stuff and I'm beginning to realized how complex this will be if I really want to be competitive at some point

[jackson923]

I have two dedicated 9mm platform rifles and have not had issues.  Guys at my local club with the early version mag blocks had a lot of issues with reliability. 

[chenault]

6 hours ago, jackson923 said:

I have two dedicated 9mm platform rifles and have not had issues.  Guys at my local club with the early version mag blocks had a lot of issues with reliability. 

 

Do your reloads differ in speed from a dedicated lower? Do they make magwells for the full size? 

[MoRivera]

As I mentioned above, the Stern Defense magwell converter has been very reliable and they also now make a flared well that you can attach to it, which helps a lot with mag changes.

 

https://www.brownells.com/rifle-parts/receiver-parts/magazine-parts/magazine-hardware/ar-15-9mm-mag-ad-flared-magwell-prod123398.aspx

 

 

But still, if given the option like in other states, I would have started with a dedicated unit.

[chenault]

Sorry, I missed that somehow

[chowellacsbd]

+1 for the Stern defense conversion. I use it on my sbr. Cross machine tool makes a very nice billet ar9 lower. No hiccups with Glock 33rd mags.

[jackson923]

On ‎12‎/‎20‎/‎2018 at 6:31 PM, chenault said:

 

Do your reloads differ in speed from a dedicated lower? Do they make magwells for the full size? 

I do not have a lower with a mag block to compare on a chronograph.  I just know that guys at my local club with mag blocks in their regular AR's have issues with feeding and reliability. 

[cconnection]

No one talked about ambi?  If you are a lefty and need ambi mag release you must use a conversion ( and they are getting better)  Because I had to use conversion I actually epoxied the blocks into the mag well so I did not have issues with blocks moving. There were no ambi dedicated lowers to be had, until recently.   I recently purchased the Gibbz Arms G-9 full Lefty setup.  ( they have standard as well ) but they are dedicated upper and lower with a dedicated bolt.  Super nice, so I am told.  will report back when I get built.