QC10 Colt Pattern Lower w/UCIW Ultra Compact Stock & UCIW Heavy Buffer - Page 1

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[ARCHIVED THREAD] - QC10 Colt Pattern Lower w/UCIW Ultra Compact Stock & UCIW Heavy Buffer

Posted: 11/16/2015 7:05:01 AM EDT

Anyone else running this combination?

I'm running a 5.5" three lug barrel with an Octane 9 HD. Using Colt mags, metalform, and converted UZI. ASC won't work, they are too damn tight. I'm having FTF issues which vary depending on the mag and ammo. Some combinations run much better than others but nothing consistent. I started with a CMMG bolt and have since switched out to a QC10 bolt with no improvement. I tried using the UCIW flat wire spring, no improvement (I was using the Slash Heavy buffer spring).

Posted: 11/16/2015 8:14:31 PM EDT

[#1]

Quoted:
Anyone else running this combination?

I'm running a 5.5" three lug barrel with an Octane 9 HD. Using Colt mags, metalform, and converted UZI. ASC won't work, they are too damn tight. I'm having FTF issues which vary depending on the mag and ammo. Some combinations run much better than others but nothing consistent. I started with a CMMG bolt and have since switched out to a QC10 bolt with no improvement. I tried using the UCIW flat wire spring, no improvement (I was using the Slash Heavy buffer spring).

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Tagging for interest as I am going to run almost this exact setup. Just waiting on the barrel...

What ammo are you running? Have you tried supersonic vs subsonic?

More details please.

Posted: 11/16/2015 8:42:45 PM EDT

[#2]

Mostly 147 (round nose and flat nose) and 158 (IMI round nose) subs but I have tried 115 & 124 supersonic ammo as well. Round nose or flat point doesn't seem to matter although flat point subs didn't feed nearly as well.

I was looking at the lower a little closer and comparing it to my factory Colt 9mm rifle. Same mag and ammo feeds flawlessly in the factory Colt rifle, exceptionally smooth compared to the QC10.

I measured the distances of both mag catches from the top of the receiver and they were easily within 0.010" of each other. I then focused in on the differences in feed ramp design and took some measurements. I noticed the lower portion of the QC10 feed ramp starts off higher when compared to the Colt feed ramp but both were about the same height at the high side. I may play around with the feed ramp a little and or just order a new one.

Posted: 11/16/2015 9:13:03 PM EDT

[#3]

Quote History

Quoted:
Mostly 147 (round nose and flat nose) and 158 (IMI round nose) subs but I have tried 115 & 124 supersonic ammo as well. Round nose or flat point doesn't seem to matter although flat point subs didn't feed nearly as well.

I was looking at the lower a little closer and comparing it to my factory Colt 9mm rifle. Same mag and ammo feeds flawlessly in the factory Colt rifle, exceptionally smooth compared to the QC10.

I measured the distances of both mag catches from the top of the receiver and they were easily within 0.010" of each other. I then focused in on the differences in feed ramp design and took some measurements. I noticed the lower portion of the QC10 feed ramp starts off higher when compared to the Colt feed ramp but both were about the same height at the high side. I may play around with the feed ramp a little and or just order a new one.

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What barrel are you using? What company that is?

Posted: 11/17/2015 12:03:10 AM EDT

[#4]

Just worked on a Blowback 45.....with a compact stock.....problem was the short tube in that instance.....basically the bolt couldn't cycle back far enough for the mag to present the round properly before it cycles forward.....pics of your rig would help.....and some of the breech face of the barrel....

Posted: 11/17/2015 5:35:38 AM EDT

[#5]

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Quoted:

What barrel are you using? What company that is?

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Quoted:

Quoted:
Mostly 147 (round nose and flat nose) and 158 (IMI round nose) subs but I have tried 115 & 124 supersonic ammo as well. Round nose or flat point doesn't seem to matter although flat point subs didn't feed nearly as well.

I was looking at the lower a little closer and comparing it to my factory Colt 9mm rifle. Same mag and ammo feeds flawlessly in the factory Colt rifle, exceptionally smooth compared to the QC10.

I measured the distances of both mag catches from the top of the receiver and they were easily within 0.010" of each other. I then focused in on the differences in feed ramp design and took some measurements. I noticed the lower portion of the QC10 feed ramp starts off higher when compared to the Colt feed ramp but both were about the same height at the high side. I may play around with the feed ramp a little and or just order a new one.

What barrel are you using? What company that is?

TROS 3 lug

Posted: 11/17/2015 6:53:07 AM EDT

[#6]

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TROS 3 lug

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Quoted:

Quoted:
Mostly 147 (round nose and flat nose) and 158 (IMI round nose) subs but I have tried 115 & 124 supersonic ammo as well. Round nose or flat point doesn't seem to matter although flat point subs didn't feed nearly as well.

I was looking at the lower a little closer and comparing it to my factory Colt 9mm rifle. Same mag and ammo feeds flawlessly in the factory Colt rifle, exceptionally smooth compared to the QC10.

I measured the distances of both mag catches from the top of the receiver and they were easily within 0.010" of each other. I then focused in on the differences in feed ramp design and took some measurements. I noticed the lower portion of the QC10 feed ramp starts off higher when compared to the Colt feed ramp but both were about the same height at the high side. I may play around with the feed ramp a little and or just order a new one.

What barrel are you using? What company that is?

TROS 3 lug

Damn. This will be my exact setup. Hope it works when it arrives.

Posted: 11/17/2015 7:32:16 AM EDT

[#7]

Let's get a pic of your gun up in here.

Posted: 11/17/2015 10:37:10 AM EDT

[#8]

I will be following this as I too have the tros barrel and cmmg bolt and was looking at the LWRC UC stock and slash buffer.

Posted: 11/17/2015 4:45:31 PM EDT

[#9]

FWIW, My QC10 lower, Vltor MUR upper, JP bolt and captured recoil spring, LWRC compact stock and carbine length tube and TROS 5"/9" 3 lug barrels run flawlessly with Colt mags. I've shot a good dozen different loads from 115 to 158 grain. I think the key is the JP captured recoil spring assembly.

ETA-suppressor is an Octane 9.

Posted: 11/17/2015 5:49:10 PM EDT

[#10]

Quote History

Quoted:
FWIW, My QC10 lower, Vltor MUR upper, JP bolt and captured recoil spring, LWRC compact stock and carbine length tube and TROS 5"/9" 3 lug barrels run flawlessly with Colt mags. I've shot a good dozen different loads from 115 to 158 grain. I think the key is the JP captured recoil spring assembly.

ETA-suppressor is an Octane 9.

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Isn't the key there the fact that you're using a carbine length buffer tube? As opposed to the short buffer tube that comes with the UCIW stock, and has it's own special circumstances.. ?

Posted: 11/17/2015 6:26:43 PM EDT

[#11]

Quote History

Quoted:

Isn't the key there the fact that you're using a carbine length buffer tube? As opposed to the short buffer tube that comes with the UCIW stock, and has it's own special circumstances.. ?

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Quoted:

Quoted:
FWIW, My QC10 lower, Vltor MUR upper, JP bolt and captured recoil spring, LWRC compact stock and carbine length tube and TROS 5"/9" 3 lug barrels run flawlessly with Colt mags. I've shot a good dozen different loads from 115 to 158 grain. I think the key is the JP captured recoil spring assembly.

ETA-suppressor is an Octane 9.

Isn't the key there the fact that you're using a carbine length buffer tube? As opposed to the short buffer tube that comes with the UCIW stock, and has it's own special circumstances.. ?

Could be that. I'd rather have a weapon that runs than one that doesn't and is a bit shorter. Too bad JP doesn't make a shorter captured spring system.

Posted: 11/17/2015 6:57:17 PM EDT

[#12]

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Quoted:
Let's get a pic of your gun up in here.

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I won't be able to get pics posted until this weekend.

Posted: 11/17/2015 10:16:51 PM EDT

[#13]

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Quoted:

Could be that. I'd rather have a weapon that runs than one that doesn't and is a bit shorter. Too bad JP doesn't make a shorter captured spring system.

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Quoted:

Quoted:
FWIW, My QC10 lower, Vltor MUR upper, JP bolt and captured recoil spring, LWRC compact stock and carbine length tube and TROS 5"/9" 3 lug barrels run flawlessly with Colt mags. I've shot a good dozen different loads from 115 to 158 grain. I think the key is the JP captured recoil spring assembly.

ETA-suppressor is an Octane 9.

Isn't the key there the fact that you're using a carbine length buffer tube? As opposed to the short buffer tube that comes with the UCIW stock, and has it's own special circumstances.. ?

Could be that. I'd rather have a weapon that runs than one that doesn't and is a bit shorter. Too bad JP doesn't make a shorter captured spring system.

There's quite a few guys running the UCIW (short)buffer tube claiming 100% function. Just a different combination of parts. I just ordered one and I'm prepared to go with Slash's UCIW buffer if necessary.

Posted: 11/17/2015 10:56:55 PM EDT

[#14]

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I won't be able to get pics posted until this weekend.

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Quoted:

Quoted:
Let's get a pic of your gun up in here.

I won't be able to get pics posted until this weekend.

Wait a minute, what buffer are you using? Just the heavy springs? It needs a heavy buffer. Are u not using slash heavy buffer? Or am I reading completely wrong?

Posted: 11/17/2015 11:18:04 PM EDT

[#15]

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Quoted:

Wait a minute, what buffer are you using? Just the heavy springs? It needs a heavy buffer. Are u not using slash heavy buffer? Or am I reading completely wrong?

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Quoted:

Quoted:
Let's get a pic of your gun up in here.

I won't be able to get pics posted until this weekend.

Wait a minute, what buffer are you using? Just the heavy springs? It needs a heavy buffer. Are u not using slash heavy buffer? Or am I reading completely wrong?

I don't think he's using slash's heavy buffer. What buffer are you using OP?

Posted: 11/18/2015 5:46:50 PM EDT

[#16]

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Quoted:

I don't think he's using slash's heavy buffer. What buffer are you using OP?

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Quoted:

Quoted:
Let's get a pic of your gun up in here.

I won't be able to get pics posted until this weekend.

Wait a minute, what buffer are you using? Just the heavy springs? It needs a heavy buffer. Are u not using slash heavy buffer? Or am I reading completely wrong?

I don't think he's using slash's heavy buffer. What buffer are you using OP?

I think he is using the buffer that came with the UC stock?

Posted: 11/18/2015 7:42:18 PM EDT

[#17]

Nope...Per the title, I'm using Slash's UCIW heavy buffer and spring. BTW, his spring was too long and coil binding, so per his instructions, I had to clip off a coil.

Posted: 11/19/2015 2:42:15 AM EDT

[#18]

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Quoted:
Nope...Per the title, I'm using Slash's UCIW heavy buffer and spring. BTW, his spring was too long and coil binding, so per his instructions, I had to clip off a coil.

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So did that make it work?

Posted: 11/19/2015 6:17:58 AM EDT

[#19]

No, it's been like that since day one. The coil bind was preventing the bolt from going back far enough to clear the bolt catch so last round bolt hold open wasn't working. CMMG bolt and Slash's buffer w/o spring cleared bolt catch. Add the spring and it didn't clear the bolt catch. When fully compressing the spring to coil bind on the buffer, it was longer than the buffer. So he said clip a coil. His first solution was to back the buffer tube out one turn. He insisted you could back out the buffer tube at least one turn to solve that issue. When backing out the buffer tube one turn I lost buffer retainer engagement. Besides that, without clipping a coil it would have always been coil binding. So all of that was a completely different issue which was solved before taking it out for the first time.

Posted: 11/19/2015 8:52:44 PM EDT

[#20]

Have you put the problematic upper on the colt lower? If so, how did it run?

Posted: 11/19/2015 9:05:30 PM EDT

[#21]

No, my Colt 9mm carbine is a pre-ban green label with a large pin lower.

Posted: 11/20/2015 6:53:43 AM EDT

[#22]

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Quoted:
No, my Colt 9mm carbine is a pre-ban green label with a large pin lower.

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Post pictures of your QC10 lower? The catch etc? Have you discussed this with them?

And to make sure, you have this one correct? http://heavybuffers.com/uciw9.html

There is also the 556 version for uciw stocks.. Very easy to mix up. Just checking.

Posted: 11/23/2015 7:37:14 PM EDT

[#23]

OK, so I had some more time to play with set-up. After playing with the feed ramp I narrowed it down to the barrel. I removed the barrel and added just a bit more radius with a corner rounding tool and that seemed to do the trick. Feeds great now when I cycle by hand. Taking it to the range tomorrow.

Posted: 11/23/2015 8:12:00 PM EDT

[#24]

Quote History

Quoted:

Post pictures of your QC10 lower? The catch etc? Have you discussed this with them?

And to make sure, you have this one correct? http://heavybuffers.com/uciw9.html

There is also the 556 version for uciw stocks.. Very easy to mix up. Just checking.

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Quote History

Quoted:

Quoted:
No, my Colt 9mm carbine is a pre-ban green label with a large pin lower.

Post pictures of your QC10 lower? The catch etc? Have you discussed this with them?

And to make sure, you have this one correct? http://heavybuffers.com/uciw9.html

There is also the 556 version for uciw stocks.. Very easy to mix up. Just checking.

Yep, I'm aware, I have the correct buffer, it's marked U 9

Posted: 11/24/2015 5:07:02 PM EDT

[#25]

Took it to the range today and it fed everything I threw at it. So it was the shallow chamfer on the breech face leading into the chamber. Adding a bit more radius did the trick.