Author Topic: 5.56 Bren 2 with pin and weld: Best gas system length?  (Read 4421 times)

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Offline Crow

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5.56 Bren 2 with pin and weld: Best gas system length?
« on: June 25, 2021, 02:11:21 PM »
Looking at getting a Bren 2 MS in 5.56. The end goal is to have a 14" barrel pinned and welded to 16" and suppressed.

I can go about this in 3 ways:
-Get the 14" model, pin and weld, buy the OEM stock and longer handguard from the 16" model (more expensive?)
-Get the 16" model, have the barrel chopped down to 14", rethread, pin and weld (more work?)
-Get the 16" model, buy a 14" barrel (if one can ever be found), pin and weld, have two barrels to swap between (more headache?)

Besides the cost/labor between those two, the biggest difference is going to be the different gas systems. Would I be better off with the shorter gas system on the 14" barrel, or will the longer gas system on the 16" prove just as effective even after losing 2"? Will it even matter once I throw a can on it and tune things up with the gas key? Would I be better off just sacrificing a chicken to the gun gods and trying to find a 14" barrel to throw onto the carbine?

I like the stock and the longer handguard on the 16" model, and not having to locate those for the 14" would be helpful. But performance and efficiency are the biggest concern here. I'm not as familiar with piston systems yet so I'm in a bit of uncharted territory. I see AK's and other piston guns with the muzzle device right up against the gas system so maybe I'm just overthinking things? Idk, that's what groups like this are for so I figured I'd ask.

Offline ///M5

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #1 on: June 25, 2021, 08:21:24 PM »
The 16" also has a much heavier barrel profile if that matters to you. I actually sold my 16" carbine to P/W a 14", and I never looked back. IMO the balance is so much better, and the accuracy I saw  from the 16" was no better than my 14. There are also more AM options for the pistol gas systems, but to be fair the carbine gas system didnt need any mods. It ran perfect for me.

I did install the HBI heavy piston spring on my 14", and ejection is now at 3. Prior to that it was at 1.

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Offline Crow

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #2 on: June 26, 2021, 03:42:11 PM »
The 16" also has a much heavier barrel profile if that matters to you. I actually sold my 16" carbine to P/W a 14", and I never looked back. IMO the balance is so much better, and the accuracy I saw  from the 16" was no better than my 14. There are also more AM options for the pistol gas systems, but to be fair the carbine gas system didnt need any mods. It ran perfect for me.

I did install the HBI heavy piston spring on my 14", and ejection is now at 3. Prior to that it was at 1.

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Cool good to know. I do like the idea of a heavier profile barrel. Rigidity and ruggedness are always a plus. I imagine that's what makes the carbine more front heavy? Are you running the 14" with the same stock as the carbine? How about the handguard? I'm concerned about being able to adjust the gas key or clean the gas system without unbolting the handguard if I put a longer one on the 14" barrel.
« Last Edit: June 26, 2021, 03:48:17 PM by Crow »

Offline ///M5

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #3 on: June 26, 2021, 04:51:51 PM »
The Hbi Bren handguard has an opening for the gas key. Yeah, I'm running the original Bren waffle stock. Not a huge fan of the carbine stock.

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Offline Crow

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #4 on: June 26, 2021, 06:59:53 PM »
The Hbi Bren handguard has an opening for the gas key. Yeah, I'm running the original Bren waffle stock. Not a huge fan of the carbine stock.

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What don't you like about the carbine stock in comparison to the waffle?

I was looking at the ACR stock on HBI but I read that it doesn't interface with the shell deflector like the OEM stocks do. Which is a shame, because I adore the ACR stock. Does the CZ carbine stock have an adjustable cheek rise like the ACR, or is it fixed?

Offline ///M5

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #5 on: June 26, 2021, 07:08:12 PM »
This is my P/W with ACR stock and Strongarm brace. I dont think the carbine had an adjustable cheek riser

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Offline Crow

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #6 on: June 26, 2021, 11:56:44 PM »
Man that looks nice.

Real talk, how much of an inconvenience is it not having the full lockup on the stock/brace when it's folded?

Offline ///M5

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #7 on: June 27, 2021, 01:07:55 AM »
Man that looks nice.

Real talk, how much of an inconvenience is it not having the full lockup on the stock/brace when it's folded?
None whatsoever. I have/had all 3, and the only one I didn't care for personally was the Carbine stock. I really didnt like the look.

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Offline Crow

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #8 on: June 27, 2021, 03:20:48 PM »
Man that looks nice.

Real talk, how much of an inconvenience is it not having the full lockup on the stock/brace when it's folded?
None whatsoever. I have/had all 3, and the only one I didn't care for personally was the Carbine stock. I really didnt like the look.

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Does the stock still hold with enough tension when folded as to not fly open?

I've heard the weight of the ACR stock helps balance the forward weight too. Is it really that much heavier than the OEM stocks or is it not that noticeable?

Offline ///M5

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #9 on: June 27, 2021, 08:03:09 PM »
Doesn't fly open, but there is not a lot of retention. The weight on the back is nice, and yes its heavier than the OG stock. Even with the heavy 1-10 LPVO I have on it, the balance is nice.

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Offline Crow

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Re: 5.56 Bren 2 with pin and weld: Best gas system length?
« Reply #10 on: June 28, 2021, 03:58:57 PM »
Doesn't fly open, but there is not a lot of retention.

Does the entire deflector obstruct the stock, or just a small corner of it?

Those deflectors are so cheap I wonder if it would be worth it to buy a few and mod them to fit with the ACR stock.