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Discussion Starter · #1 ·
my form 1 should be back within the next month, so its time for me to start looking at my options for the barrels

i really want a 10.5" barrel but bushy wont have them till mid next year according to the email they sent me, so either i chop up my op rod and have it reprofiled down to the carbine length and try to find the gas port size or order a spikes tactical 12.5 barrel and swap everything over

overall i dont like having the gas block in front of the railed handguard so i'm actually leaning on trying the 10.5

i did a quick ms paint barrel chop and heres some pics,
the 10.5


12.5


the original pic pre ms paint


what do you think?
 

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Get in touch with Spike's Tactical; I believe they are or will be offering a 12.5 solution for the ACR. Don't know how much it is or whats involved, but It's an option.
 

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Discussion Starter · #4 ·

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Discussion Starter · #6 ·
i forgot about this thread lol, i went 10.5, so far i have around 500ish rounds- 450ish suppressed and 100% reliability

check out the thread in my signature, its has a more detailed description
 

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I had mine cut to 12.5 and it is way over-gassed. I was hoping for some suggestions on how to slow the BCG down. Cycles with regulator set to S, with no can attached. With M4-2000 the extracted case is getting caught by the BCG.
 

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I had mine cut to 12.5 and it is way over-gassed. I was hoping for some suggestions on how to slow the BCG down. Cycles with regulator set to S, with no can attached. With M4-2000 the extracted case is getting caught by the BCG.
Did you have the factory barrel cut back to 12.5"? Did they bore out the gas port too?
 

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Discussion Starter · #9 ·
you could get the gas hole plugged and reduced, if you go down to around .058 it should be a good start. hk94dude was running his 10.5 with the factory 16" gas hole (.063) and it runs great(the thread is on ar15.com)

if you were to go the same route as me you can drill your gas block and tap it, i can tune my rifle to where it runs great
 

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I had mine cut to 12.5 and it is way over-gassed. I was hoping for some suggestions on how to slow the BCG down. Cycles with regulator set to S, with no can attached. With M4-2000 the extracted case is getting caught by the BCG.
Very interesting. I was thinking of getting a 12.5 but I would want to keep my 16" barrel so that I can switch them out if I wanna travel with it. I'd be curious to see how yours could be so messed up when guys are saying theirs are 10.5 and running fine. I'm thinking it can only be the fact that you cut down the factory barrel. But I don't know. Standing by...
 

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Yes the factory barrel was cut down to 12.5". I assume the gas port was opened but I didn't ask directly. I simply gave the shop my barrel and informed them that the rifle would be run suppressed, for most of the round count. I trusted them of the gas port issue. I had heard that plugging and drilling is not the best for the barrel. I was hoping someone had figured out how to mess with the gas regulator, in order to vent more gas. I could also use a stiffer aftermarket action spring (if any manufactures want to make me one, at a loss I'm sure). The barrel is on it's way back to the shop, but I'm researching possible fixes, just in case.
 

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I've seen at least one other post on arf about Adco cutting the barrel and opening the port. I think what may have happened is that they used an AR spec gas port size in that instance. If you see the size of the gas port on the ACR it is miniscule in comparison to an AR.

You could get a Spikes barrel and just swap over your parts.
If you can get BM to send a regulator you could bore it out and make a second gas port for the "U" setting with a diameter matching the gas relief port to vent the most gas. Boring out the end (facing the piston) will create more volume and help lower pressures too.
Working the gas block w/ plugs or maybe opening the gas relief port slightly.

At least the rifle runs though, that's the big thing.
 

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It only runs with weak .223 and no can. It will not run suppressed without catching the spent casing. It's on it's way back to the shop, so I will just have to see what happens. I would love a new regulator, to bore out. Will try Bushmaster, but I'm not holding my breath.
 

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Discussion Starter · #14 ·
mine did that twice when i put the 10.5" on my rifle without reducing the gas flow, the acr is very efficient in how it uses the gases. one thing i love is it is decently quiet with a m4-2000 on it
 

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Hey DSM,

So do the Spikes Barrels run efficiently with the factory components?
As far as I know. I'd trust anything with the Spike's name on it without much reservation. I think there is a guy on here with a 14.5" Spike's barrel.
 

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Awesome, I'm really thinking about avenues to practically SBR and Suppress this system. Should I wait until BS releases their factory barrel conversions? But at the same time, Spikes and Noveske barrels are probably going to be superior anyway so....

Any word on whether Spikes is going to be able to sell the barrel with needed parts for a turn key barrel swap?
 

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Any word on whether Spikes is going to be able to sell the barrel with needed parts for a turn key barrel swap?
Probably not until Bushmaster either releases the needed parts or, maybe starts selling barrel assemblies to be cannibalized. The former I highly doubt as it would mean you wouldn't need to spend as much money on their products. The latter is more of a possibility as the scrapped ACR barrel can be used elsewhere or sold off to recoup cost.

As it is, Spike's can supply the barrel in a component ready config. Swapping the barrel parts isn't hard.
 
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