Barrel cutting/dwell time

[Todd.K]

A few points to consider.

A silencer inside the handguard gets hot real fast on a rifle. Sure it looks cool but better left for a 22LR or 9mm in my opinion.

Thread on silencers tend to come loose on a semi in my experience. Several QD options fit on mounts with multiple thread options, washing the expense of the mount with not having to get your barrel rethreaded.

[K.L. Davis]

The location of the cut is more aesthetic...

Your'e doing it wrong... seriously, I don't want to sound like a jackass, but when form is placed over function - more often than not the later suffers.

That said, I would think that 11.5" is going to be a little short... I am sure you will have problems unless you open the gas port and probably leave the suppressor on.

[Clint]

Yes an 11.5" MID gas is NOT going to work, way too little duration.

11.5" CAR gas should work great.

That said, I would think that 11.5" is going to be a little short... I am sure you will have problems unless you open the gas port and probably leave the suppressor on.

An 11.5" CAR barrel with a small gas port would be a better choice.

[Iraqgunz]

I just realized he wants to cut a middy barrel. Ooops. Bad idea.

Yes an 11.5" MID gas is NOT going to work, way too little duration.

11.5" CAR gas should work great.

[Tzook]

I'm pretty sure I'm tracking with you, the motivation here is to get a bit smaller hole and make the rifle smoother, correct?

Am I also correct in thinking that this will only work suppressed?

[Dead Man]

The OP hasn't specified where exactly he wants to chop it. When we get into low-dwell setups, even a half an inch can make a pretty big difference. The 11.5 is one inch longer than the 10.5, which has a good 3" of dwell, and is considered to make a pretty big difference in overall odds of reliability. Sounds like the OP is talking about chopping down to less than 3" of the port on a mid, which would be a pretty substantial decrease in dwell ratio than even the 10.5.

It would be experimental... maybe it would work, maybe it would just be a pain in the ass. You could probably tune it to work dedicated suppressed, but unsuppressed it would operate totally different.

If you want to try it just to try it, go for it. If you're wanting to try this for the purpose of saving money and effort, do yourself a favor and sell the mid-length barrel and buy your desired length in a known-good gas configuration. If you must have a screw-on suppressor (which isn't really done in this platform), just use the adaptor sleeve.

[Rikakiah]

Your'e doing it wrong... seriously, I don't want to sound like a jackass, but when form is placed over function - more often than not the later suffers.

It's not exactly form over function. The function is to reduce the overall length for maneuverability and so it fits in my carry bag without removing the suppressor. Specifically moving the cut to inside the rails is indeed form over function, but it's a difference of .5-1.5 inches. Figured while I'm shortening it for function, I may as well make it look good, too.

A silencer inside the handguard gets hot real fast on a rifle.

I'd thought of that, but was thinking a mere inch inside the rails might not be too much of an issue. Might reconsider to within a half inch or less instead. I won't really be doing mag dumps, but I know it heats quickly regardless.

The OP hasn't specified where exactly he wants to chop it.

I'm wanting to cut it to somewhere between just in front of the gas block and an inch inside the rails

Without getting exact measurements, I estimated this would make the barrel between 12 and 13". The gas block is about 2" inside the rails, putting it roughly at around 11.5" (so an 11.5" length was out anyway).

I just realized he wants to cut a middy barrel. Ooops. Bad idea.

You and others have offered similar synopsis. However, no offense, but a "that ain't gonna work" with no explanation of why or offer to a solution is, personally, counterproductive and lazy. It doesn't attempt to answer the questions I posed and is simply negative.

Is dwell time the only real issue with cutting the barrel?
Is dwell time simply a function of back pressure?
Wouldn't a suppressor increase the back pressure, and by definition, the dwell time?
Would a roughly 6" .30 suppressor increase the dwell time sufficiently to compensate for a roughly 4" barrel reduction?

If yes, what issues would remain with a dedicated suppressed system?

If no, would this be something that could be in range to be tweaked with a buffer (perhaps the A5 system)?

Also, while it is initially an endeavor to get a shorter barrel while saving money, as stated, the initial places I've looked for barrels (Daniel and Noveske) are out of stock. If stock continues to be unavailable by the time my paperwork goes through, it will be more than financial as there won't be many other options (cut it or deal with it long and cumbersome).

[uncle money bags]

Ignore the advice of those wiser than you at your peril.

That said, i wish you luck. Should be a learning experience we can all share in so please update us on your progress.

[Col_Crocs]

Before calling a mod lazy, you might want to read back up a few posts.
Clint answered the why and he was simply agreeing.
I dont want to sound like a jerk here but you dont appear to have a clear understanding of the system at all. I would just get a factory sbr barrel since you considered doing so at some point anyway.
Rainier has a Noveske 10.5 barrel in stock:
https://www.rainierarms.com/?page=sh...roduct_id=3964
You can just shave down the FSB.
As well as Centurion's 12.5:
https://www.rainierarms.com/?page=sh...roduct_id=3430
BCM has all theirs in stock too:
http://www.bravocompanyusa.com/11-M4-Barrel-s/41.htm

[Tzook]

Is dwell time the only real issue with cutting the barrel?
Is dwell time simply a function of back pressure?
Wouldn't a suppressor increase the back pressure, and by definition, the dwell time?
Would a roughly 6" .30 suppressor increase the dwell time sufficiently to compensate for a roughly 4" barrel reduction?

If yes, what issues would remain with a dedicated suppressed system?

Ok, I'm pretty sure I've seen a setup like this. I think you can get it to function with, and ONLY with a suppressor. I don't know if there would be a difference between .30 cal and .223, but I've seen it with .223.

It doesn't make any real sense to do this for any reason other than to just do it. As other posters have mentioned you can buy a quality barrel with the correct length to gas port ratio, and get yourself a rifle that will be reliable suppressed or not.