Noveske N4 cut down to 12.5"?

jhova98040 · #1 08-26-09, 14:39

Hello,

I am interested in having ADCO cut down my 14.5" N4 to 12.5".

The primary use of this carbine is home defense and surpressed plinking. Ammo to be used is 5.56 77gr TAP for HD and XM193 for range. The finished carbine will continue to wear a Magpul MOE HG, stock, and grip; a surefire X300; an Aimpoint T-1 in LaRue, and a Gear Sector single point in a Noveske QD end plate. The surpressor is a KAC NT4.

I have a MK18 clone (all LMT with a Colt BCG), which is darn neat, but is prob. not the best choice.

Clearly the effective fragmentation range is limited and wear and tear on the system is increased as I go shorter.

With that said, are there any issues I should be aware of when having the bbl cut down? Would 11.5" be a smarter choice?

I am basically trying to run this by the more experienced members and experts before I attempt this project.

bkb0000 · #2 08-26-09, 14:59

hmm... my understanding is the shorter you go, the LESS wear and tear you'll get. speaking very generally, a 10.5 will wear less than a 12.5, which will wear less than a 14.5 carbine.. the apex is at 14.5 and mid-length systems, which will wear less than 14.5s with carbine gas.

the shorter the dwell time, the softer the action.. since a 12.5 has shorter dwell than a 14.5, it should cycle smoother.

cant say how a suppressor adds to the mix, as i don't know much about the technicals of shooting suppressed.. but i would assume it will still follow the same pattern.

Cameron · #3 08-26-09, 16:02

I thought it wore MORE because they had to open the gas port on the shorter barrels, due to the lower dwell time and this led to them being "over gassed" and wearing more.

Cameron

jhova98040 · #4 08-26-09, 16:18

Quote:

Originally Posted by bkb0000

hmm... my understanding is the shorter you go, the LESS wear and tear you'll get. speaking very generally, a 10.5 will wear less than a 12.5, which will wear less than a 14.5 carbine.. the apex is at 14.5 and mid-length systems, which will wear less than 14.5s with carbine gas.

the shorter the dwell time, the softer the action.. since a 12.5 has shorter dwell than a 14.5, it should cycle smoother.

cant say how a suppressor adds to the mix, as i don't know much about the technicals of shooting suppressed.. but i would assume it will still follow the same pattern.

I am no expert... But I think you have it backwards. I'm sure an actual expert will be along to give us accurate information.

Derek_Connor · #5 08-26-09, 17:08

shorter the barrel with a shorter gas system, the more gas port and throat erosion you will have.

I've had several N4 barrels cut down to SBRs...you'll be good to go.

bkb0000 · #6 08-26-09, 19:07

well lets just handle the question with good ol' deductive reasoning...

the shorter the muzzle is from the gas port, the less dwell time- this is a fact

the shorter the dwell time, the softer the cycle- this, too, is established fact

port size for 14.5" carbines is ~.062".... what is it for shorter barrels? I'm still newish to the whole SBR thing, so my knowledge is gappy.

obviously, if we open the port up, the weapon will cycle harder- but there's going to be a "correct" size to open it up to- a size that's proportional to dwell time to cycle the weapon reliably.

Ziptie · #7 08-26-09, 21:39

This may be a bit off-topic, but relevant to the original post. You're shooting 77's through a suppressor? I have always been under the impression that was a no-no because of the increased likelihood of a baffle strike...

jhova98040 · #8 08-26-09, 23:54

Quote:

Originally Posted by Ziptie

This may be a bit off-topic, but relevant to the original post. You're shooting 77's through a suppressor? I have always been under the impression that was a no-no because of the increased likelihood of a baffle strike...

didn't know that. can someone confirm?

edit: and if it is an issue luckily I've only been shooting 55gr through it.

hayes · #9 08-28-09, 16:54

Quote:

Originally Posted by jhova98040

didn't know that. can someone confirm?

edit: and if it is an issue luckily I've only been shooting 55gr through it.

Really? Soldiers and Marines have been shooting MK 262 Mod0/1 through suppressed weapons for many years now. MK 262 is a very hot 77 grain load.

I'm curious about the source of the 77 grain no no's in suppressed AR's.

Derek_Connor · #10 08-28-09, 17:40

77smks through a can are good to go...

Todd.K · #11 08-28-09, 18:47

Not if you have a 1/9 twist barrel.

Derek_Connor · #12 08-28-09, 19:06

Quote:

Originally Posted by Todd.K

Not if you have a 1/9 twist barrel.

Do you guys make a 1:9 N4?

87GN · #13 08-28-09, 19:15

My friend has a 12.5 N4 (built that way by Noveske).

It is tits. Go for it.

Todd.K · #14 08-28-09, 19:23

All our Light barrels are 1/7 twist.

I don't want somebody who is less knowledgeable about proper twist to put a 77SMK sideways through their can with a 1/9.

Derek_Connor · #15 08-28-09, 21:18

Quote:

Originally Posted by Todd.K

All our Light barrels are 1/7 twist.

I don't want somebody who is less knowledgeable about proper twist to put a 77SMK sideways through their can with a 1/9.

understood..

Sorry I should have been more specific in regards to the context of the question being answered...

Should have said "jhova, 77smks will be good through your barrel w/a can"

Ziptie · #16 08-28-09, 23:12

Quote:

Originally Posted by hayes

Really? Soldiers and Marines have been shooting MK 262 Mod0/1 through suppressed weapons for many years now. MK 262 is a very hot 77 grain load.

I'm curious about the source of the 77 grain no no's in suppressed AR's.

If I can be a fly in the ointment once again, are the Marines using MK262s? I thought their heavy marksman ammo was the MK294 Mod0, the moly coated 77gr sierra OTM from Black Hills. And Todd, thanks for the clarification, I had just a whisper of memory about the baffle strike issue, and it wasn't enough to remember that it was concerning the 1/9" turn rate.