KAK 1n5 twist 11.5" v. 1n7 twist 11.5" , both suppressor ready, .076 GP.

[bfoosh006]

KAK has both these available, and for some reason I am interested in them.

I typically prefer precision oriented complete uppers, when I buy a complete upper. ( most spare uppers I own I have assembled with precision oriented barrels. )

FWIW... I don't expect a KAK 11.5" upper to be a MOA "everyday" shooter. I accept it for what it is.

Both are MLGS.

1n5 twist, Fluted SS 11.5" barrel

1n7 Twist, phosphated 11.5" barrel

I will buy or the other... any valid reason NOT to get the 1n5 twist rate ?

Is the 1n5 twist rate just to fast for current match grade bullet jackets ?

I like the heavier , fluted profile of the 1n5 version... but again is that twist just to fast for any thinner jacketed 77gr match bullets ? ( first time with that fast of a twist )

Given the lack of meaningful dwell time of the gas system and GP size... could a LtWt BCG, low mass buffer setup "possibly" help allow it to function without a suppressor ? Any thoughts would be helpful in my choices.

And thoughts on a muzzle device ? ( until the suppressor arrives )

Recoil mitigation , and staying on target, flash suppression, would be the goals here. Surefire Warcomp ?

 

[bfoosh006]

1n5 twist fluted SS barrel.

1n7 twist phosphated barrel.


1n5 weight... 27oz

1n7 weight ... 21.6oz

 

[Clayman]

I personally wouldn't choose that fast twist on an 11.5 ar. Seems unnecessary for 5.56 with 2.260 coal. It would introduce the possibility of a thinner jacket coming apart and potentially damaging your silencer.

I'd consider that 1-5 or 1-6 on a lightweight bolt action designed for shooting 77-90gr stuff loaded at around 2.390 coal.

Not really sure who is asking for this.

If you only shot 70gr tsx it might be good for increased rotational energy and wounding. Discreet ballistics has some evidence that faster twist with solid copper projectiles increase bleeding and wounding but who knows.

I'd choose the 1-7.

 

[Im2bent]

Depends on how fast you can push your intended bullet and if it will spin fast enough at that speed to stabilize. So pick your heaviest pill crunch the numbers and choose

 

[MaximusDecimusMeidius]

It seems like one of the first inquiries would be to determine which projectiles would be used and at what velocities to determine what RPM's they will be spinning at then contacting the manufacturer of the projectiles to see what rpm ranges they were designed to hold together at. It seems likely some bullets with a 1:5 twist rate might exceed the rpms they were designed to hold together

 

[bfoosh006]

FWIW... this guy has already tried one. No bullets spinning apart, and "clear Gel" tests included w/ 77gr OTMs.

He beat me to the "punch".

 

[Cascade Hemi]

I really want an 11.5" MLGS CL/CHF.

 

[sinister]

A 1-in-5 twist is typically for long, solid/monolithic copper bullets. They seat deeper into a 5.56 case so there's less powder to get the projo up to speed (you either crunch powder with a compressed load or go to a powder that trades volume for pressure). A faster twist makes up a little for lower velocity.

Thin-skinned bullets (like Noslers with J4 jackets) can potentially spin themselves apart if the lands score the jackets deeply while they're spun fast. Match Kings generally have thicker skins and can better tolerate free-bore jump before hitting leades and rifling.

 

[Cascade Hemi]

A 1-in-5 twist is typically for long, solid/monolithic copper bullets. They seat deeper into a 5.56 case so there's less powder to get the projo up to speed (you either crunch powder with a compressed load or go to a powder that trades volume for pressure). A faster twist makes up a little for lower velocity.

Thin-skinned bullets (like Noslers with J4 jackets) can potentially spin themselves apart if the lands score the jackets deeply while they're spun fast. Match Kings generally have thicker skins and can better tolerate free-bore jump before hitting leades and rifling.

Heavy frangible bullets need a lot more twist too.

 

[bfoosh006]

A 1-in-5 twist is typically for long, solid/monolithic copper bullets. They seat deeper into a 5.56 case so there's less powder to get the projo up to speed (you either crunch powder with a compressed load or go to a powder that trades volume for pressure). A faster twist makes up a little for lower velocity.

Thin-skinned bullets (like Noslers with J4 jackets) can potentially spin themselves apart if the lands score the jackets deeply while they're spun fast. Match Kings generally have thicker skins and can better tolerate free-bore jump before hitting leades and rifling.

I ordered a decent amount of 70gr TSX to try from mine.