6CM barrel length recommendations

[CJ31]

I am in the process of having a 6CM built with intentions of putting it in a Rokstock lite. I don't reload so would be shooting factory ammo or purchasing through UM to get the 116TMK. is there any advantage of choosing an 18" barrel over a 16"? I will have a dedicated suppressor and considering the OG6s vs using my current TBAC Dominus. (also open to suggestions/recommendations on the suppressor choice)

My current comfortable range for hunting is inside 400 yards but if I can improve my skill set my goal would be to have effective terminal ballistics to 600 yards eventually.

Any input would be appreciated. Thank you in advance

 

[waspocrew]

An 18” gives you slightly more velocity over a 16”. Probably not enough to matter at all. Plenty of guys go short for maneuverability/balance.

I have an 18” and 20” 6 CM and the extra 2” nets me about 100 fps. I have the OG6S and like it. Sounds plenty quiet and weighs next to nothing. I’ve put several hundred rounds through it on my AR and have no problems.

With the OG6S, you can get away with a slightly longer barrel since half of the can is over the barrel compared to a standard muzzle forward can.

 

[43.6N]

I am in the process of having a 6CM built with intentions of putting it in a Rokstock lite. I don't reload so would be shooting factory ammo or purchasing through UM to get the 116TMK. is there any advantage of choosing an 18" barrel over a 16"? I will have a dedicated suppressor and considering the OG6s vs using my current TBAC Dominus. (also open to suggestions/recommendations on the suppressor choice)

My current comfortable range for hunting is inside 400 yards but if I can improve my skill set my goal would be to have effective terminal ballistics to 600 yards eventually.

Any input would be appreciated. Thank you in advance

Split the difference, ask for 17.76”

 

[CJ31]

An 18” gives you slightly more velocity over a 16”. Probably not enough to matter at all. Plenty of guys go short for maneuverability/balance.

I have an 18” and 20” 6 CM and the extra 2” nets me about 100 fps. I have the OG6S and like it. Sounds plenty quiet and weighs next to nothing. I’ve put several hundred rounds through it on my AR and have no problems.

With the OG6S, you can get away with a slightly longer barrel since half of the can is over the barrel compared to a standard muzzle forward can.

Thanks. I was wondering how much additional distance that 100fps gives from a terminal ballistics standpoint as well as just the general balance of the rifle or if I am just stuck in over analysis paralysis mode. Appreciate the input

 

[WeiserBucks]

Thanks. I was wondering how much additional distance that 100fps gives from a terminal ballistics standpoint as well as just the general balance of the rifle or if I am just stuck in over analysis paralysis mode. Appreciate the input

Plug the numbers into a ballistics calculator.

 

[dårlig jeger]

16" if using a muzzle forward can. 18" if you are using a reflex like the 6s. Do not overthink it.

 

[Tahoe1305]

Depends on exact bullet. But looking at my calculator if you think 2” will cost you 100fps (it’s probably close to that) It’ll cost you about 100yds for a given velocity you are aiming for at your mentioned ranges. About 100ft lbs of energy as well.

Example. My 18” shoots 103eldx at 2875fps. At 500yds it’s going 2230fps (1143ftlbs). 16” would be going ~2130fps (1050ftpbs).

 

[CJ31]

Depends on exact bullet. But looking at my calculator if you think 2” will cost you 100fps (it’s probably close to that) It’ll cost you about 100yds for a given velocity you are aiming for at your mentioned ranges. About 100ft lbs of energy as well.

Example. My 18” shoots 103eldx at 2875fps. At 500yds it’s going 2230fps (1143ftlbs). 16” would be going ~2130fps (1050ftpbs).

Thanks. that helps. sounds like 18" would be the right option to give me the effective range I eventually hope to get to and still keep it over that 1800fps threshold for effective terminal ballistics on an animal. Appreciate everyone's input as I am sure this has been asked and answered many times but I couldn't find it in my search.

 

[Coopsdaddy]

You gain 100fps with 2 inches difference?

 

[Hnthrdr]

I have a 20” I wish it was 18” or shorter….

 

[CJ31]

I have a 20” I wish it was 18” or shorter….

so just when I make up my mind on 18 you make me second guess and consider just going 16 and determine my max range according to my speed with the shorter barrel. lol

 

[waspocrew]

You gain 100fps with 2 inches difference?

I do. My 18” Bartlein spits factory 108 ELDM out at 2790. My 20” Preferred goes 2900 with the same ammo.

 

[waspocrew]

18” is nothing, especially with an over the barrel can like the OG6S.