Full time suppressed barrel contour

[021411]

I'm getting a build list together for a multi purpose (training/comp) bolt gun that will be 99% of the time suppressed. I have a TBAC 6.5 Ultra 7 coming in next year and in the meantime will be using a SiCo Omega which is roughly 16 oz (direct thread, anchor brake, wrap).
The plan is having a 24" or 26" finish length medium palma spun up. Is the med palma stiff enough to not have a significant POI shift with the can on or off or do I need to jump up to the heavy palma? I'm trying to keep the rifle balanced and relatively light but not so heavy where it's a bitch to carry and position. Thanks guys.

 

[wareagle700]

If its a full time suppressed gun I'd go medium or light palma and not worry about it. POI shift is generally less with a heavier profile barrel but not a big deal as long as its consistent. I think the Omega balances nice off the end of a light palma.

 

[samb300]

I personally think light palma is too light for a comp gun...run one "mad minute" stage and that thing will be screaming hot!

I run a 24" heavy palma with my 6.5 Ultra 7 on a 6.5x47L AIAX. Every gun is different, but when going from brake to suppressed, I get a shift of exactly 0.1 MIL down and 0.1 MIL right.

 

[Ledzep]

Rem varmint or medium Palma is enough.

I had a rem varmint barrel that had no perceptible poi shift, and a m24 contour barrel of a smaller caliber that had a half mil shift. It's a case by case basis.

 

[samb300]

Rem varmint or medium Palma is enough.

I had a rem varmint barrel that had no perceptible poi shift, and a m24 contour barrel of a smaller caliber that had a half mil shift. It's a case by case basis.

That probably has more to do with the harmonics of the load than anything else. Mechanically, a 16oz weight at the end of a thinner barrel will deflect more than a thicker barrel - especially when hot. Or maybe the threads or brake or timing of the suppressor system wasn't perfectly aligned in the MTU but was better on the Rem. Varmint barrel?

 

[Ledzep]

Both muzzle threads cut on the same lathe with the same setup (lri). Same can.

Also, it changes direction left/right with different barrels. I think it's a combination of the droop vs. where the can clocks and thread/bore alignment if it's not perfect.

 

[Servo93]

I agree with samb light Palma is far to light for a comp barrel. I have light Palma barrel on a 223 that I shoot suppressed and it gets hot in a real hurry.

My AI AT 6.5 Creedmoor barrel is a heavy Palma that is shot suppressed, 10 rounds straight in a match type setup and it is well on its way to being very warm.

 

[021411]

Thanks for the info. I think I'm going to split the difference between the med and heavy palma and go with the marksman.