Shoots great with can, horrible without

[flyfisherman246]

Just spun up a bartlein blank into an ar10 .308. 16" with intermediate gas system, h3 buffer. Used aero precision enhanced upper/handguard. It stacks them with a thunderbeast ultra 7 (as seen in the picture) and shoots 2-3" with a bare muzzle or with an asr brake. I have the slr adjustable block set to just lock back on empty without a can. It is was over gassed with a can, but it shoots really well. I also tried a standard buffer instead of the h3 and still shoots horrible without the can. Everything is free floating. Any ideas on what to do from here?

 

[Snuby642]

Can on changes harmonics.

I have a barrel that hates cans.
I have barrels that like them.

Do load development for it.

 

[acudaowner]

shoot it and have fun . if it shoots better with the can use it . nice looking gun and the hunting buddy , the dog looks ready to go .

 

[flyfisherman246]

I actually built it for a customer who doesn't have a can. He's not going to like it even if it shoots in the .3's with a can. Any ideas what the fix is?

 

[theLBC]

I actually built it for a customer who doesn't have a can. He's not going to like it even if it shoots in the .3's with a can. Any ideas what the fix is?

obviously the harmonics don't match whatever you are shooting out of it, so maybe try a variety of brakes and see what works, or try different ammo.

 

[Milf Dots]

Crazy idea that might help: Pull the gas block off and shoot it as a single shot rifle for group, to see what happens. If it shoots better than with the gas block installed- try a different brand/model of gas block.

 

[Snuby642]

I have a 6.5g that likes a flash hider and not an adaptor or the can.

Initial load development no better with either, strange I thought it would be easy to overcome.

Nope ?

 

[theLBC]

this guy really went down that rabbit hole (different muzzle devices)

sorry it is exhaustively long (multiple videos) but anyway, it illustrates the point that you can never tell what will work.
he mentions everyone's favorite Rex, lol.

 

[flyfisherman246]

Rex? What is that?

 

[theLBC]

Rex? What is that?

i get the impression TiborasaurusRex is not well thought of here. (if you weren't being sarcastic)

 

[Jsp556]

What ammo did you use or try? FGGM is usually the easy button but it isn’t the only option.

 

[flyfisherman246]

It was fed gmm 175. I find it hard to believe it would shoot one little hole with a can and all over the place without it. Has anybody seen it before where just trying a different load made drastic differences in a situation like this? I feel like shooting with a can, most everything would shoot at least decent. Why would it be super picky without a can? Thanks for all the help.

 

[theLBC]

i assume you put the can back on to confirm nothing else changed like the barrel connection?
i know some people running the scar-h with 16" barrel didn't like the 175 as much as 168gr, but it wasn't 2-3" bad like this.

 

[knuckleballz]

try a tuneable jpscs with spring kit. Arm or Ally has them for 137$. padom has shown how fine tuning the buffer with the jpscs and different springs can improve accuracy on a large frame.

 

[Jsp556]

My stainless mws barrel shoots 168 gr fgmm .75 moa average. It shoots 175 gr fgmm about 1.5 moa. It sucks but every barrel is an individual.

 

[flyfisherman246]

Thanks for all the help. I tried 168 bthp and two loads of varget and two loads with 8208xbr. All right around 1/2". That is amazing. How would this thing shoot so well with a can and 175 but won't shoot them at all without it?