Suppressors suppressor opening up groups

[SB545]

this sico harvester has worked great on two of my pencil barrels but when used on my target gun i'm seeing 12" groups at 700 yards when i was getting 2-5" groups at that same range consistently. this gun was shortened by a half inch to remedy a bad thread job and re-threaded by a reputable machinist that was recommended by silencerco. he also threaded one of my pencil barrels at the same time and it's shooting great. i realize a small poi shift may happen but was not expecting the groups to open up that much. any thoughts on the issue? bad crown or shoulder on the target barrel? did the loss of the half inch change the node?

 

[hlee]

Hanging the suppressor off the end may be enough to change the node. How does it shoot without the suppressor?

 

[hafejd30]

If you reload you may have to tweak the load a bit to get the same results. Adjust powder up/down .3 grains etc.

You upset your tuning fork

 

[SB545]

That's a shame because this tuning fork used to eat whatever I could put in it and still keep it below moa.

It's the factory Hornady eldm 147 that I'm shooting. I stopped reloading after finding reasonable ES and decent precision out of a couple different brands.

I really haven't had time to troubleshoot without the suppressor. I'd like to bring it in to 100 yards to limit variables and where I've been shooting that's actually harder to do than distance. If I can't do that I'll just pull the can and see what happens on on of the steel targets.

Thanks for the replies

 

[jarredsc]

That’s strange usually suppressors close groups but it could be the balance on the barrel due to the suppressor which will then change the node slightly of your load

 

[Ugly_Duck]

My sandman tightens my groups by almost half