MROD accuracy issues with a suppressor?

thanks for the response!

She was deadly accurate before and the rifle is a few months old. Since you mentioned the shroud I did remove it and reassembled. Could over tightening the shroud be the cause? And if so how tight should it be? Going to check everything again because it doesn't make sense given all the great feedback and reviews about DonnyFl’s.

Ok so I checked everything, shroud finger tight, baffles the right way. BUT I noticed the O-ring was missing on the thread adapter. Now it seems to be where it should be.

I still had two fliers out of 24, oddly they were sequential shots, 6” high and damn near the same hole. Right around 2500psi. I fill to 3k so it was about shots 11/12. Next and following shots were dead on target. 

I’ll try more shots tomorrow and see if it repeats now that neighbors barely know! 
thanks again, great site and great people. Glad i joined! 

Now its kinda boring hitting the same hole!

sure enough, the missing oring was the issue. I removed it to replicate the issue and sure enough it makes a difference after some shots.

thanks again all!

Funny you should mention that. The breech o-ring got shot through. Not the first time that happened on the mrod! 


i tested again today without the fiberglass and all went back to normal. i was not a physics major, but i was using fiberglass fabric in the suppressor. Im now thinking that while it is dense enough for sound constraint, there might be inconsistent or insufficient air flow through the suppressor causing turbulence or pressure differentials. There certainly isnt much airflow through the fiberglass cloth. Im also thinking Bernoulli’s theorem, a high vs low pressure scenario somehow. 
i will experiment more in the next few days. 

DonnyFl did respond to me about the baffles and said he personally would remove them to ensure more air going through the suppressor, which made me think of airflow through the fiberglass. 


i’ll test more setups and report.