FX Royal 400 .22 cal

Did you clean with pull through patches from the breech? Without removing the barrel? If so, I agree that the breech seal could be the problem. You would probably notice a difference in sound. A chrono run would disclose it also. The Royale is a relatively bullet proof rifle, I seldom clean mine. Something is way wrong to yield such an extreme loss of accuracy. The good news, big problems are usually easy to find. 
 
Thanks for the quick reply’s. I’ll replace breech o ring and inspect for evidence of clipping from end of barrel.


Can't hurt to check the seal, bu frankly, I've shot rifles in various stages of breech seal damage, and while they were definitely affected, accuracy was not as poor as you describe. You can tell with the tissue test if it's leaking, no need replacing if it's not. I shot a couple of 25 yard groups with my Royale when over half of the breech seal was blown away. Velocity was way down, and erratic, but it actually shot pretty well!

I assume yours is the factory standard moderator, and I can't imagine why it would suddenly start clipping, unless dropped or subject to some other pressure. I had a similar experience once, and I made the embarrassing discovery that I had not tightened the grub screws holding the barrel! Did the same with wheel lug nuts once, it was not a good outcome.