What the hell o rings come with the plug really if any primer fits that loose to be able to fit a o ring in there or to need one that's a big design flaw. I have never had blow back issues or need for o rings to make a primer fit with my omega or need to adjust head space for any reason. Trigger come with a light pull crisp n clean. I just don't understand why you would buy a product for less just to turn around & have to pump all this time & money into it to get it right. It should come as promised from the factory light trigger proper head space proper breech plug design so on. In the end after all the stuff you have to do to get the gun working right cost of parts mods adjustments so on. You end up paying double what you would have paid for a TC that out of the box would need no adjustments or mods or after market parts to shoot sub moa. I don't get it but that's just my opinion for the kinda money both cva & tc cost to buy if it don't come to me right I aint gonna keep it. Biggest upgrade I have done to my gun was a scope & sight in no further adjustments were needed. I don't see to many mods done or available to the TC guns. Maybe they don't need em & there is no market or profit in it.