The MCX I use is revision 2, with adjustable gas block control. Version 1 is the original introduction without. The quality is good, but not reaching the point I expected for a SIG product. Two issues: 1) It was very finicky about the brand of ammunition used. I had no issues with SIG elite, but experienced problems with several other brands of cartridge, mostly FTF, primer strike not heavy enough. 2) The trigger is terrible. A heavy minimum of 7-7.5 pounds is required. There are no aftermarket triggers yet or any I could find that support this rifle. Do not put a Geissele trigger in this rifle; yes it will fit and yes it may fire, but Google the problems related to aftermarket triggers in this rifle. I also understand there is a recall now on the revision 2 rifles about the triggers. I would not recommend this rifle until SIG gets their quality control and product maturity in shape. For this amount of money, I expected better.

Excellent tactical rifle. Light weight and very accurate. I opted to order the rifle in a AAC 300 Blackout. It has better ballistics than the .223 and has a better range. The dual spring kick reducer works fantastic. I can hardly feel any recoil. The only thing Sig Sauer could have done was install a higher quality trigger assembly. I replaced the factory trigger assembly with one that reduced the trigger pull to 3.5 lbs from around 10 lbs. and has a crisper feel. Now I have a tactical rifle without any downsides.