No, the Magpul Industries STR Commercial Spec Carbine Stock will only fit carbine length commercial spec buffer tubes. You would need to swap to a carbine length tube in order to use this buttstock.
This Magpul Industries STR Commercial Spec Carbine Stock fits commercial style carbine buffer tubes. The Aero Precision M5 .308 Enhanced Carbine Buffer Tube is a Mil-Spec style so you will need the stock at the link below.
https://www.opticsplanet.com/magpul-industries-str-rifle-stock-w-storage-fits-ar-15-m4-mil-spec.html
The Ruger AR556 in 300BLK uses a Mil-Spec Carbine length buffer tube. So you will need the Magpul Industries STR Mil-Spec Carbine Stock at the link below.
https://www.opticsplanet.com/magpul-industries-str-rifle-stock-w-storage-fits-ar-15-m4-mil-spec.html
This Magpul Industries STR Commercial Spec Carbine Stock fits commercial carbine length buffer tubes. If your LWRC IC DI AR has a commercial buffer tube it will work. However, from what information I could find that rifle uses a Mil-Spec carbine buffer tube so you would need the one at the link below.
https://www.opticsplanet.com/magpul-industries-str-rifle-stock-w-storage-fits-ar-15-m4-mil-spec.html
The Magpul Industries STR Commercial Spec Carbine Stock is classified as a stock and can not be put on a MK18 pistol since it will be considered an SBR.
Yes it will thank you so much McKenzie for all your help!!!
Yes, it will.
Yes, as long as your gun has a commercial-spec buffer tube.
Yes, as long as you have a carbine length buffer tube.