Based on the argument most have with 10 inch vs 11.5/12 inch barrel length for 223 sbrs/pistols most argue 10 inch causes dwell time issues, doesn't allow enough powder burn to push the bullet farther, increase wear and tear on parts which could cause reliability issues if you don't maintain your firearm very well, increased loudness at the muzzle and flash. However, for a truck gun it is the perfect length if your not using a suppressor. Most will state 11.5/12 inches they will go for max length of chopping their barrel down. Now as far as the 6.8 sbrs most tend to use the 12.5 inch barerled sbr/pistols for max powder burn/max they will go for ballistics/ dwell time/ functionality. I'm sure the 10.5 and 8.5 barrels work in lwrc six8, however; all the arguments the 223 crowd has with 10 inch vs 12 inch would apply to the 8.5 inch and 10.5 inch for lwrc. Personally, If you really want a short barrel(less than 12 inches) without using a suppressor 9 inch 300 blackout would probably fit the bill better in your truck. 9 inch in 300blackout is about the max powder burn you could go/gives you a nice length for truck gun usage/ low recoil. You could put a linear compensator on it to blast the concussion/noise forward so it won't deafen you. I don't know if you planned on using ear pro everytime you took that truck gun out, if not don't use a regular compensator as you will lose your hearing and have a pretty bad headache really fast. Maybe mroe people on here that have used the lwrc 8.5 and 10.5 can give you more info.Gents,
Now ready to jump on the LWRCi six8 train. Looking for all-around defense/truck gun. I don't want the hassle of a stamp and SBR so I will opt for pistol brace. I can't find any good reviews or feedback on LWRC SIX8 Pistol in 8.5 vs. LWRC SIX8 A5 Pistol 10.5. Just hoping y'all can give your thoughts.