I run a 125gr. bullet with about 44 gr. of H4895. shoots flat & works the comp great. If you are useing a 16" barrel & gas system, you need to go to a 20" for much softer shooting & velocity.
For briley to cut & choke w/ 3 tubes is about $175.00. They have the best tubes. Add that to the $700.00 price & now you have $ 875.00 in a M1 when you can get a M2 21" for $950.00
SRF, there is no way for someone to out run a slide. If you have ever seen a top GM doing .11 splits in super slow-mo, the slide is back into battery it seems for a long time before he even releases the trigger.