450 Bushmaster 300gn xtp mag load

[RR.44]

Have any of you loaded 300gn Hornady XTP Mag for your 450 Bushmaster? And if so how did they perform i.e. feed, group etc.?

[RR.44]

Sorry about that brain fart on my end I'm using a 38.2 gr charge of W296 out of an XM15 with a 16" barrel

[3RDGEARGRNDRR]

Yes. Look up the 450bushmaster.net reloading forums for all the reloading mojo. I have had luck with 4227 and 300mp so far. 38 & 39 grain 296 work best but with longer COL usually.
With 300 grainers i really need to port the barrel to rifle length gas system due to dwell time problems,

[RR.44]

What barrel length are you using? The XM15 has a muzzle brake that has 3 ports 1 on top and 1 on each side the bottom is solid I bought a CMMG lower that I pick up on Friday it currently is mounted on my 93 Colt sporter lower,I don't know how it will function with the CMMG yet but I will find out soon