Kwesi, I have seen several Delta Elite pistols which had sever bulges in brass in the higher impulse ranges at and above 1200 fps. The thing about handloading we can work up in increments to observe how things are working in our equipment.
While I am not an expert in the Delta Elite or the 1911's this is what concerns me...
Things that come to mind are first and far most is chamber support.
Some have had Link issues and/or recoil spring issues. This can cause unlock at the wrong time while pressures are still high.
About the Star Line brass, I feel it is softer more malleable to provide handloaders longer life with out it getting too brittle from being worked or work hardened with use. It is my opinion that is why we see case expansion or bulging that we may not see in other casings like Winchester, Hornady, Federal are probably the most brittle as I see many split on the initial firing of factory ammo.
Ammo like that of SwampFox (RIP Mike) he worked with customers to adjust loadings to better fit the pistol's workings. This is why I suggest that we study what ammo makers are doing, powder types, charge weights with particular bullets. Some make claims of certain velocities, but some don't live up to the claims and those that do sometimes are too much for some guns. As we shoot and test the ammo over a broad spectrum of pistols we observe real world data to share and learn from. For me safety is my main concern, also performance vs. reliablity.
NRA Life Member
BASS Life Member