I'm looking at ordering a 24" 243 1/9 barrel and have a few questions.
1. What feed ramps does it have? 2. Is there a guaranteed MOA? 3. I have an Armalite AR10 upper/lower. Will the barrel be compatible with this upper?
AR10 barrel types don't use M4 ramps.
No MOA guarantee as who knows how the rifle is built and what ammunition is fed them. Then there is the issue that some guys just flat can't shoot. I haven't seen one yet that would not do an MOA with a good shooter behind the trigger.
No one in the industry guarantees a barrel sold by itself for accuracy. Obviously if it's shooting a bushel basket size group they would want to look at it.
You will need to specify that it is for an Armalite as they have a different gas port location.
The best firearm for self defense? Any loaded one will do.