tackdriver Wrote:If this is way off course then I am sure someone will be quick to say so. It seems to me that 28.5 great of cfe is a very mild charge (most all here are running over 30).
I purchased an upper from a member here that was running g a type 2 bolt in a type 1 chamber. The result was case head seperate on from excessive head space. You mentioned you were shooting a type 1 bolt, are you 100% sure this is correct? If you had a type one bolt in a barrel that required a type 2 I am thinking "if" the bolt would close it could be jamming the bullets into the lands and giving a higher chamber pressure.
Again, I'm no gunsmith just been head scratching a bit. Hope you get the kinks worked out, I know they can be frustrating but this is an awsome round in the ar15 platform.
That is not way off at all. In the end it is up to the individual to know his own barrel and bolt for correct head space. It is also the individuals responsibility to know the type of chamber and ammunition they are using. If a barrel and bolt are purchased separately the barrel should always have the head space checked. I know there have been factory uppers marked 5.56 which are actually 223 chambers. This will cause pressure problems when using 5.56 spec ammo. It is wise to always check your head space after any rifle build or purchase of used firearms, bolts and barrels. It is not a bad idea to check factory built firearms chambers either. Most gun smiths will do this for free or charge a minimal fee for checking head space.
Good catch and reminder to all.