Re: Barnes 200gr XPB and 275gr TSX
Posted: Sun Sep 24, 2017 2:25 pm
Bolt thrust calculations only looks at inner case head diameter and pressure. It doesn't take into account rim diameter, case taper, dry or oiled chamber, body taper, shoulder angle, etc. Its a quick and dirty way to get a comparison. If it was the end all, be all, number, a lot of us would be breaking bolts all the time.
As to chamber friction, your correct on pressure effecting it, however, you also have surface area to consider. 450 has a lot more surface area to grab with than 5.56.
I'm not trying to argue or push you, just trying to point out a few things. If you feel you have to stay at/under 40K psi, that is your choice. You will still have a potent hunting round, and as long as your having fun, who cares.
As to chamber friction, your correct on pressure effecting it, however, you also have surface area to consider. 450 has a lot more surface area to grab with than 5.56.
I'm not trying to argue or push you, just trying to point out a few things. If you feel you have to stay at/under 40K psi, that is your choice. You will still have a potent hunting round, and as long as your having fun, who cares.