25-06 pressure vs. 270 pressure

[79inpa]

I noticed that the 25-06 is rated at 53000 cup pressure while the 270 is rated at 55000 cup? Why is this? Shouldn't the 25-06 go to 55000 also?

 

[DrMike]

Same reason the 280 is listed at a lower pressure than the 270. It was what was submitted by the respective registrant with SAAMI or CIP at the time they were listed. The 25-06 is listed at 63K psi by SAAMI and 65K psi by CIP. The 270 is rated at 65K and 62K respectively, whilst the 280 is rated at 60K and 59K respectively, the same as the 30-06. Interestingly enough, the 338-06 is rated at 65K by SAAMI, whereas the 35 Whelen is listed at 58K by CIP. If you want to explore these anomalies further, you can check out some of the web sites listing pressures (e.g. http://kwk.us/pressures.html, http://www.handloads.com/misc/saami.htm, http://www.leverguns.com/articles/saami_pressures.htm. As an aside, you must know that if you knowingly ignore standards and load to higher pressures, you assume all responsibility for your actions. There is no one to bail you out if matters accelerate beyond your control.