Hello all, A recent thread regarding 35 Whelen loads implied that chambering certain cartridges for pump rifles (or possibly semis and levers too) has led to reduced published max loads for those cartridges in the loading manuals over the last 25 or so years. I was under the impression that max loads (as published in manuals) were determined by chamber pressure. Is this correct? Also if the load was within the chamber pressure guidelines 30 yrs. ago, shouldn't it still be valid today? Thanks for the info .. this is a very helpful forum.

kbobb
SAMMI max is baised on the weakest action that the cartridge was ever chambered (see 30-06 vs 270Win pressures, the 30-06 was chambered for the origional M-95(?) Winchester, the 270 wasn't).
Pressure measuring equipment has gotten better over the years, better resulation.
Powder does change from lot to lot, and the manfacturing process have changed also over the years.
You can create a firestorm of reaction with this topic, esp with those that believe that the old "kick-n-blast" velocity/pressure sensing is more reliable than data collected with transducers and chronographs.

I determine the max loads for my individual rifles or calibers by loading and testing it at the range. I want to see what the upper limits are, but I normally don't tote a rifle using the upper limits. NO need to have a 500 yd load to go take a 75 pound black tail at 50 to 75 yds.

Use reload manuals as a reference. Work up.

Find out what your max pressures are for what rifles you own.

cheers and good shooting
seafire

Max loads are determined by only two elements...Lawyers and not being able to put your hat on because the rifle bolt is sticking out of your forehead.