The .270 Winchester is a rifle cartridge developed by Winchester Repeating Arms Company in 1923 and unveiled in 1925 as a chambering for their bolt-action Model 54. Interestingly, not long afterward, Western also pressure-tested a bunch of handloaded ammo, put together by a major bullet company using a popular computer program for predicting hand-load pressures and velocities. As you can see, the calculated results are pretty accurate and closely reflect values you would expect. So if the highest rated pressure for a cartridge is 65,000 psi, most manufactures will design to 130,000 minimum but I don,t advise that you exceed the design pressure because you will be cutting into the safety margin. If you are happy with max 270 Win ballistics any of the 270 mags will give those with reduced loads and no pressure and case life just this side of forever. chamber pressure has been well established by experimental means. When steam tables are used, a common mistake is to obtain a The .270 Win. The Pressure value used for each caliber happens to be the maximum SAAMI safe chamber pressure. Likewise, the .270 WSM kicks a little less than the 7mm WSM, … The 1908 DWM seems OK with high pressure loadings with standard cartridges (270 Winchester). In 26" barrels the 270 will see up to about 2950 with 150 grainers and 3150 with 130 grainers. However, if you are one who likes to push things a little, there is a real good chance of setting the lugs back in the receiver. When the same amount of pressure is exerted against 150-grain bullets in the .30-06 and .270 Win., velocity will be a bit higher for the .30-06 for two reasons. 60,000 .35 Whelan: 52,000 cup ... SAAMI Pistol Pressure Specifications (Maximum Average pressure) All Piezo measurements unless specified) ... Chamber & Cartridge Dimensions. Its larger base diameter gives propellant gas a larger surface area to push against and a shorter bearing surface makes it a bit less resistant to being pushed down the bore of a barrel. I think one could use loads at 270 saami pressures with no issues. For instance, in rifles of the same weight and shooting bullets of the similar sectional density loaded to the same pressure, the .270 Winchester kicks less than the .280 Remington or .30-06 Springfield. The .270 is a high-pressure round, higher by a considerable margin … .270 Winchester . In a hyperbaric oxygen therapy chamber, the air pressure is increased two to three times higher than normal air pressure. For exam-ple, at a common sterilization temperature, 270 degrees C, the pressure shown on the steam table is 41.85 psi absolute. The .270 may be a good all-around North American chambering in the minds of some, but to me it fell short because of the limited bullet weights available (now that has been corrected). handloads averaged nearly 69,000 psi, well over its SAAMI MAP of 65,000 psi. I have also had 270/308 Norma and 270/300 Win. 65,000 .351 Win SL: 45,000 cup.280 Remington . Current Levergun Makers. About Leverguns. The rifle manufactures design there actions around this pressure and add a safety factor of 100%. Under these conditions, your lungs can gather much more oxygen than would be possible breathing pure oxygen at normal air pressure. The locking lug seats are a little on the soft side. Steam tables always list absolute pressure, not gauge pressure. The 270 Wby will see 3250 and 3450. See up to about 2950 with 150 grainers and 3150 with 130 grainers 69,000,... Think one could use loads at 270 SAAMI pressures with no issues use loads at 270 SAAMI pressures with issues... 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