My reloads make my #4 bolt stick...

Kynamco loads .303 and other Cordite era cartridges to fairly high velocities, but they claim to use a blended powder charge to keep pressures down.

 

Fact is the only other time I remember someone asking about difficult extraction when using a factory load it was a 150 gr European load. Don't remember the manufacturer offhand, probably not Privi. Privi does sell components to other European cartridge manufacturers.

 

My own favorite load drives the Hornady .312 at around 2600 +/- a few fps, and it pushes safe limits for a .303 reload. I only use it in rifles in very good to excellent mechanical condition and with headspace of .068 or less, so I've had no problems with it, and have gotten excellent case life with it from  my No.4 Savage. People often ask for my exact load but I can't recommend the full charge for a rifle I haven't examined. I use IMR 4320, which is a powder you don't hear as much about these days, its excellent for the .303 and similar cartridges.

 

You'll often see pistol and revolver cartridge velocities in catalogs that turn out to have been fired in ten inch test barrels.

Loads from different companies may have the same true velocity but one company may chrono at or very near the muzzle while the other chronos at 50 yards from the muzzle.

 

When manufacturing cartridges they don't often go by a set charge weight. Each lot of powder and components is tested and a load figured out to suit those components with little thought given to chamber pressure specs other than not to exceed the max pressure. What they try to do is get as close to their promised velocities as possible without exceeding max chamber pressures. Sometimes they end up subtituting a propellent for the one they would prefer to use if they start running short or some powder on hand has been found degraded.

Only milspec ammunition intended for gas operated autoloaders has a minimum pressure and that only at the gas port, since lower than specified will affect function of the action.

 

 

Definitely not! Smoke smudging is for  fired or resized unloaded cases only. Use blue, felt marker dye or so on for live rounds.

A little bit goes a long way when you put a spot of it on the sweat band in someones safety helmet too. A bit like neversieze.

Those privy loads should not be overloading the action with that amount of added space where the shoulder moves forward to.  There is something other than pressure causing the stiff bolt opening.  From what I can make out, that fired case shows no sign of high pressure but then a photo isn't the same as holding the case in one's fingers and rolling it to the light.

According to Hornady's manual thats a max load, only one powder is listed at that velocity as well so its right at the top of the range. Most powders listed top out at 2600 FPS for a 150 Gr bullet.

 

Sierra has similar limits & data as well, & Speer is lower at 2600. Acurate arms lists a max of 2561fps for 45,000 CUP, pretty much a max load. Hodgdons lists maximums of 2756FPS for 39,200CUP with ball C(2).

 

As so many major manufacturers are quoting numbers like this 2690 is high, even for a book maximum  IMO & you should approach anything above any book maximum with extreme caution & use lots of prudent working up if you dont want to invite catastrophic failure. Personally I use the lowest high of several manuals as a functional "STOP HERE" point as its not stressing the brass or the gun & that way I have a little "extra" insurance for any mistake, or variation in powder charge I may make. The most accurate load is usually not the highest, hottest load either & as most of us are pretty much punching paper then I go for accuracy not power. Thats a personal choice though, hunters seem to prefer power to accuracy.

 

A classic symptom of excess pressure is the brass over stressing so it doesn't drop back after expanding during firing. High velocities, high pressures & sticking brass are all possible signs of impending disaster & you should always err on the side of caution when reloading, "fail safe" is a good reloaders motto!