03-27-2022, 10:26 PM
78,
'Safe' is a relative term.
In bolt guns there is more latitude to go higher than SAAMI. When I was shooting F Class all the .223 shooters could not compete out to 1,000yards without deliberately loading hot. Strong actions and chambers, plus magnum primers and smaller firing pin holes contained the pressure so you can do this for the life of the action without issue.
SAAMI limits are based on the lowest common denominator of likely action, plus a further margin of safety. Unfortunately, AR15's are about the most fragile actions you can buy. Grendel on the other hand with its same AR size bolt but wider diameter case makes it even more susceptible to pressure. Add to that loaders pushing boundaries and sooner or later one of those lugs is going to fail - it's the weakest link. Might not be immediate - might be in 1,000 rounds of constant hammering. Also depends on the quality of that bolt and how the lugs share the load with that barrel extension. This is a controversial statement but maybe you can be comfortable that it will fail sooner rather than later with a spare bolt at hand. Thinking of bolts as consumable items like we do barrels is one way of loading hotter than SAAMI - obviously not too hot but just over and carry a spare bolt.
It is the Forum's understanding that when you start to see typical overpressure signs on spent cases it is already over SAAMI. Your load is 103% full and that is compressed. Pressure climbs steeper once the case becomes compressed.
'Safe' is a relative term.
In bolt guns there is more latitude to go higher than SAAMI. When I was shooting F Class all the .223 shooters could not compete out to 1,000yards without deliberately loading hot. Strong actions and chambers, plus magnum primers and smaller firing pin holes contained the pressure so you can do this for the life of the action without issue.
SAAMI limits are based on the lowest common denominator of likely action, plus a further margin of safety. Unfortunately, AR15's are about the most fragile actions you can buy. Grendel on the other hand with its same AR size bolt but wider diameter case makes it even more susceptible to pressure. Add to that loaders pushing boundaries and sooner or later one of those lugs is going to fail - it's the weakest link. Might not be immediate - might be in 1,000 rounds of constant hammering. Also depends on the quality of that bolt and how the lugs share the load with that barrel extension. This is a controversial statement but maybe you can be comfortable that it will fail sooner rather than later with a spare bolt at hand. Thinking of bolts as consumable items like we do barrels is one way of loading hotter than SAAMI - obviously not too hot but just over and carry a spare bolt.
It is the Forum's understanding that when you start to see typical overpressure signs on spent cases it is already over SAAMI. Your load is 103% full and that is compressed. Pressure climbs steeper once the case becomes compressed.