223 loading problem

223 new load problems. Powder n120 Rifle remington 24"barrel 1in 12 twist.Load 19.3 min. 22.7 Max ...Loaded 19.3gr ,then 20,20.5,21. All cases had slight primer craters
 
223 new load problems. Powder n120 Rifle remington 24"barrel 1in 12 twist.Load 19.3 min. 22.7 Max ...Loaded 19.3gr ,then 20,20.5,21. All cases had slight primer craters

Have you used the same primers on a different, safe load? Did they crater?

Failing that do you get craters on factory primers? Cratering is not always an issue and can be down to poor firing pin fit. My hornet does it with all ammo and rem700s are noted for it
 
Have you used the same primers on a different, safe load? Did they crater?

Failing that do you get craters on factory primers? Cratering is not always an issue and can be down to poor firing pin fit. My hornet does it with all ammo and rem700s are noted for it

Well noted '25 Sharpshooter'.. I had just this same problem(?) with the relatively soft-cupped Fed 205 GM primers I use/used in my .223 loads ... again in a Rem 700 action! But even well before this kind of information exchange site was available, I reasoned that the clearances in the bolt face round the firing pin protuberance would most likely be the culprit as my initial loads in that rifle were more than a little gentle in deference to my (then) neophyte skill levels and understandings. I changed primer to the harder and perhaps even a little thicker cupped CCI BR2 and with my then light loads this cratering of fired primers more or less disappeared. So I went back to the Federal Match primers for all but my stiff, long range loads.

As mentioned, for primer checking, whether the edges are still slightly rounded over after firing or if they are sharp and flat might be a better "high pressure" indicator..

Actually this indicator too is compromised by the construction materials and general cup thicknesses of the primers used !...

ATB ....... and shoot safely
 
In the past I have noticed factory fodder produces flattened primers so feel sure they would not make standard rounds over pressure. For me the signs of over pressure are witness marks on the headstamp.
 
In the past I have noticed factory fodder produces flattened primers so feel sure they would not make standard rounds over pressure. For me the signs of over pressure are witness marks on the headstamp.

That is definitely a sign as is clean shiny bits on the brass.
Personally I think the best way to tell is check the speed. Chronographs are cheap enough now that you can add one to your kit.
Real world it’s usually not possible to make the data speeds. But if you’re getting close you are also getting near with the pressure too.
 
As noted earlier, probably soft primers.

In my .223 I get heavy bolt lift a long way before I see ejector marks in the case head, so I use that as my indicator to reduce the load.
 
Just to complicate matters, bolt lift can vary a lot depending on bolt lug & cocking cam lubrication. A dry bolt can exhibit heavy drag & galling can occur. Even different oil or grease in these areas give different bolt lift loads.

Ian
 
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