gojones said:
I bought some range brass. Many different brands and I was having some random difficulty seating a few of the primers.
I have found how easy/difficult to seat a primer depends on few factors:
- Once fired vs reloaded several times
- Unmodified vs modified primer pockets
- Headstamp variation in primer pocket dimensions
- Crimped vs uncrimped primer pockets
- size of primer cup (domestic standard/SAE sizing vs non-domestic Metric sizing)
If you use mixed range brass, you are going to find a mixture of once fired brass with tightest primer pockets and brass reloaded several times with progressively looser primer pockets. And depending on the headstamp, tightness/looseness of how well the primers seat can vary quite a bit.
For me, most domestic and European/Asian headstamp cases with small primer pockets seat domestic brand primers (with standard/SAE sized primer cups) with relative ease, even when hand priming. Exception has been S&B/RWS cases which have tighter primer pockets and take greater effort to seat domestic brand primers like CCI/Winchester to flush or slightly below flush seating depth.
I have found that some non-domestic brand primers like Fiocchi/PMC/Tula have slightly larger diameter primer cups (perhaps due to Metric sized primer cups?) and some with harder cups which make seating require greater effort and difficulty. Seating these primers in tighter once-fired cases will result in flattening the tops of primer cups to seat them flush and in once-fired S&B/RWS cases, it is often a "no go" as the primer cups won't even seat flush with the flattened primer cups (these will result in primers that are higher than flush with anvil feet not touching the bottom of primer pockets and won't ignite, even after repeated strikes as the force from the firing pin/striker won't seat the primer cup deeper).
Of course, there's a silver lining to these larger primers. If the cases you are using have been reloaded enough times to enlarge the primer pockets, these larger sized primers will work well to extend the life of the brass for reloading.