Having issues working up a load

[Rflshootr]

First I'd take the firing pin out of the bolt, clean everything inside and out, especially if you have ever had a blanked primer. Nextly, reassemble the bolt, de-cock and check firing pin protrusion. The if that is all ok, at least you have eliminated that possibility of why you are getting erratic ignition. It is strange that some of the velocities are much lower with a higher powder charge.

 

[rsbhunter]

Can you post pics with the ones that didn't fire? Primers especially...rsbhunter

 

[crkckr]

That would be my first question, what did the primers that did not fire look like? Was it a good deep dent or maybe a little lite? Are all of your primers seated all the way? Have you done or tried anything different the last time you seated primers? I would check whatever tool you use to seat the primers, first.

You said the primers didn't go off, was the primer cake broken up? Was there any primer "dust" on the powder? If not, it probably was NOT a good firing pin hit on the primer. A good solid hit that doesn't ignite the primer will usually break the cake up and put a fine dusting of primer colored dust on the powder. That could be a anvil not fully seated or a bad primer, which while unlikely, is always a possibility. Then I would investigate the ignition system - firing pin, spring, etc. I think once you investigate the primer problem fully and find out what's going on, most of your problems will simply disappear!
Cheers,
crkckr

 

[Bang4theBuck]

What brand and model is the rifle?

 

[talltexanrancher]

My first thought is headspace issues closely followed by firing pin/spring issues and then primer contamination of some kind. These can be frustrating to figure out...let us know what you find.