280 AI reloading question

[MSshooter66]

I am trying to develop a load for my rifle with the Federal Edge TLR. I am trying to load 7828 as my rifle loves it in everything else I had loaded. I presently shoot 60.6 grains 7828ssc under 160 Grain accubond with no pressure signs .25 MOA. OAL 3.335. Max listed book in nosler for 160 grains is 61.5 and for 150 grains is 63 grains. I figured Id be safe loading 61 grains and trying it. My first shot I blew a primer so I didn't fire it again. Any idea why shooting basically the same load for a 155 grain bullet and 160 grain bullet would show so much more pressure in the TLR as compared to the accubond?

I could drop the charge and try again, but too much drop would lower velocity below where id really like it. I have some RL 22, but according to Quickload they demonstrate the same speed, charge, pressure.....etc.

 

[verdugo60]

If it blew the primer it's very over pressure, probably smart to not shoot more. I'm wanting to try that same bullet in my 280 ai if I can find any in stock as it seems great for hunting elk close up and at long range.

As for your issue, I don't know the oal you're running but is there a chance the 155 is jammed into the lands? That would spike pressure. Or if it's loaded further into the case limiting capacity. At top end loads lots of small variables can stack and cause issues with a new bullet. I would drop 3-4 grains and work up to find a load. Check your coal too.

 

[Steel head]

Difference in jump or bullet shape can definitely alter pressures.