Max pressure with or without a suppressor?

[LRSNM]

First time for me reloading to first sign of pressure then backing down with a supressor. My load was developed with a supressor. It shoots .25 moa with no pressure signs. I'm now getting ready for a hunt in Canada and I can't use the supressor. I't now shows minor signs of pressure, more than normal bolt lift from my developed load with the supressor.
Is it unusual to have that much difference in pressure with and without a supressor?

 

[Doc88]

The only change I ever have with a suppressor is a little change in POA/POI. Usually the velocity and accuracy stay the same. That's my experience...others may say different. That being said I have had some pressure signs change with the same load dependent on temperature, carbon build up, rounds down barrel, etc.

 

[QuietTexan]

It'll probably be colder there, depending on the powder I'd be more worried about sliding out of a node than minor signs on the brass if you're that close to the edge.

 

[Seabeeken]

Sound like your load is on the edge and temp is moving it over the edge slightly. Like tex said, itll be cooler there. If POI hasnt moved, i wouldn't be concerned.
with that said, your load is likely overpressure before your stiffer bolt lift

 

[brant89]

I normally see a slight velocity increase with my suppressor on (25-40fps) but no significant difference in pressure. I would agree that it's probably just a byproduct of being on the ragged edge.

 

[Zen Archery]

If it were me and this was the exact same batch of ammo Then I'd say you have obvious pressure signs without the can. Drop a few kernels and rework the load without the can. It's a bummer thing to find out before a hunt but better to know now then in field.

 

[LRSNM]

Sure appreciate the advice from all. It affirms what I was thinking.