Factory Ammo with pressure signs 6.5CM

[MT380]

I have a Bergara premier Divide rifle.
Yesterday I was shooting factory Hornady 140gr ELD match ammo. I saw pressure signs on the first shot with slightly heavier bolt lift. The second shot through 17th seemed fine with switching ammo boxes after the 6th shot. However I started seeing pressure signs again on the 18th shot. I had a heavy bolt lift and ejector swiping. I waited a few minutes while inspecting the gun and bore then shot the 17th shot and it was ok. The 20th shot had hard bolt lift and ejector swiping again. I then switched to a box of 120gr ELD match, had one good shot then again heavy bolt lift with slight ejector extrusion swiping. At that time I stopped shooting for fear of damaging something or blowing up the rifle.

Rifle and shooting details:
Bergara Premier Divide with around 100 shots through he bore.
I cleaned the rifle thoroughly the day prior to shooting. Used bore tech carbon killer then copper killer then bore cleaner as described on the bottle. wet patches, then nylon brush then wet patch and dry patch until they came out clean with each solvent.
I dry patched the rifle prior to taking it out to shoot to make sure no oil was left in the barrel.
I was shooting suppressed with a Huxwrx Ventum 762 flow through can.
All Ammo was factory new.

I have read of some people having pressure signs with Hornady superformance, but nothing with ELD match. I haven't had issues with this ammo previously but prior to this day all shooting was in sub 50* temps. Yesterday was 80*. I inspected the bore and apart from some normal looking fowling I didn't see anything obstructing the bore. Looking back on the ammo I shot I had a few other shots that had some mild ejector swiping on them. Pictures attached. Any ideas on what could be the cause of this? Could it be because the barrel was heating up? All shooting took place over a period of 1 hour. There was a significant pause after the 6th shot while we moved back to the 500 yard range. I also noticed my suppressor cover had migrated forward and was overhanging the muzzle end by 1/2" and may have been impeding some of the flow through gasses exiting. What precautions would you guys suggest I take? Should I send the rifle and last 6rnds of ammo back to the manufactures for inspection? Shoot again without suppressor? Buy different ammo and try again? I do plan to reload for this rifle and have all the components to complete it I just haven't had a chance to start working up a load yet. Im not sure what would be the best course of action, I'm new to bolt action rifles and long range shooting so any help or suggestion would be greatly appreciated.

Requested Data along with other data I thought of.

Cartridge base to shoulder datum:
last six unfired rounds in 140gr box.
1.5590
1.5565
1.5565
1.5575
1.5560
1.5570

Post firing no pressure signs. all are between 1.5600 and 1.5605

post firing with pressure signs are 1.5600-1.5625 the longer ones show the most pressure signs im assuming from the bras scrap. I don't see any signs of primer extrusion or pushed primer.

Cartridge base to ogive of last 6 unfired rounds are all 2.1935-2.1940
The rifle chamber cartridge base to lands/jam measures 2.240 currently as the rifle sits dirty with hornady LNL tool.
previous measurement of clean rifle I have written down is 2.249

The velocities for the first six shots is all I had while playing with my Garmin. Hornady box lists muzzle velocity at 2710fps
2707
2707
2706
2721
2739
2710

Shots with pressure signs. Shot order left to right, top to bottom. I left out brass from shots in between that didn't show pressure signs. The single round on the bottom is the 120gr ELD match.

 

[XLR308]

Do you have the tools to measure the brass base to datum on the shoulder pre and post firing ?

 

[918v]

Cleaning with a nylon brush won’t get the carbon out. Use a bronze brush.

 

[MT380]

Do you have the tools to measure the brass base to datum on the shoulder pre and post firing ?

Yes I'll add them to the post along with more data.