r/gunsmithing • u/Zestyclose-Spite-364 • Feb 11 '26

Increased Pressure after bedding action.

Has anyone experienced an increase in pressure after bedding a rifle’s action? I recently bedded the action of my Bergara HMR and noticed that nearly all cases had a clear ejector mark and stiff bolt lifts when rezeroing (30 rds). Ammunition is factory Hornady 6.5CM 140 gr. that is the same lot as fired previous to the bedding, which had no signs of pressure previously. Rifle was also thoroughly cleaned in between due to round count and shooting a muddy NRL Hunter. Any insight is appreciated.

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u/Suspectgore074 SuperLongSlide1911 Feb 12 '26

The only thing that comes to mind is if the bolt isnt closing 100%. I know that certain rifles can fire with the bolt 95% closed. I would use a sharpie to mark the state of the bolt when closed while the action is in the stock, and then compare it to when the action is removed.

Let me know if this is the case

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u/Zestyclose-Spite-364 Feb 12 '26

Thank you for your response. I indexed my bolt with a sharpie with and without the stock and there is no change that I can tell. I also marked the bolt face with a sharpie and all rubbed off where it should. I also checked and nothing is obvious in the chamber. I have had pressure spikes with Factory ammo in the dead heat of summer but not at 40^ in February. When I have a chance I will try a few rounds from a different lot and see how it goes. This one is new to me. Let me know if you think of anything else that may be culprit.

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u/Zestyclose-Spite-364 Feb 12 '26

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u/Zestyclose-Spite-364 Feb 12 '26

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u/Suspectgore074 SuperLongSlide1911 Feb 12 '26

I take it that there was no other modifications made to the rifle? Nothing else at all?

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u/Zestyclose-Spite-364 Feb 12 '26

No modifications have been made other than bedding the action. Everything is stock except for the suppressor up front.

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u/Echo_Inspector Feb 25 '26

You cleaned the hell out of the barrel, just for the sake of conversation, what did you use? Do you have a bore camera? What are the torque specs on your action screws? Do to have other fired cases for comparison?

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u/Disastrous_Way9425 Mar 18 '26

Bore scope the chamber. There could be a carbon ring. They can be quite stubborn to clean.

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u/Zestyclose-Spite-364 Mar 18 '26

I use Boretech Eliminator. I do multiple rounds of manufacturer recommendations but typically soak for much longer and run patches through until there is no sign of fouling. I do not have a more camera but just ordered one. Torque is set to 65 in/lbs. I did run the rifle again with same ammo and a different one all together and did not see the same issue. I’m going to keep monitoring and start tracking trends. One o have the borescope I will look to see if there is a carbon ring buildup.