Info: .450 UF Game Breaker.... HS Precision, full aluminum bedding block.
The rifle came with the XMark Pro trigger, which I never liked. The Ultimate muzzleloader I have, also came with the XMark Pro trigger, which I never liked, to which I replaced it with a Timney 512. After a couple years of shooting the Timney, I decided to switch the muzzleloader trigger to a Jewell.
That said, I was playing around and figured I may as well install the Timney on the .450 Game Breaker. No big deal with the Remington 700 action. So it sat in the safe for quite some time, and after discussing the .450 Bushmaster with another, I decided to get it out and send a few rounds.
First two rounds at 100yds went perfect, which you could completely cover both bullet holes with a dime. Then I noticed immediately that the after those two rounds, that when I extracted a spent case, the bolt would not stay cocked without first placing the rifle on safe. I checked the function with it off safe with no round in the chamber and found that it would not remain in the cocked position with the safety off. Next thing I noticed, was that the trigger pull increased quite a bit.
Left the shooting bench for the house and examined the rifle completely, looking for any place that might be binding that trigger. Now this trigger worked perfectly on the muzzleloader and the trigger pull remained constant. I could NOT find a single place where the trigger assembly did not have clearance to the bedding block. I removed the stock and the trigger functioned perfectly. I reinstalled the stock and torqued the screws and the action and trigger functioned perfectly, so I headed back out to the range.
First two shots identical to the other shots, then after ejecting the spent case, I closed the bolt (clear chamber) and the bolt would not remain cocked. If I put the safety to the ON position, the bolt WOULD remain cocked and not break when the bolt was opened and closed. The trigger pull also increased. So back into the house and the bench again. I can safely say I examined that trigger assembly for at least an hour and I can not find what's binding that trigger. Remove the stock and the trigger functions perfectly. Reinstall the stock and the trigger functions perfectly, until two more rounds are fired.
My shooting at that point was over. After getting the rifle back on the bench again, another thorough examination and still, I can not find an area or spot that might be causing that trigger to bind up after just two shots. The recoil lug is firmly planted in the proper position and the pillars line up PERFECT. When installing the trigger to the action, the pins aligned perfectly.
I CAN NOT, for the life of me find the cause for the trigger binding. So, having become a "little frustrated" I decided I'd remove the Timney and reinstall the XMark Pro trigger. Now, not a single issue with the old trigger.
Any ideas???