My son has a 1980s vintage rem 700, we bought a Trigger Tech trigger and installed it, cycled safety on off and dry fired, now bolt won't open. Removed trigger but bolt still stuck in closed position. I'm thinking the bolt is out of sequence, thinking the safety is on and won't open but I don't really have any clue. Any insight would be appreciated.

The safety can’t be on if you removed the trigger. Did you only dry fire it or did you fire any live rounds?
Also try backing the front action screw out a turn or 2.

I'm assuming that since the trigger is out, the action screws are also out and it's just a naked barreled action with a bolt?

Where is the cocking piece on this bolt? Could the bolt release be stuck in the up position?

Good call! Probably no action screws to interfere with the bolt.

Correct, action is out of the stock, trigger removed, bolt won't open. Bolt cycled as normal prior to removing factory trigger and installing triggertech. No clue what I've done wrong here.

Ah the old( worked good till I fixed it ) routine. Sorry I couldn’t help myself. Wish I had an answer for you. Good luck. Edk

No trying to be a smart a$$, but it sounds to me like it's time for "Bubba' to take it to a gunsmith . . . . . .

I bet the ramp at back of the bolt needs grease, or the firing pin got jammed into the bolt face. Perhaps grease the work heavily?

This rifle used to belong to my sons grandfather, used for 30+ years with little maintenance so things were a bit gummy when we took it apart. Trigger went in without any problems, worked fine prior but something is wrong now for sure.

Did he do much dry firing before the trigger swap? If not, is it possible that the firing pin is corroded to where the additional projection of dry firing lodged the corroded section in the firing pin hole? I had a brass shaving do that with a 700 once. Wedged up the pin pretty well in the boltface.

Have you tried to lightly tap the bolt handle up? Be careful as they are sometimes not brazed on very well. It’s most certainly a cocking piece/firing pin/ spring bound issue.

Did you remove the firing pin assembly and clean them prior to the new trigger install?

Have any pictures of the action/bolt from the underside? Can you see the cocking piece through the cutout in the action?

Could be worth getting some Kroil or PB Blaster dripped onto the boltface and around the pin. Then give it a nudge with a cleaning rod to see.

This "Bubba" has been working on rifles for decades, certainly not a "smith" but not my first trigger install either. Called my smith, someone who has been building me rifles for 20 years plus and he is stumped as well. He suggested turning the action over, in the area where the trigger would normally be, take a screwdriver and try to cock the bolt and see if I can turn it. Will give it a try later.

Given the condition of the rifle, this could help.

That's entirely possible

That sounds like the most likely event

I gave the handle a solid pressure push several times, it does sound like the cocking piece / firing pin is bound. I have not removed the firing pin, don't know how. The rifle is at home but I can see the cocking piece but not being all too familiar with that view, not sure if it looks normal or not.

As previously mentioned, the action area below the stock had lots of build up gunk for old oil that accumulated pretty bad, the trigger was a gunky mess. We cleaned up what we could but not the firing pin/inner bolt. His grandfather used the rifle a lot but never cleaned it, ever that I know of.

I would assume the bolt body/firing pin is a gunky mess also. To remove the firing pin assembly you need to get the bolt out of the action first. Then it’s very simple to do.

Bigger hammer.

Why would anyone attempt to improve upon perfection?

I can't remember what a 700 looks like as far as firing pin indicator, if you have another, cycle that and see what compares, fired and cocked. If it looks fired, pour some bolt blaster down the tube, while letting her soak, get a nice BRASS rod stock in bore diameter (minus a bit) that is long enough to give a nice love tap. In fact, soak the daylights out of the works with the best solvent sauce you have and give it time to work.
If anything, tapping on the rod should tell you if the pin is protruding from the bolt face.

In that era, Remington had gone to the longer bolt shroud to fully cover the rear of the cocked firing pin. When the bolt is cocked, the rear end of the firing pin should be flush with the firing pin shroud. When in the fired position the rear end of the firing pin will be recessed below the shroud by about 1/4”.