Bolt hard to open after dry firing

Got a few questions about an 03A3 Smith Corona 1944 action I recently acquired.
A bit about the action it has been drilled and tapped for a scope, rebarreled with no markings on barrel and no front sight grove. It also has an aftermarket trigger marked Jaeger, which leads me to believe it is a Jaeger rework from the 50s or 60s. Bolt has an aftermarket Buehler two position safety and the cocking knob has been removed.

Fiddling with the action over the past month since I bought it I’ve had no issues cycling the bolt and had dryfired it once or twice but usually would hold the trigger down while lowering the bolt to keep it decocked.
Yesterday I was working on fitting it into a stock and dry fired it a few times I then had two new issues show up, the sear would sometimes not hold the firing pin rod back (rifle going to decocked as the bolt was being closed). As well as the bolt being incredibly hard to open after dryfiring.
Once I get the bolt open / cocked the action becomes easy to work again (until it is dryfired the next time).

Does anyone know what could be causing this?

Maybe the stock is gumming up the works because of a clearance issue. Take the wood off and try the mechanism.

I agree, something about the fitment...

Must be. Try without stock. If it works, then you have some collisions inside the stock due to bad bedding.

I believe that I can answer this question as my Dayton-Traister trigger works the same way.
Most commercial triggers are "sear release' triggers. The trigger, which is spring loaded, engages the sear and when the rifle is cocked, the trigger blocks the sear from releasing. When the trigger is pulled, the firing pin spring forces the cocking piece over the sear which allows the firing pin to fall. When the firing pin is forward, the sear, being spring loaded, returns to its original position and is again blocked by the trigger. On the front of the trigger assembly there is a post and there is a spring that keeps the trigger assembly in place. When the rifle is now cocked, (bolt opened), the sear is locked in place by the trigger so there is no way that the firing pin can override the sear. The entire trigger assembly must rotate to allow the firing in to override the sear. If there is no clearance at the rear of the trigger assembly, it cannot rotate. I suspect that you need to relieve the area behind the trigger assembly to allow some clearance so that the trigger assembly can move. The trigger assembly must be free to pivot abut the trigger pin or it will not work.
FWIW

Most likely it's the trigger or sear contacting the stock, but if not before modifying anything do this. Cock and dry fire like you have been doing except keep the trigger pulled to the rear each time after firing and try cycling the bolt (do this several times), if the problem does not repeat then you know it's in the trigger/ sear. If the problem still occurs then it is likely your mainspring collar was left off or something. I've seen this happen before and the fella had left the collar off, all worked ok but once in a while the tip of the spring would work over the shoulder of the firing pin and bind everything up.

Thanks to everyone for the replies.
To those that suggested dry firing with the action off of the new stock I tried this and encountered the same issue (issue wasn't present before stock fitment attempt).
Cosine26 - I'll check the spacing around the trigger, I had to make some additional space in the stock to get it to fit and may have tweaked something in that process. I also took out both the trigger mount pin (big head) as well as the custom trigger's sear pin when initially checking fitment (didn't need removal but hadn't known that till the trigger was out). I may have put a slight bend in the trigger sear pin while getting it back in. That may be the source of all the problems.
Current plan, try removing trigger assembly and see if the action opens easily.
If so I'll see if I can get the sear pin back strait and hopefully resolves the issue.
What do you mean by "spring that keeps the trigger assembly in place?" do you mean the spring in the trigger body under the sear or is there another spring?
Randy_A - I'll try that test this evening after checking the above and will reply with results.

Mainly22s
There are two springs:
One- repositions the sear after firing
Two- repositions the trigger.Incidentally this is the one that sets the trigger pull weight.
I am not familiar with the Jaeger trigger , but I believe that it is a "sear release" trigger and operates much in the same way as the Timney or Dayton-Traister.
I can offer the following suggestions which you may have already tried.
1. Remove the rifle from the stock and see if that clears the problem. If so it is probably a stock fit problem.
2. If you still have the problem, dry fire the rifle and while holding the trigger in the fired position , open the bolt , and see if the problem continues. If so,m the trigger is still blocking the sear.
3. Operated the trigger an see if it returns to the un fired position .
4. Operated the trigger with the action open and see if the trigger return spring is working or if the trigger is binding.
Hope that helps.

hey all, sorry for the delay in testing / sending a reply, I had a family emergency to attend to.
I think this may be a two part problem.
For the firing pin dropping without the trigger being contacted it seems I've misplaced the sear spring sometime while working on the stock fitment. Haven't been able to locate it so probably getting one online or next week at my local gun show. Thanks to Cosine26 for highlighting this part as it didn't appear obvious to me that there needs to be a spring there.

As to the bolt being hard to open I'm still encountering that issue occasionally even with the trigger group off. Which makes me think Randy_A's suggestion about the mainspring collar may also be an issue.
I'm going to try to disassemble the bolt and see if that is the case.

Thanks for all the help thus far.

Edit: Randy_A - in regard to the mainspring collar is that part #17 in this diagram, referenced as the Striker Sleeve? Parts Diagram - WWII 1903a3 serial #3731435

Strip the bolt completely minus the extractor collar and then check for function. I would look at the FP spring to make sure its not binding in the body, the front of the bolt is not interfering with the chamber cone and that there are no blind screws coming through the front ring or rear bridge that are binding the bolt. While its apart, use a steel ruler on the bottom of the receiver body to make sure its not twisted.

Was able to get the bolt apart this weekend. I haven't tried dryfiring it again yet, still waiting on the sear spring.
I did notice a slight burr on one side of the striker pin which i was able to clean up with a file. The action can be worked without binding, but dryfire will be the real test.

Will update once I have the sear spring.

Doco - I'll check to see if the receiver isn't twisted. I tried to separate the striker from the rest of the firing pin rod, but couldn't seem to get a good enough grip on the striker sleeve to separate the pieces.

If its nice and flat on the bottom, leave the trigger and sear off and reassemble one bit at a time starting with the extractor and you may identify the culprit!

Thanks everyone for the replies and assistance.
First off through some YouTube research and guidance from Cosine26 it turns out that the Jaeger trigger is very similar to Timney type triggers.
There isn't a sear spring and instead is a tension screw. The screw should be loosened so that the trigger pack can be installed with only finger pressure on the pin.
Once the trigger is installed on the receiver the screw is tightened down and this is what replaces the function of the sear spring.

Did some additional work on the rifle this past Friday. Mainly inletting the stock so the aftermarket trigger had proper clearance room.
Between the stock modifications, the correct trigger insertion method, and the bolt disassembly and checking I ended up shooting an accurate group at 50 yards. And once my scope was sighted in properly I managed this 50 yard grouping

Glad you got your issue sorted also nice group glad I am not the only one who gets a flyer.

I shot this group at 100yds .308 APRS 168gn A Max 3 shots with the flyer being 2nd shot the 1st went through the diamond the inner circle is 1" b*gger.....

Flyer? What's a flyer?;-D

Quote:

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Originally Posted by Ovidio

What's a flyer?

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Throwing a cabbage...

:lol:

It was a joke;-D