We've done these threads before and I've commented with advice on a few.
This one is doing my head in.
I have several HW77 stocks.
This is a second action that I'm working on. I wanted to try it in an old Tyrolean stock that I've not used before.
The stock is pre anti-bear trap so doesn't have the extra cut out for the lug. You use a longer front trigger bolt that goes straight into the action.
Out of the stock the action cocks and engages the safety. Knock the safety off and it fires. All as it should be.
If you fit it to this stock and fit front and rear trigger pins then it won't cock, engage safety or fire. If I remove the front trigger pin ... it works fine.
Same action in two other stocks ( but using lug ) and it works fine.
Take action out of stock and screw full length pin all the way into action and it still cocks and fires fine.
Another action in this Tyro stock and that won't work either. So must be stock related.
There is loads of clearance inside the stock for the trigger unit.