Probblem with Jammed Bolt

[Neuraleanus]

I took the new No 4, Mk1* to the range today, got three shots off and then the bolt jammed. Couldn't rotate the bolt to extract the cartage. Went home and after much fussing I discovered that by pulling the cocking piece back to full cock I managed to get the bolt to work again releasing the spent cartage. Testing with snap caps seems to indicate that everything is fine. I am going to re-clean everything as the mechanism is still a bit stiff feeling. I think that this rifle has not been fired much recently and that may be an issue. Thoughts?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Sapper740]

That's a puzzler for sure. What could cause your cocking piece from going from fully forward fired position to half cock by itself? Nothing I can think of. If it was the other way 'round and your cocking piece stopped at half cock when you ran a cartridge into the chamber that's fairly easy to explain.

[Neuraleanus]

I may of inadvertently put the rifle in half-cock during my fussing. In half cock everything is frozen. The question is why the bolt jammed in the first place. At least now, if this happens again I think I know of a solution.

[Alan de Enfield]

Are you using factory loads, or someones home-loads ?

[Neuraleanus]

Are you using factory loads, or someones home-loads ?

150 grain PPU. I don't think the ammunition is at fault. I'm still cleaning out traces of cosmoline. The action has been very stiff making me think that this rifle hasn't been shot in a long time.

I went over the rifle with liberal amounts of Ballistol and that has seemed to help.

[Bruce_in_Oz]

You can put a No1 or No4 into "half-cock" if the bolt handle is not ALL the way down when the trigger is "pulled".

This is what the little "islands" on the rear of the bolt body and on the cocking-piece are all about.

It is a VERY clever bit of engineering.

The idea is that during correct cycling of the bolt, these little bumps do a bit of a dance around each other.

IF the bolt is not fully locked down before firing, the "bump" on the cocking piece will strike the one on the bolt body. This will cam the bolt fully closed, (usually) but will have reduced striker energy to the point that the primer will probably NOT ignite In certain circumstances, the sear may ride off the full-cock surface and engage the half-cock notch; thus preventing any ignition and alerting the operator that 'something is wrong" and the usual "immediate action" drill should start.

NEVER use a rifle with one or both of these little island lugs missing. They were put there so you could go home went home grumpy, but with your face intact.

Certain "full-bore" types had a nasty habit of "removing" the "safety lug" from the bolt body, thereby removing a key mechanical safety mechanism.

I have TWO such ruined bolt bodies in the "Box of Shame"; along with doctored triggers, sears, sear springs, cocking-pieces, etc. Still hoping to turn up one of the "expedient" WW2 cocking pieces from Fazackerly. These had NO half-cock notch and NO grasping grooves. Maybe they figured the if it could never go to "half-cock", there was no need for grasping grooves......

[Surpmil]

Was J.P. Lee the inventor of that feature or Joseph Speed or who?