enfield bolt problems

[kwells2006]

its a 1913 BSA, given to the Irish (Fianna Fail) in 1927.

My problem is, when I fire the rifle, the bolt pops up about 5mm or so. does not open, but makes me uncomfy to shoot. was my first rifle and would like to fix the problem. anyone know what the problem is?

[Mikey]

Kwells:  The SMLEs can have some 'spring' to the bolt.  I think this was a design feature to go along with oversized chambers to assure reliability in adverse conditions but I'm not sure about this.  Possibly gunnut69, the Moderator of the Gunsmithing Forum can shed some light on this but in addition I would ask you to describe the primers from your fired cases as you may have high pressure signs. 

SMLE bolt heads are removable and come in at least 3 if not 4 different sizes.  The 303 headspaces on the rim and if your bolt head is shorter than you need the rearward thrust may be off-setting the bolt when you fire the rifle.  I would also want to run this past the gunnut69 for his advice. 
HTH. 

[coyotejoe]

I'm not sure what you mean when you say "the bolt pops up". If you mean the bolt handle lifts slightly, I'd not worry about it. If you mean the bolt body itself moves 5mm I'd not fire it. I would at least have a gunsmith look it over and check headspace. A crude headspace check you can do yourself is to take a new or full length resized case, start a primer into the primer pocket but leave it protruding about half its depth. Drop that case into the chamber and close the bolt. Now extract the case and see how much the primer still protrudes, if it's .010" or less you are OK.

[kwells2006]

the primers are fine, no pressure marks or anything

[coyotejoe]

Of course the primers will look fine on a normal fired round even if your rifle has grossly excessive headspace. When a loaded round is fired the firing pin and primer first combine to push the round as far as possible into the chamber and pushing the primer out of the pocket. Then as burning powder builds gas pressure it will push the case back tightly against the bolt face, thus reseating the primer so that it looks fine. That tells you nothing.
 I am suggesting you check your headspace by NOT FIRING the rifle. Chamber an empty case with the primer protruding from the pocket and let the caming action of the bolt seat the primer deeper. Then measure how much still protrudes, that measurement is the headspace.

[kwells2006]

thanks yote

[Langfur Buchsen]

This usually occurs when, on dry-firing, the cocking piece contacts the side of the recess in the rear of the bolt, camming the bolt slightly towards the opening direction. When a correctly adjusted smle is fired (live cartridge) the striker and hence the cocking piece will not go forward enought to hit the side of the before mentioned recess and therefore the bolt handle should remain in the closed position

........generally not a concern - hope it's just that with yours  

if, however it rises on firing (a live cartridge) then I'd have to reconsider my advice for you

[kwells2006]

when I fire a live round is the only time the bolt pops up

[Langfur Buchsen]

when I fire a live round is the only time the bolt pops up

... ah... well, as others have already pointed out, have a good look at all the headspace factors, and, have you been ensuring that the face of the bolt, the chamber & the locking faces of the lugs are free of lube/oil?

and following up on my earlier post, can you see (using marking blue perhaps) if the cocking piece (at the rear of the firing pin) is in fact impacting on the small machined slot at the rear of the bolt?

otherwise .... there may be some wear & tear factors affecting the incline of the locking lugs (you will notice that they are NOT at right angles to the bore-line, but instead advance the bolt forward slightly as they engage to the "locked" position

as smles are fortunately plentiful where I come from I must admit that if I couldn't see the reason I would be inclned to "retire" it & pick up a replacement action/rifle

[kwells2006]

id still like tos hoot it, but if its unsafe, id rather not. it was my first rifle so...