Correcting excessive headspace

[Camo tung]

I've been reading quite a bit in the Milsurp forum about different bolt heads for Enfields (#0, #1, #2 etc) that are used to correct headspace problems on these rifles and started wondering about other action types.

How is excessive headspace corrected on lever action guns, pump action guns or semi-autos....or is headspace less of an issue in those as compared to bolt guns?

For that matter, other than Enfields, how is the headspace brought back within acceptable limits on most modern bolt guns?

 

[tiriaq]

Headspace tolerances are essentially the same for any and all action types. Different boltheads are used to set final headspace by at least one major manufacturer. Savage uses the barrel nut system.
If a conventional bolt action rifle has excess headspace, to the point that the owner is uncomfortable using the rifle, about the only real remedy is to set the barrel back, and recut the chamber. This could also be done with something like a '94 Winchester, if required. Could be a bit more complicated, because of the fittings attached to the barrel.
Careful handloading can be a viable substitute for alterations to the rifle. Custom dies can be ordered, which size cases to fit the rifle.
Now, exactly how dangerous is excessive headspace? With fresh factory ammunition, how many instances are there of failures that endangered the shooter? With Lee Enfields, which often are really quite loose, how often does anything more serious than a separated case occur?

 

[Randy B]

Winchester 94 lever guns can have a differant size breech lock installed.
Trust me headspace is a serious condition as anyone who has had a face full of hot gas powder and brass bits at 50000-60000 psi will attest. never try and correct excessive headspace by loading the brass to suit. Brass becomes tired and lots of older ballon style headed stuff still floating around.
(thin webbed at head region) If in doubt seek a smith who knows his stuff.
Randy

 

[sunray]

"...how is the headspace brought back..." On most, the barrel is removed, the threads machined back and the chamber reamed. However, modern hunting rifles rarely have headspace issues. Somebody may misplace a bolt and just buy another though.
Enfields are susceptable because the bolt head comes off and most of the rifles are 50 plus yars old. Who knows if some twit changed the bolt head in that time. Lots of 'em have been assembled out of parts bins with zero QC too.

 

[Randy B]

lots of modern rifles have headspace problems!! some guys agressivley lap in the lugs And induce it!! Others are rebarreled by Wanna be Smiths using fired brass as a headspace guage. Some are just plain shot alot. IE 94's 92's . Some are just made out of junk (soft steel) Careful on some of the Chicom shotguns etc.

 

[Rembo]

lots of modern rifles do have headspace that is over tolerance but not dangerous..I have an untouched stainless 700 BDL in 243 at home that takes a NO-GO gauge quite readily...feels like maybe a half thou fore & aft movement on the gauge with a stripped bolt, doesn't worry me the slightest. My old 300 Winny would also take a NO-GO gauge...shot it for 10 years like that...if it takes a field gage then I'd fix it.

 

[SaddleTramp]

On rimmed lever action cartridges the headspace is controlled by the thickness of the rim. The biggest mistake first time reloaders make is over sizing cartridge cases when full length re-sizing. They set the shoulder back and when fired the case stretches ahead to the chambers original dimensions usually ending with cracks around the head or complete seperation all together. Even too much sizing lube on the shoulder of a bottle neck cartridge can cause this to happen.(don't lube the shoulder). Its not always the rifle that has the problem, although I have bought guns from guys who were adament that the headspace was blown on their rifles. A few factory rounds or neck-sized only reloads soon proved them wrong. The Enfields are nototious for bad headspace. I think they were built so you could chamber a wad of mud as well as the cartridge. Military Tollerances I guess. Those Brits...EH...