Problem with No4 MkI Bolt

[dewey1424]

I am having a problem with a No 4 Mk I. It is a Savage, with a matching bolt and a 1952 FTR. The problem is that when fired, the bolt head jumps out of the track. I have to hand raise it to the vertical release orientation to get the bolt open. The ammunition I used was PPU FMJ BT 174 grain.

I did check the headspace and it does not close on an 0.071 gauge. I followed the procedure in T.J. Evans's Guide to the Lee Enfield Rifle to remove and replace the extractor to perform the headspace check. I didn't dismantle the bolt further.

It seems to open and close smoothly with no round in the chamber.

The only other observation I have is that the bolt head does not tighten flush with the bolt body when the bolt and bolt head are aligned, so there is a little play between the bold head and bolt body. (Does that make sense?)

Could this problem be caused by my re-assembly or do I have a bigger problem with this rifle?

Thanks.

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.

[Alan de Enfield]

Have a look at the 'rail' that the bolt head slides in.
In the 'cut out' area where you lift the bolt head out of the rail are the corners damaged ?

This damage allows the bolt head to jump out of the rail and is potentially dangerous.

It is a common fault on Savage, and to some extent Long Branch ,and was the price to pay for speeding up production.

Once rifles had this damage they were scrapped, but in civilian life, some folks have managed to rebuild the 'corners' with weld without affecting the hardness of the action.

Have a look at this old post

https://www.milsurps.com/showthread.php?t=55809

[Brian Dick]

Bolt head overturn shouldn’t be more than 1/8”. If excessive, the recoil is transmitted to the threads instead of the locking lugs on the bolt body as designed. Not good. In service, Armourers had large supplies of bolt heads from which to select fit. We aren’t so well off these days so have to bring them back as close to spec as is possible with the parts we have.

[Parashooter]

My Savage No.4 Mk.1* arrived by US mail in 1958 - complete with a Canadian armorer's tag indicating it had been condemned for a "worn bolt guide". Having no welding skills or equipment at 13 years age, I simply peened the remains a tad to alleviate the problem. (Later, I learned a little chamfer on the bolt head could help prevent further damage.) After 62 years it still works perfectly.

[dewey1424]

Many thanks for the replies. This is my first Enfield and I clearly have a lot to learn. I will post some pictures of the receiver and bolt later today for comment.

[dewey1424]

Deleted until I can figure out how to size photos.

[dewey1424]

Here are some pictures of the receiver. It doesn't look as damaged as some in the links folks have provided.




Here are some pictures of the bolt and bolt head, trying to show the rotation and the channel.



I will be grateful for any comments or recommendations.

[lawrence_n]

Check the length of the cut-out and then check the length of the bolt head guide. I had one like your, years ago, and found out too late that some doofus had carefully filed the cut out wider, presumably because the moron thought it would make removing and/or inserting the bolt easier. Visually, I couldn't see the difference because the cut-out wasn't damaged. It was only after I took the calipers and measured it that I found out what had been done. After I took a magnifying glass to cut-out, I could see the file marks. Good luck to you.

[Brian Dick]

The cut out does appear filed at the rear cut. Unfortunately, someone may have tried to dress it up after it chipped and elongated the slot. Maybe you can peen it a bit to tighten it up. The bolt head overturn is definitely out of spec. The only cure for that is to select fit bolt heads until you find one that indexes with zero overturn.

[dewey1424]

Check the length of the cut-out and then check the length of the bolt head guide.

Looks like the bolt head guide is 0.539" and the cutout is about 0.547" (hard to measure with my HF calipers). Does anyone know the specification values?

Also, it looks like I have a Longbranch bolt head. Right?

Would that cause a problem?