Bolt slide issue number 4 Long Branch

[r.j.medals2]

... I have a Bolt slide issue on my #4 Long Branch . See photos . The bolt head catches sometimes when cycling in the bolt on this Parker Hale converted Long Branch . Can this be repaired or Just sell off the components ?I have tried another bolt head but is does the same thing.

 

[Potashminer]

Very common failure on those Long Branch and the Savages made like them - why the British preferred their No. 4 Mk1, instead of these No.4 Mk1*. I have one just like it. The work around is to file those burrs off the bolt slide rail - just at the bolt head removal slot - make them match the contour before and after, both inside and out. The bolt head shown is already dinged up - it could use a few fine file swipes to smooth off that bevel. Then, want to "stiffen" the bolt head threads - sometimes, just a dab of heavy grease is enough, more drastic is to deliberately mar the male threads on the bolt head - like they did when tightening up the threads on rear end of the firing pin. That way, the bolt head only rotates enough to allow bolt to retract, and does not want to "over rotate" which is what caused those chips and burrs in the first place. A genuine weakness in that design.

 

[Potashminer]

My wording was poor - the bolt head should not rotate at all, is what I meant to say, but if the bolt head threads are too loose, then the bolt head likes to start to rotate as the bolt body rotates.

If I understood correctly from Peter Ladler's writing, those chips at the bolt removal slot were enough to condemn that receiver, in the British service.

 

[r.j.medals2]

Thank-you Potashminer. The bolt head does move a lot . I will try out your suggestions.

 

[hollowedpoint]

Yeah it’s toast! I had a few like that and ended up selling the components and throwing away the receiver.
(Chopped in half of course)

I heard a fellow would do a wee bit of welding and filing to fix it but definitely not worth the time.

 

[woodchopper]

yup bolt ways is chipped

bit of a pain to get that fixed, need some fine TIG welding and then machining or file work.

its too bad that looks like a nice conversion.

 

[tiriaq]

Great set of parts to retrofit onto another receiver.

 

[slug]

Sometimes, changing the bolt head can fix it. It helped with a friend's No 4, but as mentioned, it's an iffy thing.

 

[r.j.medals2]

I followed Potashminers suggestions and used a narrow chisel to cross score the threads on the bolt head. The turning radius tightened up significantly with small increments and i then polished the burrs from the affected areas. The bolt now runs smoothly without any issue. The head space on the chamber is excellent and this gun is shining and good to go. Cheers and Thank-you!

 

[tiriaq]

What you accomplished is to make the bolt head turn stiffly, thus resisting popping up and out. Should work as a temporary fix.
If it is nice, good shooting rifle, keep your eyes open for a good receiver for a permanent solution.

 

[Potashminer]

Agree with Tiriaq - it is indeed a temporary fix, easily identified on a close inspection of the bolt head release slot on the rails and when checking the "clocking" of the bolt head in the bolt, but sometimes a temporary "work around" is all that is wanted. This very issue is why I looked only for No. 4 Mk 1 sporters, when I tried making up cheap and rugged "snowmobile" and "truck" rifles... Can not imagine it being acceptable, even as "temporary", on a re-stored military rifle.

But, still a fundamental weakness of this No.4 Mk 1* design. A new receiver and new bolt head will eventually end up back in this very situation, I believe.