No4 Mk1/3 Origination and bolt head track

Greetings - I just rebuilt this rifle having found it as a sporter. The suncorite was nice throughout after its FTR. If this was a Savage No4Mk1* originally would the Fazakerley FTR have removed (machined off) the "US Property" mark off the receiver wall? No other clues remain per its Pre FTR identity.

It shoots very well - however after 45 rounds and during slow prone the bolt head was jumping off its rail (only while firing and being cycled, dry fire / cycling does not produce it).

There are now 2 small chips on the edges of the rail window in the receiver. I have to research the bolt head grove modifications that armorers used to help.

So how bad do you think the receiver rail chips are? Fettle the metal?
Should I relieve the bolt head grooves?
What do you think of any scrubbed "US Property" marks on this FTR?

Shot a personal best with her less 2 points overall - just needed a couple of MOA elevation..Attachment 100628Attachment 100627Attachment 100629Attachment 100630

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Originally Posted by l1a1 breakdown

Greetings - I just rebuilt this rifle having found it as a sporter. The suncorite was nice throughout after its FTR. If this was a Savage No4Mk1* originally would the Fazakerley FTR have removed (machined off) the "US Property" mark off the receiver wall? No other clues remain per its Pre FTR identity.

It shoots very well - however after 45 rounds and during slow prone the bolt head was jumping off its rail (only while firing and being cycled, dry fire / cycling does not produce it).

There are now 2 small chips on the edges of the rail window in the receiver. I have to research the bolt head grove modifications that armorers used to help.

So how bad do you think the receiver rail chips are? Fettle the metal?
Should I relieve the bolt head grooves?
What do you think of any scrubbed "US Property" marks on this FTR?

Shot a personal best with her less 2 points overall - just needed a couple of MOA elevation..Attachment 100628Attachment 100627Attachment 100629Attachment 100630

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A not uncommon fault on both the Savage and Longbranch rifles (the Mk1* versions). It was for this reason that we 'gave away' these rifles to our allies (after the war) before, the UK produced ones (Mk1)


You can radius the corners on the damaged rail and the bolt head but it is only an Elastoplast. If you can get the chipped part welded up and re-cut without generating too much heat, that is the way forward.


As it stands it is potentially a dangerous rifle.

Here's my Savage with a badly-mangled rail. Works fine after peening it just enough to hold.

http://www.milsurps.com/images/impor.../35hllsl-1.jpg

The use of un-chamfered bolt heads is often the cause of this damage.

I've always wondered about this ill-conceived modification. Mechanically it is asking for trouble as anyone with moderate sense could see. IDS indicates it was considered before WWII - witness the trials No.4 with the said cut-out - but obviously, and despite all the fiddling around with lightened and cheapened rifles, the idea was rejected.

As UK production had all the problems with labour, enemy attacks, workspace, tooling etc. this mod should have been introduced there if anywhere! The fact that it wasn't should have alerted at least Long Branch to the likely problems. Savage perhaps just built what was ordered?

It would be interesting to know at whose instigation or instruction it came to be introduced.

[quote=Surpmil;453052]

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Originally Posted by Surpmil

It would be interesting to know at whose instigation or instruction it came to be introduced.

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I'm sure I have read that it was from a suggestion by Savage as a way of simplifying / speeding up production.
However without official 'records' it could just be 'internet theory'.

As noted above a weakness of the I*. In service this would be cause to scrap the body.

When that sad Savage shown above arrived by US Mail in 1958, it had a Canadian military tag attached - indicating it was rejected for "worn bolt rail".

Judging by the style and location of the FTR marking, and the "A" prefix serial number, I think your rifle is a BSA Shirley conversion rather than a Fazakerley one.

The BSA ones all seem to have been scrubbed of previous markings.

Mmmmmm....... We would weld and repair body track ribs if the rest of the rifle body and barrel was worth saving. But wear to the extend of thread 3 would be BER/ZF. BSA didn't do the Mk1/1 to 1/3 modification for the UK Military. But if you gathered in 20 or so needy Mk1/1's and 1/3's together for repair, it was a speedy repair at a Field or Base workshop. It was definately not permitted to remove the US Property markings on our or allies rifles. They weren't ours to interfere with! They were loaned or leased to us!

Thanks for the supporting info so far!

This was resurrected from a $101 sportster but shoots like a dream so is worth some effort to save. There is a light rub mark made by the lower side of the bolt head in the suncorite below the bolt head track. This tapers to be a heavier rub as the bolt closes - this may be the cause of the pressure challenging this bolt head out of the track at the gap. Ill look to add a chamfered edge to the bolt head to remove this rub and pressure first. if needed the end of bolt head groove chamfers can be next. I'll de-bur and round the receiver body rail edges too.

So I'm still no further into knowing the original maker of the No4Mk1* - although the FTR work is very good and thorough!

Worst case is its a very nice parts gun if the receiver continues to lose control of the bolt head. Or it waits for a good welder in my area. I was hoping to continue with this one in CMP meets and the like.

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Originally Posted by l1a1 breakdown

So I'm still no further into knowing the original maker of the No4Mk1*

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There is only a choice of two.

I like rifle "forensics" though! My last pass / chance at finding its origin would have been ratifying an FTR removal of "US Property" marks as a policy or process- there could be feint traces remaining - when you try to look for such things, eyes and inferred images can be deceiving. Of course I can go through every inch of it again in a future total strip down for the tiny odd marks / tells that I may have missed this time. I also have a set or two of early low wall No4 wood which is more age appropriate for it - albeit marked by Sykes.

The Ml1* bolt removal system probably "seemed a good idea at the time, your Worship", if starting with brand-new, correctly specced components.

However as bodies and bolts wear, the amount of "vertical' wobble increases and the lug on the bolthead floats up and down more. There is almost NO "vertical" support for the bolt body as it travels, apart from a bit of radiused surface in the top and bottom of the raceway. That "vertical float" causes the bolt-head to "rock" up and down and thus catch the ends of the gap.

A good TIG welder operator can build up the ribs with minimal "clean-up" required. The family motor-cycle mechanic and welding guru advises that a copper or similar shield with an extended centre tab to fit the "gap" and other edges to match the tapered profile of the slot will reduce the "clean-up" and act as a heat-sink.

How hard would it have been to fabricate a simple piece of "clock-spring" such that the bottom end hooked under the RHS sidewall and was clamped in place by the fore-end and with the top end folded in to "fill" the gap and having a small, turned-down tab to retract it? "What if" and all that jazz.

Oh, and chamfer the ends of the bolt-head "rib" for good measure.

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Originally Posted by Peter Laidler

BSA didn't do the Mk1/1 to 1/3 modification for the UK Military.

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But they did for commercial non-MOD contracts?

Yes, they did them convert Mk1's and 1/1's commercially. The reason was because they wanted to keep their own ROF's busy. BSA only got the No8 contracts later through gritted teeth for a couple of commercial reasons

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Originally Posted by l1a1 breakdown

...snip...
So I'm still no further into knowing the original maker of the No4Mk1* - although the FTR work is very good and thorough!

...snip...

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This particular rifle appears to have been a Savage.

The "give away" is the second cut at the base of the front "pad relief" recess, and the "pad relief" itself - Long Branch never contoured their receivers this way.
Attachment 100668

Looking at engraving, I'd say that BSA never engraved their work as badly as that. That is dire..... Looks like someone did it in the dark, with his feet......

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Originally Posted by Peter Laidler

Looks like someone did it in the dark, with his feet

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So, that would be a "Fail" for a craftsman...?:rofl: Pretty bad.

Thanks Lee Enfield - An observation and snippet I did not previously know (I skipped receiver profile class). It does have a couple of Savage marked parts in the mix also. PL - Keep the engraving mirth coming - I'm dying with laughter here! It still shoots well IMHO :) Maybe optically occluded pedal finishing is the way to go?...

Quote:

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Originally Posted by l1a1 breakdown

Thanks for the supporting info so far!

This was resurrected from a $101 sportster but shoots like a dream so is worth some effort to save. There is a light rub mark made by the lower side of the bolt head in the suncorite below the bolt head track. This tapers to be a heavier rub as the bolt closes - this may be the cause of the pressure challenging this bolt head out of the track at the gap. Ill look to add a chamfered edge to the bolt head to remove this rub and pressure first. if needed the end of bolt head groove chamfers can be next. I'll de-bur and round the receiver body rail edges too.

So I'm still no further into knowing the original maker of the No4Mk1* - although the FTR work is very good and thorough!

Worst case is its a very nice parts gun if the receiver continues to lose control of the bolt head. Or it waits for a good welder in my area. I was hoping to continue with this one in CMP meets and the like.

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If you want to save it maybe take a piece of brass flat bar of the right thickness and profile the edge to match the bolt head guide, insert under the remaining rail and get the missing bits built up with TIG welding. I guess if you really wanted to get clever, you could take a piece of say, 1/8" flat and have that profile machined into one edge about 3/16 back from the original edge. That should leave you with a little projecting block that you could machine to fit precisely to the size of the original bolt head release slot. Then all your welder has to do is work up to the edges and build up enough for you to file it back to match the original profile of the rail. Then sell or rent it to those who want to repair their own!