No. 5 or No. 4 bolt?

[clarkmilitaria]

Hello,

I have read that some bolts from No. 4 rifles had hollowed out handles as well as the no. 5 bolts, and the differneces are in the hole diameter. Can anyone determine if the bolt pictured is from a No. 5 or 4? The hole diameter measures between 8 and 9 mm.

Thanks,
Jim

Information

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[Rumpelhardt]

I have a No.4 with a hollowed bolt handle. The hole is quite a bit smaller.

[clarkmilitaria]

That's good news. I have never seen a hollowed no.4 bolt in person to remember what it looks like compared to mine.

[Peter Laidler]

There are zillions of hollowed out No4 bolts in the system and they were quite common. This subject has bee aired several times but it made absolutely no difference to Armourers or those blanket stackers in the Ordnance world. Bolts were fully interchangeable. Some old and tired No5's that still had their presumably original bolts were the same but the face surrounding the hole just seemed to be ground back a bit more than usual or radiussed slightly more deeply giving the appearance of a bigger hole - if you'll excuse the phrase.

Different manufacturers were permitted to delete the hole in the bolt hande in order to increase production while making the best and most economic use of their machinery and production facilities.

[S-A-M3]

All BSA made bolts[M47] have a hollowed out bolt handle, so there is no difference between the No4 and No5 bolts on BSA made rifles. ROF made No5`s seem to have a variation in Bolt hole
diameters, the early ones seem to be larger. This has been my experience of collecting them for 17 years and owning 15 or so and working another 20.

[enscien]

The original No.4 Rifle bolt drawing is DD(E) 450/7, revised and redrawn on 2-2-1940. This was updated on 21-8-1941 to show a flat at the end of the 0.80" diameter knob, 0.34" from the centre. In addition a hole of 5/16" diameter (max) and 0.55" max depth 'to assist manufacture' was allowed for, but 'may be omitted if desired'. On 14-6-1945 this drawing was endorsed as obsolescent.
Parts specific to the No.5 Rifle have the parent number DD(E) 3579, the bolt being DD(E) 3579/6, sealed on 29-04-1944. One would expect this to show the lightening hole, but curiously it does not, showing a spherical knob of diameter 0.80" without even the flat.
Several of the No.5 rifle components were subsequently used for the later No.4 rifle production, including the bolt and DD(E) 3579/6 evidently succeeded DD(E) 450/7, being updated as late as 1968 as Part No. CR 430. There is no evidence that a hole has been deleted from this drawing in updates (which essentially relate to finish).
Staff at the Royal Armouries, Leeds kindly checked six No.5 rifles for me and the hole in the bolt varied from 0.308" to 0.502", with no consistency for any one manufacturer. Very strange! It is possible that the modification was carried out to another 'IM' (Internal modification') drawing which no longer exists.

[Maxwell Smart]

What is the serial number on the bolt?

Might not this give some clue as to No4 or No5 origin?

[Peter Laidler]

Given that info Ensci and others, it ties in together with the fact that as the hole was permitted in order to make best use of the manufacturers facilities, such as a holding or locating facility, then the size of the hole was also fairly academic too - within reason of course. Hence the variation in hole size

I seem to remember that the change in finish during 1968 that affected the interchangeable No4 and 5 bolt, as mentioned by Ensci was the deembrttlement of the phosphate finish of the bolt