Webley Junior wood grip (pinned piston and frame/cylinder band)

Webley Junior wood grip (pinned piston and frame/cylinder band) 

With thanks to Steve.

Veteran writer and all-round vintage airgun expert, John Atkins, points out that pinning a solid piston head into a piston made from steel tube was common practice on wood-grip 1st pattern Juniors, until it was dropped in favour of solid steel, turned pistons. He's seen six in total and owns the two below:

Serial no. J1070:

Serial no. J413:

John Griffiths, author of the Encyclopedia of Spring Air Pistols, comments that in his experience of making pistons as an amateur, making pistons from steel tube and pinned solid heads is easier and more economical than solid steel bar:

Some years back I had concluded that the two-piece approach for most of my reproduction pistol pistons was the best (for the amateur) in terms of simplicity and cost saving.  As an example, the following shows the sequence used for the piston for my reproduction overlever Lincoln. This piston resembles the Junior piston quite closely. The sequence starts with thick-wall drawn steel tubing, and the lip on the piston is easily catered for by turning down the outer diameter of the tubing a little. 

Tubing is much cheaper than solid round bar, and it avoids the need to deep bore the bar and waste a lot of material.  Deep boring also requires time, a very expensive large drill bit, and an even more expensive end- mill to get the flat bottom to the hole.

The other advantage of the two-piece approach is that you can make the solid piston head from expensive carbon steel which can then be heat hardened before it is pinned in place.  Any mistakes made in turning, drilling and threading the head are not then such  a big deal, as a replacement can be made without too much trouble.

With a one-piece piston, any problems with the head would mean having to make the whole thing from scratch.  I sweated the piston head in place and drilled and pinned it, just as Webley did with the Junior piston.

John Atkins added that another pinning practice on early Juniors was a lateral pin across the upper part of the front frame band and the top of the cylinder, presumably to fix the two together. It was later dropped.

Steve estimates it was dropped some time between metal grip Juniors (second pattern) serial no. J2734 and J13443:

Later, John Griffiths wrote:

John Atkins has now provided some very interesting, and previously unknown, information about the first Webley Junior piston construction. He has access to the original factory blueprint for the Junior, courtesy of Webley expert Jeff Hyder, who himself originally received the document from the late Chris Dunn, of Webley & Scott. To summarise John’s comments:

The blueprint, undated but most certainly from 1928/9, clearly shows the pin for the piston head. One amendment on the blueprint, dated 1933 shows the separate piston head as then becoming obsolete.
Len’s very early Junior with serial number J121 is problematic. It could have had a replacement later one-piece piston, but it is also possible that an even earlier blueprint than Jeff’s undated version existed showing a one-piece piston, in which case Len’s Junior piston is perfectly original. However, as no mention is made on the existing blueprint of an even earlier piston, this situation seemed unlikely to John. Unfortunately examples of the Junior found from the first 100 or are extremely rare, so until more of these are found for examination, we cannot be certain about the originality of Len’s piston.

John also commented on the end-rim of the piston:
The blueprint shows the piston tube only in part, with half-an-inch or so of the tube coming off the head, so we can’t see the piston tail with its raised rim, or lip.
However, the ‘piston end-fixing ring’ (as Webley referred to it) is shown as a separate component with dimensions elsewhere on the blueprint. There is no trace of brass colour on the early pistons examined, and Jeff Hyder has surmised that these rings were pressed on and hard silver soldered, rather than brazed. This separate end ring was lightly crossed out on the 1933 blueprint, and the lip was then produced by machining when the one-piece turned piston was introduced.

John’s discussions with Jeff Hyder also brought up some interesting previously unpublished information about the grip plates used on the Junior pistol.
Long ago, Jeff established that in the pre-war 1930s, the Webley 'Junior' air pistol's 'corrugated' pressed steel stock-sides - which collectors call 'tin grips' were outsourced to W. Crowley & Son, at a cost of 12 shillings gross pairs. Although listed in May 1935 they were in use a couple of years before that date. Presumably these came in ready blued with the new style ferrule in place for the stock screw.

John also asked Jeff Hyder if he had ever discovered the name of the plastic moulders Webley used for their later Mark 1 and Senior pistols and he had a trawl through the manuscript of his sadly, unpublished book on Webley air pistols and came up with the name F. W. Evans, Plastics Works, Long Acre, Birmingham. Where he got the name from, Jeff can't recall but maybe it was from past Webley workers Albert Green or John Boland.