I have never seen this type of primer crimping on a 455 Webley.
Would anyone have information?
wow, 6 crimps, I haven’t seen also, maybe a special military contract ?
I have similar crimps (4) on some MkII blanks, but nothing like that.
Headstamp doesn’t seem to indicate a military contract. The additional primer crimps could indicate an attempt to overcome a problem with loose primer pocket. Just a guess at a possibility as I’ve not seen this before.
I have the same but with an Eley headstamp.
Thank you for these first informations.
Just a thought - I have seen these a few times in cased sets of the Webley Fosbery auto revolver. Could it be that they thought they needed a more secure primer for the auto recoil of this action ? Just a wild thought !!!
Interesting thought Jim
Might well explain the crimps being found on two makers products.
The crimps look to be somewhat similar in application but with different tooling, as the crimps seem wider in the Eley, so that begs the question crimped by whom.
I’ve added a cropped photo of the round in question next to mine for easy comparison.
Very interesting thought.
I am of the opinion that the primer crimps on the Kynoch 455 cases were solely intended to prevent primer set-back on blanks. I suspect their use on ball rounds was simply accidental or the company was using any available cases or perhaps a special order.
If you will forgive me, I will use the 450 cartridge, with which I am more familiar, to explain my thought process (my 455 collection went to a good home some years ago!).
Kynoch’s primer-crimping of blanks goes back many years – at least to the 1920’s and continued well into the 1960’s if not the 1970’s. Early drawings (e.g. Kynoch BK 46-89 of 1926 and Eley #753) stated that the primer should be “riveted” – a term used back then for the circular crimp one finds around primers. The practice of primer-crimping on blanks continued on cases provided by Norma after Kynoch stopped 450 case production in about 1962 – relying on Norma cases after that point (Kynoch/IMI dwg APS854, Norma dwg 22021). The blank shown below with the nickel primer and open “4” uses a Norma-supplied case.
I do not know enough about internal ballistics to state that the pressure peak of a blackpowder blank of that period was sufficient to force the primer out of its pocket – potentially jamming the weapon in which it was fired. However, that Kynoch added primer crimps on many blanks is evidence that someone at Kynoch thought it was a problem though I have found no documentation from Kynoch which mentions such an issue. In fact, Kynoch loaded and sold blackpowder blanks without crimps during the same period – in identical boxes. However, the majority of Kynoch blanks that I have in .450 caliber are crimped – a similar ratio applied to the Kynoch blanks I had in .455 Cal.
There is nothing to suggest that the blanks with crimps were for military purposes – in fact they were sold in commercial packets. There is nothing on the packaging that would suggest industrial use. The only Kynoch theatrical blank packet I have is the typical red/green box with an over-label and is dated 8 March 1966 and the blanks it contains have no primer crimp.
I have found .450 ball rounds with primer crimps but in such small numbers that I suspect that it was the use of available cases or the accidental use of a cases intended to be used for blank loading.
This is a small selection of the many blanks variations from Kynoch in this caliber. Note Norma-supplied case on far right.
Box dated 11 May 1936 – blanks show a circular crimp plus 6 stab crimps
Later and more common style of BP blank packaging. Box dated 3 March 1959
Thanks to Chris for this information
One thought which occurred to me as I was researching this topic was that these crimps appear mostly on the large primer (a.k.a. Cap No. 36) of about 0.24” diameter. One exception is the Norma-supplied case which has a normal small Boxer primer of about 0.20” diameter which is sometimes crimped.
I have not seen a blank using the smaller 0.175” diameter Berdan primer or Cap No. 31 (0.215”) with a primer crimp.
It could be possible that the Cap No. 36, at least when used on blank loading, was susceptible to primer set back while other sizes were not?
Interesting thought Chris.
I suppose that cap might have a composition that could cause set-back but I have no answer because I’m ignorant of the actual energy developed. But if this cap was also used on ball rounds where the combined energy of the propelling gas and primer compound would be much greater then I’d think crimps would definitely be needed.
A blank shouldn’t generate much primer set-back judging by the recoil felt when they are fired? I’m asking again being ignorant of the back force generated by firing a primer, in a case. I do know they can & do move, but in a revolver with a recoil shield plus the firing pin / hammer, how much?
Perhaps the crimping of the blanks was part of the standard production, and it was just easier / cheaper to continue to use than to eliminate from the production tooling?
Most of the movie blanks I’m aware of don’t seem to have primer crimps, unless the original case being used was produced with them, or the blank was to be part of cycling the firearm. These being, for the most part, for revolver usage, I wonder if some set-back would be that much of a problem?
Hopefully others with more practical knowledge, will reply.
Ball rounds and blanks, of all calibres, do frequently set back but the case usually drives backwards when the main charge fires and thus reseats the primer. Blanks of lower power frequently leave the primer proud.
A ball round, with the main charge removed, will other leave the primer standing proud.