.303 British S.L.?


#1



Ok, I picked up two of these at S.L.I.C.S. but so far I can find no information on this headstamp.
Both are headstamped “KYNOCH .303 S.L.”. If you look at the headstamp to the right of the name Kynoch there is a dark mark. This is purple ink or die and it is present on both cartridges. They also both have “- 1/2” marked in purple ink or die on the side of the case. Anyone know what the “S.L.” stands for? Are they a special loading? What is the “- 1/2” stand for?
Thanks
Zac


#2

There are others who know more about this than I do, but ‘SL’ indicates that the cartridge is loaded with a boat tail bullet for long distance target shooting…

Happy collecting, Peter


#3

I also think this is a match round, and S.L. stands as far as I know for “stream lined” refering to the boattailed bullet.

I have no idea why -1/2 was written on the case.

hope this helps.

Joost.


#4

This is one for TonyE but with my limited knowledge the fact that Kynoch is spelled out rather than expessed with a “K” indicated a civilian varient and is almost certainly a match round. Tony will know for sure and can probably date it. The writing looks like a modern marker pen and is presumably recent.


#5

“S.L.” does indeed stand for “Streamlined” and these are commercial rounds intended for Match Rifle competition at Bisley and other ranges. These two rounds seem to be internal Kynoch test rounds as evidenced by the purple markings, and the “-1/2” refers to a loading of 0.5 grains less than the standard load.

Roger Mundy wrote and excellent article on the history of these match rifle cartridges in the Journal a year or so ago. (I cannot remember which number)

Regards
TonyE


#6

Thank you all. You have been most helpful.
Zac


#7

Note also the lack if the expected level of crimp which is usually quite pronounced on .303s almost to the extent of being overcrimped. I presume that is because it was an internal test round and not intended to leave the factory.


#8

The reason that this round does not have the familiar deep 3 x 120 slit crimps is because they are neither needed no deirable in a match round. The cartridge is not going to be subject to the rough handling of service, and is only going to be single loaded. More importantly, an even bullet pull is needed to ensure match accuracy which would not be achieved with a military crimp.

Regards
TonyE


#9

Tony
You are right, a military style crimp would not be suitable for a match round but even a match round would need a light roll crimp to overcome the inevetable handling and transportation. I know match shooters often don’t crimp their reloads and neither do benchrest shooters.
I was just pointing out the lack of any crimp as being interesting and a further indication on top of the writing that it was never intended to leave the factory. So I imagine it probably left via the back door and would be all the more collectable for that.

Can you date it?


#10

Match shooters seldom, if ever, crimp. Match bullets usually do not have a crimping groove so there’d be no way to do so even if they were so inclined. Neck tension is controlled by neck sizing using custom dies. The ideal neck tension is zero which can be accomplished with specially made cases, dies, and chamber. But, it was found that the extra work to produce that perfect cartridge did not result in appreciable improvement in accuracy.

The very first Cal .30 US National Match ammunition (1908 and 1909) used a smooth M1906 CN bullet without a crimping groove. That was changed to the cannelured bullet from 1910 to 1919. A new smooth bullet was introduced in 1920 and uncannelured bullets continued to be used until the last National Match ammunition was manufactured in 1996. Though not technically National Match, the M118 Long Range cartridge is still loaded with the smooth Sierra MatchKing bullet.


#11

And, of course, .22 rimfire match ammunition is crimped and shoots very well indeed, so crimping isn’t necessarily fatal to the enterprise. Jack


#12

Jack

Even the venerable 22 RF can be made to shoot better with custom bullets and no crimp. And, of course, it cannot even come close to competing with a match 22 CF under any circumstance.

Ray


#13

Ray: So how to they get the crimp out of the rimfire cases? Or are uncrimped empty cases available? From my experience those crimps are really aggressive. Jack


#14

Jack

Some of them use new cases that they manage to get somewhere. One guy that I know in Nevada has made dies to remove the crimp from factory loaded cases after he pulls the lead bullet. He also loads several of the small caliber rimfire wildcats using those same cases.

While it does work, the time and cost involved doesn’t really justify the gains in accuracy so I don’t think you’ll see it catching on. Guys that do that sort of thing are known to be intelligent, but not particularly bright. Sort of like wildcatters. ;) ;)

They also make their own bullets. I think some of the bullets have been patented. I seem to recall an article or two in the JOURNAL that showed some of them.

Ray


#15

Ray: So this is an activity so arcane there’s not likely to be any systematic description of it in a regularly accessible publication? After my first question to you about 75 or 80 more came to me but in deference to you and the forum I’ll keep 'em to myself. Interesting. Jack


#16

Getting back to the original question, and specifically the question of the date, it is difficult to say, but I suspect post war.
The design of the bullet would date it more precisely as it tended to change quite frequently.

I have most, if not all, of the drawings for the .303 Match rifle bullets from 1919 to 1947 and they vary considerably. As I said in a previous post, see Roger Mundy’s excellent article in a recent Journal.

Some of the bullets have cannelures and others do not. This first picture is Kynoch drawing BK62-40 dated 8 March 1927 and shows the 1927 Pattern Streamline bullet which is a slightly heeled boat tailed bullet without cannelure. The 1928 and 1929 bullets were similar.

Incidentally, note how similar this bullet is to the Mark VIIIz bullet introduced in 1938. The War Office took a great deal of interest in thes .303 match cartridges as an aid in developing a long range Vickers bullet.

The second drawing, BK251-52, shows the 1947 Pattern bullet, which does have a slight undercut cannelure. there are a couple of interesting points on this drawing; note it states that the mouth of the case should be coned into the bullet cannelure, although the actual drawing shows this is very slight. This is explained by the text below the drawing which was too large to scan.

This states:

CASE:
CAPPED CASES FROM STORES (MADE TO STANDARD .303 DIMENSIONS) WERE GAUGED TO A LENGTH OF 2.211 H 2.206 L, INTERNALLY & EXTERNALLY MOUTH CHAMFERED & GAUGED FOR MAX. VARIATION IN MOUTH THICKNESS OF 0.0015 & FOR MAX. ECCENTRICITY OF NECK WITH BODY OF 0.003. THE BASES ONLY WERE SPRAYED WITH BLACK N.C. VARNISH.

BULLET.
ALL BULLETS WERE GAUGED FOR POSITION OF .303 DIAM.

It appears therefore that the mouth of the case was thinned by being internally and externally chamfered, preumably to lessen bullet retention force.

Trust this helps explain these match rounds,

Regards
TonyE


#17

I have these Streamlined rounds with military headstamps.
K35 S.L. is one which springs to mind


#18

I think these are commercial headstamps, but dated to show which bullet is loaded. As mentioned previously, there were a number of different bullet designs all under the general identification of “.303 S.L.” so it was important to have some way of identifying each year’s type.

Since the bullets were known by “1927 Pattern”, “1922 Pattern” etc, it makes sense to include the date in the headstamp.

Regards
TonyE


#19

Would this ammunition be made for general sale or would it have been made under contract for the NRA?


#20

They would have been generally available I am sure. Back in the 1960s Fultons used to sell the Kynoch .303 S.L. rounds.

Also, there were a number of ranges in other parts of the UK where Match Rifle competitions took place.

Regards
TonyE