doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Star crimp origin?

Just curious who is credited with inventing the star crimp and when.

Burrard mentions that in 1939 Imperial Chemical Industries Limited produced a new type of cartridge in which the paper tube was made of a specially waxed paper and which was sealed with the crimp turnover instead of the usual rolled turn over and over shot wad. He also states that in 1947 American manufacturers adopted the crimp turnover and at that time the standard length of the case was increased to two and three-quarter inches because the crimp turnover needs a greater length of case for the actual turnover than the roll crimp. But all this still does not tell me who is credited with the invention.

Good question. It was certainly used on brass cartridges loaded back in the late 1800's as a sort of half star crimp in the form of a taper used to hold the top wad in place. I have seen in in slightly later brass cartridges as a full crimp and also in aluminium ones of Belgian origin. I don't think it appeared in the U.K. in relation to paper until sometime in the 1950's where it was first used on the 1 ounce Eley 'Impax' game load. Lagopus.....

I highly suspect a little factor known as WWII slowed the acceptance of the Star Crimp. Burrard definitely seems to imply it was introduced in England prior to the war in paper cases. It would also seem that pressure & velocity tests were run at this time & it was determined that normal velocities & pressures could be maintained with the ordinary 2�" load put up in the 2 3/4" hull. The primary concern seems to have been that had the regular case length been maintained by using a suitable wad column the resulting shorter "Loaded" shells might be mistaken for 2" cases, which normally actually ran a bit longer than the nominal 2" after firing. I don't recall that Burrard actually mentioned who the originator of the Star Crimp was.

I think Burrard may be missing something, at least on our side of the pond. If the standard length of the case didn't reach 2 3/4" until after WWII, then why would all American gunmakers have standardized on a 2 3/4" chamber length for 12-16-20-28ga guns prior to WWII? We've discussed the wide variety of shell lengths that existed prior to WWI. However, at least according to my 1940 Shooter's Bible, those had almost entirely disappeared by WWII. You had the old, standardized short lengths of 2 5/8" for the 12ga, 2 9/16" for the 16ga, and 2 1/2" for the 20ga, and then you had 2 3/4"--the "new standard"--for all 3 of them. And I believe that the last gunmaker to switch to 2 3/4" as standard was Hunter Arms (LC Smith), which had stuck to the old 2 9/16" 16ga standard until about 1940.

Very good point, Larry. The trail grows warmer.

In the U.S., Western Cartridge Co. introduced the Super-Seal Crimp in their Xpert Super-Trap and Super-Skeet shells for the 1940 season. The Super-Seal crimp is on their Super-X hunting loads by the March 1948 Western Ammunition Handbook.

Here is a post-WW-II but still roll crimp 20-gauge Super-X box --



It is a bit hard to read at this angle, but it is the only picture I have. In the blue field at the bottom of the front of the box it reads -- "LONG RANGE - SHORT SHOT STRING / SHOTGUN SHELLS / SEAL-TITE WADS - SCUFF PROOF / PROGRESSIVE BURNING SMOKELESS POWDER / NON-CORROSIVE PRIMERS"

Here is a 1948 or later Super-X 20-gauge box with the Super-Seal Crimp --

The 6 Point Star crimp was also in the 1943 catalog that I have for the Winchester shotshells
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My goodness, ammunition was extremely expensive back then! $1.00 in 1940 had the same buying power as $16.12 in 2012.
Annual inflation over this period was 3.94%. That would mean that case of shells cost $677.00 with today's purchasing power. Whew!!! Think I'd taken up worm fishing...

True those prices are expensive for the day, but we are probably looking at war time markups for all ammunition.

No, that doesn't explain it. My VL and D catalog from 1930 shows most shotgun shells at $50-$60 per thousand, which in today's dollars would be over $400 for 500.