7.62x51mm Hollow Projectile Development / Experiments

HIGH PERFORMANCE HOLLOW PROJECTILES, FINAL TECHNICAL REPORT, 17 August 1973. dtic.mil/dtic/tr/fulltext/u2/768907.pdf

Not a new idea but from the looks of this report considerable effort was applied in trying to develop hollow projectile ammunition for the U.S. Army back in the early 1970’s.
The images are the best possible which is common with DTIC reports.

Are there any surviving examples out there?

Thanks a lot for sharing this link.

Brian, thanks a lot for all the endless digging you do to find all these docs on that site!

Other hollow or tubular projectile ”projects” primarily looking at higher velocity and flat trajectory-

Pistol caliber; rifle fired grenade ring airfoil projectile (RAP) (tubular projectiles): viewtopic.php?f=1&t=4583

0.65 Cal. TUBULAR PROJECTILE RESEARCH 2004. This refers to a DTIC listing entitled Summary of .65 Caliber Tubular Projectile Characteristics (a Powerpoint presentation) by Abe Flatau (developer of the Ring Airfoil rifle grenade & Ring Airfoil Projectile (RAP) nonlethal rubber projectile discussed in the IAA Forum thread listed above) with a title page of “Some Comments Regarding Performance Potential for a New Machine Gun and Ammunition Concepts

[b]Photo showing cartridge comparison including .65 tubular projectile cartridge, photo from the DTIC listed presentation shown above.

[/b]20 mm Tubular Projectiles, 1944. RETARDATION OF TUBULAR PROJECTILES DEVELOPED FROM THE 20MM AMER ICAN BALL. dtic.mil/dtic/tr/fulltext/u2/491944.pdf

30 mm Tubular Projectiles 1984. 30-MM TUBULAR PROJECTILE. dtic.mil/dtic/tr/fulltext/u2/b087370.pdf

Pictures and description of a 25x137mm cartridge with a tubular projectile. Described as a Dutch experimental projectile designed and tested by the former NWM (you have to log in to see the pictures). bocn.co.uk/vbforum/threads/5 … 2-chaingun

Thanks again!

Here the link to the .65 cal, seems you forgot it:
google.de/url?sa=t&rct=j&q=& … whohiYeUyQ