Ten Mile Knives
Member
- Joined
- Aug 18, 2020
- Messages
- 15
I am interested in a cartridge imaginary or possibly one that already exists which falls in-between 5.7x28 and 9mm par. What I mean by that is a cartridge which utilizes a slightly smaller diameter bullet and casing to increase velocity and magazine capacity, and that has a greater overall length than 9mm to maintain some performance lost by shrinking diameter.
The motivation for the cartridge comes from the trend over the last 40 years for cartridges to favor smaller, higher velocity rounds (part of the motivation of the 5.7 in the first place) and the desire for highly effective "personal defense weapons". This push was in its heyday in the 90's during the development of weapons like the FN P90 and the HK MP7. There was, and still is a departure away from "sub machine guns" to "personal defense weapon" these are both loosely defined terms but generally it means a smaller diameter, body armor defeating cartridge with good performance in short suppressed weapons. This also includes the wave of SBR AR-15 derivatives which demonstrate this trend as well. Generally speaking, it seems that we are more interested in penetration and speed of delivering rounds, than we are in "knock down power" (see the fall of 45 acp in popularity).
9mm has really found a sweet spot in today's combat thinking, and I am not sure if it will stay as popular as it has over the last 100 years, but I definitely see one area where a new cartridge could fill a perceived gap.
I imagine the PDW cartridge as having a smaller base diameter than 9mm, longer length (but short enough to fit in a pistol grip), give at least 1500 fps, and able to hold a bullet weight at least 70 gr. This would land us somewhere around the following dimensions:
Base Diameter: about 0.35
Bullet Diameter: about 0.307
OAL: about 1.20"
During my research I came across a couple cartridges which actually come close to this, .30 cabine, 7,62 Tokarev, .22 TCM, and . this group while quite diverse does give the performance I am interested in. What I am imagining is either a necked up .22 TCM, a shortened .30 carbine, or a shrunken 7,62 Tokarev. Side note, I imagine that the case would be slightly shouldered, I think you would get better performance out of that than a straight walled case.
Someone let me know if this concept makes any sense or if it even matters, I am sure there is a reason why there seems to be such a large gap between the velocity and mag cap. of 5.7x28 and the effectiveness of 9mm despite its shortcomings.
To clarify I am a gun enthusiast and a mechanical engineer. This is strictly a side interest to me and my knowledge on these subjects is mostly superficial. I am posting just out of a technical or historical interest, and do not intend to make any objective statements about the performance of cartridges.
The motivation for the cartridge comes from the trend over the last 40 years for cartridges to favor smaller, higher velocity rounds (part of the motivation of the 5.7 in the first place) and the desire for highly effective "personal defense weapons". This push was in its heyday in the 90's during the development of weapons like the FN P90 and the HK MP7. There was, and still is a departure away from "sub machine guns" to "personal defense weapon" these are both loosely defined terms but generally it means a smaller diameter, body armor defeating cartridge with good performance in short suppressed weapons. This also includes the wave of SBR AR-15 derivatives which demonstrate this trend as well. Generally speaking, it seems that we are more interested in penetration and speed of delivering rounds, than we are in "knock down power" (see the fall of 45 acp in popularity).
9mm has really found a sweet spot in today's combat thinking, and I am not sure if it will stay as popular as it has over the last 100 years, but I definitely see one area where a new cartridge could fill a perceived gap.
I imagine the PDW cartridge as having a smaller base diameter than 9mm, longer length (but short enough to fit in a pistol grip), give at least 1500 fps, and able to hold a bullet weight at least 70 gr. This would land us somewhere around the following dimensions:
Base Diameter: about 0.35
Bullet Diameter: about 0.307
OAL: about 1.20"
During my research I came across a couple cartridges which actually come close to this, .30 cabine, 7,62 Tokarev, .22 TCM, and . this group while quite diverse does give the performance I am interested in. What I am imagining is either a necked up .22 TCM, a shortened .30 carbine, or a shrunken 7,62 Tokarev. Side note, I imagine that the case would be slightly shouldered, I think you would get better performance out of that than a straight walled case.
Someone let me know if this concept makes any sense or if it even matters, I am sure there is a reason why there seems to be such a large gap between the velocity and mag cap. of 5.7x28 and the effectiveness of 9mm despite its shortcomings.
To clarify I am a gun enthusiast and a mechanical engineer. This is strictly a side interest to me and my knowledge on these subjects is mostly superficial. I am posting just out of a technical or historical interest, and do not intend to make any objective statements about the performance of cartridges.
