30-40 Krag is a cartridge also called 30 Army. It uses a 30 caliber bullet and 40 grains of smokeless powder.
7.62X39mm
Unless you are in a life or death/survival situation, NEVER SHOOT AMMUNITION THAT IS NOT DESIGNED FOR YOUR WEAPON!!!!!!!!!!!
A 3040 window typically refers to a window size that measures 30 inches wide by 40 inches high. This designation is commonly used in the United States for standard window sizes. The dimensions are often expressed in inches and are used for both residential and commercial applications. Always check with local building codes and specifications for precise measurements and installation requirements.
5.56mm
Choosing the best weapon for self defense is a matter of personal preference. The .45 ACP is generally considered a very good defense weapon. There are very few handguns that shoot a larger projectile, but bullet size is a trade off with capacity (how many rounds a pistol can hold). Typically, a .45 ACP pistol holds 7-8 rounds, compared to a 9mm's 14 rounds or more. If one is expecting to be in a prolonged gun fight, one might prefer having more rounds.
magazines available in 20, 30 & 40 rounds
The Glock 17 (full-size 9mm) holds 17 rounds in a factory magazine. The Glock 19 (compact 9mm) holds 15 rounds in a factory magazine. The Glock 26 (teeny-tiny 9mm) holds 10 rounds in a factory magazine. The Glock 17L/34 (competition) also holds 17 rounds.
The Glock 17 (full-size 9mm) holds 17 rounds in a factory magazine. The Glock 19 (compact 9mm) holds 15 rounds in a factory magazine. The Glock 26 (teeny-tiny 9mm) holds 10 rounds in a factory magazine. The Glock 17L/34 (competition) also holds 17 rounds.
5.56x45
Caliber is the size designation for rifle and handgun bullets. Guage is the size designation for shotgun rounds.
6 1/2 inch rounds
You need to see a gunsmith.