Cartridge comparison
20/577 Alexander Henry vs .577 Black Powder Express
20/577 Alexander Henry and .577 Black Powder Express are both in the reference; see the full spec comparison below.
Side by side
| 20/577 Alexander Henry | .577 Black Powder Express | |
|---|---|---|
| Type | Rifle | Rifle |
| Introduced | 1895 | 1870 |
| Bullet diameter | 0.584″ | 0.585″ |
| Case length | 2.75″ | 3″ |
| Max pressure | 35,500 psi | 18,000 psi |
| Recoil | 88.4 ft·lb | 86.4–110.6 ft·lb |
| Effective range | 150 yd | 100 yd |
| SAAMI | Not SAAMI standardized | Not SAAMI standardized |
| CIP | Not standardized | Not standardized |
| Obsolete | Obsolete | Obsolete |
Highlighted cells hold the clear edge where both sides have a number. Every figure is a range maximum from the reference; typical loads run lower.
Case profiles, to scale
Drawn to the same scale, so the proportions are true. Physical size varies with your screen.
