The Standard Manufacturing Jackhammer is a semiautomatic pistol chambered in .22 LR. It runs a blowback, magazine-fed action with a 5.75-inch barrel, and it feeds from a 10-round stick magazine designed for consistent cycling during range sessions. The frame includes Picatinny rail mounting provisions and an ambidextrous safety/decocker, which makes it usable straight out of the box for either left- or right-handed shooters. 
 

Key Specifications 

• Brand: Standard Manufacturing 
• Model: Jackhammer 
• Caliber: .22 LR 
• Action: Semi Auto 
• Capacity: 10 rounds 
• Barrel Length: 5.75 in 
   

Detailed Features 

• Blowback-operated semi-automatic action cycles standard .22 LR ammunition. 
• Feeds from a 10-round stick magazine for extended range sessions. 
• Picatinny rail mounting provisions allow an optic or other accessory to be added. 
• Ambidextrous safety/decocker supports both left- and right-handed shooters. 
• 5.75-inch barrel keeps the overall package compact for a rimfire pistol.

Owners of the Jackhammer generally describe the blowback action as reliable once it has a bit of ammunition through it, which is typical for .22 LR semi-autos: some bulk-pack loads run cleaner than others, and a handful of buyers mention needing to try a few brands before finding one the pistol cycles consistently. Cleaning intervals get mentioned often, since rimfire actions foul faster than centerfire guns.

On handling, people like how light the recoil is and how easy the pistol is to shoot for long range sessions without fatigue. The Picatinny rail draws praise for making it simple to add a red dot, and the ambidextrous safety/decocker is called out as a nice touch for left-handed shooters who often get overlooked on rimfire pistols.

Value-wise, the Jackhammer gets bought mostly for cheap practice and plinking, and owners like that .22 LR keeps range trips affordable. The 10-round stick magazine is seen as adequate but not exceptional by shooters used to higher-capacity rimfire pistols, and a few wish spare magazines were easier to find.