The CZ 457 American Synthetic is a bolt-action rimfire rifle chambered in .17 HMR. It has a 20.5-inch barrel, black nitride finish on the barrel and receiver, and a fixed black synthetic stock. 
 

Key Specifications 

• Model: CZ 457 American Synthetic 
• Caliber: .17 HMR 
• Action: Bolt Action 
• Capacity: 5+1 rounds 
• Barrel Length: 20.5 inches 
• Weight: 6.17 lbs 
• Finish: Black synthetic stock with black nitride barrel and receiver 
• Safety Mechanism: Two-position safety 
• Trigger Type: Adjustable 
   

Features 

• Adjustable trigger with user-settable pull weight 
• Integral 11mm dovetail for scope mounting without additional bases 
• Threaded muzzle for suppressors or muzzle devices 
• Fixed American-style synthetic stock 
• CZ 457 platform accepts barrel swaps to other rimfire calibers 
   

Usage 

.17 HMR shoots flat and hits hard for a rimfire — it is well-suited to small game and pest control at distances where .22 LR starts to drop off. The 20.5-inch barrel keeps the package reasonably compact. At 6.17 lbs., it handles well for extended field use. The threaded muzzle adds suppressor compatibility without modification. The 5-round magazine is standard for the platform; larger-capacity aftermarket options are available.

Owners of the CZ 457 American Synthetic in .17 HMR tend to focus on accuracy first. Most report tight groups out of the box, and the adjustable trigger gets frequent praise — it comes from the factory at a reasonable weight and can be tuned lighter for those who prefer it.

The bolt action is smooth for a production rimfire. The synthetic stock is functional and holds up well but nothing exceptional — a few owners swap to wood or aftermarket chassis for looks or a better fit.

Barrel swap capability is a recurring topic. The 457 platform lets you change calibers without buying a new rifle, which appeals to owners who want to move between .17 HMR, .22 LR, and .22 WMR.

The .17 HMR caliber itself divides opinion somewhat. Fans of it love the flat trajectory and low recoil. Critics point to ammo cost being higher than .22 LR and note that the caliber is less forgiving on barrel life at high volumes. Neither camp disputes that it is effective for varmint work.

Price-to-performance is consistently mentioned positively. The CZ 457 competes well against more expensive rimfire bolt guns on accuracy metrics, which is the main reason it sells.