HORNADY A257 257 ROBERTS LOCK-N-LOAD MODIFIED CASE

The Hornady Lock-N-Load Modified Case 257 Roberts (A257) is a brass tool case for reloaders who use Hornady O.A.L. and Precision Gauges to set exact bullet seating depth in 257 Roberts chambers. This A257 modified case for 257 Roberts works with Lock-N-Load gauges so you can match cartridge overall length to your own rifle instead of relying only on manual data.

Key Features

• Manufacturer part number: A257
• Cartridge: 257 Roberts
• Case family: Hornady Lock-N-Load Modified Case A Series
• Intended use: for use with Hornady Lock-N-Load O.A.L. and Precision Gauges
• Material: brass modified case
• Case body: manufactured to SAAMI 257 Roberts chamber dimensions
• Neck: approximately 0.002 inch oversize to accept the same bullets you plan to load
• Case head: special fine thread at the head to attach directly to Hornady gauges and keep the case square in the chamber
• Quantity: one modified case per package

Special Features

• The A257 modified case uses a fine threaded case head that screws securely into Hornady gauges so the case stays aligned while you push the bullet up to the lands.
• The slightly opened neck lets a 25-caliber bullet slip into the case mouth easily while maintaining light grip, which supports smooth and repeatable movement during length checks.
• Hornady builds the A257 to SAAMI specifications, giving you a realistic 257 Roberts chamber baseline instead of a generic test tube or simulated case.
• Interchangeable A Series modified cases like the A257 let you run one Hornady gauge body across many calibers by swapping cases.

Practical Benefits

• The Hornady Lock-N-Load Modified Case 257 Roberts (A257) gives you a repeatable way to find the cartridge length that fits your rifle’s freebore so you can tune seating depth for accuracy instead of guessing from book lengths.
• Because the A257 case works with compatible straight and curved Hornady gauges, it fits many classic and modern 257 Roberts rifles that accept the tool and lets you standardize your process across multiple guns.
• The brass construction and oversize neck let you test with the same bullets you intend to load, so the distance to the lands you measure transfers cleanly to your seating die settings.
• If you load 257 Roberts for deer, varmints, or general field use, the Hornady Lock-N-Load Modified Case 257 Roberts (A257) is a practical choice that helps your handloads match your chamber and perform the way you built them