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Removal of Barrel:

1. Loosen barrel band screw (B-69) & slide off barrel band (B-68);

2. Remove wood stock screw (B-65) from receiver (B-1);

3. Put safety in center position & remove barrel/receiver unit from stock;

4. Remove 2 Allen-head screws (B-67) from V-Block (B-66);

5. Remove barrel from receiver.

Installation of the WhistlePig Bull Barrel:

1. Requires a new bull- barrel stock or modify factory stock;

2. Fitting the new barrel into the receiver should be a snug fit. The barrel end (shankis machined slightly oversized. If the barrel is anodized, it will add thickness. If too tight, first oil the shank, bottom of the barrel between the V-block and shank area and where the barrel fits into the receiver side. If still too tight, sand the shank with the supplied emery cloth strip, sanding the shank evenly around. Do a little sanding at a time. Oil the shank and receiver port again and try to insert the barrel into the receiver. If still too tight, repeat the process;

3. Re-install V-Block with Allen-head screws with an equal amount of torque;

4. Re-install barrel and receiver in the bull-barrel stock with the bolt in the locked position.
Cleaning the Barrel Liner:

Choice of a cleaning rod with a cotton swab or patch with solvent and push it through the bore or a weed-wacker line with a cotton or synthetic patch. When using solvents, be careful not to get solvent on receiver and wood stock surfaces as it can damage the finish. The use of a BoreSnake is highly recommended with a foaming anti-corrosive bore cleaner (Gunslick, Break-Free). These are available at any sporting goods store. Use the proper caliber BoreSnake and clean from the chamber out to the muzzle. One to two pulls of the Snake is usually sufficient. Spray a small amount of foaming cleaner in front of and on the brush area of the Snake and a few inches behind. Grasp the cord weighted end with your free hand and pull.

It will be very hard pulling.

Maintenance of Matte, Brushed & Polish Finishes:

Matte Finish - The barrel is glass beaded to produce a matte finish. Gun oil is applied to the barrel prior to shipment. If you get any smudges or fingerprints on the barrel after the installation, apply some additional oil with a soft cloth and then remove the excess oil with a clean, dry cloth or wash the barrel with dish soap and a soft brush and re-oil.

Brushed Finish - use a 3M Scotch Brite #07447 (maroon color) or steel wool to renew the finish and re-oil.

Polished Finish – to renew the shine, use a Mag/Aluminum Wheel polish (like Mother’s brand)


It will take from 100 – 125 rounds of shooting to fully break - in the new barrel. .22 LR - It is recommended to try 4 – 5 different brands of ammo during break-in. The barrel will “tell you” which one it likes the best. Every barrel tends to like different ammo. This process is the most important aspect of having an accurate rifle.

Clean the barrel every 25 rounds for the first 100 and then as needed after that. Your groups will dictate when the barrel needs to be cleaned. The .22LR generally can go many rounds before cleaning is needed. A slightly dirty barrel is preferred for maximum accuracy. For the Magnum (WMR), , clean barrels at least every 75 – 100 rounds for maximum performance.

After the barrel is broken in - reset the scope for final sight-in and enjoy.

Magnum (WMR):

Due to a timing issue, It is not recommend the use of a soft polyurethane bolt buffer Use only the factory steel buffer pin or a hard polyurethane pin. Weak guide rod spring (bolt handle part) and hammer spring may also need to be replaced. Clean the barrel (liner) at least every 75-100 rounds.


All caliber barrels were tested with factory receiver components unless noted otherwise. Any third-party replacement parts to the bolt and trigger assemblies may affect the functionality and performance of the barrel. In no event shall WhistlePig GunBarrel Company (WPGBC, LLC) be liable to the buyer or any third party for any loss or damage, of any type, including by not limited to incidental and/or consequential damage, resulting from the purchase or use of this product. Buyer hererby agrees to indemnify and hold harmless seller, its officers, employees and agents from and against all claims, losses, damages, expenses or liabilities of nature or kind whatsoever together with attendant costs of litigation and attorney fees including any and all claims, losses, costs, damages, expenses or liabilities from the purchase of this product or services.