Custom Heavy Barrels For Ruger Model 77/17

Ruger’s line of Model 77 rimfire rifles has become very popular among target shooters, small-game and varmint hunters. This fine little rifle is chambered for the ubiquitous .22 Long Rifle, as well as the .22 Winchester Magnum Rimfire and the more recent .17 Hornady Magnum Rimfire. Some shooters would like to have both of these fine rimfire versions, but for one reason or other this isn’t within their budget. Adding an extra barrel to the rifle they already have is a very viable solution.

Both rifles use the same magazine and exchanging barrels is easy, requiring only a screwdriver and an Allen wrench for a very solid lockup. Fitting a Second Barrel Barrel selection is a matter of preference. A barrel with similar contour requires no barrel channel alteration. Some prefer a heavier, or match grade, barrel with inherently better accuracy and less involved barrel contour work.

Enlarging the stock barrel channel to make the fit takes little time and doesn’t detract from the rifle’s aesthetic appearance. Barrel twist rate should conform to the cartridge standard when choosing a barrel. For example, the .22 WMR does well with a 1:14 rifl ing twist. The work I performed involved adding a .22 Winchester Magnum Rim- 22 WMR and .17 HRM. A Weaver T-10 scope is seen here with integral Ruger rings. fi re barrel to a Ruger Model 77/17 rifle chambered in .17 Hornady Magnum Rimfire.

A straight taper, Green Mountain 0.918-inch diameter, 22-inch, 1:14-twist stainless barrel was chosen. In setting up for doing the machining work, follow the barrel specifications of the original barrel very closely. The barrel is attached to the receiver with two socket head screws by a special V-block retainer.

The barrel shank must be closely fitted to the receiver socket, which has a diameter of 0.688 inches, whereas the barrel shank is 0.685" in diameter and 0.873" in length from the barrel shoulder to the breech face. This length establishes the exact headspace for both cartridges based on SAAMI cartridge rim thickness. The next critical diameter specifi cation is immediately forward of the barrel shoulder. At this point the diameter is 0.918" for at least 1.10" just past the barrel retaining V-block notch.

This section of the barrel rests on top of a short, semicircular tang extending beyond the receiver for a length of 0.475" forming part of the V-block attachment as the barrel is secured in place. The barrel diameter here should be exactly 0.918" as it fits the milled

From left, Ruger 17 HRM and .22 WMR. receiver tang radius at this point, further stabilizing the barrel. Actually, the barrel diameter should not exceed 0.918", which is the diameter I left the .22 WMR as I turned it. Ordering a replacement barrel of less than 0.918" diameter would be too small. With the barrel shank correctly fitted to the receiver, the V-block attachment groove is cut into the barrel. Take a close look at the picture of the barrel I have provided as well as the barrel shank you are duplicating.

This V-block cutout must be very close to the original. The top lip of the 45-degree angled cutout must extend 0.513" beyond the barrel shoulder. The rearward lip of the cutout is then formed at a 45-degree angle duplicating that of the original barrel. A 45-degree dovetail cutter will do the job, or if you are really handy, a correctly angled machinist fi le will suffi ce. Here is where you must take your time. Then, with the barrel fitted to the receiver, the chamber can be reamed.

I used a reamer made by Dave Manson Precision Reamers (mansonreamers.com). The rimfire chamber is cut precisely flush with 22 WMR chamber for the new barrel. The extractor slots are cut very close to the rim of the new chamber for proper case extraction. the breech face of the barrel for proper headspace. Take your time here to avoid too deep a cut beyond the step on the reamer. Then, with everything completed on the barrel thus far, the two slots are cut for the cartridge support and extractor.

The extractor is on the right side of the bolt and the cartridge support on the left. Both are commonly called extractors,

22 WMR barrel protruding into the action. Note the angled position of the laterally opposing extractor slots. 22 WMR barrel. Note the angled position of the extractor. which is a misnomer. The cartridge support has no notch that would extract a chambered case, whereas the extractor does. Both have a beveled tip and have the same spring-loaded function enabling them to slip over a chambered cartridge rim as the bolt is closed.

The cartridge support holds the rimmed case firmly into the extractor as it is pulled out and ejected. Aside from this, the two laterally opposing parts look quite alike. Here we run into a caution area in forming the extractor and cartridge support slot. These extractor slots are at an angle on the barrel as the picture I have provided will show. So, put the original barrel in place and have a close look at things with the V-block locking the barrel.

The opposing slots area few degrees clockwise from square and must be marked and cut accordingly. As you view the positioned barrel through the magazine cutout, these slots will appear close to 9:30 and 3:30 by the clock. So as you mill the slots, be sure they are correctly positioned. Here the use of a Woodruff keyseat cutter of the correct size does an excellent job.

The barrel is held in the milling vise at 90-degrees to the key seat cutter at the proper barrel rotation to correspond with the original barrel and with a slot width the same as the original barrel. In finishing, I made a recessed muzzle crown with the usual round-head brass screw micro finish after forming the muzzle recess on the lathe. The barrel channel was formed to fit the new barrel, leaving it free-floating. Best accuracy is usually attained in this way.

Following barrel fitting, the rifle was test fi red for function and accuracy. Cartridges in both calibers fed and extracted smoothly. The Hawkeye bore scope showed a near perfect chamber made with the Dave Manson reamer. Accuracy at 50 yards with the .17 HMR was most excellent using a variety of 17 grain bullet loads. Five shot groups as small as 3/8-inches at 50 yards were common. Groups with the new .22 WMR were close behind

This forms a very sturdy lock-up of the barrel. 22 WMR barrel securely locked to the receiver on the Ruger 77/22-17 action. Barrels can be switched in just minutes with the use of an Allen wrench. this performance using a number of ammunition brands. For some reason the full-metal-case bullet produced the best accuracy. The Winchester brand worked out best here with groups as small as 1/2inch at 50 yards.

Conclusion The Ruger Model 77 rimfire rifle series is an excellent, cost effective approach to adding another barrel. This is particularly true where the D ’ M A! Complete your American Gunsmith collection. Or read up on a special subject! A limited number of the following