M70 Winchester Extractor Retroit

There are many reasons for replacing parts on a firearm. Chief among these area lost or worn part, or where modification of an existing part is necessary. When a crucial part can put a halt to your shooting, it’s high time to do something. While in the process of chambering a 6mm PPC cartridge for a post- 1964 Model 70 Winchester pushfeed style rifle, I discovered a major problem with cartridge extraction.

In this particular rifle I would be using 6mm PPC and 6mm Remington cartridges as a switch-barrel system despite the differing case rim diameters. The difference in rim diameter of these two cartridges is 0.031" by most cartridge manufacturers. The 6mm PPC Sako case rim diameter is smaller than the 6mm Remington by 0.031", requiring a different extractor. Below center: The older style Model 70 extractor using a spring and plunger which was not only too short, but very sluggish in operation.

The normal SAAMI specifications are 0.472" for the 6mm Remington and 0.441" for the 6mm PPC and .22 PPC cartridges derived from the .220 Russian case. While most Remington Model 700 series extractors fitted for the .308 family of cartridges will extract PPC cartridges, the M70 I was working with will not. While exploring my options, which were very limited, I decided to make a totally new extractor for the Model 70 bolt.

In changing and making the new extractor I studied the existing push-feed style extractor used on the post-1964 Model 70s. There appeared a flat hook-style extractor fitted directly into the right side of the slotted bolt lug. This part has two laterally opposing rails that fit directly into the slots milled into each side level with the flat plane of the bolt face. These flat rails fit into and slide along the bolt lug grooves and are on the same plane as the bolt face.

The integral extraction hook is part of the extraction body and is pushed laterally by the case rim against the top bevel, snapping and locking into the case extractor groove. The extractor is activated and held in place by a spring-loaded plunger beneath it. The plunger, with its 82-degree angle, engages a coned hole in the extractor from below. This brings the extractor back to center after it engages the case rim, all ready for extraction.

In the retrofitting process, I substituted the spring-loaded, coneshaped plunger with a ball bearing and spring that fit the same bolt hole. The ball bearing worked more smoothly as it moved up and down in an 82-degree angled hole as the extractor functioned. Now to make the new extractor. There would be some difference in the new extractor which would be 0.035" longer with a longer, some-

As few as 0.010" hole position will make a crucial difference here. An extractor claw that fails to extend far enough into the bolt face can spell trouble. what more shallow bevel at the top of the extractor claw. It would require more lateral movement to engage both the 6mm Remington and 6mm PPC cartridge rims. I milled the extractor body to pretty much the same dimensions as the existing part from apiece of semi-hard steel.

I then shaped the extractor hook to proper case rim radius and length and made sure it worked smoothly into the bolt slots. Though a small part, the extractor performs an extremely important function. The transition requires close attention to detail, particularly when the extractor serves different size cartridges. It was a "must work" situation or the secondary cartridge would noth ave been adaptable.

Sometimes the precision in making an intricate, little part can consume an inordinate amount of a gunsmith’s time. The key is getting started and to just do it. AG Where the extractor is a little over length between the detent and claw, this is easily remedied by using an end mill to cut it back and shorten it. If it’s too short it becomes a problem. Measure twice and cut once is the old carpenter’s warning.