For convenience and cost savings, here are the first two sizes in the Bellm Accuracy Encore Oversize Hinge Pin system.
Follow the recommendations given for the 1x and 2x pins given individually here on the store, trying the smaller pin size before trying the next larger one. The 1x and 2x pack will give a good fit in most barrel and frame combinations and may be all you need. This 2-pin package is a good place to start if you want to try to get what you need in one order. The degree of looseness of the factory hinge pins in the holes will tell you a lot. If you feel much wiggle room at all, the 2x pin will probably fit fine, but having the 1x pin gives another test and may be what you want for a looser fit on occasions when swapping barrels often is likely or when accuracy requirements are not as great. Have fun with this. Shoot for group with the 1x pin, then shoot for group with the 2x pin. See if there is a measurable difference in group sizes between the two.
If your barrel drops open easily and has any side to side movement when opened, that "play" at the hinge does not go away when the barrel is closed, and it permits the barrel to move in an inconsistent manner while the bullet is traveling through it. To reach a barrels accuracy potential, this play at the hinge area must be removed. Stop wasting ammo trying to get your barrel to shoot, just oversize the hinge pin.
The hinge pin holes in Encore barrels and frames vary much more than the holes in Contenders, so much so that in some instances the hinge pin must be at least .003" larger than "stock" in order to get the same degree of precision fit common to the Bellm Oversize Contender Hinge Pins. Stainless steel frames are prone to accept the 2x pin, a result of galling and/or lack of lubrication.
Reaming for these 2x pins is sometimes necessary but with our quality hinge pins often avoidable. The 1x at .4377" and 2x at .438" they fit most all factory and custom barrel hinge pin holes. Testing the fit of the 1x pin then the 2x pin in each hole gives an indication as to whether the next larger pin is needed to get the optimum fit desired, that of a bank vault door opening and closing. I know, you never had the privilege, but you get the idea. It does not shake and rattle all over the place.
Use the 1x pin then the 2x pin as a gauge pin. Simply lubricate the hinge pin, frame and barrel hole with a common cutting/tapping or heavy viscosity oil. Center the hinge pin on a given hole checking for axial play and resistance. If it is not tight enough, consider it as a gauging tool to determine if a larger pin is called for. When installing the oversized hinge pin, always install the stock hinge pin first, then tap out of the way with the oversized pin. Always remember the lube.
Taking accurate measurements of pins and holes is common among machinists, but not in the realm most folks are familiar with. Thus, the best solution I have found to bridge this technology gap is to simply use a process of elimination by going from one size pin to the next. Anyone can tell if a pin is loose or tight, right? The Encore hinge pin system is a well proven system. "Trial and error" is working very well, and groups are tightening. That is what counts.
So, start with the 1x pin then the 2x unless you have a means of accurately measuring your hinge pin holes in your barrels and frames. By the way, calipers are not accurate enough to give more than a rough idea. Trying a pin is still the best method available to most shooters.
Add a 1x2x pin to your cart and get started toward better shooting Encore barrels.