Hi BBBBill,
I've used the Marvel jig & liked it okay, but it is made of anodized aluminum & it wore through pretty quick (maybe I was too rough with it??). Brownells stood behind it & replaced it with a Power Series 1 fixture which I thought would be more durable. The other complaint with the Marvel, is that I found the sear angle hard to set & change. The sear is held in place by a threaded shaft, using an interface with the hammer to establish the angle. Changing the angle is a hard thing to do, as there is not a set screw that locates the angle of the sear (like a Wilson jig).
The Powers Series I is a nice versatile tool, but I got one that was made "out of square" (it cuts the surface more on one side than the other). I'm still waiting on the arrival of it's replacement from Brownells. No one else (that I know of) has ever had this problem with the Power fixture. I sent the fixture first back to Ron Power (over a year ago) & they "replaced" it. Anyhow, the "second" fixture cut them just as crooked as the first (about .005" across the width of a 1911 sear). It sat on my shelf for a year, with me feeling bad about it, until I got in touch with Randy Bimson at Brownells tech department. Randy & Brownells are really stand-up guys and deserve our business. They are replacing the fixture.
I've also got the Power Series II fixture for stoning hammer hooks. It works good, but requires a special stone (trapezoidal shape) that is only available in "fine india" grade. I like a brighter finish on my hooks, but finer stones are not to be found, in my experience. The Marvel jig is really good for hammer hooks. You get excellent adjustability of angle & depth, as well as working with 1/2" X 6" stones.
The most useful sear jig on the market (IMO) is available from Brownells and is called "Brownells / Yavapai 1911 sear tool". It works great! It is very easy to change the primary angle setting. It also has a 25X magnifier that sits above a set of test engagement pins, allowing you to get a really good look at your engagement. It even cuts a sear square
. It is a little slower than the Powers Series I to change from the setting to cut the primary angle to the secondary angle, but all things considered, it is the best single purpose jig on the market.
Yes, I still use my Wilson sear & hammer jigs too! They are what kept me going while I was fooling around with the afore mentioned products. The Wilson hammer jig has been customized with the addition of a "fence" mace of tool steel that takes away the need for quite a much "touch" in keeping the hooks straight from side to side.
Sorry this got so long, I think you might have touched one of my "hot" buttons
Regards,
John Harrison