Brownells Gunsmith Tech Corner - March 2007

By Monty Crain

Question: I was looking at Wolff 1911 Auto Recoil springs in your Catalog on page 157 and had a question. Is it possible to calculate what strength spring is required given bullet weight and velocity?

Answer: The barrel, as well as slide to frame fit come into play in this situation. The general rule is if the brass falls more than 9' away the spring is too light for the load you are shooting, and if the brass falls less than 3' away the spring is too heavy.



Question: I have a Tech .22 and it doesn’t seem to want to eject the bullet casings every time. My boyfriend bought a new magazine as well as a new firing pin and spring. Sometimes it ejects but it’s gets so every other time it jams and I have to pull the bolt handle back to get it out. Do you have any suggestions?

Answer: There can be many reasons a semi-automatic gun will not function correctly. Sometimes simply changing to another brand of ammunition is enough to make it work. Other times a good cleaning is all that is needed. However, it may be that the extractor is simply worn out or the chamber has become rough. It is often very difficult to identify the problem and you may have to take it to a gunsmith for a proper diagnosis. If a good cleaning doesn’t help, I’d take it to a gunshop.



Question: My aging eyes are causing me trouble, and fiber optic front sights in combination with factory rear target sights offer a fairly inexpensive solution for two of my S&W's.

I recently ordered a Hi-Viz Front Sight N-frame (#638-000-002) for my 57-1. I can easily drill the pin hole in my own shop but was disappointed to find that the sight channel doesn't fit-- I'll need to have it milled to fit the narrow sight channel of the gun. The description states that it fits the N-frame, but I don't know much about after-market S&W sights or Smith's production variations--maybe this is standard and I'll just need to file it down or have it machined. Not a big deal, though if I can exchange it for something that fits off the shelf I'd like to do so.

I've also got a new J-frame M60-15 with a 3" bbl. and factory target sights--the front blade is secured with a roll pin. Although I can't find any fiber blades specifically for J-frames in your catalog, the height of the Hi-Viz I mention above is also correct for this gun--both the M57 and the M60 have .250" blades. Maybe I can use the Hi-Viz on the M60 instead?

The M60 is a service weapon and I need something durable and secure like the over-molded S&W Hi-Viz type. The target-type blades on other models look a little fragile and cumbersome for concealed carry.

Sorry to be so long-winded. All I'm looking for are your best recommendations for fiber optic blades for my 6" M57-1 N-frame and 3" M60-15 J-frame. They need to work with the factory rear sights. The M57 is a target and hunting pistol, while the M60 is a concealed defensive weapon (though it's accurate and comfortable enough for enjoyable plinking and paper-punching).

Thanks for any assistance and recommendations you can offer.

Answer: The early models such as your 57-1 were more hand fitted and thus that is probably why the variation of the sight slot. The current models slots are more standardized and that is what all the aftermarket sights are made for. As far as it fitting on your J-frame, you can try it and if it fits then that will be great since the height sounds right. They don’t say it will fit it, but it is worth a try. I don’t have much more info since there is nothing specifically made for the J-frames. And it looks like no matter what sight you get for the 57, it will probably need to be fitted.