cajungeo has it right, you WILL break firing pins by dry firing. If you slam a firing pin into the bolt enough times, the firing pin tail will be repeatedly stressed, as there is no primer to cushion the blow, and you are bound to get stress fractures and breakage, probably at the most inconvenient times. And the replacement (blue only) lists for $25.70 at www.e-gunparts.com (Brownells doesn't even list it) -- 5 times the price I pay for a milspec M14 chrome-plated firing pin.
I bought a commercial dry fire device for my M1As and Garand, but these go for about $15 and must be ordered, yet the principle is really simple. (A snap cap would also work, but not nearly as well.) If you use the dry fire device, the hammer never contacts the firing pin, it hits the bottom rear edge of the bolt, and only after a very short fall, so much less wear and tear. And it is convenient, because you only pull the op rod maybe 5/8" to rec0ck the hammer, which makes it much easier, so you are likely to do more dry firing, which helps your scores quite a bit.
I wanted to try the same thing on the Mini-14, and I found I could put a fired 7.62x39 shell casing (I prefer using a brass one) and set it in the mouth of the .223 chamber to do the same thing. Only problem is it tends to fall out when you rec0ck the hammer, so you need to point the muzzle down. Eventually I may solder a spent .223 casing on the neck of the 7.62x39 case so it stays in the chamber better (but if it comes off, this would require a broken shell extractor to remove, so I haven't tried it yet). You could also do the same thing with a short piece of wood or plastic dowel. If you make one from a dowel, you could paint it orange so you can use it as an unloaded chamber indicator at the range.
As for the mag questions/comments, I bought 2 mags (said to be Masens) on eBay, and was appalled that the plastic tab that should activate the bolt hold-open was in front of the hold-open activating lever! Not a very good fit! It could be that it is being held too high in the rear, but it seems to lock up okay, so I don't want to file anything. I swapped in the follower from one of the Rugers, and it now holds open ~80% of the time.
Some mags drop free better than others -- a few seem to be a bit wider and drag on the wood on one side. My PMI needs to be yanked free, while Rugers, ProMags, and most USAs seem to drop free. The new 10 rd ProMags made for their OEM acceptance run are very impressive, equal to OEM Ruger quality, just missing the logo.
-- cw
I bought a commercial dry fire device for my M1As and Garand, but these go for about $15 and must be ordered, yet the principle is really simple. (A snap cap would also work, but not nearly as well.) If you use the dry fire device, the hammer never contacts the firing pin, it hits the bottom rear edge of the bolt, and only after a very short fall, so much less wear and tear. And it is convenient, because you only pull the op rod maybe 5/8" to rec0ck the hammer, which makes it much easier, so you are likely to do more dry firing, which helps your scores quite a bit.
I wanted to try the same thing on the Mini-14, and I found I could put a fired 7.62x39 shell casing (I prefer using a brass one) and set it in the mouth of the .223 chamber to do the same thing. Only problem is it tends to fall out when you rec0ck the hammer, so you need to point the muzzle down. Eventually I may solder a spent .223 casing on the neck of the 7.62x39 case so it stays in the chamber better (but if it comes off, this would require a broken shell extractor to remove, so I haven't tried it yet). You could also do the same thing with a short piece of wood or plastic dowel. If you make one from a dowel, you could paint it orange so you can use it as an unloaded chamber indicator at the range.
As for the mag questions/comments, I bought 2 mags (said to be Masens) on eBay, and was appalled that the plastic tab that should activate the bolt hold-open was in front of the hold-open activating lever! Not a very good fit! It could be that it is being held too high in the rear, but it seems to lock up okay, so I don't want to file anything. I swapped in the follower from one of the Rugers, and it now holds open ~80% of the time.
Some mags drop free better than others -- a few seem to be a bit wider and drag on the wood on one side. My PMI needs to be yanked free, while Rugers, ProMags, and most USAs seem to drop free. The new 10 rd ProMags made for their OEM acceptance run are very impressive, equal to OEM Ruger quality, just missing the logo.
-- cw
