Throckmorton,23149 Posted June 17, 2017 Share Posted June 17, 2017 Used to see a gunsmith friend check the HAMMER spring weight with a trigger pull gauge, wondering if anyone else does ? And for ....say... CCI primers, what wight is optimal ? EDIT:: the purpose was to lessen the lever 'resistance' but have all rounds fire. Mine right now is 2.5 lbs, with no ignition problems. Have I just been lucky, or is this about 'average' ? thanks Link to comment Share on other sites More sharing options...
Larsen E. Pettifogger, SASS #32933 Posted June 17, 2017 Share Posted June 17, 2017 There is no optimal weight. Depends on how much friction the firing pin extension has in the frame, firing pin spring strength, etc. If yours works it is the correct weight. Link to comment Share on other sites More sharing options...
The Original Lumpy Gritz Posted June 17, 2017 Share Posted June 17, 2017 One really has nut'n to do with the other. It's all about the smack force of the hammer, transmitted to the primer. OLG Link to comment Share on other sites More sharing options...
Red Cent Posted June 17, 2017 Share Posted June 17, 2017 If you have a heavy trigger pull, look at the leaf ("iron bar" ) under/behind the trigger. You have an adjustment screw for the main (hammer) spring also. Link to comment Share on other sites More sharing options...
Larsen E. Pettifogger, SASS #32933 Posted June 17, 2017 Share Posted June 17, 2017 Looks what we have here is a failure to communicate. The OP asked about checking the hammer spring weight using a trigger pull gauge. You can measure hammer pull with a trigger pull gauge. People do it all the time particularly when they are setting up a double action revolver for competition. That is what I responded to. A couple of the other responses answered about the trigger pull weight. OP you need to clarify what you are talking about. Link to comment Share on other sites More sharing options...
CodyMaverick Posted June 17, 2017 Share Posted June 17, 2017 It sounds like your friend is gauging the hammer spring weight by measuring trigger pull weight. While hammer spring tension certainly plays a role in the measurement, the resulting data (2.5lbs) doesn't really tell you much unless it's being used to test the relative differences of some other variable. e.g. You can tell whether one hammer spring is heavier than another if you kept all other factors constant. I set mine such that the hammer will go completely down, overcoming the firing pin spring and any frictional losses as Larsen described. I test it with the lever fully closed and the hammer at rest, I pull back on the hammer slightly and watch the firing pin extension (FPE) as it moves out due to the firing pin spring pressure. Then I gently ease the hammer back down against the FPE and see that it compresses the firing pin spring and that when I push the hammer spur forward it does not go in any further. If the pressure from the firing pin spring pushes the hammer back or prevents it from going fully forward, then I tighten the tension screw just enough to overcome the firing pin spring. I know that I can adjust it lighter and it will still fire, but the only way to know for sure if it is too light is to test it by live firing a bunch of ammo or primed cases. Using the method above I can check this and make an adjustment if necessary at the loading table before I load the rifle. I also look in the gap at the front of the bolt and see that the tip of the firing pin goes in and out of the bolt like it's supposed to. All of this tells me that the firing pin and its spring are not broken or jammed and that there is sufficient hammer spring tension. This probably sounds overly anal but the more confidence I have in my equipment, the better I can focus on shooting the stage. Link to comment Share on other sites More sharing options...
John Boy Posted June 18, 2017 Share Posted June 18, 2017 Quote It's all about the smack force of the hammer, transmitted to the primer. OLG Any primer regardless of force of hammer has to be hit Fast & Hard to crush the primer anvils! Link to comment Share on other sites More sharing options...
Nate Kiowa Jones #6765 Posted June 18, 2017 Share Posted June 18, 2017 On 6/17/2017 at 2:19 PM, CodyMaverick said: ...................................... I set mine such that the hammer will go completely down, overcoming the firing pin spring and any frictional losses as Larsen described. I test it with the lever fully closed and the hammer at rest, I pull back on the hammer slightly and watch the firing pin extension (FPE) as it moves out due to the firing pin spring pressure. Then I gently ease the hammer back down against the FPE and see that it compresses the firing pin spring and that when I push the hammer spur forward it does not go in any further. ............................................................................. If you don't have a spent case chambered you might get a false reading. Without a case chambered the front of the bolt can be pushed up by the extractor. The case assures everything is centered. Link to comment Share on other sites More sharing options...
CodyMaverick Posted June 18, 2017 Share Posted June 18, 2017 3 hours ago, Nate Kiowa Jones #6765 said: If you don't have a spent case chambered you might get a false reading. Without a case chambered the front of the bolt can be pushed up by the extractor. The case assures everything is centered. Howdy Nate! Thanks for pointing this out. It does seem that many and perhaps even most '73 will exhibit this 'feature' where the bolt cams up slightly when closed with out a case chambered and this puts more friction on the FPE than the firing pin spring can overcome and it will appear to be stuck. I have 3 '73s and none of them do that but one of them used to (long story) and the gunsmith at Taylors tried to convince me that it was normal and they all do it. I guess my method of setting and checking my mainspring would not work for everybody. I just do it this way so that I can easily check it at the loading table and gain some additional confidence that all is well. Link to comment Share on other sites More sharing options...
Nate Kiowa Jones #6765 Posted June 19, 2017 Share Posted June 19, 2017 Yep, It's most notable with the worn/loose original 73's and sometimes over smithed or poorly fitted clones. Link to comment Share on other sites More sharing options...
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