lock trouble

[David R. Pennington]

Took my latest build (#3) to the range Saturday to shoot the first time and although the wind was whipping I managed to put some pretty good patterns on the paper but left frustrated. I believe the Green Mountain .40 barrell will be a good shooter and I really like the balance and feel of the rifle but I am very disapointed with my lock choice. I saw this lock in one of the catalogs and liked the style and supposedly it was made by one of the reputable manufacturers. It laid around in my shop for about a year till I got around to it and when I began to look at getting it ready for the rifle I realized it had some flaws. This was a new assembled lock but the tumbler fit in the plate was way too sloppy for a new lock so I turned a bushing and refitted. Frizzen fit was sloppy too so I brazed up the hole and made a new screw, etc..., After a lot of additional tuning, honing, polishing, I thought I had a pretty good lock. Put it through the paces with a flint in place and snapped a few times and got some nice sparks in the pan.
 First shot went great. Although it is a large fowler style lock the ignition seemed almost instant. I was feeling pretty good,but it went downhill from there. I couldn't get more than 2 or 3 shots off before it would quit sparking. I had to have a perfect razor sharp flint edge or no spark.
 Back in the shop I checked the frizzen with a file and it seems plenty hard. My suspicions now turn to the mainspring which seems really wimpy compared to the one in my round face Chambers lock (about the same size). Even my Siler seems to have a lot stouter mainspring.
 Well I tried opening up the spring a little and retempering but ended up breaking the thing. Forged out a blank from an old hayrake tooth and will try making a new spring. This time I'll draw the temper real soft and work back the other way if I need it harder.
 I believe I could have made two or three more rifles by the time I get this lock right!

[smylee grouch]

Could you get a new spring from the Mgf. who made the lock? Maybe a new spring will be stronger than the original. 

[Blacksmoke]

David:  The two main lock problems for no spark are:   A. soft frizzen and B.  Too weak a mainspring.   I've been tuning and building locks for over 30 yrs. now and these are the two main weaknesses that I,ve found in contemporary factory made locks.   If you are going to make your own main spring I suggest for you to use an old truck leaf spring as your base metal.  Anneal - shape to dimension and bend with heat - harden - draw the temper to blue/almost grey and quench in oil before the temper heat can go any further.  There is your new mainsping!           Hugh Toenjes

[Dphariss]

Took my latest build (#3) to the range Saturday to shoot the first time and although the wind was whipping I managed to put some pretty good patterns on the paper but left frustrated. I believe the Green Mountain .40 barrell will be a good shooter and I really like the balance and feel of the rifle but I am very disapointed with my lock choice. I saw this lock in one of the catalogs and liked the style and supposedly it was made by one of the reputable manufacturers. It laid around in my shop for about a year till I got around to it and when I began to look at getting it ready for the rifle I realized it had some flaws. This was a new assembled lock but the tumbler fit in the plate was way too sloppy for a new lock so I turned a bushing and refitted. Frizzen fit was sloppy too so I brazed up the hole and made a new screw, etc..., After a lot of additional tuning, honing, polishing, I thought I had a pretty good lock. Put it through the paces with a flint in place and snapped a few times and got some nice sparks in the pan.
 First shot went great. Although it is a large fowler style lock the ignition seemed almost instant. I was feeling pretty good,but it went downhill from there. I couldn't get more than 2 or 3 shots off before it would quit sparking. I had to have a perfect razor sharp flint edge or no spark.
 Back in the shop I checked the frizzen with a file and it seems plenty hard. My suspicions now turn to the mainspring which seems really wimpy compared to the one in my round face Chambers lock (about the same size). Even my Siler seems to have a lot stouter mainspring.
 Well I tried opening up the spring a little and retempering but ended up breaking the thing. Forged out a blank from an old hayrake tooth and will try making a new spring. This time I'll draw the temper real soft and work back the other way if I need it harder.
 I believe I could have made two or three more rifles by the time I get this lock right!

The spring may not have enough preload. It is possible to re-arch a spring by polishing it bright then carefully heating it to blue any bend put on the spring leaf should stay if the spring is flexed and held and the leaf heated to blue. I clamp the bend in a vise and bend with a vise-grip.
If the spring goes flat i would heat it cherry, bend to the shape I want then re-heat quench and then temper to a nice blue. I make springs from 0-1 tool steel or for 1075 if I can get that, 1095 if not. I don't make springs from scrap unless really desperate. Takes too much time. I have some 1095 that is a pain to use since its hot rolled and needs to be carefully annealed before doing any work on it.

Its possible the frizzen is too hard. Bakeing in an oven pre-heated to 375 (use 2 oven theometers not the dial) for an hour will fix a too hard frizzen. Go much over 375 and you will need to re-heat-treat.

Dan

[mattdog]

I'm going to agree with Dan here.  The clue is when you said "it will spark but onlywith a very sharp flint"   It is possible to get a frizzen too hard, so hard that an average flint can't pull metal from it.  The cure is to bake it at 350 - 375 deg. like Dan mentioned.  I use a toaster oven with an independant thermometer.

Matt    

[David R. Pennington]

Thanks for all the input guys. The frizzen may well be too hard but I'm going to have to make a new mainspring anyway, because I ended up breaking the old one after I tried opening it up a little. Didn't draw the temper soft enough. I'm one of those fellows who has to try something just to see if I can do it. I don't have any spring stock wide enough on hand so I think the hay rake tooth might work.
I forged out a blank last evening and began filing it to rough shape this evening. We'll see.
Never really made a mainspring yet but I made a spring for a post vise the other day. A little bit bigger than a lock spring. If I get a good stout spring in and it still won't spark I'll try softening the frizzen a little.

[David R. Pennington]

Well I finished the homemade replacement mainspring for the lock I was having trouble with. The little Kit Ravenshear book on springs was very helpful. I didn't have any spring stock large enough and didn't want to wait for the mail order so I forged out a blank from an old hayrake tooth and filed to shape. My first attempt at a mainspring and had a little trouble getting the bend to work out right but finally got it to fit and cycle in the lock. Heated the spring carefully in the coal forge moving it around so the small sections didn't overheat. Tested it frequently with a magnet and when the magnet wouldn't draw it I quenched in oil. I followed Kit's procedure for drawing the temper by boiling in oil till all the oil burned off. Although this seemed to work great I probably used more oil than I needed and ended up with quite a blaze!
 Well the spring is in the lock and apears to work great! With the same half dull flint I already had in the hammer ( the one I couldn't get hardly a spark out of with the old spring) I got showers of sparks every time I tried till I finally got too tired and went to bed!

[D. Taylor Sapergia]

Congratulations are in order!  This is what it is all about.  It's so good to hear a success story like yours, and all it took was a little confidence and some time (and invaluable information).