How heavy a mainspring

[bigted]

My smoothie has a very heavy to cock mainspring. Are they spose to be so heavy that it is difficult to cock with just my index finger. I use mypalm below my pinky finger ... or my thumb because the last little bit of the mainspring is very hard to cock.

Is this necesasary to get reliable sparking action.

 

[bigted]

I had to lighten my percusion mountain rifles mainspring for a better action and easier cocking by grinding then polishing the mainspring to lessen the end of the spring action. Can i do the same with this flintlock.

 

[rdstrain49]

Unless you are very skilled, grinding a main spring is a bad idea. Just a bit too much heat and you end up with a main spring looking chunk of metal.

Regarding how heavy, all of my flinters have heavier main springs than my cap guns. I'd rather have heavier than lighter on a flint gun.

 

[Stumpkiller]

My Kit Ravenshear Light Infantry fusil took about 20 lbs to cock. I cocked it with my middle finger over the top jaw screw. Threw a bushel of sparks, though.

The larger military style muskets and fusils have larger and stronger springs.

 

[dave_person]

Hi,
Balancing the forces of the frizzen spring and the mainspring is one of the keys to good sparking. A flintlock mainspring does not have to be really heavy as long as it kicks the frizzen over quickly and produces spark. Generally, I want the force to open the frizzen to be about 1/3 the force required to bring the lock to full cock. A heavy mainspring generally will make a lock faster but can also be hard on flints if the lock geometry is not quite right. A good mainspring should be strong but have a whippy feel such that it gets a little easier as you pull the flintcock back to full cock. That feel also has to do with the way the hook of the mainspring rides up the toe of the tumbler. You might try grinding a bevel on the mainspring and tapering the thickness of the lower leaf of the spring a little. Don't worry very much about over heating the spring because they are usually tempered at about 700-750 degrees. Hold it in your bare fingers as you grind. That way you will feel the heat building and can dip it in water when it starts getting hot.

dave

 

[rich pierce]

Just remember the bowmaker's rule: reduce width by half and you've reduced pull by half. Reduce thickness by half and now it has 1/4th the original pull. So any thinning must be very judicious.

 

[rdstrain49]

I still maintain that power tools and amateur gunsmiths are a poor combination. The temptation to hurry up and get done is too great for many to resist. But then my experience is limited to 30 years of fixing other peoples mistakes.

 

[ZUG]

I had to lighten my percusion mountain rifles mainspring for a better action and easier cocking by grinding then polishing the mainspring to lessen the end of the spring action. Can i do the same with this flintlock.

Buy yourself a spare spring and using a light touch on the grinder put a light bevel on the spring, polish it then give it a try - if it works to your satisfaction then STOP with any more rework - if not grind a bit more until you either get it where you want it or you need to buy another spring.:v This is something only YOU can determine :hmm:

 

[bigted]

Yes i have been aquanted with metal work for bout 30 years ( several years as a millwrite ).

Just wondered if it were as easy to get rite as was a couple capper springs.

Guess better order nother spring so as to have it on hand before playin with this one.

Davis round face lock so parts should be available id think.

Slowly getting this smoothie to an understanding ... Maybe itz gettin me to an understanding. Not sure

 

[Artificer]

Hi,
Balancing the forces of the frizzen spring and the mainspring is one of the keys to good sparking. A flintlock mainspring does not have to be really heavy as long as it kicks the frizzen over quickly and produces spark. Generally, I want the force to open the frizzen to be about 1/3 the force required to bring the lock to full cock. A heavy mainspring generally will make a lock faster but can also be hard on flints if the lock geometry is not quite right. A good mainspring should be strong but have a whippy feel such that it gets a little easier as you pull the flintcock back to full cock. That feel also has to do with the way the hook of the mainspring rides up the toe of the tumbler. You might try grinding a bevel on the mainspring and tapering the thickness of the lower leaf of the spring a little. Don't worry very much about over heating the spring because they are usually tempered at about 700-750 degrees. Hold it in your bare fingers as you grind. That way you will feel the heat building and can dip it in water when it starts getting hot.

dave

Hi Dave,

Very interesting post. Thank you. I did have a question on the following sentence you wrote:

"That feel also has to do with the way the hook of the mainspring rides up the toe of the tumbler."

Does this mean the top of the tumbler area where the mainspring toe rides should be flat and maybe angling down a bit as it goes forward towards the mainspring? I always wondered if/how that area affected trigger pull beyond polishing the surface.

Also, back in the late 90's or early 2000's, New Old Stock Original mainsprings for M1842 muskets were going way too cheap AND they are designed like a Brown Bess mainspring in that they have a hole in the top for a mainspring retaining screw. I bought one and compared it to my Pedersoli Bess mainspring and it was very similar, so I went back and bought some more. My thinking was that they would make good mainsprings for a Brown Bess lock plate kit?

Now these springs seem to be very heavy, but I have yet to put one in a Brown Bess lock plate kit because the Model 1842 being a percussion lock, did not have a frizzen spring and I wasn't sure how heavy of a frizzen spring would be required.

Gus

 

[kingsax26]

I would ask myself this, are you able to cock it ? does it beat up flints? does it throw sparks? if you can cock it, it doesnt beat up flints and it throws a good spark why mess with it. I have some flintlocks that i can cock with one finger, and others that i have to use a fist to open ....doesnt mean its a bad thing as long as everything is working together

 

[dave_person]

Hi Gus,
I am not sure if a flat, inclined, or concave toe on the tumbler has much effect on feel. It might. What I was referring to was if the hook on the spring is long such that its toe rides up the tumbler and almost butts up against the center of the tumbler at full cock, there will be a distinct let off in tension. There is nothing wrong with heavy springs as long as the lock geometry is correct so flints don't get smashed. The advantage of heavy mainsprings on flintlock muskets is that the power drives the big flintcocks faster throughout their long arc and the force also helps sparking when the frizzen and flint get covered with fouling and crud. A powerful spring drives the flint into the frizzen face scraping away the crud and getting to the steel. Also as the fouling accumulates on the frizzen spring it causes resistance to the frizzen opening. A powerful mainspring whacks the frizzen harder overcoming that added resistance. I demonstrated those qualities with a Pedersoli Bess I reworked for a member of Lamb's Artillery. My reworked Bess had balanced but stronger spring power than the other unmodified Besses in the group. They were part of a Memorial Day parade and every so often loaded and fired blanks. My Bess never failed to fire. The others started having sparking issues after only 3-4 rounds.

dave

 

[dave_person]

Hi Gus,
I think the model 1842 springs should be good on a Bess lock. If you are building one up from cast parts you should be able to adapt the spring easily. Because Bess tumblers rotate over a long arc, make sure the hook on the M1842 spring has sufficient clearance for the tip of the tumbler toe at full cock but also does not hit the bolster on the lock plate. Also Gus, in another post you asked about Blackley's parts. I have done quite a bit of business with them over the years and their components are superb. However, they currently seem to be no better than TRS with respect to customer service and waiting times unless you buy parts on hand at a show like Baltimore. If you want to get Bess parts quickly, try Paul Ackermann (www.ackermannarms.com). He seems to have a number of TRS part sets on hand for the same price you would buy them from TRS.

dave

 

[Eric Krewson]

I reduce the springs (draw filed and polished the edges) on the Chambers locks on my first two builds to keep the main spring out of the barrel channels.

After shooting my third build with a Chambers late Ketland lock (fast, fast, fast) with a full sized spring, I ordered new springs for my first two locks, made my lock inlets a little deeper and went back to locks they way they were designed to work.

I like fast, I found the locks don't eat flints like I expected.

 

[dave_person]

Hi Eric,
As long as the spring clears the barrel don't worry overly about the mortice for the mainspring breaking in to the barrel channel. I would rather have the right strength in the spring and an opening into the barrel channel than no opening and a weak spring. Some guys obsess about the mortice breaking into the channel but you will see that happening on many originals, even high-end ones and it does not compromise strength in the lock area.

dave

 

[rich pierce]

The Davis round faced colonial lock is the best sparker in my parts bin.

 

[Artificer]

Hi Dave,
“What I was referring to was if the hook on the spring is long such that its toe rides up the tumbler and almost butts up against the center of the tumbler at full cock, there will be a distinct let off in tension.”

Ah”¦.. now I think I see what you meant. I think you are referring to the mechanical advantage of the hook being close, but not too close to the center of the the tumbler and of course not actually mashing against the tumbler boss. Thank you, that’s a great tip. I knew the rear of the hook should not mash against the tumbler, but I did not realize it being close would give that mechanical advantage. That’s a “duh” on my part.

There is no doubt in my mind that one of your tuned/corrected locks would be much superior to standard Pedersoli locks.

I really appreciate you sharing your knowledge and experience so freely, Dave.

Gus

 

[Rifleman1776]

Speed beats out power in the sparkability department every time.
I have found the El Cheapo import locks can be improved by filing, not grinding, on the outside and thinning the width a bit. Filing and polishing the outside of the flats can help also sometimes. Having spare mainsprings is a good idea. Even quality ones can break.

 

[waksupi]

I just hog out some barrel material to let a mainspring fit, rather than reduce the spring.