Swivel Breech Mainspring Alternative

[pushboater]

For those of you building a Swivel breech using Dave Waters book as a road map, but using the internals of the L&R Backaction Lock, I've found a great alternative to the very long Mainspring that makes the Lock look, IMHO, way to long! You can shorten the lock up considerably by using the Mainspring off the L&R small pistol Backaction Lock. This is a small Darringer size lock that has a very strong mainspring for its size. An added bonus is that you can eliminate the sear spring and screw as the bottom of the Mainspring serves that purpose! It fit my shortened Lock plate perfectly. The only modification I had to do was to shorten the lower arm of the mainspring where it rests upon the top of the sear slightly. Here's the Clevis block version,



And here is the same lock with the Small Backaction Pistol Lock Mainspring installed. Big difference, and very easy to install!

[Curtis]

That's a great idea!  Simple is good!  I assume there is a pin on the new spring that holds it in place on the lock plate?

Curtis

[pushboater]

That's correct Curtis. Exactly one pin. Mounting it was a simple process of drilling one well placed hole. Couldn't get any more simple than that. If I had located the hole a little more accurately I wouldn't have had to file a 1/64" off the lower arm where it rests on the sear.

David

[smart dog]

Hi David,
That looks like a great plan.  Dave Price's action uses a similar spring but he also has a separate sear spring.  How heavy is the spring load on the sear?  The location that the spring touches the sear looks exactly right.  Can you create a nice crisp but light trigger pull?

dave

[pushboater]

It takes quite a pit of effort to trip the sear with my hand. I think I'm going to try tapering the sear part of the mainspring a little and see if that doesn't make it a little easier to trip. Also, I plan on polishing the top of the sear where the mainspring makes contact and polishing the sear end of the mainspring. I think doing those two items should help to lighten the effort required to trip the sear.

David

[Tonyhd98]

My compliments Dave, well done and thanks for the engineering info!

[pushboater]

You're welcome Tony. I wish I could find more time to work on it. Between my job and moving it's been a very LONG journey. I'm making a New Years Resolution to finish it in 2017! I'll just have to reset my priorities and "Get er Done"!

Capt. David

[Timothy88]

I really like your idea of using the smaller mainspring.

Where did you purchase the spring from the small pistol back action lock? I can't seem to find it.

[Gunnermike]

He used the L&R Small Pistol Lock - Model# 750 mainspring.  Found at this link: http://www.lr-rpl.com/index.php?option=com_content&view=article&id=99:small-pistol-lock-model-750&catid=38:lar-locks&Itemid=61

It looks like the mainspring is about $22.50 according to L&R's current Price List.  I'd contact them at 803-481-5790 to make sure you get the correct part.  I didn't see this lock listed at Track of the Wolf or Muzzleloader Builder's Supply, so no parts available except from L&R.

That is a nice looking lock Pushboater made, ain't it!  Later, Mike

[Firelock]

That is very cool! Great tip.

[Timothy88]

Thank you Gunnermike.