Questions on hammer bobbing.....

[Stradawhovious]

Alright, before I begin.... <flame suit on>..... There. do your worst.

I'm looking to bob the hammer on one of my revolvers for a myriad of reasons, and have some questions about practicality. I have seen some hammers where only the spur is removed, some where a ton of material is removed to leave the least possible amount for the hammer to properly function, and everything in between. I guess my question is what is the practicality of the two extremes?

I understand only removing the spur to lessen the likelyhood of getting caught on the draw for concealed carry, but I can't imagine it does all that much to alleviate the impact on the frame when the hammer strikes it.

I understand that removing a lot of material will help keep the inadvertant movement to a minimum.

The big question I have is what is the trade off between weight and speed. [My] Simple physics would dictate that the lighter the hammer, the faster it moves and the less it jolts the frame on impact, but there would be force lost with the lighter weight. Where is the trade off? What determines how much to remove?

I'm sure I will probably be talked into waiting until I get the cash to have it done professionally, but right now I'm cash poor, time rich and have the tools and motor skills required. That, and I love to tinker, and with this job I can't see any inherent safety issues like there would be with mussing with a single action sear or the like. Worst case scenario (I can think of) is I ruin the hammer, and have to get another one. Besides, I'm not sure I would want to be without the gun for the time it takes to get the job accomplished. Even if/when I do send it off, it wouldn't satisfy my curiosity on the more involved "hows" and "whys" of the modification.

To add more information, this would be a 625 model with a frame mounted firing pin.

Thanks for entertaining my rookie dumbass question.

[Stradawhovious]

To add an initial though, My thinking was for the first attempt to simply put the hammer in the "fire" position (hammer down and firint pin engaged), trace the outline of the frame on the hammer, and remove the portion above it. Aesthetically, this makes sense, and does remove quite a bit of weight.

Alright, fire away!

[Tom E]

You're lightening the hammer so you can then lighten the mainspring (which means you can then lighten the rebound spring keeping things "in balance") to lighten your DA pull. CF primers like hammer velocity, you can get the same necessary velocity with less mainspring with a lighter hammer. If you have an MIM hammer (MIM hammers DO NOT have pinned sears, easy way to tell) a replacement will be a drop-in so why not do it right? Draw a stright line that keeps the stirrup attachment intact and removes about 40% of the hammer depth at the top and wack it. If cosmetics are a priority, do what is pretty, but you lose part of the benefit. The weight removal that gives the most benefit is the weight removed farthest from the hammer pivot. I have guns with each version.

[Jaxshooter]

I have six S&W N frame revolers with bobbed hammers. They are all cut to the maximum. One was done by Randy Lee and the other 5 were done by Mike Carmoney. If you want the maximum benefit cut them to the max.

[Carmoney]

The primary purpose of the Carmonized hammer (i.e. cut down to minimal dimensions that reduce the curb weight of the hammer by about 50 percent) is to allow the hammer to run at a significantly higher velocity when it falls, decreasing lock-time and imparting that "fast slap" on the primer that is most efficient for ignition. As I have mentioned here previously, I got the idea from an old photo of a PPC revolver done by a west-coast gunsmith back in the '70s. As indicated above, with a Carmonized hammer you can lighten up the spring tensions noticeably, and yet still maintain full ignition reliability.

The secondary benefit of Carmonizing the hammer is that it reduces the jarring and jostling upon impact when the hammer falls, which may improve inherent accuracy and definitely creates a tangible and noticeable improvement in feel. Here's an interesting visual depiction of this effect:

Lightening the hammer works with both types of hammers--those designed for the frame-mounted firing pin, and the older style with the hammer nose.

[Tom E]

The primary purpose of the Carmonized hammer (i.e. cut down to minimal dimensions that reduce the curb weight of the hammer by about 50 percent) is to allow the hammer to run at a significantly higher velocity when it falls, decreasing lock-time and imparting that "fast slap" on the primer that is most efficient for ignition.

If you don't lighten the mainspring you get a very obvious decrease in lock time. But the light hammer allows you to drop the mainspring tension (lessening your DA pull) down to duplicate the velocity of the heavier hammer. That pretty much negates any faster lock time but it does reduce how much the gun is upset by the hammer falling because the hammer is lighter. Maybe this should be named after the west coast gunsmith doing this in the 70's where the idea came from.

Edited June 2, 2010 by Tom E

[Stradawhovious]

Thanks for the input folks, it's much appreciated.

Just so i have this straight, when cutting the hammer down as far as it can go, you're pretty much removing all the material to the left of the red line in the photo, correct? What keeps the lock work form getting all gummed up with shit in the meantime? Just clean it out more often? I was under the understanding that you wanted to open the sideplate as infrequently as humanly possible.

Pic of hammer.

[Tom E]

Looks like what I do. Stuff falling in the frame opening has never been an issue, but I do this on guns meant for competition, not carry guns.

[CJDOUBLETAP]

The powder and lead residue can't get back there, you should be good to go.

[Stradawhovious]

Well, the surgery was a great success, and it made a surprisingly noticable difference.. Thanks for the input! Can't wait to get it to the range.

[Carmoney]

Congratulations on a successful surgery, Strad!

Edited June 3, 2010 by Carmoney

[Stradawhovious]

Congratulations on a successful surgery, Strad!

Yeah, and if I get off of work early tonight, I am going to risk making a fool of myself by shooting at OGS's USPSA match without testing it at the range first. It's all fun and games until the gun doesn't work for the first string! But its not a points match, nor is there anything on the line so it will be a fun gamble.

I'm still amazed at what a difference this made in how everything feels when that hammer falls. Simply amazed.

[Tom E]

I'm still amazed at what a difference this made in how everything feels when that hammer falls. Simply amazed.

Same springs or did you lighten the mainspring?

[Stradawhovious]

I'm still amazed at what a difference this made in how everything feels when that hammer falls. Simply amazed.

Same springs or did you lighten the mainspring?

Right now I have an after karket spring set, the "Miculek" spring kit in there. When I have some time (and a quiet range) I will put the original back in and putz arounsd with it some, just to see how nice I can make this thing.

[Tom E]

I don't think you'll want the original spring, at least not without bending it. You may want to play with the strain screw length with the Miculek spring.

[Stradawhovious]

I don't think you'll want the original spring, at least not without bending it. You may want to play with the strain screw length with the Miculek spring.

Alright, this leads me to another question altogether. I wasn't going to bring it up in fear of starting a royal pissing match, but my curiosity has just overwhelmed any blow my consious might take from instigating said match......

I will start it in a seperate thread, and link it here.

http://www.brianenos.com/forums/index.php?showtopic=107653

[Stradawhovious]

I also wanted to add some pics of my handywork, simply because I'm proud of it. I'm sure it could have been done better, but I'm thrilled with how it turned out.

[Kevin Pledger]

Will the type of trigger work described here work on 686 style of hammers as I notice this is on a .45 revolver so with a different hammer.

I have some spare hammers and would like to try this modification see if their is any significant difference to my PPC revolvers.

Thanks.

Cheers ....

[MrBorland]

Kevin -

Yep, the radical bobbing works on 686s as well. I'm a big fan of radically-bobbed hammers, and it ought to work well for PPC. Though Carmoney didn't accurize my 686 per se, I immediately noted improved accuracy, likely due to less lock time and hammer jar (see vid above in Carmoney's reply).

Here's my 686 with a semi-Carmonized hammer. Since it's my IDPA gun, the internal lock must be retained, and the fully-Carmonized hammer won't hold the locking flag, but a semi-Carmonized hammer will. Works great.

Since Mike's not taking on work, I took a whack at bobbing my 5" 625. It's somewhere between a full & semi-Carmonization. I polished the innards, bent the factory mainspring, and installed a 12lb rebound spring, installed an Apex FP/spring, and LPA rear sight. Trigger pull measures 6lbs, and it lights off Federal primers without having to hand-seat them.

Tom

[Kevin Pledger]

Kevin -

Yep, the radical bobbing works on 686s as well. I'm a big fan of radically-bobbed hammers, and it ought to work well for PPC. Though Carmoney didn't accurize my 686 per se, I immediately noted improved accuracy, likely due to less lock time and hammer jar (see vid above in Carmoney's reply).

Here's my 686 with a semi-Carmonized hammer. Since it's my IDPA gun, the internal lock must be retained, and the fully-Carmonized hammer won't hold the locking flag, but a semi-Carmonized hammer will. Works great.

Since Mike's not taking on work, I took a whack at bobbing my 5" 625. It's somewhere between a full & semi-Carmonization. I polished the innards, bent the factory mainspring, and installed a 12lb rebound spring, installed an Apex FP/spring, and LPA rear sight. Trigger pull measures 6lbs, and it lights off Federal primers without having to hand-seat them.

Tom

Tom,

Thanks for the reply, gives me some interesting idea's.

You would have by any chance some pictures of the hammer in the firearm with the side cover removed, so I can gauge just how much to remove.

My present revolvers are 686-2 / 3 models, which have been extensively worked for PPC / Bianchi Matches(both double action only), so would like to see the difference between a bobbed hammer,(which I have now) and either a semi (as yours) or a fully carmonized hammer.

Thanks.

Cheers ....

Kevin.

[MrBorland]

Kein - I took a quick pic before heading off to work. Look at the pic in post #7. Cut along the line as drawn give a fully Carmonized hammer. I didn't get quite that aggressive. Imagine placing a point midway along that cut line, then pulling that point back a bit and contouring the top to match the frame contour.

BTW, keen eyes will note that I also replaced the trigger with a forged trigger from Power Custom. I'm no MIM whiner, but was curious if the sear surfaces of a forged trigger could be polished better than MIM. Jury's still out. For action shooting, I wouldn't bother. If there's a difference, it may only show up when fine target accuracy is required.

Tom

edit:

My present revolvers are 686-2 / 3 models

I just noticed this - these have hammer-mounted firing pins, no? If so, you'll likely not be able to contour the upper hammer as aggressively. Still, plenty of inertial mass can be taken off at the back of the hammer. As far as I can tell, that mass only functions to keep crud from getting inside, and to interact with the cylinder release bolt so the action can't be cycled when the cylinder's open. For a competition gun, not a biggie, IMO.

Edited December 5, 2011 by GrandBoule

[Suicycle]

Great job on the spur. Thanks GrandBoule for the pic with the hood off. I have been interested in how much was left at the back of the hammer. I might have to carve on my 66 some more now...

[Kevin Pledger]

edit:

My present revolvers are 686-2 / 3 models

I just noticed this - these have hammer-mounted firing pins, no? If so, you'll likely not be able to contour the upper hammer as aggressively. Still, plenty of inertial mass can be taken off at the back of the hammer. As far as I can tell, that mass only functions to keep crud from getting inside, and to interact with the cylinder release bolt so the action can't be cycled when the cylinder's open. For a competition gun, not a biggie, IMO.

Tom,

Thanks for the update. Yes hammer mounted firing pins. That is why I was hoping Mike, may chime in and give his opinion and advice before I start removing metal to experiment.

Problem here also is we only have factory ammo, of which is Winchester, Magtech .38special ammo, inconsistent primers. My revolvers were setup originally for Winchester / Federal primers, and I still have some reloaded match ammo and some really good Winchester Match Ammo. I can always play with the rebound and mainsprings.

Appreciate your help.

Kevin

[Carmoney]

Hi Kevin,

Here's a picture of the hammer from the 25-2 my son Sam shoots in USPSA matches. As you can see, I messed around taking off weight in a couple other places (probably not worth the effort, by the way). When you cut away the back half of the hammer like this, you remove about 1/2 the original mass--which seems to be about right. Can you tell I'm not much of a scientist or engineer?

Start cutting! If you mess up really bad, no big thing--there are plenty of extra hammers laying around. Just make sure you don't get too close to the channel at the top where the hammer nose pivots. You want to maintain most of the metal behind that area. I got a little too close for comfort on the hammer in the picture.

Edited December 6, 2011 by Carmoney

[Kevin Pledger]

Hi Kevin,

Here's a picture of the hammer from the 25-2 my son Sam shoots in USPSA matches. As you can see, I messed around taking off weight in a couple other places (probably not worth the effort, by the way). When you cut away the back half of the hammer like this, you remove about 1/2 the original mass--which seems to be about right. Can you tell I'm not much of a scientist or engineer?

Start cutting! If you mess up really bad, no big thing--there are plenty of extra hammers laying around. Just make sure you don't get too close to the channel at the top where the hammer nose pivots. You want to maintain most of the metal behind that area. I got a little too close for comfort on the hammer in the picture.

Mike,

Thank you very much for the information. Like everything you learn by trial and error. Even though my present revolvers have excellant double action trigger pulls, one must always fiddle.

We have a lot of 625's in our club now, and here its not easy to get any modifications done. So the owners are fiddling and some are messing up quite badly, so they turn to me, so I end going back to standard configuration so the revolver works as intended and then slow polish and get the trigger lighter.

Off to check my stocks of old hammers, as they say let the fun begin !

Kevin