Hammer bobbing

BobR · December 20, 2000, 06:24 PM

I have a S&W model 37 (Airweight) with an exposed hammer. I have recently gone from an OWB carry to a Galco Deep Cover IWB carry for this gun. I am going to have to bob the hammer not only for comfort but also practicality. There is no one in my local area to do this work so I will Have to send it off

. My question is this...should I just get a new hammer from numrich and send it to someone to bob, or do I need to send the entire gun. Once I have the hammer, there is someone locally to do the installation. I would prefer to just send a hammer to someone.

Lavan · December 20, 2000, 06:53 PM

It is easy to do yourself with a Dremel tool. Just be sure to take the hammer out of the gun so u dont slip and hit the frame with the grinder.
Do a little at a time and be sure not to get the hammer HOT.
Quench it regularly and just keep going.
If you get a new hammer, it will not be fitted to the trigger and the pull may be atrocious.

BobR · December 20, 2000, 07:46 PM

Thanks for the advice, that sounds easy enough...is it much of a problem to get the hammer out, I am assuming it does no take to much. Anywhere I can get instructions on stripping the S&W pistol would be appreciated.

thanks

Lavan · December 20, 2000, 08:38 PM

It is easy to take it out. Once the sideplate is out and the mainspring taken out there is no load on anything so usually you can see very easily which piece goes where.
A local gunsmith should be able to do it very cheaply.

Wallew · December 20, 2000, 08:44 PM

I've bobbed several. And it's fairly easy to do, once the hammer is out. I ALWAYS replace the hammer, so I don't do any modifications to the original. IF, after having the bobbed hammer installed by replacing the original hammer, you find you have 'an atrocious trigger pull' consider having a 'trigger job' done AFTER you have bobbed the hammer. Shouldn't cost you a whole lot more than just having the hammer replaced. Gun is already apart, and all the smith has to do is stone (polish) the correct surfaces, without changing them any.

If you came to me, with a new hammer, I would charge $100. That would be $50 for bobbing the hammer and $50 for the trigger job. If you brought me a bobbed hammer, then I would only charge you $50 for the trigger job.

Jerry Kuhnhausen has a great book on S&W revolvers that I can recommend. It's about $30 - $35 and well worth the investment. If you bought his book and have the patience to sit down and learn this, it's FAIRLY straight forward. And you will have learned one more skill to add to your kit bag. You can get the book through Brownells at http://www.brownells.com.

**Mike Irwin** · December 21, 2000, 03:09 AM

WARNING!

Removing the hammer spur from the hammer CAN change the mass of the hammer enough that it can cause failures to fire.

This can especially be the case if you are using a lightened mainspring.

If you do this, fire a MINIMUM of 100, more is preferable, rounds of your carry ammo through your gun BEFORE you start carrying it.

BBBBill · December 21, 2000, 10:10 AM

To expand on what Mike said, if the headspace & endshake are not dead nuts on, then lightened hammer and/or mainspring will almost certainly cause a problem. Not a big deal for an experienced smith to fix, but if you don't have the tools/knowledge to handle this, seek an experienced smith to handle it for you. You might not need a total bob job, just enough to "de snag" it. A small spur stub might even be handy for helping to retain the safety strap. I tend to leave a little more mass in the head of J frame hammers when I do a bob job compared to K/L/M hammers.

Wallew · December 21, 2000, 01:12 PM

These two guys are correct. All of my work on bobbing hammers are done on N Frames. On N frame S&W's, the hammer is forged steel.

Most of the new airweights have mim parts. MIM stands for Metal Injected Moldings. And some of these mim parts don't take to being modified very well. They can have all sorts of problems. If all you are going to do is bob the hammer and not modify the mainspring, you probably won't have any problems, BUT better safe than sorry.

December 20, 2000, 06:24 PM	#1
BobR Senior Member Join Date: December 4, 2000 Location: The Dry Side of WA Posts: 561	I have a S&W model 37 (Airweight) with an exposed hammer. I have recently gone from an OWB carry to a Galco Deep Cover IWB carry for this gun. I am going to have to bob the hammer not only for comfort but also practicality. There is no one in my local area to do this work so I will Have to send it off. My question is this...should I just get a new hammer from numrich and send it to someone to bob, or do I need to send the entire gun. Once I have the hammer, there is someone locally to do the installation. I would prefer to just send a hammer to someone.

December 20, 2000, 06:53 PM	#2
Lavan Senior Member Join Date: December 10, 1999 Location: California Posts: 2,740	It is easy to do yourself with a Dremel tool. Just be sure to take the hammer out of the gun so u dont slip and hit the frame with the grinder. Do a little at a time and be sure not to get the hammer HOT. Quench it regularly and just keep going. If you get a new hammer, it will not be fitted to the trigger and the pull may be atrocious.

December 20, 2000, 07:46 PM	#3
BobR Senior Member Join Date: December 4, 2000 Location: The Dry Side of WA Posts: 561	Thanks for the advice, that sounds easy enough...is it much of a problem to get the hammer out, I am assuming it does no take to much. Anywhere I can get instructions on stripping the S&W pistol would be appreciated. thanks

December 20, 2000, 08:38 PM	#4
Lavan Senior Member Join Date: December 10, 1999 Location: California Posts: 2,740	It is easy to take it out. Once the sideplate is out and the mainspring taken out there is no load on anything so usually you can see very easily which piece goes where. A local gunsmith should be able to do it very cheaply.

December 20, 2000, 08:44 PM	#5
Wallew Junior member Join Date: October 3, 1999 Posts: 910	I've bobbed several. And it's fairly easy to do, once the hammer is out. I ALWAYS replace the hammer, so I don't do any modifications to the original. IF, after having the bobbed hammer installed by replacing the original hammer, you find you have 'an atrocious trigger pull' consider having a 'trigger job' done AFTER you have bobbed the hammer. Shouldn't cost you a whole lot more than just having the hammer replaced. Gun is already apart, and all the smith has to do is stone (polish) the correct surfaces, without changing them any. If you came to me, with a new hammer, I would charge $100. That would be $50 for bobbing the hammer and $50 for the trigger job. If you brought me a bobbed hammer, then I would only charge you $50 for the trigger job. Jerry Kuhnhausen has a great book on S&W revolvers that I can recommend. It's about $30 - $35 and well worth the investment. If you bought his book and have the patience to sit down and learn this, it's FAIRLY straight forward. And you will have learned one more skill to add to your kit bag. You can get the book through Brownells at http://www.brownells.com.

December 21, 2000, 03:09 AM	#6
Mike Irwin Staff Join Date: April 14, 2000 Location: Northern Virginia Posts: 41,642	WARNING! Removing the hammer spur from the hammer CAN change the mass of the hammer enough that it can cause failures to fire. This can especially be the case if you are using a lightened mainspring. If you do this, fire a MINIMUM of 100, more is preferable, rounds of your carry ammo through your gun BEFORE you start carrying it.

December 21, 2000, 10:10 AM	#7
BBBBill Senior Member Join Date: January 5, 2000 Location: Alabama Posts: 197	To expand on what Mike said, if the headspace & endshake are not dead nuts on, then lightened hammer and/or mainspring will almost certainly cause a problem. Not a big deal for an experienced smith to fix, but if you don't have the tools/knowledge to handle this, seek an experienced smith to handle it for you. You might not need a total bob job, just enough to "de snag" it. A small spur stub might even be handy for helping to retain the safety strap. I tend to leave a little more mass in the head of J frame hammers when I do a bob job compared to K/L/M hammers.

December 21, 2000, 01:12 PM	#8
Wallew Junior member Join Date: October 3, 1999 Posts: 910	These two guys are correct. All of my work on bobbing hammers are done on N Frames. On N frame S&W's, the hammer is forged steel. Most of the new airweights have mim parts. MIM stands for Metal Injected Moldings. And some of these mim parts don't take to being modified very well. They can have all sorts of problems. If all you are going to do is bob the hammer and not modify the mainspring, you probably won't have any problems, BUT better safe than sorry.