Sear spring issues

[Dragon11]

This is my first post on the forum. This is my second season shooting revolver in USPSA. I currently have a 625-8 and a 625-2. Here is my issue. I dryfire alot and in my 625-8 I have now broken three sear springs. I have played around with changing the sear spring in my 625-2, and with the pin holding in the sear, I have had no problems doing this. The sear hammer assembly in my 625-8 is much different and I have not been successful in changing the spring.

The sear drops in from the side of the hammer and I can't get the spring to squeeze in between the frame of the hammer and the sear. I end up kinking the spring and breaking it. I need expertise with putting the spring in. I have heard dryfiring is hard on revolvers, but don't understand why the sear spring would be breaking this much. I am looking for any help that I can get as I am always looking for ways to prevent problems in the future and to also be able to fix gun problems myself. My ears and mind are open.

[a.roberts]

I used a knife blade to compress the spring into the DA sear. Then slide into the hammer. Remove the knife blade.

[earplug]

There is something wrong with your sear/hammer/revolver if its breaking springs.

Dry firing and shooting live ammo would have the same effect on the spring.

By chance are you using the correct length spring?

If have never heard of a sear spring problem with multiple failures. I ruin mine by releasing them accidently into the void.

[Brian B]

Here is the tool:

http://www.brownells.com/.aspx/pid=774/Product/S-W-REBOUND-SLIDE-SPRING-TOOL

Here is how to use it:

http://www.wonderhowto.com/how-to-install-spring-kit-revolver-204279/

I also use the Apex competition Extended firing pin:

https://apextactical.com/store/product-info.php?pid2.html

This sounds like a simple job for a qualified gunsmith (complicated and unreliable for the rest of us, as your busted springs demonstrate?) So it sounds like you'll have to spend some money, get a quotation before authorizing the work?

Good luck

[BlueOvalBandit]

Here is the tool:

http://www.brownells.com/.aspx/pid=774/Product/S-W-REBOUND-SLIDE-SPRING-TOOL

Here is how to use it:

http://www.wonderhowto.com/how-to-install-spring-kit-revolver-204279/

I also use the Apex competition Extended firing pin:

https://apextactical.com/store/product-info.php?pid2.html

This sounds like a simple job for a qualified gunsmith (complicated and unreliable for the rest of us, as your busted springs demonstrate?) So it sounds like you'll have to spend some money, get a quotation before authorizing the work?

Good luck

This has nothing to do with sear springs....

A.roberts has the right technique, I do something similar but with a small flat head screw driver. Also are you sure you have the right sear springs? The older pinned sears used longer springs than the new MIM sears that slide in. Off the top of my head the MIM sear spring is like 1/2 the size but I'd have to look.

Edited May 28, 2012 by BlueOvalBandit

[bikerburgess]

Here is the tool:

http://www.brownells.com/.aspx/pid=774/Product/S-W-REBOUND-SLIDE-SPRING-TOOL

Here is how to use it:

http://www.wonderhowto.com/how-to-install-spring-kit-revolver-204279/

I also use the Apex competition Extended firing pin:

https://apextactical.com/store/product-info.php?pid2.html

This sounds like a simple job for a qualified gunsmith (complicated and unreliable for the rest of us, as your busted springs demonstrate?) So it sounds like you'll have to spend some money, get a quotation before authorizing the work?

Good luck

That tool is for the rebound spring the op was having trouble with their sear spring

I have mangled a couple of sear springs putting them in as well, the best I have done is with the blade of a exacto knife.

I have no idea why a properly installed sear spring would fail so my first thought is make sure you are getting it all the way into the recess in the sear and hammer and it's not bound up in any way.

Mike

[Gregg K]

I have mangled a couple of sear springs putting them in as well, the best I have done is with the blade of a exacto knife.

Mike

Yep, a number 11 X-ACTO blade is what I use to slide in the sear spring.

[Dragon11]

The springs I have bought to replace them were purchased from Brownells. I know that they are the same length as the the spring in my 625-2. My gun broke in the middle of The Ohio Championship yesterday, and while looking at it with a friend, he believed my replacement spring was to long, but didn't know for sure. Nowt hat you have said that, it totally makes sense and I wished I was smart enough to pick up on it myslef.

I think they broke in the past because the spring was to long, and was being squeezed between the sear and the hammer wall. I know I dryfire alot, but didn't think that would be the cause of a sear spring breaking. At any rate, will make some calls tomorrow to get the right length, and work on putting it in. I hate to have someone else fix the gun for me when its such a small part to replace. Have had some other problems with my 625-2, but I'll leave that story for another time. At any rate thanks for responding you guys have helped alot.

[BlueOvalBandit]

I believe this is the spring you need

http://www.brownells.com/.aspx/pid=14712/sku=940-000-508/Product/Sear-Spring-MIM-Hammer

it's kind of a PITA to find on brownells

Edited May 28, 2012 by BlueOvalBandit

[Carmoney]

The sear spring is different on a MIM gun (like your 625-8 and my 625-6), as others have pointed out. You won't need a tool to install it without kinking. Place the sear spring in the recess hole in the sear. Gently press the other end of the spring against the hammer and simply pivot the top part of the sear into its proper position in the hammer. If necessary, use a small tool (small screwdriver, toothpick, whatever) to slide the hammer end of the spring into its recess.

Bingo, you're done--it takes about 5 seconds.

If they aren't kinked, sear springs will last indefinitely. As a general rule, dry-firing doesn't hurt revolvers--as long as you don't take it to a ridiculous extreme like some of the crazy wheelgunners I know!

[jester121]

The sear spring is different on a MIM gun (like your 625-8 and my 625-6), as others have pointed out.

Carmoney, could you explain what a "MIM" gun is? Newb here, not familiar with that term.

[Dragon11]

I ordered new sear springs today for MIM hammer. Should have them in a couple of days. It didn't seem normal to me that they would break, and am positive the ones that broke before did so because of being kinked. I appreciate the help everyone has given. I have to admit, I was getting frustrated and thought I was doing something wrong. I was getting to the point didn't want to dryfire anymore because I thought I was breaking my guns. Was hoping that wasn't the case, because its something I enjoy doing, I enjoy problem solving. At any rate, will let you know how the installation goes.

[RePete]

The sear spring is different on a MIM gun (like your 625-8 and my 625-6), as others have pointed out.

Carmoney, could you explain what a "MIM" gun is? Newb here, not familiar with that term.

MIM = Metal Injection Moulded.

This has been the norm for a few years now.

[jester121]

MIM = Metal Injection Moulded.

This has been the norm for a few years now.

Thanks!

[The_Vigilante]

So what is the disadvantage to using MIM parts? What was used before MIM parts became universal? I take it it all comes down to cost?

[BlueOvalBandit]

So what is the disadvantage to using MIM parts? What was used before MIM parts became universal? I take it it all comes down to cost?

Forgings where used before... I can't think of any disadvantages really(cosmetic sprue marks don't matter to me), but a whole lot of pluses. Some of the pluses included tighter tolerances on the finished part, more easily mass produced, they polish beautifully, MIM hammers also eliminated the pins retaining the stirrup and the DA sear, also the mim sear is almost damn near plug and play (still needs the small chamfer on the front) unlike the pinned sear which took quite a bit of fitting(relative, needed to cut it down) brand new. Properly done MIM is every bit as strong as a forging, S&W does it right.

Visual comparison of the forged and MIM hammers.

http://smith-wessonforum.com/s-w-revolvers-1980-present/172881-do-you-know-if-innards-interchangable.html

[Tom E]

Forged hammers have the pinned sear. MIM hammers have the "slide in" sear.

There are two sear springs: the forged hammer sear spring, 0702, and the MIM hammer sear spring, 21577. They don't interchange. These are S&W part #s.

[Carmoney]

So what is the disadvantage to using MIM parts? What was used before MIM parts became universal? I take it it all comes down to cost?

Forgings where used before... I can't think of any disadvantages really(cosmetic sprue marks don't matter to me), but a whole lot of pluses. Some of the pluses included tighter tolerances on the finished part, more easily mass produced, they polish beautifully, MIM hammers also eliminated the pins retaining the stirrup and the DA sear, also the mim sear is almost damn near plug and play (still needs the small chamfer on the front) unlike the pinned sear which took quite a bit of fitting(relative, needed to cut it down) brand new. Properly done MIM is every bit as strong as a forging, S&W does it right.

Visual comparison of the forged and MIM hammers.

http://smith-wessonforum.com/s-w-revolvers-1980-present/172881-do-you-know-if-innards-interchangable.html

I agree.

[Toolguy]

I agree too. There is nothing wrong with the MIM parts.

[Dragon11]

Got the parts in and it went in much easier then the longer sear spring. Guns working great. Almost feel like I know what I'm doing. OK maybe not, but I at least I got a small boost of confidence. Thought you guys might want to know, thanks for the help.