Low mass hammer?

[Tanfogliofan]

I have a Tanfoglio stock 2 that I'm considering taking some weight off the trigger. The reason I want to do this is I want to be able to use a lighter trigger spring to lower the trigger pull weight. Another reason is I want to be able to use any primer that's available whether it be soft or hard primers. I'm just not sure if I will get the results that I want.

I have an open gun that has a cylinder and slide light speed 2 hammer and it works on even the most finicky primers. If I was to take some mass out of my tanfoglio hammer would this help in my two goals I have above? I don't want to start butchering my hammer without getting some form of confirmation from some of you with this type of experience.

I've noticed on Eric Graufal's Tanfoglio that he has the thumb part of the hammer cut off completely and I believe he did this to lower the mass of his hammer. I never spoke to him or his gunsmith to find out but I think I'm making a good assumption.

Another reason is that i just got a 22lr conversion kit for the thing and even with the factory hammer and spring I'm getting nothing but light strikes.

[CHA-LEE]

If you are getting light strikes then a heavier hammer (more mass) would work better, not a lighter one. With a production gun you have to use the stock firing pin, which is short and requires a more solid strike to set off the primers. With the Limited and Open guns you can use extra long firing pins which allow you to use lighter hammer springs and lighter hammers to achieve the same primer striking force.

The other thing to consider is that you need to manually decock the hammer after loading a round in the chamber when you make ready for a stage run. If you cut down the hammer this is going to make decocking it a lot harder.

Unfortunately if you want too be on the razors edge of a kick ass trigger job on a Production DA/SA gun you need to run soft primers to ensure consistent ignition.

[Jeff686]

Well, the 22 kit not withstanding (which is a totally separate beast), use tanfoglioparts.com. Buy the EGW sear, EGW hammer, XL firing pin, and a 14 lb hammer spring. Polish the snot out of the important parts, especially where the transfer bar hits the plunger, and the top of the plunger.

[Tanfogliofan]

Your totally right about the 22LR being a separate beast. The parts for the thing are completely different from the parts in the standard pistols. None of the standard parts are interchangeable with it. Might be with the small frame but not with the large frame. The geometry of the whole thing is different. I am writing on another thread about the 22lr and the frustrations I'm experiencing. The hammer was just another theory I had for getting the thing to ignite the 22lr round. My production gun absolutely sings with the hammer I have on it now. It had a smooth 8lb 2oz double and a scary 2lb 3 oz single. I didn't like to shoot it like that because of fear of AD's. The take up on the trigger is a steady 1lb 8oz so if you do the math that doesn't leave much room on prepping the trigger for long shots so I set it back to 11lb double and a 3lb single. My goal is to get these dang 22lr rounds to ignite.

[Braxton1]

Actually, because the formula for "energy" is "velocity squared times mass", an proportionate increase in velocity due to a decrease in mass will result in more energy to the firing pin.

This is counter-intuitive, but true (within limits. You couldn't take the mass down to the point where the hammer bounces off the firing pin upon contact.)

[Tanfogliofan]

That's the answer I was looking for! I knew their had to be a mathematical equation to the it! Now to determine the energy created by a fifteen lb hammer spring! The hammer I swapped out of my open gun wasn't an ultra light hammer and I had all kinds of problems with light strikes and when I switched no more problems.

The guy who invented guns never would have done it if he never pulled the trigger. The hammer is hitting the band saw!!! Wish me luck!

Thank you all for your posts! Every bit of info is helpful and it's nice to get it from so many prospectives.

[smokshwn]

Actually, because the formula for "energy" is "velocity squared times mass", an proportionate increase in velocity due to a decrease in mass will result in more energy to the firing pin.

This is counter-intuitive, but true (within limits. You couldn't take the mass down to the point where the hammer bounces off the firing pin upon contact.)

Beat me to it. In this scenario

F = mv2/r

You could experiment taking a little weight off at a time to increase the velocity and therefore increase the force.

[bkeeler]

So a lighter hammer hits harder than a heavier hammer?

[sperman]

So a lighter hammer hits harder than a heavier hammer?

The increase in acceleration (v^2) has to be greater than the reduction in mass in order for the hammer to hit harder. Because this is angular velocity, the distance of the MOI from the point of rotation also enters into the equation.

The short answer: Try it and see if it helps.

The long answer: Take a bunch of measurements, perform a bunch of calculations, guess at friction and other factors, try it and see if it works.

[bkeeler]

[Tanfogliofan]

I'm jumping in head first on this one! I've traced out what I'm going to take off at first. It is a substantial amount but from what I saw in weight difference of the low mass one on my open gun and the previous hammer I'm only half way there. I'll keep posting as I make progress.

[Tanfogliofan]

So I went ahead and cut away on the hammer. It's not much to look at but I heard someone say once that pretty guns that don't work are not better than ugly guns that do. Not that mine wasn't working. I just want to be able to use any type of primer and use my rim fire conversion.

I broke out the pen for the pen test. Before I started cutting on it I stuck a pen down the barrel to see how far the firing pin would shoot the pen out when I squeezed the trigger. I recorded the distance so when I did the modification I would have a bench. So I put the pen down the barrel and squeezed. To my surprise it went about two more feet than it did before. I went and picked up the pen and did it again to see if i was just holding it different. Still two feet more and then some! Eureka!!

The feel of the trigger is dramatically different than when it was stock. It's as though I put the thing into warp speed! The snap of it is so right now! I did the test in single action and double with the same result.

I would now feel confident in dropping the spring weight considerably to lighten the trigger up. Not that I would because I went that route prior to a match and let's just say thank god I was pointing it in the direction of the target! A hair trigger isn't always the best trigger. I'll be taking it to a plate match to try it out on Thursday. I'll give you all the results when I get the chance.

Thanks again to all of you for the input over this subject. This is quite crucial to me for I am attempting to develop a trigger package for this particular gun and have it for sale in the near future. I can currently get a consistent 2lb 3oz trigger using Federal primers but I'd like to get that weight with the ability to use any primer. Reliability and consistency is the key and I have to say that I'm headed in the right direction Thanks to you!

Sean.

Edited November 4, 2010 by Tanfogliofan

[jasond]

The revolver guys, myself included, have tested the low mass hammer thing to death, and the answer is that light hammers need less spring force to light primers. When every shot is DA, we'll go to lengths to make it light!

I haven't messed around with any .22 revolvers, but consensus is that lightened hammers do not work better, and if anything will require more force from the spring. I'd like to know more about why this is, but I don't.

Here's a link to Apex Tactical's revolver parts, check out the difference between the RF and CF hammers:

https://apextactical.com/store/product-list.php?pg1-cid4.html

[sperman]

A titanium hammer strut will help also.

[Tanfogliofan]

Wow! That's quite the difference from stock! The 22lr hammer really looks cool installed. I have research to do with the 22lr conversion now! One thing I notice is the point of which the firing pin makes contact with the 22lr. in my conversion. It's just inside of the rim so it's not hitting the rim itself Do you think this might have something to do with it?

Edited November 3, 2010 by Tanfogliofan

[Tanfogliofan]

I took it out to the plate match last night with much success. I really liked the snappiness of the trigger. I made a mixed bag of ammo to shoot last night. I used three different kinds of primers and two different weights of bullets. Federals small pistol, Winchester small rifle and CCI small pistol magnums. It was a total of 300 rounds that I went through. This is the part that I'm so glad to say. All rounds ignited! No light strikes what so ever! The CCI spm were the ones I was most worried about so I made sure to inspect the casings and there were no signs of light strikes at all. Such a relief! Now if I can only get my conversion kit to work.

My friends down at the range always give me a hard time because there's always something I'm doing to my guns. One guy said that someone should take away my power tools before I end up with half a gun. In so many ways he's right!

[Steve RA]

Usually you'll find that rifle primers have a thicker - heavier gauge - cup than pistol primers so they are (usually) the hardest to ignite.

Edited November 5, 2010 by Steve RA