M1/M14 Speedhammer

[jmoore]

So why can't you just go out and buy one? This one weighs 63% of a regular hammer and has thousands of cycles on it so far. It's ugly, but it has been on several diets to get to this point. I think there MAY be a bit more that could go, the web is at 0.090" now. This is a commercial CAST hammer, BTW!

I think its an idea worth manufacturing, so be my guest! Just remember it was plastered here first!















Also, another "modded" part thrown in:

Information

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[Bill Hollinger]

So how much does it lighten the rifle?

[jmoore]

I was thinking the lightened hammer is more for improved locktime and less "jarring" on impact than for absolute weight reduction. There's plenty of Lightened hammers available for ARs, never mind 1911 pistols. Its more an accuracy mod than anything.

The trigger housing cuts only pulled out a few ounces, but they add up if its done in enough places. The housing mod was originally done by Springfield (the Government run one) during the development of the M14. I saw a pic and went from there.

[Bodyman]

I'm really stretching to remember. I can't remember who it was that tried this but someone did some work in this area with regard to the Garand - whether it was the Air Force guys (that rings a bell) or the fellas at Springfield Armory themselves - but one of the match conditioning teams tried to improve lock time by lightening the hammers.

If I recall correctly, there was no discernable improvement so they did not continue with the idea (as it was a considerable amount of work). Scratching my gray matter to remember where this was written but I think it might have been Kuhnhausen (??), or maybe, ... dunno.

Really cool hammer though ... nice job.

[Maniac]

Couldn't one make their own speedhammer by drilling holes through the side, taking care to ensure said hole(s) aren't too close to where the hammer strikes the firing pin? If a cast hammer as shown can hold up it seems that a forged hammer could stand to have holes through it. I'm not a metallurgist or engineer so this is just a WAG.

[togor]

Interesting idea. As the hammer is rotating on a pin, what counts is to reduce its Moment of Intertia, more than just its weight. Moment of Inertia is in rotational motion what ordinary mass is in linear motion. The quirky thing about rotation is that not all mass is created equal. The further away you get from the pivot point, the stronger contribution a bit of mass makes to the Moment. It is really just a matter of leverage. So if you remove a mg of hammer mass 20mm away from the pivot point, it will have a 5 times greater effect than a bit of mass removed only 4mm away. If it's true that the lightened hammer does not reduce lockup much, one reason might be that up at the top, around the hooks and camming lug, where it counts the most, it isn't possible to remove much material. Cool picture though.

[jmoore]

Understand about moments, went a got a degree in mechanical engineering, which I promptly never used upon graduation. The mass at the periphery was left to maintain functional interaction w/o getting too experimental. I have no quantitative measurements, but I like it! If you want to get more scientific, I'd be interested in your ideas in how you would measure improvements.

[jmoore]

A few on going notes on this test piece-

Some recent primer hits. Hammer still popping them nicely!





Regular old GI hammer spring, BTW.




AND TRW GI barrel. Chrome's not doing well, but...

Shot this 5 round group today, so it doesn't seem to hurt ignition or disturb the rifle on impact:

[madrad62]

way too many words with multipul sylibles,your killing me.

[Ericc]

We where talking about this a few months back when discussing some of John Garand's comments about improving lock time in the M1. There is a little room for improvement in the hammer spring as well.