Patriot Defense Sledge Hammer Heavy

[Jeff O]

Has anyone tried one of these? Wonder if it hits harder than the Titan?

[HesedTech]

1 hour ago, Jeff O said:

Has anyone tried one of these? Wonder if it hits harder than the Titan?

Yes, a little. 

What you really need to do is tune the whole combo including the bolo. Get extra hammer springs because you need to tune the length of the spring to get max compression without binding.  Is it worth the money is really the question. 

[Jeff O]

3 minutes ago, HesedTech said:

Yes, a little. 

What you really need to do is tune the whole combo including the bolo. Get extra hammer springs because you need to tune the length of the spring to get max compression without binding.  Is it worth the money is really the question. 

The gun was built by Patriot Defense and it's a Stock I SF, so no bolo. It's just not 100% reliable w 15.5 spring except w Federal SPP's.

[Jeff O]

Just now, Jeff O said:

The gun was built by Patriot Defense and it's a Stock I SF, so no bolo. It's just not 100% reliable w 15.5 spring except w Federal SPP's.

Also how do I know if I'm getting 100% compression?

[HesedTech]

6 hours ago, Jeff O said:

Also how do I know if I'm getting 100% compression?

First use their 16 lb spring. To check for full compression and no binding it’s basically trial and error. Start with full spring do a DA pencil test, put pencil in barrel, point straight up with gun against floor and DA. Measure height of pencil, cut a half a coil off and do it again.  If it was binding it will go higher. While close Tanfoglio hammer spring pockets are not all the same length/depth. 

[Jeff O]

2 hours ago, HesedTech said:

First use their 16 lb spring. To check for full compression and no binding it’s basically trial and error. Start with full spring do a DA pencil test, put pencil in barrel, point straight up with gun against floor and DA. Measure height of pencil, cut a half a coil off and do it again.  If it was binding it will go higher. While close Tanfoglio hammer spring pockets are not all the same length/depth. 

They make a 16.5?

[HesedTech]

3 hours ago, Jeff O said:

They make a 16.5?

My error, yes 16.5 lb. I have it in one of mine, Limited Pro,  and it took one coil clipped off to run well. 
 

https://patriotdefense.com/patriot-defense-optimized-hammer-springs/

[Jeff O]

OK, so far best bet w the Titan hammer is the 16.5 minus 1 coil. It lights Federals, Winchesters, CCIs and Fiocchis 100 %. With the full length 16.5 it even lights the hard Ginexs but the trigger pull suffers a lot. Will have a Sledge Hammer Heavy Monday, I'll let ya know.

[Jeff O]

Final report. The "Sledge Hammer" turned out to be a very small ball peen hammer. In the pencil test it is no better, if not worse, than the Titan. I'm going with the Titan and the 16.5. Waste of $99.

[Polymer]

16 hours ago, Jeff O said:

Final report. The "Sledge Hammer" turned out to be a very small ball peen hammer. In the pencil test it is no better, if not worse, than the Titan. I'm going with the Titan and the 16.5. Waste of $99.

Thanks for the update.

[HesedTech]

15 hours ago, Jeff O said:

The "Sledge Hammer" turned out to be a very small ball peen hammer.

Thanks for the report.

 

There is the argument that a lighter hammer has more speed when it hits the pin. The pencil test should demonstrate the physics if it's true. The idea of the sledge hammer is the ability, because of extra mass, to make a bigger dent in the primer, especially in DA and thus set off harder primers with lighter hammer springs.

 

 

[Jeff O]

28 minutes ago, HesedTech said:

Thanks for the report.

 

There is the argument that a lighter hammer has more speed when it hits the pin. The pencil test should demonstrate the physics if it's true. The idea of the sledge hammer is the ability, because of extra mass, to make a bigger dent in the primer, especially in DA and thus set off harder primers with lighter hammer springs.

 

 

It weighs EXACTLY the same as the Titan.

[HesedTech]

9 hours ago, Jeff O said:

It weighs EXACTLY the same as the Titan.

I haven’t weighed the two, but I was thinking of the skeleton hammers, like the EGW I have on Limited and on 1911. 
 

I have both the Titan and the Sledge, some day I’ll weigh them. 
 

Thanks for the input. 

[Bill Schwab]

PD just announced Sledge Lite hammers as well. All their hammers in different finishes too.

[whan]

On 4/11/2023 at 7:51 AM, HesedTech said:

Thanks for the report.

 

There is the argument that a lighter hammer has more speed when it hits the pin. The pencil test should demonstrate the physics if it's true. The idea of the sledge hammer is the ability, because of extra mass, to make a bigger dent in the primer, especially in DA and thus set off harder primers with lighter hammer springs.

 

 

 

It's actually an interesting physics question, though as you mentioned most practically / easily tested using the pencil test

 

But based on my understanding of physics, a heavier hammer should be more effective at setting off primers, despite having a slower speed than a lighter hammer, all else being equal. Because we are using the same mainspring and the hammers travel the same distance from cocked to fully dropped, the kinetic energy of both hammers at the time it hits the firing pin should be the same. The spring is producing the same force on the hammer over the same distance.

 

In physics, there are two types of collisions - inelastic and elastic. Both should maintain momentum of the system (total momentum of post collision should = sum of objects pre-collision), but in perfectly elastic collisions, kinetic energy is maintained, otherwise it is an inelastic collision where kinetic energy is not. All real world collisions are at least in part inelastic, due to loss of energy to sound and heat

 

If we were to model a hammer colliding with a firing pin as an inelastic collision, a heavier hammer will transfer more kinetic energy to the firing pin than a lighter hammer, despite having a slower speed. More kinetic energy to the firing pin means more force and thus more pressure exerted by the firing pin on the primer, leading to better ignition

 

If interested, below is some math assuming a perfectly inelastic collision of the hammer and firing pin using simplified illustrative Mass and Velocity, but assuming the same energy of the hammer when it hits the pin (which we know to be true given constant spring force and same distance)

 

Hammer with Mass of 1.0 and Velocity 1.0 (energy of 0.5)

Hammer Pin Combined (after collision) Mass 1.00 0.50 1.50 Velocity 1.00 0.00 0.67 Momentum (m*v) 1.00 0.00 1.00 Energy (0.5*m*v^2) 0.50 0.00 0.33

 

Hammer with Mass of 2.0 and Velocity 0.707 (energy of 0.5)

	Hammer	Pin	Combined (after collision)
Mass	2.00	0.50	2.50
Velocity	0.71	0.00	0.57
Momentum (m*v)	1.41	0.00	1.41
Energy (0.5*m*v^2)	0.50	0.00	0.40

 

Edited April 12, 2023 by whan

[Jeff O]

At the end of the day with the Titan and the 16.5 (with hammer contact points, pin holes, hammer strut and hammer spring channel polished) the trigger pulls are 5.12 DA and 2.4 SA. This spring wins the pencil test by 2" over the closest competitor. 

[whan]

JUST REALIZED MY PHYSICS MODEL WAS OFF!

 

Was just thinking more about the physics model, and I think I actually came to the wrong / opposite conclusion. The key factor I missed is that in a hammer fired gun, the firing pin continues moving to hit the primer after the hammer actually hits the firing pin stop. So at the point in which the firing pin strikes the primer, the hammer is no longer touching the back of the pin, and thus cannot impart its energy to the primer. The above model I looked at looked at energy of the combined hammer/pin, which is not accurate once the pin hits the primer

 

In this case, the pin energy is dependent on the speed of the firing pin, and in which case, a lighter hammer should actually work better. I've revised some math below, looking at both inelastic and elastic models, and increasing the hammer weight decreases the pin speed, which makes it have less energy in both inelastic and elastic models (by the same % actually). For the elastic collision model, equations to determine post collision velocities are found here http://hyperphysics.phy-astr.gsu.edu/hbase/elacol2.html

 

Inelastic Collision
	Hammer	Pin	Combined (after collision)	Pin Only (After Collision)
Mass	1.00	0.50	1.50	0.50
Velocity	1.00	0.00	0.67	0.67
Momentum (m*v)	1.00	0.00	1.00	0.33
Energy (0.5*m*v^2)	0.50	0.00	0.33	0.11
	Hammer	Pin	Combined (after collision)	Pin Only (After Collision)
Mass	2.00	0.50	2.50	0.50
Velocity	0.71	0.00	0.57	0.57
Momentum (m*v)	1.41	0.00	1.41	0.28
Energy (0.5*m*v^2)	0.50	0.00	0.40	0.08
			% Decrease in Pin Energy	(28%)
Elastic Collision
	Hammer	Pin	Hammer (After Collision)	Pin (After Collision)
Mass	1.00	0.50	1.00	0.50
Velocity	1.00	0.00	0.33	1.33
Momentum (m*v)	1.00	0.00	0.33	0.67
Energy (0.5*m*v^2)	0.50	0.00	0.06	0.44
	Hammer	Pin	Hammer (After Collision)	Pin (After Collision)
Mass	2.00	0.50	2.00	0.50
Velocity	0.71	0.00	0.42	1.13
Momentum (m*v)	1.41	0.00	0.85	0.57
Energy (0.5*m*v^2)	0.50	0.00	0.18	0.32
			% Decrease in Pin Energy	(28%)

 

The one unconsidered variable though is that for a brief moment when the hammer is moving the pin, but not yet hitting the firing pin stop, they are moving together against the force of the firing pin spring. Having a higher kinetic energy of the combined hammer and pin during this period assuming an inelastic collision can be favorable

Edited April 12, 2023 by whan

[HesedTech]

7 hours ago, whan said:

JUST REALIZED MY PHYSICS MODEL WAS OFF!

 

Cool analysis. 
 

I heard the lighter hammer theory from the 2011/1911 and SA only crowd. The weight and bearing surfaces of the firing pin also count.  
 

 

[whan]

14 hours ago, HesedTech said:

Cool analysis. 
 

I heard the lighter hammer theory from the 2011/1911 and SA only crowd. The weight and bearing surfaces of the firing pin also count.  
 

 

 

Doing some additional analysis on this - even my second conclusion was somewhat off. What I'm actually finding is that the greatest pin velocity/energy is when the mass of the hammer equals the mass of the pin. Looking at both models, you'll see that an increase in hammer weight does help with pin energy if the hammer is lighter than the pin

 

Inelastic Collision
	Hammer	Pin	Combined (after collision)	Pin Only (After Collision)
Mass	0.50	1.00	1.50	1.00
Velocity	1.00	0.00	0.33	0.33
Momentum (m*v)	0.50	0.00	0.50	0.33
Energy (0.5*m*v^2)	0.50	0.00	0.08	0.06
	Hammer	Pin	Combined (after collision)	Pin Only (After Collision)
Mass	1.00	1.00	2.00	1.00
Velocity	0.71	0.00	0.35	0.35
Momentum (m*v)	0.71	0.00	0.71	0.35
Energy (0.5*m*v^2)	0.50	0.00	0.13	0.06
			% Change in Pin Energy	13%
Elastic Collision
	Hammer	Pin	Hammer (After Collision)	Pin (After Collision)
Mass	0.50	1.00	0.50	1.00
Velocity	1.00	0.00	(0.33)	0.67
Momentum (m*v)	0.50	0.00	(0.17)	0.67
Energy (0.5*m*v^2)	0.50	0.00	0.03	0.22
	Hammer	Pin	Hammer (After Collision)	Pin (After Collision)
Mass	1.00	1.00	1.00	1.00
Velocity	0.71	0.00	0.00	0.71
Momentum (m*v)	0.71	0.00	0.00	0.71
Energy (0.5*m*v^2)	0.50	0.00	0.00	0.25
			% Change in Pin Energy	13%

 

 

This analysis also holds true for the pin weight as well, in theory for a given hammer weight, having the pin be closest in mass to the hammer is most ideal to maximize pin energy

Edited April 13, 2023 by whan

[whan]

That being said, there is an interesting consideration to whether the kinetic energy of the pin is the only variable that matters to detonate primers. I think the model for that can be a lot more complex, since it may not be solely reliant on energy (at the very minimum, I'm sure the thickness of the pin tip matters in terms of pressure applied)

 

I was able to find an interesting paper by someone who developed a low-mass rifle striker system who actually goes into a lot of the physics details that supports my analysis above. He also notes that the Army specs primers by detailing the energy required to set them off. However, he does mention that anecdotally, a lighter pin may be more effective at setting off primers - IE reliable primer ignition may not be solely dependent on the kinetic energy delivered to the system. In this case, having higher pin velocities with a lighter pin could be more advantageous, even if total kinetic energy of the pin is lower

 

https://www.davidtubb.com/index.php?route=account/download/free&download_id=28

 

Would caveat that his math is specific to striker assemblies, and doesn't quite apply to the hammer fired pistols we commonly use. As mentioned before, the hammer is no longer in contact with the pin at the point when the pin strikes the primer (as it stops at the firing pin stop), so any energy remaining in the hammer is not transmitted to the primer. For a striker model, the entire assembly moves as one unit and strikes the primer, so in this case the energy delivered to the primer is solely dependent on the mainspring strength. The analysis I've been doing above is specific to figuring out the remaining FP kinetic energy and velocity in hammer fired guns

 

So what is the conclusion of all of this?

What my calculations suggest is that it is best to match hammer weight to pin weight. Ideally they are close to equal, in order to transmit the most energy and speed from the hammer into the pin. Per the anecdotes that Tubb mentions, it is also possible that a lighter system overall will have advantages, as it appears pin velocity may have additional advantages over kinetic energy alone. But again, if you are using a lightened firing pin, it could be worth matching with a lightened hammer as well in order to maximize energy transfer. However you'd need to weigh both to see if it's necessary.

 

The above is really just analysis on a theoretical level. The reality is that the best way to test everything practically is still just the pencil test. Higher pencil = more energy transmitted to the primer. The three guaranteed items that will help primer detonation are a stronger mainspring (of course sacrificed against DA pull weight), lighter weight firing pin spring (less resistance against the pin once it is moving forward to hit the primer), and an extended firing pin (less distance from tip to primer means less distance working against the FP spring until contact).

 

But hopefully the above helps when it comes to thinking about what upgrades to consider in order to help with reliable ignition

[HesedTech]

1 hour ago, whan said:

for a given hammer weight, having the pin be closest in mass to the hammer is most ideal to maximize pin energy

I like the idea. Haven't weighed either, maybe it's time to break out the scientific scale I use for rifle reloading.

 

If the pin is significantly lighter using hardened tool steel, can another heavier metal be used and provide the wear needed by being struck by the hammer (not getting peened and flattened)?

 

Boy, there is always more things we can spend money on in this sport. Reminds me of the curve of improvement vs cost and time.  To eke out that last bit of performance the cost and time increase exponentially. 

 

Overall the goal is a consistent running gun that can be relied upon to make the ammo go bang.

 

[Jeff O]

20 minutes ago, HesedTech said:

I like the idea. Haven't weighed either, maybe it's time to break out the scientific scale I use for rifle reloading.

 

If the pin is significantly lighter using hardened tool steel, can another heavier metal be used and provide the wear needed by being struck by the hammer (not getting peened and flattened)?

 

Boy, there is always more things we can spend money on in this sport. Reminds me of the curve of improvement vs cost and time.  To eke out that last bit of performance the cost and time increase exponentially. 

 

Overall the goal is a consistent running gun that can be relied upon to make the ammo go bang.

 

Based on the size requirements of the hammer and the firing pin there would be more no more than hundredths of an ounce of difference.

[Earthpig]

Well, I had the same issues. It got fixed by a wolf 13 LB hammer spring and monitor the firing pin spring. Yes the firing spring breaks it  does not ignite anything reliably