DPM Recoil Reduction System test

[BadDay]

Below is a short write-up on a test I performed with the DPM recoil reduction system in my CZ P10-F.

 

Background: I am always looking for ways to better control my firearms, doubly so with any polymer framed guns where the weight advantage is not on my side. While good form and strong grip are paramount, recoil and muzzle flip are disturbances in my sight picture that must be mitigated, and any advantage is an advantage.

Enter the DPM recoil reduction system; simply, it's a triple-spring guide rod replacement that is meant to counter the inertia of the firearm's slide moving rearward after ignition by spreading out the resistance over three progressively stiffer springs. Other similar systems have existed for some time (sprinco, et al), but DPM is popular and supports a massive variety of platforms, which is why I chose to test it. There are plenty of youtube and forum reviews offering subjective opinions on 'feel' and 'change in impulse,' but little in the way of measurement of factors I am interested in, specifically recovery time and muzzle flip angle. As I come into this from a competition frame of mind, I want to know what objective, measurable difference,* if any,* the system provides.

 

The setup: a modified P10-F (see my other post) firing 147g LAX ammo at ~135pf and measured with a MantisX 10.

One string of 10 rounds with each of the following: - Stock guide rod, stock spring - DPM guide rod, short (lightest) spring - DPM guide rod, medium spring - DPM guide rod, long (heaviest) spring

 

Results:

Stock

 

Light

 

Medium

 

Heavy

 

Analysis: As you can see, the difference between stock and the lightest spring setup is evident but minimal, with significant movement in both. Notably, the lightest DPM spring did average out to a reduced recovery time. One primary functional difference between them is that even the lightest DPM spring is significantly harder to rack than stock. Even though the DPM feels much stiffer, I did not see significantly increased nose-diving.

 

The major differences came with the medium and long DPM springs. The average recovery time for both was 0.3 seconds, a marked improvement from stock! Also, the muzzle movement plot for both is significantly tamed from the erratic movement of the lighter springs. This was obvious while shooting, as the dot was very constrained and easy to track throughout the slide's movement. Barring an outlier shot, the heavy spring resulted in muzzle movement of a small concentric circle around the target before settling, and readjustment between shots was extremely minimal. The recoil angle and muzzle rise were also categorically reduced from stock and lighter springs, and resulted in a very tight, repeatable pattern.

 

In the end, for my purposes, I decided on the use of the medium spring, even though the heavy spring objectively resulted in the greatest reduction of muzzle flip and recovery time. Why? Because by the graphs above, you can see the medium spring resulted in the majority of muzzle travel above the level X line, whereas the heavy spring produced much of its movement below; this is obvious nose-diving caused by the heavy spring weight, and not a type of sight picture disturbance I am as practiced with countering. I much preferred recovering from the majority-upward motion of the medium spring, as it was closer to the way my conventional spring setups behave.

 

Edited January 12, 2022 by BadDay
image insert

[UpYoursPal]

Thanks for the writeup.  However, I'm curious which tests correspond to which image?  I can't seem to open the Imgur links

[BadDay]

Aaaand I just discovered the Insert function. Should display properly now.

[bokbok_2020]

On 1/13/2022 at 12:04 AM, BadDay said:

Below is a short write-up on a test I performed with the DPM recoil reduction system in my CZ P10-F.

 

Background: I am always looking for ways to better control my firearms, doubly so with any polymer framed guns where the weight advantage is not on my side. While good form and strong grip are paramount, recoil and muzzle flip are disturbances in my sight picture that must be mitigated, and any advantage is an advantage.

Enter the DPM recoil reduction system; simply, it's a triple-spring guide rod replacement that is meant to counter the inertia of the firearm's slide moving rearward after ignition by spreading out the resistance over three progressively stiffer springs. Other similar systems have existed for some time (sprinco, et al), but DPM is popular and supports a massive variety of platforms, which is why I chose to test it. There are plenty of youtube and forum reviews offering subjective opinions on 'feel' and 'change in impulse,' but little in the way of measurement of factors I am interested in, specifically recovery time and muzzle flip angle. As I come into this from a competition frame of mind, I want to know what objective, measurable difference,* if any,* the system provides.

 

The setup: a modified P10-F (see my other post) firing 147g LAX ammo at ~135pf and measured with a MantisX 10.

One string of 10 rounds with each of the following: - Stock guide rod, stock spring - DPM guide rod, short (lightest) spring - DPM guide rod, medium spring - DPM guide rod, long (heaviest) spring

 

Results:

Stock

 

Light

 

Medium

 

Heavy

 

Analysis: As you can see, the difference between stock and the lightest spring setup is evident but minimal, with significant movement in both. Notably, the lightest DPM spring did average out to a reduced recovery time. One primary functional difference between them is that even the lightest DPM spring is significantly harder to rack than stock. Even though the DPM feels much stiffer, I did not see significantly increased nose-diving.

 

The major differences came with the medium and long DPM springs. The average recovery time for both was 0.3 seconds, a marked improvement from stock! Also, the muzzle movement plot for both is significantly tamed from the erratic movement of the lighter springs. This was obvious while shooting, as the dot was very constrained and easy to track throughout the slide's movement. Barring an outlier shot, the heavy spring resulted in muzzle movement of a small concentric circle around the target before settling, and readjustment between shots was extremely minimal. The recoil angle and muzzle rise were also categorically reduced from stock and lighter springs, and resulted in a very tight, repeatable pattern.

 

In the end, for my purposes, I decided on the use of the medium spring, even though the heavy spring objectively resulted in the greatest reduction of muzzle flip and recovery time. Why? Because by the graphs above, you can see the medium spring resulted in the majority of muzzle travel above the level X line, whereas the heavy spring produced much of its movement below; this is obvious nose-diving caused by the heavy spring weight, and not a type of sight picture disturbance I am as practiced with countering. I much preferred recovering from the majority-upward motion of the medium spring, as it was closer to the way my conventional spring setups behave.

 

May I know what spacer size did you install together with the medium spring?

[MuayThaiJJ]

I love my DPM systems. I have them on my Tanfoglio, TSO, CZ75, and 1911 6"

[riden]

Advice or feedback on the effectiveness of their systems vs. just standard guide rods & spring choices?

[riden]

On 5/19/2022 at 12:06 AM, MuayThaiJJ said:

I love my DPM systems. I have them on my Tanfoglio, TSO, CZ75, and 1911 6"

I just entered a separate post on this. How did you arrive then at which spring to use? 

[GigG]

Never heard of them but I question any company that would make this like it was a good idea.

 

https://www.dpmsystems.com/magazine-floorplate-glass-breaker

[ima45dv8]

Merged topics.

-Admin

[Twilk73]

On 2/8/2023 at 12:58 PM, riden said:

I just entered a separate post on this. How did you arrive then at which spring to use? 

I used a shot timer and visual target performance to determine what spring to use. Truthfully you want the lightest spring you can get that’s still reliable. That’s the spring you would use. 
 

For me I did 5 shots as fast as I could and as accurate as I could at 7 yards. I did this three times with each spring and each time I wrote down my splits and monitored my groups. I took the average of the three sets and compared them. The spring that gave me the best splits is the spring I chose. The groups were all very similar. 

[Degnan]

I just did a similar experiment comparing recoil across different pistols I own.  However, my data did not include recovery time for the vast majority of shots taken.  I think it is due to running a combination of rapid fire and doubles drills.

 

Where you getting data for "slow fire", or what was the time between shots? 

If so, were you receiving reliable data for recovery time?

 

Attached is my average muzzle rise for each pistol.  

[MuayThaiJJ]

On 2/8/2023 at 9:58 AM, riden said:

I just entered a separate post on this. How did you arrive then at which spring to use? 

 

First I tried them all to see which cycled. Then I fine tuned it and clipped a coil at time until it had the right feel. If it was too strong it felt jerky, if I clipped it too much it didn't feed as well.

[Tip3008]

Based on what I am seeing all of the DPM springs performed worse than the stock spring… Sure, your average follow up shots were quicker, but if you look deeper into it that was purely based on you shooting faster not the spring performing better. The muzzle rise and angle of rise were higher in every spring except for the softest spring which was the only spring that had a lower anoubt of muzzle rise, however, it still had a way higher angle of muzzle rise so I wouldn’t even say that out performed stock. Looking at the numbers, the only thing preventing faster follow up shots with the stock spring was you brother, the gun was recoiling up less and at a slighter angle so really it was back on target before the others you just weren’t shooting yet.. That’s my interpretation of what those results show anyways.. Also the data of how accurate the hits were on the follow up shots  are a fairly important factor as well that is missing.. Anybody can pick up the pace of their shooting from one setup to the next, but when the data straight shows that you were shooting faster when there was a higher amount of recoil as well as angle of recoil, then to me that says you simply shot at a faster pace but the gun wasn’t nearly as controllable so I think you are keying in on the wrong information that the results are showing you..