Beretta’s D hammer spring in PX4 Storms- Evaluation after long term use

[DAB]

good info. Wilson says the 12# is for competition only. if for self defense, don't go below the D spring.

[LangdonTactical]

OK, we are mixing and matching here once again. There are two different guns being discussed here. The 92 and the PX4. While the hammer springs will physically interchange between the two, they have a different impact on each gun.

The 92 D model spring is not the same as the PX4/8000 D model spring. For example, the 92 D model spring is heavier than the F model spring in a PX4.

The PX4, 92 and 8000 have different hammer strut shapes. Therefore the spring imparts different energy to the hammer, and why the 92 hammer springs are of a heavier weight than the PX4 and the 8000 Cougars. So you have to be specific to the model gun when making decisions about spring weights.

Also, they are springs and can vary from spring to spring and batch to batch. I have seen differences in spring weight from one batch of 92D springs to another in both overall length and weight. For production guns, they have a tolerance they the need to meet within a range, plus or minus.

There is also more to the spring weight that just the length or number of coils. The wire diameter is also a key factor along with several other things such as the material of the wire and how tightly it is wound (outside and inside diameter)

When I started down the PX4 path a few years back, I was working with a sample of three guns and even fewer springs in the beginning. Now, several years later, I have settled on the 12# CS spring because of the consistency and durability of that spring.

Also, the fact that it is a chrome silicon spring and not a music wire spring means it last quite a bit longer before losing significant energy.

I have always used NRA weights to measure trigger pull as I have never been very trusting of digital scales when it comes to that. Also because all the competition sanctioning bodies also use NRA style weights as well.

Double action pulls are especially difficult as the location of the weight or gage on the trigger makes a significant difference in the pull weight. Blah blah blah.... Archimedes... blah blah blah leverage.....

Also, I find that from a shootablity standpoint, consistency in the weight of the pull is more important than the total weight. I mean I would rather have a consistent 8 pounds from start to finish than 7 pounds that build from 4 to 7 right at the very end of the pull.

All this being said. I am not an engineer, physicist nor am I a spring expert.

I just start with fundamental principles and then make sure it works with a bunch of testing and shooting.

Hope this helps.

[CraigS]

....
Double action pulls are especially difficult as the location of the weight or gage on the trigger makes a significant difference in the pull weight. Blah blah blah.... Archimedes... blah blah blah leverage.....

I have noticed this when using my Lyman gauge. I have to pull, at the beginning, w/ the gauge at a significant angle (from parallel to the barrel) or it slides up the trigger toward the frame and I have 10# showing before the trigger is half way through it's travel. How do you do it w/ your weights? Do you start w/ the pistol at an angle to hold the rod near the end of the trigger?

[PX4 Storm Tracker]

OK, we are mixing and matching here once again. There are two different guns being discussed here. The 92 and the PX4. While the hammer springs will physically interchange between the two, they have a different impact on each gun.

The 92 D model spring is not the same as the PX4/8000 D model spring. For example, the 92 D model spring is heavier than the F model spring in a PX4.

The PX4, 92 and 8000 have different hammer strut shapes. Therefore the spring imparts different energy to the hammer, and why the 92 hammer springs are of a heavier weight than the PX4 and the 8000 Cougars. So you have to be specific to the model gun when making decisions about spring weights.

Also, they are springs and can vary from spring to spring and batch to batch. I have seen differences in spring weight from one batch of 92D springs to another in both overall length and weight. For production guns, they have a tolerance they the need to meet within a range, plus or minus.

There is also more to the spring weight that just the length or number of coils. The wire diameter is also a key factor along with several other things such as the material of the wire and how tightly it is wound (outside and inside diameter)

When I started down the PX4 path a few years back, I was working with a sample of three guns and even fewer springs in the beginning. Now, several years later, I have settled on the 12# CS spring because of the consistency and durability of that spring.

Also, the fact that it is a chrome silicon spring and not a music wire spring means it last quite a bit longer before losing significant energy.

I have always used NRA weights to measure trigger pull as I have never been very trusting of digital scales when it comes to that. Also because all the competition sanctioning bodies also use NRA style weights as well.

Double action pulls are especially difficult as the location of the weight or gage on the trigger makes a significant difference in the pull weight. Blah blah blah.... Archimedes... blah blah blah leverage.....

Also, I find that from a shootablity standpoint, consistency in the weight of the pull is more important than the total weight. I mean I would rather have a consistent 8 pounds from start to finish than 7 pounds that build from 4 to 7 right at the very end of the pull.

All this being said. I am not an engineer, physicist nor am I a spring expert.

I just start with fundamental principles and then make sure it works with a bunch of testing and shooting.

Hope this helps.

Thank you for all that great information!

I am concerned with the Cougar D spring in a PX4. How did your use of it in your Compact go? How many rounds did it go? Did you have to replace it, etc.?

[LangdonTactical]

Thank you for all that great information!

I am concerned with the Cougar D spring in a PX4. How did your use of it in your Compact go? How many rounds did it go? Did you have to replace it, etc.?

I only used a couple of the Cougar D springs in the compact. I don't think I ran any of them to failure. At the time, Beretta was often out of stock of the D Cougar springs, so that is the other reason that I ended up with the CS spring.

Hope this helps.

[PX4 Storm Tracker]

I only used a couple of the Cougar D springs in the compact. I don't think I ran any of them to failure. At the time, Beretta was often out of stock of the D Cougar springs, so that is the other reason that I ended up with the CS spring.

Hope this helps.

Thanks for your patience and participation in this thread.

[Storm SD]

I have a D-Spring in my PX4 Storm SD. It currently has 20,076 rounds on that spring. So far, I haven't had any light strikes and the D-Spring has held up well and been smooth, consistent and reliable.

[holmes168]

Is there a decent you tube video anywhere showing how to replace the hammer spring on the PX4?

[PX4 Storm Tracker]

Is there a decent you tube video anywhere showing how to replace the hammer spring on the PX4?

Try this: https://youtu.be/8cU1PQEsbCQ

[Storm SD]

Is there a decent you tube video anywhere showing how to replace the hammer spring on the PX4?

If you choose to put in a D spring, the best place to get one is directly from Beretta. The part number for the D spring for a PX4 Storm is EU00043. Here is the link: http://www.berettausa.com/en-us/spri...l-mods/c90160/

Also, the guy in the video that PX4 Storm Tracker provided uses a multi tool to pull the wire clip out that holds the backstrap on from the bottom of the handle. This method runs the risk of slipping and scratching up the frame. I would suggest wading up a paper towel and putting it on the bottom of the handle at the most forward portion. Take a flat screwdriver and insert the head into the center notch under the wire clip and pry the wire up with the screwdriver prying against the frame with the paper towel between the frame and the screwdriver. Once it is forced up enough, I would take the shaft of the screwdriver and insert it under the wire clip. Pulling straight up on both sides of the screwdriver shaft, you should be able to pull the clip up smoothly and with control while avoiding the risk of scratching up your pistol. Instead of prying the backstrap off with the screwdriver, you can take the rubber handle end of your screwdriver and gently tap the backstrap away from the rest of the pistol and it will easily come loose so that you can remove it by hand.