Flat Bottom Firing Pin Stop

[Jtigertic]

Ok so I have an ro elite operator 1911 10mm and by doing some research seems like a lot of people prefer to run the flat bottom Firing pin stop. I have a couple questions first what is the actual benefit of changing this and secondly where should I order one from and which one do I need for my firearm?

[Kenk]

Morning Jtigertic,
My reasoning to get this for my RIA Ultra was to lessen the distance my brass fly's (25-30') along with a 25lb main spring. Mine should be returning from RIA Friday

Ken

[Jtigertic]

Would this work? I understand there may be a little fitting needed.


https://www.egwguns.com/oversized-firing-pin-stop-series-70-9-38-40-10-blue-cut-for-adjustable-sight-10375

[sqlbullet]

The flat bottom firing pin stop changes the leverage relationship between the slide movement to the rear and the compression of the main (hammer) spring.  You will feel the difference as soon as you have it installed.  Racking the slide with the hammer down becomes significantly more difficult as the hammer is forced to the cocked position much more abruptly.  If you think of the bottom of the firing pin stop like the fulcrum of a lever, you are moving the fulcrum away from the force and towards the load.

This has the effect of eating up quite a bit of the initial recoil impulse.  Ned Christiansen of Michiguns did some testing years ago using Shok-buffs as an indicator.  He came to the conclusion that a 1911 in 10mm with a flat bottom stop and a 25 lb main(hammer) spring resulted in slide velocities with full power 10mm load that were simillar to 45 ACP in an un-modified 1911 (23 lb mainspring and a radius bottom firing pin stop). 

Some reading that offers more insight:

https://rangehot.com/reduced-radius-firing-pin-stop-1911/

[Kenk]

Great info, thanks sqlbullet!

[Jtigertic]

So changed out the firing pin stops on my 1911's 10mm and 45 to see the difference. I noticed a huge difference with my 45 the recoil was much less and brass didn't move as far. The 10mm I did notice a little less recoil but not much difference in the brass issue but in the guns defense I'm running some hand load 180 cast at over 1300fps so not a weak load. I did add a little more spring weight to the 10mm it had an 18.5lb and I went up to a 20lb recoil spring and added a shock buffer to the recoil lug.