STI Perfect 10 and Dan Wesson Bruin-Spring Weight Irony

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I bought an STI  Perfect 10 several months ago and contacted STI to find out the spring weights and how often they should be replaced. An STI rep emailed me stating the Perfect 10 has an 18 lb recoil spring and a 22 lb mainspring. Last Saturday, I purchased a Dan Wesson Bruin online and emailed CZ/Dan Wesson to ask the same questions. The CZ/Dan Wesson rep communicated the Bruin uses a 22 lb recoil spring and an 18 lb mainspring. The complete opposite of the STI.

I'm new to the 1911 platform and I suppose there is a window of spring weights which would work just fine in these pistols depending on the ammo being used but it just surprised me to see such a difference in spring weights between them.     

     

[DM1906]

There are too many variable factors to assume similar pistols designs will have similar requirements. Slide mass, slide travel allowance, cam/link ratios, hammer MOA departure, mainspring lever ratio, etc. They are machines, and none are exactly the same. The designation "1911", any more, is little more than a design direction, rather than a specific design parameter. Even the "clones" aren't really clones. They are variations on a theme.

[sqlbullet]

In todays world saying you have a 1911 is like saying you have an ar-15.  All you really know is the general profile of the lower receiver!

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Understood and thank you gentleman. I really appreciate the feedback. I intend to follow what the manufacturer recommends for both pistols.

Interestingly, a search on this forum and others will find people who change recoil spring weights to compensate for light or heavy loads in the 10mm. It looks like some even change mainsprings to lighten trigger pull. In fact, it seems quite a few people recommend spring changes to various pistols quite routinely. If this was needed, wouldn't the manufacturer publicize this?  An example would be the Witness Hunter which comes with three different spring weights.

STI's take on this to me was if you are shooting light target loads, change the springs every 5,000-6,000 rounds. If you are shooting really hot loads change the springs every 3,000 rounds. CZ/Dan Wesson simply said change the spring every 2,500 rounds.

I'm not criticizing those who vary from the manufacturer's recommendations, I just find it interesting. Regardless of brand, these are amazing machines and as far as I am concerned, we are living in a golden age of ammunition and firearms manufacturing.