10mm-Auto

General => Gunsmithing => Topic started by: Deadguy on August 17 2012 07:29:37 PM MDT

Title: Spring weight experiment
Post by: Deadguy on August 17 2012 07:29:37 PM MDT
My 10mm CCO came sprung with a 22# recoil spring an 21# mainspring. I currently have a 24# RS in it and everything is running smoothly. The 22# was causing the brass from hotter loads to get crunched a bit on the barrel hood on ejection.

I want to minimize frame battering as much as possible, so I will be trying a 25# MS and a 20# RS. There's a good chance that it could operate fine with an 18# RS, but I still need the spring to keep the slide closed long enough for optimal ammo performance. Ammo will be Scottsdale 180 TMJ and Underwood DE GD 180's. I wish I had a 23# MS to try first, but we shall see how this test goes.

Thoughts?
Title: Re: Spring weight experiment
Post by: Intercooler on August 17 2012 08:13:41 PM MDT
Did you see my Witness test in the ammo section? Will be interesting to see what you get... shame you don't have a Chrony to get numbers there too.
Title: Re: Spring weight experiment
Post by: Deadguy on August 18 2012 05:03:52 AM MDT
I'll check it out now.
Title: Re: Spring weight experiment
Post by: sqlbullet on August 20 2012 08:10:25 AM MDT
25 lb mainspring + a flat bottom firing pin stop.  Then run a standard CCO recoil spring, which I think is around 20 lbs.
Title: Re: Spring weight experiment
Post by: Deadguy on August 20 2012 09:13:57 AM MDT
that's exactly the plan!  Hopefully Friday.
Title: Re: Spring weight experiment
Post by: Deadguy on September 20 2012 07:01:59 AM MDT
Finally got a chance to try the combo two weeks ago.  25# MS and 22# RS and she runs like a top.  Brass ejection is perfect with no brass marks on the port and no case crunching out of the 250 rounds fired.  Have just a few rounds over 2000 through it now and look forward to the next 2000.