What strength for pistol extractor spring?

dyl · April 30, 2019, 12:36 AM

I'm looking to replace a pistol extractor spring but have no idea what poundage / Newtons I'm looking for.

The situation: outdated pistol (Bernardelli P-one) with no parts available. Had started grinding a backup extractor out of Grade 5 bolt just in case the current one let go. I got side tracked and have since lost the plunger and spring that provides tension against the extractor (I am a genius you see).

The setup is much like a Glock, a rod with a short spring on the end away from the extractor. The difference is that the Glock spring is too wide and won't fit in the hole. Otherwise I'd just chop the Glock plunger to the right size / shape. The hole is a blind hole much shorter than the full length plunger of a Glock, maybe 1 inch deep. It's 3 mm wide exactly. I know because a 3mm drill bit leftover from a Polymer 80 lower "glock" project fit perfectly - which I plan to chop down to be the new plunger.

I have a lead on a 3mm OD spring from a popular online shopping site that rhymes with "Bamazon" with a load capacity of 8.6 Newtons and a spring rate of 2.7 N/mm. Seeing as how I'd have to buy 10 of them for a total of 18 bucks!! I'd like to avoid being way off the mark.

Anyone know of any place to get strong springs with an Outer Diameter of 3mm or slightly less? Or have any idea if a spring rate of 2.7 Newtons/mm (according to google = 23 inch pounds)is adequate?

Bill DeShivs · April 30, 2019, 01:36 AM

Wolff Gunsprings.
https://www.gunsprings.com/

dyl · April 30, 2019, 01:33 PM

Ha! Thanks Bill. Will you look at that. They have a section for just "extractor springs" which is just what I needed. And here I thought Wolff only made recoil springs.

I tried to see if a Kahr CM9 spring/plunger would fit and they nearly do. While I could file them down a tad to fit them without weakening the spring much, for the same cost I could get a whole batch of springs (that I'll never use up unless there's an extractor spring plague or something) and DIY.

April 30, 2019, 12:36 AM	#1
dyl Senior Member Join Date: October 31, 2009 Location: Ohio Posts: 1,310	What strength for pistol extractor spring? I'm looking to replace a pistol extractor spring but have no idea what poundage / Newtons I'm looking for. The situation: outdated pistol (Bernardelli P-one) with no parts available. Had started grinding a backup extractor out of Grade 5 bolt just in case the current one let go. I got side tracked and have since lost the plunger and spring that provides tension against the extractor (I am a genius you see). The setup is much like a Glock, a rod with a short spring on the end away from the extractor. The difference is that the Glock spring is too wide and won't fit in the hole. Otherwise I'd just chop the Glock plunger to the right size / shape. The hole is a blind hole much shorter than the full length plunger of a Glock, maybe 1 inch deep. It's 3 mm wide exactly. I know because a 3mm drill bit leftover from a Polymer 80 lower "glock" project fit perfectly - which I plan to chop down to be the new plunger. I have a lead on a 3mm OD spring from a popular online shopping site that rhymes with "Bamazon" with a load capacity of 8.6 Newtons and a spring rate of 2.7 N/mm. Seeing as how I'd have to buy 10 of them for a total of 18 bucks!! I'd like to avoid being way off the mark. Anyone know of any place to get strong springs with an Outer Diameter of 3mm or slightly less? Or have any idea if a spring rate of 2.7 Newtons/mm (according to google = 23 inch pounds)is adequate?

April 30, 2019, 01:36 AM	#2
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 10,981	Wolff Gunsprings. https://www.gunsprings.com/ __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

April 30, 2019, 01:33 PM	#3
dyl Senior Member Join Date: October 31, 2009 Location: Ohio Posts: 1,310	Ha! Thanks Bill. Will you look at that. They have a section for just "extractor springs" which is just what I needed. And here I thought Wolff only made recoil springs. I tried to see if a Kahr CM9 spring/plunger would fit and they nearly do. While I could file them down a tad to fit them without weakening the spring much, for the same cost I could get a whole batch of springs (that I'll never use up unless there's an extractor spring plague or something) and DIY.