Author Topic: Firing pin spring pressure (Read 2955 times)

barrelguy · « **on:** February 18, 2019, 02:48:18 PM »

I feel that my gun requires too much cranking torque cocking the bolts on the cocking ramp. As best I can measure, about 30 in. lbs.

Is this about right or are my firing pin springs too stiff? I got those a couple of years ago from Paul. I am about ready to try different springs.

What is everyone using now? What supplier and spring number?

Sparky_NY · « **Reply #1 on:** February 18, 2019, 05:00:15 PM »

these are the ones I used in both the 22 and 357 gatlings. I got them from grainger, they have 3 different wire diameters in this size, the ones I used are the least powerful, 13.5 lb/in

https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6\'>https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6

Others here used different springs from various vendors but when I checked they had about a $60 minimum order, not counting shipping ! OUCH

Stirlingking · « **Reply #2 on:** February 18, 2019, 05:11:59 PM »

these are the ones I used in both the 22 and 357 gatlings. I got them from grainger, they have 3 different wire diameters in this size, the ones I used are the least powerful, 13.5 lb/in

https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6\'>https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6

Others here used different springs from various vendors but when I checked they had about a $60 minimum order, not counting shipping ! OUCH

I don\'t know if this can help people looking for springs, but I have a small hand cranked spring winder and an assortment of spring wire sizes. I am going to wind all my springs, all 20+ of them.

If we can collectively figure out how to help the forum members with springs and stuff, I work cheaply.

Stirlingking

Cutter · « **Reply #3 on:** February 18, 2019, 05:42:50 PM »

these are the ones I used in both the 22 and 357 gatlings. I got them from grainger, they have 3 different wire diameters in this size, the ones I used are the least powerful, 13.5 lb/in

https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6\'>https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6

Others here used different springs from various vendors but when I checked they had about a $60 minimum order, not counting shipping ! OUCH

Sparky or barrelguy

Give me the spring spec. you think will work

I think I can get it sampled out

barrelguy · « **Reply #4 on:** February 18, 2019, 06:25:11 PM »

these are the ones I used in both the 22 and 357 gatlings. I got them from grainger, they have 3 different wire diameters in this size, the ones I used are the least powerful, 13.5 lb/in

https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6\'>https://www.grainger.com/product/GRAINGER-APPROVED-Compress-Spring-1NCD6?searchBar=true&searchQuery=1NCD6

Others here used different springs from various vendors but when I checked they had about a $60 minimum order, not counting shipping ! OUCH

Sparky, thanks for the lead on these springs. The price is sure right. I\'ll try them

Roller · « **Reply #5 on:** February 18, 2019, 06:47:22 PM »

You could also try MSC Industrial Supply, that\'s where I got my springs.

Frank

Sparky_NY · « **Reply #6 on:** February 18, 2019, 08:35:34 PM »

Sparky or barrelguy

Give me the spring spec. you think will work

I think I can get it sampled out

The graingers link I posted has all the specs. I used the one posted, .038 wire, there is also .042 and .045 which have much higher ratings.

My primer strikes look good, maybe a touch on the light side BUT they detonate just fine. That being said.... spring selection is going to vary by individual firing pin design, the weight of the pin has a effect as does its travel along with the spring. Preload on the spring makes a BIG difference too. (this is more for others than Cutter, he has experimented with springs in depth before)

Google searching the other day, I found info that said 20-23 lbs spring rate for center fires was common. My pins are .062 dia, commercial rifles are either .062 or .078 dia from what I seen. (guys dont seem to like the .078, many reworked to .062)

Another triva point..... clearance of the pin tip to its hole.... .002 to .006 is the common range that seems to present no problems. (this is on rifle cartridges that have MUCH higher pressure than the 357 so its quite safe for the 357)

Timcor123 · « **Reply #7 on:** February 24, 2020, 08:24:27 PM »

My springs are .026, but most important is how the pins strike the rim of the cartridge. They must hit on the very edge for a light spring to work. Also, the shape of my firing pins are .025 X .050. I used 4mm square key stock, soldered in .050 drill rod and shaped the end to .025. This also required a matching 4mm square hole in the spring retainer to keep the pin from rotating.

Pretty sure the springs are from â€œLeeâ€ and supplied by MSC.

Hope this helps.

Tim

Timcor123 · « **Reply #8 on:** February 24, 2020, 08:53:49 PM »

Correction on pin diameter. The .050 drill rod is wrong. I used .086 as the print states in a .089 hole. Then shaped to .025 X .050.

Sorry for any confusion.

Tim

Cutter · « **Reply #9 on:** February 25, 2020, 06:32:47 PM »

Tim,

I believe your building a D & E is that correct ?

Timcor123 · « **Reply #10 on:** February 25, 2020, 10:04:08 PM »

Yes. Guess I should have mentioned that.

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Author Topic: Firing pin spring pressure (Read 2955 times)