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Best Firing Pin Spring for STI Open Gun?


RaylanGivens

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I shoot a 9mm STI Trubor in Open...  The firing pin spring is starting to wear on the sides...  I'd like to get another FP spring, but I don't want to use a super long, super heavy Wolff spring.

 

I use Wolff variable rate recoil springs, so I have lots of the firing pin springs that come with their recoil springs...  I don't understand why anyone would want an "extra power" firing pin spring?  Doesn't that just make it harder for the hammer to push the firing pin into the primer?  More resistance from the spring?  Plus, they are super long.

 

What's a good firing pin spring for an STI Open gun?

 

 

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1 minute ago, RaylanGivens said:

I shoot a 9mm STI Trubor in Open...  The firing pin spring is starting to wear on the sides...  I'd like to get another FP spring, but I don't want to use a super long, super heavy Wolff spring.

 

I use Wolff variable rate recoil springs, so I have lots of the firing pin springs that come with their recoil springs...  I don't understand why anyone would want an "extra power" firing pin spring?  Doesn't that just make it harder for the hammer to push the firing pin into the primer?  More resistance from the spring?  Plus, they are super long.

 

What's a good firing pin spring for an STI Open gun?

 

 

Are they super long, or is yours super short? I asked my builder about it and he said the wolff are fine. I put one in mine and didn’t feel any difference

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It’s extra power so it doesn’t stick or swipe/drag on the primer after the gun fires and starts to unlock.

 

your hammer won’t know the difference unless your using something silly like a 7lb mainspring but even then the inertia of the hammer is greater that the mass of the firing pin (newton’s 1st law) 

 

the wolf springs aren’t really “super long” rather your current spring is sprung and has shortened due to wear. Put the “super long” spring in it and next time you check it will be much shorter than the same pile of springs you grabbed it from.

 

theres a reason they ship new recoil spring with a new fp spring, they’re meant to be replaced

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14 hours ago, Sarge said:

Are they super long, or is yours super short? I asked my builder about it and he said the wolff are fine. I put one in mine and didn’t feel any difference

 

Good question...  I assumed mine was lower powered because it was shorter...  Maybe it was just worn out...  I use standard springs in my Limited and SingleStack guns and have never noticed any wear.

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9 hours ago, drewbeck said:

It’s extra power so it doesn’t stick or swipe/drag on the primer after the gun fires and starts to unlock.

 

your hammer won’t know the difference unless your using something silly like a 7lb mainspring but even then the inertia of the hammer is greater that the mass of the firing pin (newton’s 1st law) 

 

the wolf springs aren’t really “super long” rather your current spring is sprung and has shortened due to wear. Put the “super long” spring in it and next time you check it will be much shorter than the same pile of springs you grabbed it from.

 

theres a reason they ship new recoil spring with a new fp spring, they’re meant to be replaced

 

Thank you for a great explanation...  I couldn't figure out why Wolff packaged extra power long springs with all their recoil springs...  An extra power recoil spring just seemed backwards to me.

 

I have been having trouble with the firing pin binding in the firing pin hole in my TruBor's slide...  Maybe my 'probably worn out' spring is causing the firing pin to rattle around and gall the sides of the firing pin opening in the slide...  making it bind.

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4 hours ago, 191138sc said:

+1 Been using Wolff spring and Matt McLearn M2i firing pin combo for years. Have eliminate virtually all light strikes.

 

First I have heard of the Matt McLearn firing pins...  They look like a quality product and Shooters Connection (my favorite store and an Enos sponsor) sells them...  One thing I noticed is that the McLearn firing pin is .069 at the tip, while the Dawson Precision extended firing pins are .067 at the tip...  Not sure if that would cause any problems for me...  Already having a binding issue...  I'll try one and see how it works.

 

For now, I'm going to put one of the Wolff springs in and try it.

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On 2/23/2018 at 1:29 PM, RaylanGivens said:

 

First I have heard of the Matt McLearn firing pins...  They look like a quality product and Shooters Connection (my favorite store and an Enos sponsor) sells them...  One thing I noticed is that the McLearn firing pin is .069 at the tip, while the Dawson Precision extended firing pins are .067 at the tip...  Not sure if that would cause any problems for me...  Already having a binding issue...  I'll try one and see how it works.

 

For now, I'm going to put one of the Wolff springs in and try it.

I polish mine down to size with appox .001 smaller OD to the ID of the hole in the slide.

Appox meaning until it moves in and out with out any hint of drag. 

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If I can continue the firing pin discussion. Having some light strike issues with my 9 mm Trubor.

Is there a downside to installing a Dawson extended firing pin and reduced spring to try to eliminate the problem?

I can’t imagine it’s not just a parts swap?

Thanks

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I have a Trubor 9mm and had light strike issues. I swapped in the Dawson extended firing pin and Wolff reduced spring and rarely have a problem running Winchester rifle primers for major loads. It is a parts swap. Clean out the bore while you are in there. I used a 22 rim fire brush that I had.

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On 2/24/2018 at 4:36 PM, jcc7x7 said:

I polish mine down to size with appox .001 smaller OD to the ID of the hole in the slide.

Appox meaning until it moves in and out with out any hint of drag. 

 

Received my McClearn firing pin today...  The tip is .069" diameter as claimed...  It is slightly tight in the firing pin opening.

 

How do you polish the tip down in size while keeping it round?  Maybe put some 1200 grit sandpaper down on a flat surface and then press the firing pin tip down against it...  then spin the other end of the FP with your finger?

 

...or is there a more accurate method?

Edited by RaylanGivens
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25 minutes ago, jcc7x7 said:

Drill/Drill press, chuck it up

Indicate it .0005 or less and politely sand paper to size.

Or chuck it up "eyeball" straight and sandpaper it to size

 

Much better idea...  Thanks!

 

Dont' have a drill press, but do have a drill...  I work slow and try to be careful, but I'm probably closer to a blacksmith than a gunsmith...

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1 hour ago, RaylanGivens said:

 

Much better idea...  Thanks!

 

Dont' have a drill press, but do have a drill...  I work slow and try to be careful, but I'm probably closer to a blacksmith than a gunsmith...

Not as critical as you might think but don't go to far under size.

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Curious about adding oil to the firing pin hole...

 

I've never added oil to the firing pin hole in any gun I've had...  and never had it cause any problems...  This includes two STI Edge Limited guns and a Springfield SingleStack gun...  However my STI Trubor Open gun has had some firing pin binding issues of late...  Could lack of oil be a problem?

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On 2/25/2018 at 7:44 AM, TANFARM said:

If I can continue the firing pin discussion. Having some light strike issues with my 9 mm Trubor.

Is there a downside to installing a Dawson extended firing pin and reduced spring to try to eliminate the problem?

I can’t imagine it’s not just a parts swap?

Thanks

I installed the Dawson extended and it made my gun 100% 

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I prefer ISMI standard weight firing pin springs.

 

If there is some binding in the firing pin hole, I prefer to polish the hole rather than reducing the diameter of the pin.  I have several STI Ti pins that I decided I didn't like.  I take one, rub some abrasives grease on it and run it back and forth through the hole.  600 grit non-embedding bore polish works great.  I also put a minute chamfer on both ends of the hole to make sure there are no burrs.

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On 3/5/2018 at 12:13 PM, zzt said:

I prefer ISMI standard weight firing pin springs.

 

If there is some binding in the firing pin hole, I prefer to polish the hole rather than reducing the diameter of the pin.  I have several STI Ti pins that I decided I didn't like.  I take one, rub some abrasives grease on it and run it back and forth through the hole.  600 grit non-embedding bore polish works great.  I also put a minute chamfer on both ends of the hole to make sure there are no burrs.

 

Never heard of abrasive grease or 600 grit non-embedding bore polish...  Found these on Google:

 

http://www.formaxmfg.com/coated-abrasive-grease-sticks

 

https://www.amazon.com/J-B-Non-Embedding-Bore-Cleaning-Compound/dp/B0018L9UOW

 

I took a fairly sharp 1/8" drill bit and spun it by hand against the firing pin hole going in through the firing pin stop end of the slide...  Couldn't make much headway.

 

My Dawson Precision extended firing pin (.067") now slide freely through the firing pin hole, but the Matt McLearn firing pin (.069") hits a hard spot about 1/4" into the firing pin hole (when pushing it in through the breech hole.

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