Author Topic: Pencil test results, not good.  (Read 408 times)

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Offline Hypo

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Pencil test results, not good.
« on: January 08, 2018, 01:53:23 AM »
After doing the action smoothing including polishing the firing pin block and firing pin, I decided to do the pencil test to see how far it would shoot it.

My Shadow 2 will fire a pencil straight up about 2 feet.
My TriStar L-120 didn't even get it out of the barrel.
The gun fires reliably even hard Tula steel case ammo.
The pin return spring is very stiff.
I also noticed that the hammer does not come back as far in DA as it is when fired from SA.
Either way, DA or SA, it still will not get the pencil up and out of the barrel.

I have the CGW spring kit on order and it should be here soon.
Will that change it with the lighter return spring?

What controls how far back the hammer goes in DA?  The Ramps on the underside of the Sear cage and the trigger bar curvature and height at the nose?

I polished all of those areas.  Perhaps I removed too much metal in the smoothing? 
Only used hand pressure and paper on a flat surface., no Dremel.

Still , that doesn't explain the weak SA firing.

Thanks.

Offline M1A4ME

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Re: Pencil test results, not good.
« Reply #1 on: January 08, 2018, 05:53:48 AM »
Very little pencil "bounce."  I've seen the same thing with every striker fired pistol I own except the XDMs.  Those will at least raise the pencil up enough to see the eraser. 

I remember sticking a pencil in the ceiling at the office one night (Colt Combat Commander) and hoping the Chief wouldn't see the mark in the celotex (I think that's what that suff was called).

I have not compared a CZ 75 with an extended firing pit to one with a factory firing pin, so I can't say if there's a difference.

Can your pistol use a CGW CZ extended firing pin?  Are they similar enough?  Or a CGW CZ reduded power firing pin return spring?
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline Hypo

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Re: Pencil test results, not good.
« Reply #2 on: January 08, 2018, 06:35:18 AM »
Yes,I have the reduced firing pin return spring on order.
Mail seems to be running very slowly after the holidays.
Have the tracking number and it has been in Atlanta for 3 days.
I need to measure the firing pin diameters in my Shadow and TriStar to see how they compare.

Offline inthevalley

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Re: Pencil test results, not good.
« Reply #3 on: January 08, 2018, 02:30:38 PM »
If it is lighting of Tula with the stock parts, why would you replace anything? I feel that is just asking for trouble when your gun is functioning perfectly fine

That is strange the pencil wouldn't even clear a barrel but pencil tests are really best used for comparing reliability of modifications between different models of the same gun. Different guns are gonna produce different results and cannot be directly compared. As the previous poster mentioned, striker guns all appear to fail the pencil test, yet they usually light off hard primers just fine.

Doesn't the shadow have an extended firing pin? I bet that makes a big difference.

Offline Boriqua

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Re: Pencil test results, not good.
« Reply #4 on: January 08, 2018, 05:01:14 PM »
I would check with something that has a smaller diameter and a flat bottom. I had a similar experience after changing springs on my t100 and using the pencil test and thought "oh crap." Pencil barely moved.

I had some 1/4 wooden dowel and put it in there and "pow." I got a satisfying reaction. I am not sure why and it doesnt blast off like my 1911 commander but it easily cleared the muzzle by 6 inches.

Offline M1A4ME

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Re: Pencil test results, not good.
« Reply #5 on: January 08, 2018, 08:48:12 PM »
I would check with something that has a smaller diameter and a flat bottom. I had a similar experience after changing springs on my t100 and using the pencil test and thought "oh crap." Pencil barely moved.

I had some 1/4 wooden dowel and put it in there and "pow." I got a satisfying reaction. I am not sure why and it doesnt blast off like my 1911 commander but it easily cleared the muzzle by 6 inches.

Did you see my post?  I busted out laughing when I read yours because, BTDT.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.