trigger kit unreliable

[Tom E]

From my experience when I use the extended pin I can let the strain screw out about 1/2 to 3/4, of a turn, more and still get good reliability.

What's the length of the firing pin you replaced with an (I assume) C&S firing pin? Or are you calling a .495 ("correct" length) firing pin an "extended pin"?

Tom, I was comparing the original factory pin to the Apex (.495), sorry I did not measure the length of the factory pin.

Thx, that was my point. Your original pin could easily have been a "short" one. There is a point (seems to be .495 unless you have an unusual tolerance stacking issue) where the pin is "long enough" and being longer adds nothing. The C&S pins seem to be made long enough to fire loose .45acp rds in a 625. The chambers I've meaured have all been cut ~.015" too deep for loose rds to headspace correctly. But, with the (common) undersize chambers many (most?) rds will literally jam in the chamber before going in far enough to actually headspace on the case mouth.

[toothguy]

From my experience when I use the extended pin I can let the strain screw out about 1/2 to 3/4, of a turn, more and still get good reliability.

What's the length of the firing pin you replaced with an (I assume) C&S firing pin? Or are you calling a .495 ("correct" length) firing pin an "extended pin"?

Tom, I was comparing the original factory pin to the Apex (.495), sorry I did not measure the length of the factory pin.

Thx, that was my point. Your original pin could easily have been a "short" one. There is a point (seems to be .495 unless you have an unusual tolerance stacking issue) where the pin is "long enough" and being longer adds nothing. The C&S pins seem to be made long enough to fire loose .45acp rds in a 625. The chambers I've meaured have all been cut ~.015" too deep for loose rds to headspace correctly. But, with the (common) undersize chambers many (most?) rds will literally jam in the chamber before going in far enough to actually headspace on the case mouth.

I think the thing to do now would be to test one of the C&S .510 pins against the Apex .495 and see if there is an advantage with fully seated primers.

Edited September 21, 2013 by toothguy

[Tom E]

I think the thing to do now would be to test one of the C&S .510 pins against the Apex .495 and see if there is an advantage with fully seated primers.

Let us know what your results are, I use the titanium .495 S&W firing pin and haven't found anything that works better.

[bountyhunter]

I think the thing to do now would be to test one of the C&S .510 pins against the Apex .495 and see if there is an advantage with fully seated primers.

Let us know what your results are, I use the titanium .495 S&W firing pin and haven't found anything that works better.

Me either. I tested the C+S extended pins and they sure don't. Edited September 21, 2013 by bountyhunter

[bountyhunter]

What's the length of the firing pin you replaced with an (I assume) C&S firing pin? Or are you calling a .495 ("correct" length) firing pin an "extended pin"?

The Apex pins came about at a time when we couldn't get the .495 factory firing pins. What we were seeing in the guns were <.490 in several configurations as were the pins we were getting as parts. The last S&W pins I've bought have been the .495 length again. I have a few on BO currently, we'll see what they are.

I believe .495" is the correct standard pin length. I am not stunned if SW has problems with piece part quality. Somebody posted they thought the "shorties" were made to pass the California muzzle drop test, so the FP won't come forward as far. I never heard that before, but it's possible. At any rate, I think .495 is the correct length. I wonder if SW has two different part numbers or if they would admit it? Edited September 21, 2013 by bountyhunter

[bountyhunter]

From my experience when I use the extended pin I can let the strain screw out about 1/2 to 3/4, of a turn, more and still get good reliability.

That is the test I did on my 66 and 686 guns and saw no difference at all with factory .38 ammo. I was specifically looking for any advantage and it wasn't there. I suspect (based on testing) that if the factory FP is good and proper length (.495) performance does not change. If the pin is too short, it will. In all my guns, I think I found two pins a shade under .495 and replaced them with the stock .495 FP. I just saw no change with standard factory ammo like Sellier Bellot, UMC the usual junk.

Just curious, what is the reliable trigger pull weight on your 686 with your current loads (not flattened primers) ? Also what was the length of the extra length firing pins (greater than .495) that are prone to breakage and who made them?

I found those C&S pins I got from Bill and the package says Extended Firing Pin New Style. I measured the pin and came up with .510, is this the pin you are talking about?

I recall the C+S pins were .510. Most of the stock SW pins were .495, I recall a couple were .490 and I chucked them. Interestingly, I have seen both steel and titanium .495 pins from SW.

The DA pull weights I can get now on MIM guns are typically in the 6.5# ballpark because I am shooting factory ammo with harder primers.

I had an old 686 with hammer mounted FP that I got down to 5# DA but that was shooting reloads with softer primers. It wouldn't ignite factory ammo set that low.

Edited September 21, 2013 by bountyhunter

[Toolguy]

FYI - If you need a longer FP on a hammer mounted version, you take the FP off the hammer, grind back the face of the hammer the desired amount (a few thousandths) making sure to keep the original angle on the face of the hammer and reinstall the FP. You can reuse the pin that holds the FP on. The FP will stick out the face of the recoil shield further by the amount ground off the hammer.

[toothguy]

I went out this morning to run some tests. I used my 627 with an Apex hammer installed, shooting Federal primers, seated .008-.011 in Starline brass. To measure the hammer spring I used a RCBS trigger pull gauge (spring scale) with a thin wire attached to the hook. I placed the wire on the hammer face were it strikes the firing pin. The spring scale will fluctuate slightly pulling back on the hammer and letting up pressure on the hammer. I tried to balance the force to get as accurate a measurement on the actual hammer spring force. The trigger pull measurements were made with a Lyman electronic trigger pull gauge (11lb rebound spring installed). I tested for reliability, meaning always fires with or without moon clips, fast or slow fire.

I started at 40 oz. on the hammer spring and was able to go down to about 32 oz. using the Apex (.495) firing pin (6 lbs 1 oz. trigger pull). With the C&S (.510) firing pin I could go down to 27 oz. (5 lbs 7 oz. trigger pull). The lighter hammer spring requires less rebound so I think I could definitely get a lighter trigger pull on both.

I only used about 100 rounds to do this test. I also noticed the Apex pin tip is sharper, about half the surface area of the more blunt C&S pin. I wonder if it would be and advantage to slightly taper the tip of the C&S pin. I used the firing spring that came with the Apex because the C&S pin does not give you a new spring.

The next thing that I need to find out is how long will the new style C&S pin last. Hope this helps, or at least makes you curious to run your own test.

[Tom E]

I tested for reliability, meaning always fires with or without moon clips, fast or slow fire.

I would expect to see the C&S pin to do better with loose rds, but I'm not sure that matters.

What was the result with moonclipped rds?

Have the chambers been reamed?

Edited September 22, 2013 by Tom E

[toothguy]

I tested for reliability, meaning always fires with or without moon clips, fast or slow fire.

I would expect to see the C&S pin to do better with loose rds, but I'm not sure that matters.

What was the result with moonclipped rds?

Have the chambers been reamed?

With both pins I got greater reliability with moon clips (Hearthco) and the chambers have not been reamed. It was a Performance Center gun if that matters.

[Tom E]

With both pins I got greater reliability with moon clips (Hearthco) and the chambers have not been reamed. It was a Performance Center gun if that matters.

But WITH moonclipped rds, ignoring the loose rds data, was ignition better with one of the firing pins? If so, which one? Or the same?

[toothguy]

With both pins I got greater reliability with moon clips (Hearthco) and the chambers have not been reamed. It was a Performance Center gun if that matters.

But WITH moonclipped rds, ignoring the loose rds data, was ignition better with one of the firing pins? If so, which one? Or the same?

It was important to me that the gun be reliable with or without the moon clips since I don't use moons to practice. I found that with the moon clips, both pins would fire at lower hammer tension more reliably than with the loose rounds. Since I did not find it reliable with both, I tightened the strain screw until the gun was reliable with the loose rounds then measured the hammer spring tension.

[TonyT]

The combination of Wolf reduced power mainspring and 13 lb. recoil spring seem to work well in most of my revolvers - 100% reliability with Federal primers fully seated and an Apex firing pin.