Commander FP double strikes?

[egumpher]

Hello,

Today I brought some brass home to inspect and saw that two of the casings have evidence of a FP double strikes. Please see the mark above the FP strike on this picture:

http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6395.jpg

Some of the other brass had drag marks.

I use an extra power FP spring I got from Wilson . I have four new standard springs available for test.

Are these marks a concern?

Thank you and best regards
Eric

[log man]

I see firing pin wipe not a double strike.

LOG

[egumpher]

I see firing pin wipe not a double strike.

LOG

Thank you for the correct terminology.

Is this normal?

Rgds
Eric

[log man]

Some guns do it more than others, it is an indication that the gun is opening rather quickly. It means the slide is opening and going back faster than the firing pin. It could indicate that the barrel is unlocking early, as it is the barrels downward motion when the firing pin is still in contact with the primer that marks it. Would be a good experiment to try an EGW square bottom firing pin stop and no other changes to see if it adds enough lag to stop it.

LOG

[sal1911A1]

you could try a wolf extra power firing pin spring

when was the last time you replace the one in that gun??

If the new spring does not correct it, maybe have a smith give it a look see.

looks like the primer strike was a tad off center no big deal,

try a new spring,

what you are seeing is the firing pin not retracting fast enough after the primer strike,

It could be weak firing pin spring or a out of spec firing pin hole in the slide.
but my guess is the spring.

Also what recoil spring (16lbs I hope) and what mainspring do you have(23lbs I hope) It could be a timing issue as well.

[egumpher]

I would like to thank everyone for their responses.

I intalled an EGW O/S FPS.

Could this change the timing as described?

I have a bone stock recoil spring purchased directly from Colt (less than 500 rnds) with the original (3000 rounds) main spring.

Rgds
Eric

[1911Tuner]

That's not a simple "tadpole tail" wipe. Note the defined edge. A wipe wouldn't do that. A strike would.

I'll let ya'll figure it out.

Cheers...

[sal1911A1]

Nice Tuner, how is it going, I hope all is well

OK looking at the pic, could it be a burr on the breech face wall

or the firing pin shifts during a strike,

now I'm lost, because I know your watching,

could you please tell us :)

[kenhwind]

I'll try one guess:
The firing pin is too long!

[saltydog]

I'd hazzard a wild guess that the firing pin return spring is allowing the pin to run back and forth in an unruly fashion. Dunno...

salty

[egumpher]

Hello,

This is a series 80 pistol.

I think that:

1: The hammer falls on the FP forcing it to compress the FP spring and hit the primer.

2: The FP strikes the primer.

3: The primer crushes and ignites the powder.

4: Once the primer is crushed there is still enough energy in the FP so it bounces back.

5: With extra power from the FP spring and the rebound energy the FP travels back against the hammer.

6: The FP again bounces off the hammer sending the FP in the opposite direction.

7: The FP has enough momentum to compress the FP spring and contact the primer again but now the cartridge has moved.

8: This makes the second "ding" in the primer.

Just a thought.

Eric

[egumpher]

I'll try one guess:
The firing pin is too long!


Huh, I just measured 2.262 OAL. Kuhnhausen says a "normal series 70" should be 2.296 -.006.

It appears to be 1/32 too short.

Huh.

This would support my previous post too.

Eric

[kenhwind]

It appears to be 1/32 too short
Do any of the parts in your gun look battered in any way, particulary the Firing Pin Plunger?

[kenhwind]

The timing is off in the firing pin safety system and the firing pin is getting binded by the plunger and is not retracting properly.

[egumpher]

Do any of the parts in your gun look battered in any way, particulary the Firing Pin Plunger?

No. I inspect the plunger often.


The timing is off in the firing pin safety system and the firing pin is getting binded by the plunger and is not retracting properly.

No signs of this using X10 and X20 magnification that I use when I inspect these parts.


Recall that I just installed the EGW O/S FPS. This thing has to change timing because it should take more energy/time to overcome the sharper corner on the bottom of the FPS.

Rgds
Eric

[1911Tuner]

It appears to be 1/32 too short.

In law enforcement circles, this is known as... a CLEW.

[kenhwind]

The firing pin is too short and the firing pin stop is retarding proper firing pin retraction?

[egumpher]

In law enforcement circles, this is known as... a CLEW.


I own a Colts New Agent and a Springfield TRP Opperator. The TRP uses a non-serise-80 firing pin so I can't swap it with the Commnader.

Will the New Agent FP fit the Commander?

Never mind. I will just order a new FP for the Commander and be done with it.

Thank you
Eric

[log man]

A new Ed Brown 45 firing pin measures 2.258". The special Springfield and 9mm/38 super measure 2.294"

LOG

[kenhwind]

Kuhnhausen in Book one shows an OAL for Series 80 FP as 2.262 - 2.265

[tonka]

The too-short firing pin is hanging up on the FPS and contacting the primer as the slide returns forward.......no, never mind, 'cuz that's too close to a slam-fire and Tuner did not tell Egumpher to refrain from firing the pistol until the offending part gets changed out.

Looks like Ken already floated a similar theory. I need to read more slower.

[egumpher]

Kuhnhausen in Book one shows an OAL for Series 80 FP as 2.262 - 2.265


Good catch......I went staight to book two but didn't see any length specific to the Commander.


Rgds
Eric

[1911Tuner]

ausen in Book one shows an OAL for Series 80 FP as 2.262 - 2.265

Maybe the overall length isn't telling the story...

I went staight to book two but didn't see any length specific to the Commander.

Commander...Government Model...All same-same.

[kenhwind]

Firing pin diameter?
I looked at some empty .45 cases last night, and some of the primers looked awkward. these aparantlly aren't from my guns, but some looked like the gun used a same diameter firing pin and the primer strikes where similar to but not like the ones pictured.

I just can't picture this in my meathead.

[niemi24s]

Maybe the overall length isn't telling the story...Maybe this is a red herring.

Maybe it's hammer bounce. Hammer bounce? Yeah, hammer bounce - that's it! ;)

Regards

[Edited: No, not hammer bounce. FP tip & breechface hole too close of a fit. Hammer can propel FP out with little problem, but FP stays out too long and gets pushed back in when primer backs out of case - making the second dent.]

[1911Tuner]

Clews:

1. The operation of a .45 caliber 1911 pistol isn't smooth. It's a fairly violent, slam-bang event, with a lotta bouncin' and such. There are many who don't believe that the firing pin can double strike...but I know that it can. I'm pretty tired of arguing the point, but these pictures show strong evidence with primary and secondary craters giving proof that there were indeed two separate strikes.

2. Once everything starts movin'...Newton 1A and 1B apply in full force.

3. It's not the firing pin diameter and it's not hammer bounce and the barrel isn't "unlocking" early. Remember that the barrel and slide lugs are locked horizontally under shearing stress until the bullet exits. Before that happens, if the link can cause the barrel to move vertically at all...it can't move it as much as the pictures show.

Of all the forces at work here, Newton 1B...(Objects in motion tend to remain in motion)...provides the strongest clew to the reason that this is happening...but there is also a spec issue SOMEWHERE within the firing pin channel.

Ya'll have fun, now. Hear? :)

[niemi24s]

Remember that the barrel and slide lugs are locked horizontally under shearing stress until the bullet exits. Before that happens, if the link can cause the barrel to move vertically at all...it can't move it as much as the pictures show.OK, so the second dent is made after the bullet leaves the barrel and the barrel has started to link down - maybe 0.05" or so (from crude scaling off of Eric's pic).

If the gun doesn't have a whole lot of vertical engagement, that might be about the time VIS contact is made. Extraction of the empty case begins shortly after VIS contact when the slide travels about another 0.04", putting the extractor claw in contact with the forward surface of the case rim.

The impact of the claw against the rim causes the case to rebound back up against the breechface where it meets the not-yet-fully-retracted FP and gets its second indentation.

The reason the FP has not yet fully retracted is because the counterbore in the FP tunnel is not deep enough, and pinches the tapered part of the FP - keeping its tip protruding from the breech face just enough to make the indentation, but not so far out from the breechface that is causes a teardrop drag mark on the primer during linkdown.

[Pant, puff, wheeze! ;) ] Warmer or colder?

[log man]

That's not a simple "tadpole tail" wipe. Note the defined edge. A wipe wouldn't do that. A strike would.

I'll let ya'll figure it out.

Cheers...
Okay, that's good. ...Oh, the firing pin is thought to be short of spec. ?

In law enforcement circles, this is known as... a CLEW.
So, law enforcement forget to check the spec. which is the same as the OP's??
Maybe the overall length isn't telling the story...

So......?? It wasn't a clue (clew) after all??
Clews:

1. The operation of a .45 caliber 1911 pistol isn't smooth. It's a fairly violent, slam-bang event, with a lotta bouncin' and such. There are many who don't believe that the firing pin can double strike...but I know that it can. I'm pretty tired of arguing the point, but these pictures show strong evidence with primary and secondary craters giving proof that there were indeed two separate strikes.

2. Once everything starts movin'...Newton 1A and 1B apply in full force.

3. It's not the firing pin diameterI didn't see any reference to firing pin diameter?and it's not hammer bounce and the barrel isn't "unlocking" early. Remember that the barrel and slide lugs are locked horizontally under shearing stress until the bullet exits. Before that happens, if the link can cause the barrel to move vertically at all...it can't move it as much as the pictures show.

Of all the forces at work here, Newton 1B...(Objects in motion tend to remain in motion)...provides the strongest clew to the reason that this is happening...but there is also a spec issue SOMEWHERE within the firing pin channel.

Ya'll have fun, now. Hear? :)

Okay.....after watching Tripps video, bounce around and up and down back and forth is obvious.

Does the firing pin safety groove show peening. And possibly getting stuck momentary? As soon as the slide goes back the plunger lever would no longer be engaging the plunger. Does it do it without the Series 80 parts in place? Is the firing pin spring on backwards? The tight goes on first.

LOG

[1911Tuner]

So......?? It wasn't a clue (clew) after all??

Ya musta missed the clew... :)

[log man]

Ya musta missed the clew... :)
Well, since it isn't short and is a standard series 80 firing pin I guess that is the clue. A clew out here is the corner of a sail. :)

LOG

[egumpher]

No clues here: (everythink looks smooooooth)
Must neet a longer/standar FP or replace my EGW O/S FPS with stock.

http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6397.jpg
http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6399.jpg
http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6401.jpg

Rgds
Eric

[egumpher]

Well,

For now I vote that it is as I tried to descried earlier and Tuner eludes to:

That is that it is normal for a 1911 to have 10-20% FP bounce.

Because every part looks so good and the last time I measured my vertical lockup I measured .048-ish...

Rgds
Eric

[log man]

Yep, those look great, the firing pin looks like an airplane view of a flag pole. :) I've noticed with some firing pin channels are off center and if the stop is off center there could be a slight bind on the return. From what's being gathered and not understood in the beginning is this started after you put in the EGW stop is that correct.

LOG

[egumpher]

Yep, those look great, the firing pin looks like an airplane view of a flag pole. :) I've noticed with some firing pin channels are off center and if the stop is off center there could be a slight bind on the return. From what's being gathered and not understood in the beginning is this started after you put in the EGW stop is that correct.

LOG

It is hard to tell when this started because I only inspected my brass on my last range visit after I saw brass shavings next to my disconnector a few weeks ago. No shavings just double strikes this time. One more and I may be out!

Eric

[kenhwind]

Firing pin spring, didn't you install an extra power FP spring

[log man]

It is hard to tell when this started because I only inspected my brass after I saw brass shavings next to my disconnector on my last range visit.

Eric
Oh yeah, I remember, that does mean the stop is snug and pushed to the left, which doesn't mean it isn't centered, but if it isn't centered...

LOG

[egumpher]

Firing pin spring, didn't you install an extra power FP spring


Yes. I installed one from a Wilson kit some time ago.....to avoid whatever problem a stock FP spring would create I guess. I have 4 stock FP springs just laying around. Jeezes marketing works huh...

Eric

[kenhwind]

I'm speculating, because Tuner knows its right in front of our eyes.
Is the Wilson for a Series 70, or for a Series 80?

[egumpher]

I'm speculating, because Tuner knows its right in front of our eyes.
Is the Wilson for a Series 70, or for a Series 80?

Don't know, I can't find the reciept.

Eric

[log man]

There is no difference between firing pin springs 70 or 80, they all have or should have sufficient coils so they stack at a point that stops the firing pin from binding or sticking in the hole when dry firing. X-power have a greater helix, the coils are further apart.

LOG

[egumpher]

OK I'll go out on a limb.

Per Tuner.....the corner of the sail in where the sail attaches to the ship and transmits force.....this would be the mainspring in the 1911.

I need a new mainspring.

Rgds
Eric

[kenhwind]

Hmmm!
Yes I looked CLEW up in my dictionary.
I use factory rated mainsprings only.
A lot of the issues on this forum I haven't experienced, and I have owned over 30 different 1911 type guns. Mostly Colts and GMs

[log man]

OK I'll go out on a limb.

Per Tuner.....the corner of the sail in where the sail attaches to the ship and transmits force.....this would be the mainspring in the 1911.

I need a new mainspring.

Rgds
Eric
LOL,LOL, I hope you've got a parachute on. Clew does mean the corner of a sail, and it is also one of those words that means other things like clue also, a little different, but like center and centre or color and colour.

LOG

[egumpher]

LOL,LOL, I hope you've got a parachute on. Clew does mean the corner of a sail, and it is also one of those words that means other things like clue also, a little different, but like center and centre or color and colour.

LOG

The "limbs" on the palm trees here in FL are very tall. I will probably bounce :D

Rgds
Eric

[sourdough1938]

I bet if you put a empty case with a new primer in the chamber and fired the primer you would only have one dent in the primer. Is this a clew or a clue?

[egumpher]

I bet if you put a empty case with a new primer in the chamber and fired the primer you would only have one dent in the primer. Is this a clew or a clue?

I wouldn't take that bet because you are right. The bounce that throws the FP back and forth to double strike the primer comes from recoil.

How can we control the bounce?

Rgds
Eric

[kenhwind]

The "limbs" on the palm trees here in FL are very tall. I will probably bounce
Where in FL do you hail from brother?

[sourdough1938]

The case had to move at least part way out of the chamber for the 2nd dent to be where it is. Agreed?

[egumpher]

Where in FL do you hail from brother?

Originally Merritt Island......now just north of Tampa in Lutz....although I go back often to visit family :)

Rgds
Eric

[sourdough1938]

Also, the case has to be still in contact with the slide, but the base has moved a fraction in some direction for the dent to be off center. I am just trying to get an idea where or when the dent is happening.

[sourdough1938]

I have never owned or used a series 80 but my understanding is there is a firing pin block. Could the firing pin be hitting the block and rebounding to strike the primer again just before the case is ejected? I think I am probably to ignorant of the series 80 to carry this any farther!

[tonka]

'Dough made some pretty good points in his last three posts. It would be nice to know in what position the second strike occurs, 12 o'clock, six, whichever.

Egumpher, what recoil and main springs are you running? 16#/23#? I only ask because, as Tuner says, the cycle is pretty violent, and I wonder if too strong a recoil spring may be creating some extra slide bounce. Alternately, maybe too light a mainspring would allow hammer bounce. Or am I just filling the room with zebras?

[egumpher]

I have never owned or used a series 80 but my understanding is there is a firing pin block. Could the firing pin be hitting the block and rebounding to strike the primer again just before the case is ejected? I think I am probably to ignorant of the series 80 to carry this any farther!


Hello,

This is a great question. I included pictures of the firing pin block and firing pin that I took when I inspected their surfaces for any signs of "peening" or "witness marks" but didn't see any.

Here is a picture of the firing pin and block for reference:
http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6399.jpg

Recall this picture:

http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6395.jpg

There are extractor marks at 3:00 on both and an ejector mark at 7:00 on the case to the right. This makes the second strike at 12:00.

Last time I checked I had about .048 vertical lockup.

Rgds
Eric

[Tom]

....now just north of Tampa in Lutz...
I used to live just north of you - in the Land of Butter. LOL

[egumpher]

Hello,

I have decided that a few double strikes pose no significant problem to my Commander because all the internals look great. But as part preventative measures I intend to:

1. Lower my recol spring from the stock Colt 18-lb to 16-lb (if I can find one)
2. Replace my old mainspring with stock (23-lb I think).
3. Replace my extra-power FP spring with stock.
4. Keep the EGW reduced radius (almost square bottom) FPS.

I will sample brass from my next few range trips to see if this make any differnce and hopefully my changes won't create a new problem.

I want to thank everyone who participated in this thread......thank you.

Rgds
Eric

[1911Tuner]

I have decided that a few double strike pose no significant problem to my Commander because all the internals look great. But as part preventative measures I intend to:


Whoa!

Okay...

This is a matter of inertia and rebound...and the timing of those two factors during the recoil impulse. Nothing more.

Change one thing at a time...starting with the recoil spring. Then, go to a standard Wolff firing pin spring. I think you'll find that one of those two changes will solve the problem.

Yes. A double strike combined with the drag will eventually cause a problem with the firing pin. Notice that you have both, as evidenced by the clean indent AND a short tadpole tail.

ALL .45 caliber 1911 firing pins bounce, and all double strike...and probably almost every time, though that's mostly based in theory and strong suspicion. (Nobody believed me when I told'em that bolts on semiauto rifles bounced, either...but Virgil Tripp's video proved it.)

The reason that we don't see it on every one is that the second strike comes earlier than in the ones that do show it. I've seen it in various stages. In some, the second strike was so close to the first one that it had to be examined carefully under a magnifying glass to see it inside the original indention. Others were out near the edge far enough to see it clearly. Some few others are like this one. Sometimes a slight change in the timing cured it. Sometimes it required a new firing pin. Sometimes just a new firing pin spring.

So...Change one thing at a time until you find the sweet spot.

Good luck, and happy tunin'.

[egumpher]

Whoa!

Okay...

This is a matter of inertia and rebound...and the timing of those two factors during the recoil impulse. Nothing more.

Change one thing at a time...starting with the recoil spring. Then, go to a standard Wolff firing pin spring. I think you'll find that one of those two changes will solve the problem.


So...Change one thing at a time until you find the sweet spot.

Good luck, and happy tunin'.

Hello and thank you for your advice Tuner. Thank you.

I will change one thing at a time as you suggested. This is a simple one variable "design of experiments". The only thing lost or gained with this method is the interrelationship of two variables.

Considering that I am relatively new to 1911s one at a time IS best.

As an engineer I always strive to remove "emotion" from the decision making process and let test results guide the way. Only after inspecting the firing mechanisms parts on my Commander did I decide that double strikes must be normal to a 1911 operation. (recall I only found 2 out of 10 with these marks)

Thanks again.........always looking for the truth in mother nature....
Eric

[toolman]

Maybe I'm not reading close enough but I still haven't seen anyone say what causes the double strikes in 1911's.

I'll go out on a limb and put in my own best guess. If an object at rest tends to stay at rest, does this mean that when the slide begins to travel to the rear the firing pin stays at rest while the slide travels to the rear? If this is the case does the firing pin not begin traveling to the rear with the slide until the tip of the firing pin has contacted the primer a second time?

[1911Tuner]

Maybe I'm not reading close enough but I still haven't seen anyone say what causes the double strikes in 1911's.

You weren't payin' attention.
This is a matter of inertia and rebound...and the timing of those two factors during the recoil impulse. Nothing more.

There's also the possibility of a length issue with the firing pin...but not the overall length. The length from the back of the shoulder to the tip.

There are several factors which alone wouldn't cause it...but when they all come together in one gun, you can see this fairly rare occurrence. FWIW, I've never seen a double strike and a tadpole tail drag mark present at the same time. I've seen true double strikes in only about a half dozen guns over the years, and it nearly drove me over the top tryin' to dope it out.

As an added factor, this one only does it intermittently, which suggests that the only variable...the powder charge in the cartridge...is altering the timing of the whole event just at the right instant.

I saw it once in a gun that only did it with the shooter's pet reload of a 230-grain cast bullet and 5 grains of Bullseye. A change to 6 grains of Unique...which pretty much duplicated the chronographed velocity...or a change to a jacketed 230-grain bullet...stopped it. Never happened again until he went back to Bullseye and his cast bullet. Go figger...

[kenhwind]

The reason that we don't see it on every one is that the second strike comes earlier than in the ones that do show it. I've seen it in various stages.
This would explain the slight indent inside the larger indent in the primer from the intial firing pin strike.

[egumpher]

The reason that we don't see it on every one is that the second strike comes earlier than in the ones that do show it. I've seen it in various stages. In some, the second strike was so close to the first one that it had to be examined carefully under a magnifying glass to see it inside the original indention.

OK....the pistol double strikes everytime with WWB 230gr ammo just as Tuner stated....see the picture below

I will replace my FP spring with a normal pressure first while I order a standard Wolff firing pin spring and Ed Brown FP.

http://i536.photobucket.com/albums/ff327/ewgewgewg/IMG_6403.jpg

Rgds
Eric