Slowing down slide/barrel unlocking?

[Mike_Fontenot]

I think the stronger mainspring (combined with the flat-bottomed firing-pin-stop) will also eliminate the firing-pin-wipe I've been seeing on my primer craters.  I had replaced the extra-strong firing-pin spring with an extra-extra-strong one, and it helped some, but didn't eliminate the problem.

Surprising (to me at least), there was little if any reduction in the "firing-pin-wipe" on the edge of the primer craters.  The increase in the mainspring stiffness (from 18 to 25 lbs) was so large that I was almost certain that it would solve the firing-pin-wipe problem.  (This was with a (fairly) flat-bottomed firing-pin stop, and an extra-extra-stiff firing-pin spring).  I even saw it on a few casings of the fairly wimpy American Eagle rounds.

I'm out of ideas, so I'm going to try to ignore it, and hope it never causes me any problem.

[Intercooler]

Interesting. I have to look at my 1006 brass with hot stuff next time out. I think it may not give it.

[sqlbullet]

I get wipes with all my EAA pistols.  Not so much on my Para though.  I wouldn't worry about it personally.

[Mike_Fontenot]

I get wipes with all my EAA pistols.  Not so much on my Para though.  I wouldn't worry about it personally.

I think I've got no choice but to ignore it ... no ideas left about what I might do to be able to eliminate it.

I apparently don't understand the actual cause of it ... I THOUGHT I knew that, but the much stiffer mainspring (combined with the flat-bottomed firing-pin-stop) would have fixed it if my understanding of the problem had been correct.

It still seems to me, though, that having a side-load on the tip of the firing pin is a bad thing ... if it ever causes the firing-pin to get slightly bent, that might keep the firing pin from withdrawing AT ALL, and that might then cause a runaway.  Or, slightly less scary, the tip might break off, and thus prevent any follow-up shots.  I'll just have to hope that the wipes won't cause me either of these problems.

[The_Shadow]

I saw some wipe marks while testing some 10mm & 9x25 Dillon at the extreme end of performance on a 99 degree day.
However the testing of the commercial ammo that was pulled down/reloaded showed no primer wipe marks from my S&W1006 as tested. The one exception was the Underwood 135 gr @ 1700 which the primer was blown out!

Sometimes dirt, carbon and bits of primer cups (shear or plating) can slow the firing pin if accumilation builds. 
Some primers may be softer cups and exaggerate the issue!

[Mike_Fontenot]

The one exception was the Underwood 135 gr @ 1700 which the primer was blown out!

I've found three or four casings from my Underwood rounds that are missing the primers.  I shoot both 180gr and 155gr Underwoods, so I don't know which bullet weight lost the primers.  My gunsmith dropped a new primer into the pocket, and it just fell right out.  I haven't seen that on the other full-power rounds I shoot (DoubleTap 180gr and 150gr, and BuffaloBore 180gr), but I'm never able to collect all my brass ... they get thrown a LONG way.

[The_Shadow]

Underwood's stuff is up there...
Sometimes loose fitting or small primers come can come out...however extreme loads are known for expanding the primer pockets also.  When the Underwood primer came out of the tested load, it pushed the casing off the extractor leaving the casing in the chamber.  You should have seen me looking for the casing for collection.  I scoured the area looking, when I realized that all the time it was in chamber as I held the gun! 

CCI's seem to be tighter from my experience, having to exert more pressure to fully seat them...
I bought a batch of NEW Winchester 10mm brass that refused to accept CCI's LP's, (some were crushed) but Winchester LP's worked well.

[Mike_Fontenot]

When the Underwood primer came out of the tested load, it pushed the casing off the extractor leaving the casing in the chamber. 

So far, it hasn't caused a jam for me ... somehow, both the casing and the (separated) primer have gotten ejected OK.  But it HAS occurred to me that it COULD shut me down ... I'm not carrying the Underwood's anymore ... just carry the DoubleTaps (with the Nosler bullets, not the XTP's), which so far have been the most trouble-free for me.

I think, before my next range trip, I'll put in a 20-lb recoil spring, and see if that eliminates the firing-pin primer-wipe I'm still seeing.  If not, as a final change I may put in a 27-lb mainspring (replacing the 25-lb mainspring that I recently installed (up from an 18-lb mainspring)).

[REDLINE]

The one exception was the Underwood 135 gr @ 1700 which the primer was blown out!

I sure would like to know what pressures some of those are reaching.  Not because I think it is some insanely high crazy number, but just to know in general.

[The_Shadow]

I don't know why I got such a rediculously high velocity number (1700 fps) and a blown primer from this load, others have pushed them a whole lot more, with even more powder...   I might need to swap to my 24 lbs recoil spring for my S&W1006 to see if it makes a difference.

[REDLINE]

It's worth looking into in my opinion.

[Mike_Fontenot]

I think, before my next range trip, I'll put in a 20-lb recoil spring, and see if that eliminates the firing-pin primer-wipe I'm still seeing.  If not, as a final change I may put in a 27-lb mainspring (replacing the 25-lb mainspring that I recently installed (up from an 18-lb mainspring)).

I tried the 20lb recoil spring yesterday at the range ... no difference in the firing-pin wipes, as far as I can tell.  And again, I saw a few of the full-power rounds with perfect primer craters, and a few of the very wimpy American Eagles that had the wipe ... that just doesn't make any sense to me.  Neither does the fact that the MUCH stiffer mainspring (25 lbs, compared to 18 lbs), together with the short-radius firing-pin stop, made little if any difference in the wipes.

I looked on Midway, and they list a 26lb and a 28lb mainspring (currently out of stock ... expected in March sometime), so I'm going to buy both of them when I can.  Apparently there ISN'T a 27lb mainspring.
If neither of those eliminate the wipes, I guess I'll just have to quit worrying about it.

[REDLINE]

I wish there were aftermarket slides available in different weights to try in general and in conjunction with various weight recoil springs.

[The_Shadow]

Mike_Fontenot, I see firing pin wipe marks as the firing pin not being retracted as the round is being extracted as discussed earlier.  It is weird that the lower power ammo (AE) was showing the wipes.
Ammunition can be cause for wipes...
Cleaning of the firing pin channel to insure no debris is causing it to remain sticking out...
In the 1911's they have a firing pin stop, could this be culprit?...
Firing pin spring change maybe in order...

If it isn't too much of an issue, live with it...as long as it doesn't damage the firing pin.

[Mike_Fontenot]

Cleaning of the firing pin channel to insure no debris is causing it to remain sticking out...

No problem there ... I routinely use a small wooden dowel to push the firing pin far into the chamber, back and forth very fast, and it is completely smooth.

In the 1911's they have a firing pin stop, could this be culprit?...

When I do the exercise described above, it never hangs up on the firing-pin-stop hole.

Firing pin spring change maybe in order...

Already put in an extra-extra-strong firing-pin spring ... there's nothing stronger.

If it isn't too much of an issue, live with it...as long as it doesn't damage the firing pin.

I'm going to try a 26lb and a 28lb mainspring as soon as I can.  If that doesn't work, I'll have no choice but to just hope it never causes a problem.  Nothing's making sense to me ... I've made huge changes, and yet no improvement ... that seems to suggest that my diagnosis of the problem is completely wrong, but I don't understand what else could be the cause.