What options/tips/tricks can be used to slow down slide/barrel unlocking?
I'm specifically thinking toward my G20 with HOT loads, but even for whatever gun ammo combo.
In a Glock your option is pretty much a heavier recoil spring. Or a longer barrel/slide.
For guns with hammers a heavier mainspring and a flat bottom firing pin stop.
If money and weight don't matter I suppose you could have a slide made from tungsten....
I know all of mine still throw the brass forever! Next for me is trying some of those flat wire springs and the RZ-10 is first up!
Quote from: REDLINE on July 06 2012 05:39:17 PM MDT
What options/tips/tricks can be used to slow down slide/barrel unlocking?
I'm specifically thinking toward my G20 with HOT loads, but even for whatever gun ammo combo.
There are 3 ways to slow down the slide in your G20:
- stiffer recoil spring (guide rod weight makes zero difference to slide speed)
- increase slide weight (long slide)
- use a muzzle brake
The muzzle brake and heavy slide are far more effective than the stiffer recoil spring.
In a 1911, remove the recoil spring from the above list, but add:
- flat bottom firing pin stop
- stiffer hammer spring
Quote from: Yondering on July 06 2012 09:22:38 PM MDT
increase slide weight (long slide)
Does anyone know the difference in weight between the slide of a longslide for a G20 compared to a standard G20 slide?
Quote from: Yondering on July 06 2012 09:22:38 PM MDT
In a 1911, remove the recoil spring from the above list, but add:
Why do you suggest a stiffer recoil spring won't slow down the slide on a 1911?
Quote from: sqlbullet on July 09 2012 02:46:05 PM MDT
Quote from: Yondering on July 06 2012 09:22:38 PM MDT
In a 1911, remove the recoil spring from the above list, but add:
Why do you suggest a stiffer recoil spring won't slow down the slide on a 1911?
2 reasons:
- more knowledgeable gunsmiths than myself say so
- most 1911 springs apply about the same force with the slide in the locked position; heavier springs have different spring rates so they are stiffer as the slide retracts. In the Glock, the springs I've measured all have about the same rate, but stiffer springs have higher initial preload in the locked position. This is all based on my own spring measurements, not published data.
I'm not saying a stiffer recoil spring won't delay unlocking at all in a 1911, just that if there's an effect, it's insignificant compared to a flat bottom firing pin stop or stiffer hammer spring.
Quote from: Yondering on July 09 2012 03:45:48 PM MDT
it's insignificant compared to a flat bottom firing pin stop or stiffer hammer spring.
This I am on-board with. But it does certainly have an effect.
I would be curious if you have any citations of the gunsmiths that have indicated the springs don't slow down unlock. I would really like to read what they have to say. My own reading and conversations with Steve of Mars Guns has been that a heavier spring is definitely worthwhile up to about 22-24 lbs. Beyond that and the slide will start to abuse the slide stop pin and frame when returning to battery.
I can see this being true of variable spring rate springs, but all my 1911's and Witnesses have constant rate springs, same a Glocks. Maybe I am missing something, but all three are variations of Brownings tilt lock mechanism, so all should have the same basic rules, it seems.
You'd have to search around the 1911 forum to find that; it's been a while.
The correct way to delay slide unlocking on a 1911 is a FBFPS or stiffer hammer spring. A Glock doesn't have those options, and has to use other methods, like the recoil spring to delay unlocking. Glocks also don't suffer from damaging the barrel bottom lugs with a heavy recoil spring.
Quote from: sqlbullet on July 10 2012 08:11:28 AM MDT
I can see this being true of variable spring rate springs, but all my 1911's and Witnesses have constant rate springs, same a Glocks.
Just because they are constant rate, does not mean they are the same rate.
Quote from: Yondering on July 10 2012 10:45:52 AM MDT
Quote from: sqlbullet on July 10 2012 08:11:28 AM MDT
I can see this being true of variable spring rate springs, but all my 1911's and Witnesses have constant rate springs, same a Glocks.
Just because they are constant rate, does not mean they are the same rate.
Yes, I am aware of the meaning. My undergrad work was in ME before I became a computer geek. I was just referencing that neither the Glock nor the 1911 take variable rate springs in standard set-ups.
And, I am 100% on board with FBFPS and main spring. My Para has both the EGW and a wolff 25 lb mainspring. First line of defense because they directly and immediately affect unlock, and the energy they absorb doesn't hammer the gun again when the action closes.
I will poke around a little.
I did a little fiddling around for an Ammo company that wanted to build a magnum out of the 1911 and here is what I learned.
1. Max slide weight. If you are doing a buildup with aftermarket parts like Caspian, ask what is their heaviest slide. Caspian, for example, has a Stainless and Carbon slide which they can mill different options from. Buy the heaviest slide and do not cut or cut as little as possible.
2. Max Barrel Weight. Go with a bull barrel that has cone lockup in the front and a ramp. All that mass has to be moved first before the slide gets going, so the more, better.
3. Increase Hammer spring first, then flat firing pin retainer, then shock buff, THEN recoil spring. Extreme Recoil spring pressure has all its own set of problems, some of which are made worse by hard kicking. A hard recoil spring hammers the gun in lockup, it allows very little time for the cartridges to rise in the magazine, the slide can sometime slap the cartridge so hard that it nosedives into the feedramp or even the front of the magazine, it makes it difficult to jam clear, etc. Start with 20lbs, which should be plenty and only then and reluctantly go higher.
Fit tightly. If you have ever seen the Dan Wesson Commander 10mm's they are an art form, fitted like a bank vault. Not tight, just perfect.
Lastly, if you are still having problems, send the weapon to Mag-Na-Port and ask them for their porting job angled back 20 degrees (the max they will do). It makes a difference.
I agree 100%, except for the Magna Port. Pretty much any muzzle brake out there will have a much greater effect than just barrel porting, and the porting has too many disadvantages.
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Does anyone know the difference in weight between the slide of a longslide for a G20 compared to a standard G20 slide?
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FWIW, the G20SF slide weighs ~ 17 oz. My LW solid top G21L slide weighs ~ 21 oz. I'd think the G20L would be about the same in the solid top version.
Quote from: EdMc on September 01 2012 12:02:11 PM MDT
Does anyone know the difference in weight between the slide of a longslide for a G20 compared to a standard G20 slide?
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FWIW, the G20SF slide weighs ~ 17 oz. My LW solid top G21L slide weighs ~ 21 oz. I'd think the G20L would be about the same in the solid top version.
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Sounds about right. My 20LS slide weighs 20 oz, probably the same as your 21LS, just different scales. My RMR'ed G21 slide weighs 16 oz, and my G19 slide weighs 12 oz.
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Sounds about right. My 20LS slide weighs 20 oz, probably the same as your 21LS, just different scales. My RMR'ed G21 slide weighs 16 oz, and my G19 slide weighs 12 oz.
Yeah, I used some food scales with calibration referenced back to ...........China? ;D That's why I used the '~'. Also, there would be a slight difference in the weight of the Glock plastic sights and the metal Dawson's on the LW long slide.
BTW, I ordered the cyl throat reamer to use on the Blackhawk. You'll bankrupt me yet. :P
Yeah, I have the plastic Glock sights on mine.
How's that 21 LS working for ya?
Quote from: Yondering on September 01 2012 04:47:43 PM MDT
How's that 21 LS working for ya?
It's not...as I posted in the original thread Lone Wolf has extended the backorder date till 5 Oct. from 24 Aug. on the threaded barrel. I get the feeling they don't order from their supplier until they get X number of 'pre-paid' orders. A shame the OEM doesn't sell direct. heh........
Quote from: sqlbullet on July 10 2012 08:11:28 AM MDT
Beyond that and the slide will start to abuse the slide stop pin and frame when returning to battery.
Where on the frame does the potential abuse occur? I know that the slide-lock pin contacts the forward-facing vertical portion of the barrel under-lug, and I THINK that's what normally stops the forward motion of the slide. Also possibly (at least in some non-Mil-Spec 1911's) the slide is stopped when the slide contacts the barrel hood, and forces the barrel forward until it's stopped by the slide/barrel lugs. So in that case, presumably there could potentially be wear on the barrel-hood/slide-breechface contact point, and/or on the rearward-facing slide lug surfaces and the forward-facing barrel lug surfaces. But what part of the frame is potentially subject to abuse? Maybe at the two holes in the frame where the slide-lock pin goes through? Or is my picture (from memory), of how all the parts move, mistaken?
Quote from: Mike_Fontenot on December 30 2012 10:52:04 AM MST
Where on the frame does the potential abuse occur? ... Maybe at the two holes in the frame where the slide-lock pin goes through?
That is the spot. The slide stop pin holes will become oval over time. Once that occurs a new frame is needed to correct the problem. You will also see abuse in the barrel link, usually before the frame damage becomes severe. That is a much smaller concern since the part is only a few dollars and is replaced with relative ease.
Quote from: sqlbullet on January 02 2013 08:19:04 AM MST
[...] You will also see abuse in the barrel link, usually before the frame damage becomes severe. That is a much smaller concern since the part is only a few dollars and is replaced with relative ease.
I would have guessed that the abuse in that case would be on the forward-facing vertical surfaces of the barrel under-lug (the two sides of the lug that the slide-lock pin smacks against when stopping the slide's forward motion).
As far as to abuse on the link itself (as opposed to the barrel under-lug structure that the link is attached to), where does the abuse typically occur? In the hole that the slide-lock goes through, or the smaller hole where the link is pinned to the under-lug, or somewhere else?
My purpose here is to learn enough to know exactly where to look to spot wear before it becomes a big problem. I need to know exactly what areas to closely inspect, in order to detect wear both from the slide slamming rearward AND slamming forward. The rearward case might be the more likely in my case, because my gunsmith put a lighter-than-stock mainspring on my gun (18 lbs, in order to get a lighter trigger), and I've also stuck with the 18.5 lb stock recoil spring. I also shoot full-power (commercial) 10mm loads.
Yes...Lower hole the slide stop pin goes through.
18.5 should be fine, if you are running a flat bottom firing pin stop and a 25 lb mainspring. You should not see any different wear to the frame with 10mm and that combo than with a stock 45 acp 1911 setup.
Slide is a different story. The 1911 service life data is based on the 45 acp. This cartridge operates at 21,000 psi for standard ammo and 23,000 psi for +P ammo. The 38 super has identical service life data in 1911 as a gun running 45 ACP +P ammo. This is because though the pressure is higher for 38 Super (36,500 psi) the area is less, resulting in the same actual force to be contained.
The 10mm is slightly more pressure than the 38 Super at 37,500 psi, but is also more area than the 38 Super. This means the total force the slide/barrel lockup must contain is 30% higher for the 10mm than for 38 Super or 45 ACP. The result is the slide will stretch and ultimately crack much sooner in a 10mm 1911 than a 45 ACP or 38 Super 1911.
That said, the service life for a 45 ACP slide is 100,000-150,000 rounds. In 10mm a slide failure will probably occur before the 100,000 round mark, but well after the 50,000 round mark. Having a slide replaced should cost at the most $400 including fitting by a good gunsmith. That works out to about $0.008 per shot at the very high side. Quite acceptable, and most shooters will NEVER put that many rounds through a gun.
Quote from: sqlbullet on January 02 2013 10:59:04 AM MST
18.5 should be fine [for the recoil spring], if you are running a flat bottom firing pin stop and a 25 lb mainspring.
But that's my problem: my gunsmith reduced my stock 21 lb mainspring to 18 lbs, in the process of lightening my trigger pull. I would like to take the advice to go with a heavy mainspring, but I don't want to give up that nice trigger ... it's a "catch 22".
Quote
Slide is a different story. [...] The result is the slide will stretch and ultimately crack much sooner in a 10mm 1911 than a 45 ACP or 38 Super 1911.
Just to be sure I understand, does the slide tend to crack at the junction between the vertical surface at the aft end of the dust-cover and the upper part of the slide? My understanding is that that vertical surface slams into the guide rod flange (which is already pressed against a vertical surface in the frame), and that's what gets most of the "stopping-load" of the aft movement of the slide. I tried to mitigate that problem by installing a Wilson shock-buff, but immediately took it out because I could no longer "slingshot" my slide to manually chamber a round.
Quote from: Mike_Fontenot on January 02 2013 11:39:51 AM MST
Quote from: sqlbullet on January 02 2013 10:59:04 AM MST
18.5 should be fine [for the recoil spring], if you are running a flat bottom firing pin stop and a 25 lb mainspring.
But that's my problem: my gunsmith reduced my stock 21 lb mainspring to 18 lbs, in the process of lightening my trigger pull. I would like to take the advice to go with a heavy mainspring, but I don't want to give up that nice trigger ... it's a "catch 22".
You might want to explain to your gunsmith what you want, or find a better gunsmith. Reducing the mainspring weight works to reduce trigger pull, but is just a shortcut around setting the hammer and sear contact surfaces correctly. You can have a heavy mainspring and a nice trigger too.
Quote from: sqlbullet on January 02 2013 08:19:04 AM MSTThe slide stop pin holes will become oval over time. Once that occurs a new frame is needed to correct the problem.
Would it work to refill the ovals with JB Weld and redrill the holes out to proper size?
Quote from: Yondering on January 02 2013 11:45:27 AM MST
[...] Reducing the mainspring weight works to reduce trigger pull, but is just a shortcut around setting the hammer and sear contact surfaces correctly. You can have a heavy mainspring and a nice trigger too.
My current trigger pull is about 3-1/2 lbs. I had asked him for 2-1/2, but after trying to accomplish that, he said he couldn't get it below 3-1/2 lbs and still be safe, because the sear-pin holes weren't quite positioned correctly ... about 0.002" off, he said.
Given a 3-1/2 lb trigger, with an 18 lb mainspring, and assuming that the other aspects of the trigger job were done correctly (which I suspect is the case, for my gunsmith's job), what do you think the trigger weight would be if I replaced my 18 lb mainspring with a 25 lb mainspring, with no other changes?
I would guess 4lbs. Mainspring weight really doesn't impact trigger pull that much if the sear and hammer have the proper angles in relation to each other.
Your mileage may vary, especially if the gun is out of spec.
Quote from: REDLINE on January 02 2013 12:24:00 PM MST
Would it work to refill the ovals with JB Weld and redrill the holes out to proper size?
I wouldn't want to trust such a gun. A frame is only about $200 from a good vendor like Caspian, and relatively easy to fit a slide, barrel, etc to.
At such a low price, why risk JB Weld.
Quote from: sqlbullet on January 02 2013 02:53:03 PM MST
I would guess 4lbs [an increase of 1/2 lb]. Mainspring weight really doesn't impact trigger pull that much if the sear and hammer have the proper angles in relation to each other.
You were right-on.
This morning, I got my gunsmith to replace my 18 lb mainspring with a 25 lb one. He measured the trigger pull before the change to be between 2-1/2 lbs and 3 lbs, and after the change he measured it to be between 3 lbs and 3-1/2 lbs ... about a 1/2 lb increase. When dry-firing, I definitely can feel the increase, but I think I can live with it.
I'll probably be able to test it next weekend ... snowstorm predicted this weekend. I THINK it will make the full power 10mm loads that I shoot easier on my gun ... it's noticeably MUCH harder now to rack the slide with the hammer down ... hard to get the motion started, which is exactly what I'm looking for.
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.
Thanks for all the useful comments.
Quote from: Mike_Fontenot on January 10 2013 02:55:39 PM MST
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.
Interesting. I have to look at my 1006 brass with hot stuff next time out. I think it may not give it.
I get wipes with all my EAA pistols. Not so much on my Para though. I wouldn't worry about it personally.
Quote from: sqlbullet on January 21 2013 08:12:55 AM MST
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.
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!
Quote from: The_Shadow on January 21 2013 09:33:57 AM MST
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.
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! :o
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.
Quote from: The_Shadow on February 04 2013 03:19:40 PM MST
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)).
Quote from: The_Shadow on January 21 2013 09:33:57 AM MSTThe 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.
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.
It's worth looking into in my opinion.
Quote from: Mike_Fontenot on February 04 2013 04:16:04 PM MST
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.
I wish there were aftermarket slides available in different weights to try in general and in conjunction with various weight recoil springs.
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. :(
Quote from: The_Shadow on February 19 2013 12:18:55 PM MST
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.
Quote
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.
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Firing pin spring change maybe in order...
Already put in an extra-extra-strong firing-pin spring ... there's nothing stronger.
Quote
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.