Broken slide stop
- Thread starter Brad
- Start date
Did some reading online regarding this. Some suggest an under power recoil spring. The thinking is that much of the damage is from the slide slamming forward on return to battery. The slide stop top absorbs all the energy so a weaker spring would mean the slide has less energy going forward.
Bill?
Bill?
F
freebullet
Guest
Sure glad you found some!
Pistolero
Well-Known Member
Sounds OK to me. Light springs work fine in 1911s. I run a 9 lb spring in my .38 Super Comp gun, actually never
checked the spring in the .45 ACP twin, probably also light. Folks will tell you that it will "batter the frame".... not in
my experience, although I ran shock buffs back in the day when HUGE quantities were shot
per year. The spring is for closing the slide.
If you have enough power to strip a round and chamber it, that is all you need. The spring does very, very
little to affect the time to unlock, that is mostly the hammer spring and inertia of the slide and parts. The reason the
hammer spring (and firing pin stop bottom radius) are important is the extremely bad mechanical advantage
so the force needed to cock the hammer is far higher than the recoil spring force.
Rack a slide with the hammer down (esp with small radius firing pin stop) and then rack the slide with the hammer
cocked to see the difference. Mostly inertia holding slide, but hammer spring helps significantly. Recoils spring,
slightly.
If nobody makes a lighter spring, locate some piano wire about .003" smaller diam and wind
one over a mandrel smaller than you want the final diameter to be.....exactly how small is a
trial and error thing. Drill a hole through the mandrel, put the wire through, set up the
threading on your lathe for the correct pitch and hold the wire with pliers (tongue depressor
pads) on the tool post and rotate the chuck by hand. Bake the spring at 450F oven for
20 min or so is said to reduce the chance of breakage, probably worth the minor effort. Put
the tight last couple of coils, if it has them, by unclutching the apron lever from the leadscrew.
Bill
checked the spring in the .45 ACP twin, probably also light. Folks will tell you that it will "batter the frame".... not in
my experience, although I ran shock buffs back in the day when HUGE quantities were shot
per year. The spring is for closing the slide.
If you have enough power to strip a round and chamber it, that is all you need. The spring does very, very
little to affect the time to unlock, that is mostly the hammer spring and inertia of the slide and parts. The reason the
hammer spring (and firing pin stop bottom radius) are important is the extremely bad mechanical advantage
so the force needed to cock the hammer is far higher than the recoil spring force.
Rack a slide with the hammer down (esp with small radius firing pin stop) and then rack the slide with the hammer
cocked to see the difference. Mostly inertia holding slide, but hammer spring helps significantly. Recoils spring,
slightly.
If nobody makes a lighter spring, locate some piano wire about .003" smaller diam and wind
one over a mandrel smaller than you want the final diameter to be.....exactly how small is a
trial and error thing. Drill a hole through the mandrel, put the wire through, set up the
threading on your lathe for the correct pitch and hold the wire with pliers (tongue depressor
pads) on the tool post and rotate the chuck by hand. Bake the spring at 450F oven for
20 min or so is said to reduce the chance of breakage, probably worth the minor effort. Put
the tight last couple of coils, if it has them, by unclutching the apron lever from the leadscrew.
Bill
Last edited:
Wolff makes springs for the CZ in a wide variety of weights so that isn't an issue.
Found an interesting discussion online regarding spring strength in this handgun. Goal seemed to be to use a spring that allowed ejected cases to go 6-8'. Less meant to much spring, farther meant too little. Of course this meant balancing the spring to the load fired. I found it to be an interesting way of looking at the issue.
Found an interesting discussion online regarding spring strength in this handgun. Goal seemed to be to use a spring that allowed ejected cases to go 6-8'. Less meant to much spring, farther meant too little. Of course this meant balancing the spring to the load fired. I found it to be an interesting way of looking at the issue.
Oh, I put a small radius firing pin stop on my 1911. Changed the preceived recoil immensely. Far more recoil energy is going into cocking the hammer so the slide doesn't continue to carry the energy as far back. I find it gives a bit else muzzle flip, or st least it feels that way. Racking the slide with the hammer down is far more difficult but it is easy enough to cock the hammer and eliminate that issue.
quicksylver
Well-Known Member
So under normal competition use they would break once a season ?....I don't think so
You might rattle a gun loose wear out the slide / frame...but break that piece?
At least you have a fix and a way to prevent it from happening..but you shouldn't have too.
I would also check the holes to see if they have been elongated..
Good luck..
You might rattle a gun loose wear out the slide / frame...but break that piece?
At least you have a fix and a way to prevent it from happening..but you shouldn't have too.
I would also check the holes to see if they have been elongated..
Good luck..
Pistolero
Well-Known Member
Brad,
You now have a 1911 that runs the way John Browning intended. In 1924 the US Army in it's infinite wisdom decided
that it was too hard to rack the slide (and why not cock the hammer first?) and increased the radius on the firing pin
stop. So, they increased the recoil, increased frame battering and changed the timing of the weapon without much
thought. Yet, they still run well, a tribute to the flexibility built in to the design.
I have been replacing my "for serious" guns' firing pin stops with hand fitted ones with 5/64th radius like the original
design prints show. Yes, muzzle flip is less. Essentially all muzzle flip on conventional Browning design of
semiauto pistols occurs when the slide hits the frame at the end of the slide stroke, basicly
no muzzle rise before that - from high speed motion pictures that I have seen - and was quite surprised
by.
A side benefit of the tightly fitted firing pin stop is more consistent ejection since the extractor
is held solidly in rotation. Usually not too important, but some guns (probably loose tolerance
on the extractor slot) do better with this.
As to ejection as a measure of spring force, seems OK for upper end, but a pretty meaningless indicator on the low side of spring
weight. I would reword that to "at least 6 -8 ft" ejection range. If the CZ75 will run with a weaker spring to avoid
breaking the slide stop, and ejection is farther, I'd accept that as the price of reliability with that particular design.
Bill
You now have a 1911 that runs the way John Browning intended. In 1924 the US Army in it's infinite wisdom decided
that it was too hard to rack the slide (and why not cock the hammer first?) and increased the radius on the firing pin
stop. So, they increased the recoil, increased frame battering and changed the timing of the weapon without much
thought. Yet, they still run well, a tribute to the flexibility built in to the design.
I have been replacing my "for serious" guns' firing pin stops with hand fitted ones with 5/64th radius like the original
design prints show. Yes, muzzle flip is less. Essentially all muzzle flip on conventional Browning design of
semiauto pistols occurs when the slide hits the frame at the end of the slide stroke, basicly
no muzzle rise before that - from high speed motion pictures that I have seen - and was quite surprised
by.
A side benefit of the tightly fitted firing pin stop is more consistent ejection since the extractor
is held solidly in rotation. Usually not too important, but some guns (probably loose tolerance
on the extractor slot) do better with this.
As to ejection as a measure of spring force, seems OK for upper end, but a pretty meaningless indicator on the low side of spring
weight. I would reword that to "at least 6 -8 ft" ejection range. If the CZ75 will run with a weaker spring to avoid
breaking the slide stop, and ejection is farther, I'd accept that as the price of reliability with that particular design.
Bill
Last edited:
fiver
Well-Known Member
6-8'?
I got mine now so that the cases pop out about 1' back and about 2' to the right I could just about put a bucket down and all the cases would drop in it.
I'm wondering about the spring thing though because both of my Norinco 213's, the Para Ord black op's, and the SIL's sumthin or other czech made gun drops them in the same exact place.
they can't all have the same spring rate, and they definitely don't have the same frame mass.
so some of this has to have to do with powder expansion ratios and burn speed and unlock timing?
I got mine now so that the cases pop out about 1' back and about 2' to the right I could just about put a bucket down and all the cases would drop in it.
I'm wondering about the spring thing though because both of my Norinco 213's, the Para Ord black op's, and the SIL's sumthin or other czech made gun drops them in the same exact place.
they can't all have the same spring rate, and they definitely don't have the same frame mass.
so some of this has to have to do with powder expansion ratios and burn speed and unlock timing?
Pistolero
Well-Known Member
Lower powered loads will do that. As long as it is consistent and reliable, no problem. I think the 6-8 ft is
to ensure a margin of safety on a fighting weapon. You are probably getting somewhat close to failing to pick up the
next round in the magazine at that level, but as long as it is reliable - why would it be a problem?
If you have any factory ammo (comes from stores all ready to shoot, in nice boxes, you might
have seen some before) I doubt it will do that with any of those guns.
Bill
to ensure a margin of safety on a fighting weapon. You are probably getting somewhat close to failing to pick up the
next round in the magazine at that level, but as long as it is reliable - why would it be a problem?
If you have any factory ammo (comes from stores all ready to shoot, in nice boxes, you might
have seen some before) I doubt it will do that with any of those guns.
Bill
fiver
Well-Known Member
it's reliable, every 9 we have runs 100% on the load.
even the blow-back hi-point carbine is reliable.
it doesn't matter if I use red-dot or bulls-eye the load just functions.
I'm just wondering about the ejection distance.
I know I have seen it with 'normal' loads.
but I also wonder if 'normal' loads aren't just a bit too much and affect the service life of the pistol.
it's like seeing 80 MPH speed limits everywhere and driving 85 constantly.
the car might show 120-K miles but the higher rpms and road rattle has to be affecting the drive train life.
even the blow-back hi-point carbine is reliable.
it doesn't matter if I use red-dot or bulls-eye the load just functions.
I'm just wondering about the ejection distance.
I know I have seen it with 'normal' loads.
but I also wonder if 'normal' loads aren't just a bit too much and affect the service life of the pistol.
it's like seeing 80 MPH speed limits everywhere and driving 85 constantly.
the car might show 120-K miles but the higher rpms and road rattle has to be affecting the drive train life.
https://cajungunworks.com/technical-support/
It is related to powder burn rate and pressure, not just bullet weight.
It is related to powder burn rate and pressure, not just bullet weight.
Ian
Notorious member
Mine is knife-sharp at the bottom front and curves all the way to the bottom of the hole. Maybe if I fix that I can drop back to a 12 or 14lb spring and reduce barrel hood and slide stop pin wear.
Pistolero
Well-Known Member
John Browning specified a 5/64 radius, so 5/32 drill bit is a match. I use EGW stainless ones. You have to fit the width
and the thickness of the two side rails, and then clear the top and rt side of the ejector(left side of notch in FP stop) , and finally,
once it is sitting in place, located by the FP, trim off the bottom to be flush with the slide. About 1/2 hour with a couple of fine cut files. EGW
comes with about a 1/16th inch radius or less on the bottom corner, but you should wait to do the radius until finally fitted.
Leave it JUST clear on the sides to hold the extractor snugly. Less critical front to back, but easy enough to leave it at .001
to .002 clearance. I mark with Sharpie and tap it in, then file where the Sharpie is wiped off.
I made the one in my carry Commander myself on the mill from bar, for fun and because I couldn't locate a SS one at that time.
I'm not sure would leave the radius like Brad has, but I am also not really sure if it will harm anything. It will hold the
slide forward harder, since the mech adv is even less favorable with a near zero radius. Testing will tell. I tend to
refer back to JB's original ideas and stay there, other than ergonomics. I have both Kuhnhausen's books and the original
GI blueprints and do refer to both. One of my best books is a little self published one from a guy that I met from
OK, used to see him at gunshows for decades, but his health was failing about 10 yrs ago and when we last spoke he
said he was about to quit the gunshow circuit. He had been an AF match armorer on 1911s and had put down all the
basic, old-school working techniques. Some things are dated, now that we can get wonderfully high quality new parts,
but much is still valuable knowledge. Long out of print, not sure if he is still around, either. Nice guy, perfectly willing
to explain anything if you asked.
Bill
and the thickness of the two side rails, and then clear the top and rt side of the ejector(left side of notch in FP stop) , and finally,
once it is sitting in place, located by the FP, trim off the bottom to be flush with the slide. About 1/2 hour with a couple of fine cut files. EGW
comes with about a 1/16th inch radius or less on the bottom corner, but you should wait to do the radius until finally fitted.
Leave it JUST clear on the sides to hold the extractor snugly. Less critical front to back, but easy enough to leave it at .001
to .002 clearance. I mark with Sharpie and tap it in, then file where the Sharpie is wiped off.
I made the one in my carry Commander myself on the mill from bar, for fun and because I couldn't locate a SS one at that time.
I'm not sure would leave the radius like Brad has, but I am also not really sure if it will harm anything. It will hold the
slide forward harder, since the mech adv is even less favorable with a near zero radius. Testing will tell. I tend to
refer back to JB's original ideas and stay there, other than ergonomics. I have both Kuhnhausen's books and the original
GI blueprints and do refer to both. One of my best books is a little self published one from a guy that I met from
OK, used to see him at gunshows for decades, but his health was failing about 10 yrs ago and when we last spoke he
said he was about to quit the gunshow circuit. He had been an AF match armorer on 1911s and had put down all the
basic, old-school working techniques. Some things are dated, now that we can get wonderfully high quality new parts,
but much is still valuable knowledge. Long out of print, not sure if he is still around, either. Nice guy, perfectly willing
to explain anything if you asked.
Bill