Should I be using a heavier recoil spring?

[KMaC]

I have been shooting 9mm 115 grain Fiocchi or Sellier & Bellot ammo for the last year. I recently looked at the specs for the ammo and noticed that the muzzle velocity is 1200 fps for Fiocchi and 1280 fps for S&B. These velocities are higher than some manufacturers' +P rated ammo.
I had a Tristar T-120 (an aluminum frame model) develop a frame crack at 13,000 rounds (about 6,000 rounds were the Fiocchi and S&B) in May. Now I'm wondering if the high velocity ammo was the cause of the frame crack. The recoil spring was a Tristar supplied #14 spring that had about 5,000 rounds on it but was functioning fine.

I have other aluminum frame Tristars that I don't want to damage not to mention polymer frame guns. Are steel frame guns with standard recoil springs safe from damage with this ammo?
What is INGO's mindset on this?
Is it ok to shoot this ammo but change #14 recoil springs at 2,000 rounds. Shoot the ammo but change to #16 springs. Change ammo to something in the 1150 fps range.

 

[Jim McKalip]

Try a 16 lb. spring with the 1200 & 1280 fps ammo. If the pistol still cycles reliably, question answered,

 

[russc2542]

13k rounds might just have needed swapping the recoil spring sooner.


Most +p is heavier bullets. That speed's within the normal range for 115gr (lighter = faster). +p rating is based peak pressure generated during firing, NOT the resulting FPS.

That being said, yes, S&B is on the hot side. Fast burning powder.

 

[KMaC]

13k rounds might just have needed swapping the recoil spring sooner.
This wasn't the original spring, it was on it's 2nd spring, changing them around 6,000. I was due for a new spring but I didn't change it soon enough.

Most +p is heavier bullets. That speed's within the normal range for 115gr (lighter = faster). +p rating is based peak pressure generated during firing, NOT the resulting FPS.
I have learned that +P psi and fps are not directly related since starting this thread. I have also learned that Tristars are not rated for +P but my ammo, while hot, isn't the cause of the crack.
I asked Tristar if I should have replaced the hammer spring but they said it was likely due to recoil spring weakness. Tristar recommended changing the recoil spring at 2500 rounds and I will follow that guideline from now on even though it seems pretty short life. I had been under the impression that ejection issues would signal a need for spring replacement but I guess I'm wrong.

That being said, yes, S&B is on the hot side. Fast burning powder.

I will also try a 16# spring to see if it softens the recoil impact to the frame and still cycles reliably.

 

[russc2542]

I will also try a 16# spring to see if it softens the recoil impact to the frame and still cycles reliably.

2500rnds? could be worse... Kimber micro 9 is recommended at 1000 if I recall.

 

[Disposable Heart]

While "not rated for +P" the ammo you were using was certainly SAAMI spec for standard pressure 9mm. The CZ based designs are robust, but Turkish execution of CZ designs and metallurgy can be spotty (not all the time, but in some cases).

6k or 13k on a recoil spring, for any design, is a really long of a service schedule. Not sure why people are comparing it to the Micro 9 from Kimber: That's a really small gun with a really fast moving light slide, it will require FAR shorter service intervals. Any larger service sized weapon, regardless of its make, would be better served with 2k intervals for recoil. I'm sure the weapon was still reliable as the CZ design's more straightforward action makes it hard to "fail" but you found one of the Achilles's heels of its designs. I cracked a Jericho frame from the same thing. Reliable, no issues, until there was an expensive FRAME issue. lol

Ammo had nothing to do with this, service interval did.

Teriarily: There is no need to replace the factory strength spring (Go WOLFF!) with a higher poundage. On the CZ design, it's mostly to cycle the action, not necessarily mitigate slide velocity. Helps, but not the key actor. Replace your mainspring at similar intervals as well. CZs (and 1911s) use the main spring as a slide control/recoil actuation method as well. If it wears out, it can affect recoil pattern and characteristics.

Don't screw around with "buffers" as they are a unreliable gimmick that bandaids poor service (not to mention they are a liability in breaking up and getting into the lockwork of the piece).

 

[KMaC]

While "not rated for +P" the ammo you were using was certainly SAAMI spec for standard pressure 9mm. The CZ based designs are robust, but Turkish execution of CZ designs and metallurgy can be spotty (not all the time, but in some cases).

6k or 13k on a recoil spring, for any design, is a really long of a service schedule. Not sure why people are comparing it to the Micro 9 from Kimber: That's a really small gun with a really fast moving light slide, it will require FAR shorter service intervals. Any larger service sized weapon, regardless of its make, would be better served with 2k intervals for recoil. I'm sure the weapon was still reliable as the CZ design's more straightforward action makes it hard to "fail" but you found one of the Achilles's heels of its designs. I cracked a Jericho frame from the same thing. Reliable, no issues, until there was an expensive FRAME issue. lol

Ammo had nothing to do with this, service interval did.

Teriarily: There is no need to replace the factory strength spring (Go WOLFF!) with a higher poundage. On the CZ design, it's mostly to cycle the action, not necessarily mitigate slide velocity. Helps, but not the key actor. Replace your mainspring at similar intervals as well. CZs (and 1911s) use the main spring as a slide control/recoil actuation method as well. If it wears out, it can affect recoil pattern and characteristics.

Don't screw around with "buffers" as they are a unreliable gimmick that bandaids poor service (not to mention they are a liability in breaking up and getting into the lockwork of the piece).

Thanks for the thorough explanation. Time to order some springs.
This is the first I've heard of replacing main springs so often. But I wasn't changing recoil springs on time either.
Guns seem to be the only product that doesn't have ANY direction for parts replacement in their owners manuals. I get more guidance from my toaster's manual than from a gun's.

 

[Grelber]

Most folks judge recoil spring weight either by desired feel or distance of ejection of the brass, and I have never heard of anyone going above the weight of the oem supplied recoil spring weight. OEM's are usually very conservative.

I suspect your gun cracked due to a gun problem and not a spring problem, if brass is flying 10' away from the gun you might be onto something with spring weight though.

Maintenance wise I have never replaced a recoil spring except for tuning the gun to how I like it to feel and have only replaced mainsprings on a couple guns that I have set up sort of on the edge of reliability in order to get very light double action (CZ's and Tanfo's)

 

[russc2542]

I only bring up the Micro9 because of the comments about manuals. I agree that gun manuals are horrible for what maintenance is to be done. Most places I've read (forums, articles, live chats, NOT mfrs) suggest it after seeing problems or anywhere from every 2k rounds to 20k rounds.

Granted part of the problem is the variety of uses of the guns... anywhere from safe queens to competition tools, the range of conditions and usages: weather, carry style, ammo used, etc, how over-engineered the gun is to start with (IE tristar CZ75 clone vs HK USP)

Most folks judge recoil spring weight either by desired feel or distance of ejection of the brass, and I have never heard of anyone going above the weight of the oem supplied recoil spring weight. OEM's are usually very conservative.

I suspect your gun cracked due to a gun problem and not a spring problem, if brass is flying 10' away from the gun you might be onto something with spring weight though.

Maintenance wise I have never replaced a recoil spring except for tuning the gun to how I like it to feel and have only replaced mainsprings on a couple guns that I have set up sort of on the edge of reliability in order to get very light double action (CZ's and Tanfo's)

Since the factory DOES say replace the spring at 2500 rnds, and the OP ran it to 6k+, I'd start there. Aluminum is notoriously unforgiving to shock loads (like the slide hitting the frame). Yes it's a gun problem, but the fix/bandaid for the gun problem is to replace the spring proactively per the factory.

I've heard of going higher but that's for hotter ammo (IE 45 super vs 45ACP) which I suppose this is in the same ballpark as. Too high of a recoil spring pressure can cause cycling issues with standard power ammo.

 

[KMaC]

Since the factory DOES say replace the spring at 2500 rnds, and the OP ran it to 6k+, I'd start there. Aluminum is notoriously unforgiving to shock loads (like the slide hitting the frame). Yes it's a gun problem, but the fix/bandaid for the gun problem is to replace the spring proactively per the factory.

The factory says that if you call them and ask. How many people ever call the factory? If a worn out recoil spring was actually the cause of the crack it could have been avoided by having some guidance on spring life in the manual.

 

[russc2542]

The factory says that if you call them and ask. How many people ever call the factory? If a worn out recoil spring was actually the cause of the crack it could have been avoided by having some guidance on spring life in the manual.

haha but then you wouldn't have to go out and buy a new pistol and support the industry!

 

[KMaC]

haha but then you wouldn't have to go out and buy a new pistol and support the industry!

OK, I sheepishly admit that I have replaced the broken gun but I'm stickin it to The Man by buying a used gun. I stumbled onto a 1999 CZ 75B with satin nickel finish in very nice condition. I already have a 75 but I was blinded by the bling and couldn't get my wallet out fast enough.
Updating the original topic, I got recoil springs from CGW and CZ and they are different from each other and different from the Tristar OEM spring. The CZ springs are tapered and will not accept the full length guide rod of the Tristar. So the CGW springs will go in the second Tristar and the CZ springs will go in the 75s. Everything has new springs now and I still don't know if it had anything to do with my gun cracking.

 

[russc2542]

OK, I sheepishly admit that I have replaced the broken gun but I'm stickin it to The Man by buying a used gun. I stumbled onto a 1999 CZ 75B with satin nickel finish in very nice condition. I already have a 75 but I was blinded by the bling and couldn't get my wallet out fast enough.
Updating the original topic, I got recoil springs from CGW and CZ and they are different from each other and different from the Tristar OEM spring. The CZ springs are tapered and will not accept the full length guide rod of the Tristar. So the CGW springs will go in the second Tristar and the CZ springs will go in the 75s. Everything has new springs now and I still don't know if it had anything to do with my gun cracking.

nice. I'd say <10% of my collection was bought new. Like cars, the new stuff doesn't offer much I can't get in an older model. not to mention the older stuff is far more interesting from a design/engineering standpoint.

Some things can never be known definitively. I'd say the old springs are certainly low hanging fruit on the blame tree.

Side note, ordered a new recoil spring and buffer (from the factory!) for my P30 cause lord only knows how many rounds are on it.