Clipping recoil spring coils?

[WalterJones]

Bought an M&P 10mm 4" barrel. Made a post about full power loads and that led me down a rabbit hole to changing out the recoil spring for full powr loads and using bullets 200 grains and up.

Called S&W twice and they convinced me that my pistol uses the same recoil spring as the M&P .45

Well, got my springs from Wolff and I can honestly say that S&W was wrong. Springs and guide rod are too long. Maybe correct for the 4.6" model.

Not going to pay the shipping to send back a couple of $8-ish springs. Talked to Wolff this a.m. and they have the pistols on order so they can spec them to eventually make springs.

I've been reading a bunch online that recommend against cutting coils off a spring. But how does it all work if the spring is too long to begin with?

When I install the 22# spring and try to put the slide back on, fully compressed it appears the slide is somewhere between 1/4 to 1/2 inch from sliding back to the point where I can flip the takedown lever to reattach the slide.

[ysr_racer]

Cut a coil, give it try.

When you cut coils you actually increase the spring rate. Think about a thin metal yardstick. If you fling it it will bend pretty easily.

If you cut it down to 12 inches, it's pretty stiff.

A spring it just a coiled yardstick. It works the same way.

[ojisan]

The spring is coil binding, all the space between the coils is compressed and the spring is now a solid rod.
OK to cut coils, cut one coil at a time until the spring is just short enough for the slide to move full travel.
There has to be preload on the spring to keep the breech closed the right amount of time so don't cut too short.
The stronger the round, the more powerfull the spring needs to be.

[WalterJones]

Great, thanks guys.

A friend of mine just picked up the 4.6" model. If we can coordinate, we might try the spring and rod in his model to see if it fits before I do any cutting.

[hambam105]

Proper spring tension to ensure proper handgun function is over rated.

But I must advise not to cut.

When the novice owner and the Smith & Weasel Factory representative are at technical odds then the
correct answer is always to apply blunt force to the spring via a hammer. The bigger the better.

[ar15barrels]

Bought an M&P 10mm 4" barrel. Made a post about full power loads and that led me down a rabbit hole to changing out the recoil spring for full powr loads and using bullets 200 grains and up.

Called S&W twice and they convinced me that my pistol uses the same recoil spring as the M&P .45

Well, got my springs from Wolff and I can honestly say that S&W was wrong. Springs and guide rod are too long. Maybe correct for the 4.6" model.

Not going to pay the shipping to send back a couple of $8-ish springs. Talked to Wolff this a.m. and they have the pistols on order so they can spec them to eventually make springs.

I've been reading a bunch online that recommend against cutting coils off a spring. But how does it all work if the spring is too long to begin with?

When I install the 22# spring and try to put the slide back on, fully compressed it appears the slide is somewhere between 1/4 to 1/2 inch from sliding back to the point where I can flip the takedown lever to reattach the slide.

You don't clip coils to solve a compressed length problem.
You change springs.

Clipping coils will make the springs the completely wrong RATE and preload by the time you have shortened the spring enough to solve your compressed length problem.

[hambam105]

You don't clip coils to solve a compressed length problem.
You change springs.

Clipping coils will make the springs the completely wrong RATE and preload by the time you have shortened the spring enough to solve your compressed length problem.

I don't think the OP is going to believe you.

[ar15barrels]

I don't think the OP is going to believe you.

He will probably figure it out on his own after he solves the coil bind problem but the gun won't function.
It's the typical forum deal where a forum user asks a question and is really just looking to confirm the answer they have already chosen.
They ignore anyone who is not agreeing with the answer they wanted to hear.

[NeilMo]

1/4 to 1/2 inch from the slide being rearward enough for the TD pin to rotate is more than one coil cut will correct. Two or three might not even do it. OP, you're concerned with firing full power loads with the stock spring, but are willing to guess and modify a totally different spring? I think I'd wait for Wolff to produce an increased power spring, and in the mean time buy an M&P 45 to go with those other springs.

[WalterJones]

He will probably figure it out on his own after he solves the coil bind problem but the gun won't function.
It's the typical forum deal where a forum user asks a question and is really just looking to confirm the answer they have already chosen.
They ignore anyone who is not agreeing with the answer they wanted to hear.

Every once in a while, along comes an OP who actually pays attention to wisdom for various reasons. Maybe the first reason is that he respects Randall's wisdom and is glad.he posted. And maye the second reason is that he plans to carry the gun in question in to bear country and it has to reliably go bang when need most.

I get your frustrations with the average armchar calguns commando, but I, for one, will heed the advice of the knowledgeable.

The problem here is: S&W CAN'T EVEN TELL ME WHAT THE CORRECT SPRING IS!!! And it's a very frustrating predicament.

[Helmut]

Reminds me of the people who cut the springs on their cars to lower them. Only to find out that it worsens the ride.

[naz]

maye the second reason is that he plans to carry the gun in question in to bear country and it has to reliably go bang when need most.

[G-forceJunkie]

Then leave it stock. Who cares if its over powered. "Oh know, after I shoot a bear 2000 times the slide might crack!!!"

Every once in a while, along comes an OP who actually pays attention to wisdom for various reasons. Maybe the first reason is that he respects Randall's wisdom and is glad.he posted. And maye the second reason is that he plans to carry the gun in question in to bear country and it has to reliably go bang when need most.

[ar15barrels]

The problem here is: S&W CAN'T EVEN TELL ME WHAT THE CORRECT SPRING IS!!!
And it's a very frustrating predicament.

It's probably too new of a model for the aftermarket spring companies to have even figured it out, let alone S&W tech support.

[subscriber]

When you cut coils you actually increase the spring rate.

Yes. But you reduce the preload by the length you cut off. That results in a reduction in slide closing force; throughout the slide travel, despite the increase in spring rate.