Flat wire coil springs

[Narragansett]

What is the advantage of a flat coiled spring over traditional coiled springs?

 

[CAJUNLAWYER]

Along those lines what are the advantages of frame mounted vs hammer mounted firing pins?

 

[LVSteve]

It is my understanding that flat wound springs have the following advantages:

1) When fully compressed, there is no way for a coil to become entangled.

2) They keep their shape better on the guide rod, so the clearances around the recoil spring assembly can be made smaller, allowing more compact guns.

3) It is alleged that flat wound springs can be produced with tighter tolerances in the spring rate.

 

[chief38]

I am not a spring expert so I can't say for sure but I do have a few Colt Pistols with flat wound recoil springs and they are the original springs at well over 100 years old. I guess they last as they still work perfectly.

If I had to guess, the flat part might add dimension to actually make them stronger, similar to how a flange on sheet metal makes it stronger. I would expect them to be more expensive to make, so that is one reason they might not be so common anymore. I have also seen Remington M11 and Browning A5 recoil springs in vintage semi auto shotguns with flat wound springs.

 

[stansdds]

I think flat wound springs also last longer.

 

[JRD]

Flat wire allows you to get more "spring" into a length constrained volume. Pistol recoil springs, particularly in compact slide length models, are designed near their limits of allowable stress in order to get sufficient force.
The flat (actually rectangular) wire shape can generate higher forces than a round wire spring while staying below material stress thresholds- in a given length.
Flat wire springs are more complicated and expensive to design and manufacture than round wire springs. The primary reason to use them is to get more spring force in a shorter length- which is very common in compact pistols.

 

[GnarlsR2]

Just looking at the physics...

Do Flat Wire springs require a small guide rod diameter?

Do Flat Wire springs cause more friction against the guide rod during compression, which can cause more force to rack a slide?

 

[Oldsalt66]

It's believed that they last longer.

 

[dave1918a2]

I have a Wilson flat 22 LB recoil spring in My 1911 custom. Previously had a 22 LB from Wolff. Seems to shoot softer now than before and a couple of shooters at the Club say the same thing.

 

[LVSteve]

I have a Wilson flat 22 LB recoil spring in My 1911 custom. Previously had a 22 LB from Wolff. Seems to shoot softer now than before and a couple of shooters at the Club say the same thing.

That's interesting. I've seen a couple of YouTube reviewers say the same thing.

 

[Mike SC Hunter]

But.......One question (from above) was never answered......Do you have to use a guide rod with a flat wound spring?.........If yes I don't really see an advantage in full size auto's.

 

[elpac3]

Flat springs can compress more that the standard coil spring. They will generally result in softer felt recoil as a result of the increase in compression

 

[JRD]

All springs with a length to coil diameter ratio past a certain point will buckle if they are not constrained. Long skinny springs (like recoil springs in pistols) will squirt out to the side unless you have something to hold them in line.
The constraint can either be internal (a guide rod) or external (a tube or passage such as an AR buffer tube).

It's only worth messing with flat wire springs when you need to fit more spring force into a fixed length than you can fit with a round wire. In a full size pistol, round wire springs are just fine.

Any perception in felt recoil isn't based on wire shape. It is based on storing more recoil energy in a stronger spring before your slide reaches the end of travel and delivers an impulse to the frame which is transferred into your hand.

Flat wire springs definitely don't rely on friction on a guide rod. You want springs to operate freely. Spring coils rubbing hard on a guide rod would be a detrimental thing for reliable function.

 

[Mike SC Hunter]

All springs with a length to coil diameter ratio past a certain point will buckle if they are not constrained. Long skinny springs (like recoil springs in pistols) will squirt out to the side unless you have something to hold them in line.
The constraint can either be internal (a guide rod) or external (a tube or passage such as an AR buffer tube).

It's only worth messing with flat wire springs when you need to fit more spring force into a fixed length than you can fit with a round wire. In a full size pistol, round wire springs are just fine.

Any perception in felt recoil isn't based on wire shape. It is based on storing more recoil energy in a stronger spring before your slide reaches the end of travel and delivers an impulse to the frame which is transferred into your hand.

Flat wire springs definitely don't rely on friction on a guide rod. You want springs to operate freely. Spring coils rubbing hard on a guide rod would be a detrimental thing for reliable function.

So.........Still the question.....Do you need a guide rod for flat wound springs in a full size pistol such as a 1911? Simple yes or no.

 

[sceva]

I have never felt the need for anything but standard round recoil springs in my 1911. Wolff preferably. But then I do not shoot thousands of rounds a year in it.

 

[S&W Fan]

I’ve tried same weight flat and round recoil springs in my 1995 Les Baer PII and can’t tell any difference in recoil impulse, operation or anything else. I shoot either 230gr fmj or standard pressure 230gr jhp. I’ve been shooting 1911s since a wee lad of 12, 68 now. I use Wolff springs.