Correct recoil spring weight for 9mm 1911 with 115gr WWB

[Little Creek]

I have a RIA 1911 style 9mm pistol. I have been using both 9 & 10 round Metalform magazines. Sometimes the slide fails to lock back on am empty magazine after firing. What recoil spring weight comes in the pistol? What spring weight do those of you with a similar pistol recommend for this pistol/ammo combination? I am thinking I need to purchase a 12# recoil spring.

[farscott]

I am not sure what weight recoil spring comes in a RIA 9x19 1911. There are a lot of variables that drive the recoil spring weight. The load is one of them; two more subtle ones are the mainspring weight as the slide needs to cock the hammer and the radius (or lack thereof) on the slide stop as that determine how high (torque change) the slide impacts the hammer. The force needed to unlock the gun is another variable, one that makes the 9x19 1911 a bit more of an experiment in parts selection. With 9x19 1911 pistols, I treat each one uniquely. I have one gun with a 9# spring and another gun with a 12# spring. I have others that use 10# and 11#.

In any event, I do not use whether the slide locks back on a empty magazine to set the recoil spring weight as that may be a symptom of not enough travel or the magazine follower not pushing the slide stop in a timely enough fashion to seat in the slide notch. I use the pattern of the ejected brass to select the proper recoil spring for the load. I am looking for a nice pile on a sheet about four to six feet from the gun. I suggest grabbing a few Wolff springs in rates from 9# to 13# and experimenting until you get the brass in a nice pile not too far from the gun, yet not dribbling out the ejection port.

[OlongJohnson]

I know it's not your question, but I've never had any pistol put its best groups on paper with WWB 115.

[Little Creek]

I am not sure what weight recoil spring comes in a RIA 9x19 1911. There are a lot of variables that drive the recoil spring weight. The load is one of them; two more subtle ones are the mainspring weight as the slide needs to cock the hammer and the radius (or lack thereof) on the slide stop as that determine how high (torque change) the slide impacts the hammer. The force needed to unlock the gun is another variable, one that makes the 9x19 1911 a bit more of an experiment in parts selection. With 9x19 1911 pistols, I treat each one uniquely. I have one gun with a 9# spring and another gun with a 12# spring. I have others that use 10# and 11#.

In any event, I do not use whether the slide locks back on a empty magazine to set the recoil spring weight as that may be a symptom of not enough travel or the magazine follower not pushing the slide stop in a timely enough fashion to seat in the slide notch. I use the pattern of the ejected brass to select the proper recoil spring for the load. I am looking for a nice pile on a sheet about four to six feet from the gun. I suggest grabbing a few Wolff springs in rates from 9# to 13# and experimenting until you get the brass in a nice pile not too far from the gun, yet not dribbling out the ejection port.

FWIW, I replaced the mainspring with a 19#. No misfires. I also replaced the sear spring with a competition spring. I do not plan to carry this pistol. It is a range tox only.

[Little Creek]

I know it's not your question, but I've never had any pistol put its best groups on paper with WWB 115.

Understood. I believe JHP or truncated cone flat tip 147 grain to be among the most accurate. I also shoot the new USA Forged 115. It is about $1.67 per 50 rounds less expensive than WWB where I live. Most of my shooting is within 15 yards and most of that is 5-10 yards. I shoot multiple shots from concealment or low ready. High in the chest or head shots. 4" groups at 15 yards are easy. That is all the accuracy I need for training and practice.

[Wobblie]

https://shop.harrisoncustom.com/wolff-recoil-springs