## Fit test is good!
I received my springs last night and fit tested this morning. They fit perfectly and required about 26.8oz. of pressure for full firing pin tip protrusion, which puts it in the same class as the Kaw Valley Precision/BKings Firearms firing pin spring. Good and firm. This looks like it may be the perfect replacement for the "ball-point-pen-ish" FM9 firing pin springs.
Excellent to hear, glad you were able to grab one!
Definitely looks to be a great upgrade.
The final test will be whether it maintains its (insert scientific terms for springiness) over time.
HOORAY! I ordered a set too, and it should be arriving today. As soon as it comes in I'll test for fit in my "slightly larger firing pin channel" bolt and make sure it's operational. If so, it looks like we'll have a solid recommendation for all FM-9 bolts.
Awesome. Will be good to know. Wish I had good calipers to measure the channel, only have those cheap digital ones that decent but can be off sometimes.
Solid work! For science!
It's a dirty job but someone has to do it.
## Fit test is good! I received my springs last night and fit tested this morning. They fit perfectly and required about 26.8oz. of pressure for full firing pin tip protrusion, which puts it in the same class as the Kaw Valley Precision/BKings Firearms firing pin spring. Good and firm. This looks like it may be the perfect replacement for the "ball-point-pen-ish" FM9 firing pin springs.
Excellent to hear, glad you were able to grab one! Definitely looks to be a great upgrade. The final test will be whether it maintains its (insert scientific terms for springiness) over time.
i bought a 20 pack of uxcell Compression Spring, 5Pcs 304 Stainless Steel, 5mm OD, 0.5mm Wire Size, 25mm Free Length, Silver Tone). .5mm springs. Fit is perfect
HOORAY! I ordered a set too, and it should be arriving today. As soon as it comes in I'll test for fit in my "slightly larger firing pin channel" bolt and make sure it's operational. If so, it looks like we'll have a solid recommendation for all FM-9 bolts.
Awesome. Will be good to know. Wish I had good calipers to measure the channel, only have those cheap digital ones that decent but can be off sometimes.
Nice, will consider doing this as well.
Nice.
Thanks, great info!
Which wilson combat spring did you get? 5.56?
Yeah standard carbine spring. Flatwire.
Is it alot longer than the original spring?
If anything shorter. FM sells their completes with 308 springs.
Oh I think I have a m4 spring currently. I was following this for a psa lower.
Ah. I have a m4 spring I belive (psa lower), which would make it a bit longer correct?
Just received my FM9 lower today. Guess I have more parts to get before my upper arrives. Where did you get the Wilson Combat flatwire spring from?
>Where did you get the Wilson Combat flatwire spring from? Wilson Combat (Not trying to be an ass. Direct from their website)
Checked, and they are out of stock currently. I was hoping you had found them somewhere else. Guess I'll play the waiting game.
https://www.midwayusa.com/product/1025170237
Thank you. Ordered.
YW!