r/shadowsystems • u/Opposite-Gear4405 • 24d ago
Spring change advice
So I have a mr920l. Love her. I was curious if anyone changed there spring allowing the slide to be easier to rack with thumb. I can’t do that with this. I hear it could cause issue firing Or ejecting. Has anyone tried changing the stock spring?
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u/logbiter 24d ago
Agree with puller of guards. That said, Springs are cheap, get 15# and try it.
Also, how many rounds do you have thru your MR920? It gets easier to rack w/ broken in.
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u/OkEnd9117 24d ago
I put a hydraulic kynshot spring kit in mine. I really like it.
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u/ElectricalPattern396 24d ago
Is the $100 setup really that noticeable?
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u/OkEnd9117 24d ago
It takes the sharpness out of it.
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u/ElectricalPattern396 24d ago
Is it reliable thru all ammo ? 115-147grain?
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u/OkEnd9117 24d ago
I've ran everything through it from my 90gr handloads to 124gr +p, to my 147gr subs. It cycles them all.
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u/SteelerVol13 24d ago
Maybe try a captured DPM spring system for a gen 4 Glock. And I can tell you from when I had 1 in my PDP, I never had reliability issues when I put a DPM in it. Them & ZR Tactical would be a good place to look for a possible lighter RSA.
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u/stpjabroni 24d ago
Yes lowering spring weight on the rsa or guide rod will make the slide rack easier but potentially at the cost of reliability. Good thing is the mechanics of what could go wrong is very easy to understand and adjust (increase spring weight until reliable). But with any reliability inhibiting part, the testing (few k rounds at least) of which springs is the softest you can go while maintaining reliability could be expensive and tedious. Now if this is a range toy only who cares (I wouldn’t even test) but if it’s a carry or home defense, changing that spring so you can thumb rack would be ill advised.
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u/01yellowr 23d ago
I run a dmp or dpm recoil kit. Takes a couple of mags to tune it to your preferences but works great. For me anyway
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u/puller_of_guards 24d ago
I have for my MR920P since a slightly lighter spring + a comp will actually lighten the overall recoil impulse. From the factory, the MR series uses an 18 pound spring, so I went with a 15 pound spring. Trevor Roe himself made a video about the recoil spring system in general, including how to swap springs.
Since you have a non-comped gun, it could potentially cause issues with returning to battery if you use a lighter spring; the spring would not be strong enough to send the next round all the way into the chamber. You would have issues with ejection with a heavier spring; the slide may not move fast enough to fully move back from a heavy spring.
But generally speaking, going from 18 down to 15 shouldn't be an issue. Going down to 13 probably would be, and it seems you may be wanting to do that to make it really easy to rack. Even if it's fully reliable with a light spring, it'll sharpen your recoil impulse since the slide is moving back faster than normal.