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Pulse Sniper

I still have it from a local save. Could re-upload it if the original mod author approves.

OET - Redux also features a full auto rifle that operates in a similar fashion.

what happened to the M4A1 Pulse Rifle that use to be a mod?

There is a mechanic for shots to pass through as I remember. The modding tools for this are actually simple enough to use for anyone, even if youre not a programmer/havent modded before.

I will come back to this eventually, but in the mean time you may be able to achieve what you want by going to the mode editor in the game and editing mine

(Now I'm wondering if there's a mechanic for a "penetrator round", where the bullet continues past the initial target to hit others in a line 5-8m beyond it? Would be an interesting variant! Give a couple of both types to your survivors and make a mess! ^_^)

(After testing)
I think my guess was right. I'm not seeing the splash damage on any adjacent targets, even small bugs close together. It's a bit difficult to see how often the stun effect is triggering, since low-hp creatures tend to be one-hit-kills. My recommendation would be to double the splash range to 3m (if that's a variable you can control) and see if it's actually hitting more than the initial target. Then we can worry if the stuns are working on the splash zone targets or not.

As it stands now, it's already a great upgrade for the sniper (want to call it "Sniper 3.0"?) where a hit on large, high-hp monsters will stop their advance with a stun for a bit longer to give you an extra shot in. Not so powerful that my handful of survivors can just stand on a hill and mow down entire swarms without having to do some dodging. Still got to work a bit for the victory, as we ought.

This looks like a great addition! A respectable upgrade, without being absurdly overpowered.
(checks the below comment) ... provided it actually works, of course. -_-

(thinks a bit) I wonder if 1.5m is quite enough radius to hit other targets more than rarely? If it's true to scale, that's less than the height of many of the survivors. Might not reach the bigger creatures next to each other, only hitting small bugs in tight clusters. Try doubling that to a 3m splash radius and see if that helps hit a few more targets. (Rereads Mantastic's comment more carefully) ...or is it that other targets in the splash range are being hit fine, but just the stun effect isn't triggering?

...Well, enough supposition. Time to test this one myself. ^_^

Some feedback. The Stun effect only seems to be affecting the one target the bullet hits, which makes it fairly useless for crowd control. Might need some adjustment?

Nice! I'll give it a whirl.