Semi auto barrel/ loader ideas

[Creator]

Hey, new member that has been lurking for some time. I have a 1/4 in slide valve/qev combo and was wondering what the best semi auto type loader would be for 1/4 in steel balls.

[Ragnarok]

I'd probably suggest a simple blow-forward bolt, as it's fairly reliable and works well for spherical ammunition like that, although it does increase the dead-space between the valve and projectile.

Blow-back loaders tend to need more fine-tuning, and a pneumatically operated bolt would be rather overkill for a small bore like that.