Question about ammos

Jeff543 · Oct 21, 2025

I just can't wrap my head around this. How can an ammo have high pressure but still be slow, like subsonic speed? That just doesn't compute for me.

duraBrick · Oct 22, 2025

I remember scratching my head over this very thing when I first dove into reloading and setting up suppressors. It just didn't add up to me. But everything clicked when I started working with subsonic .300 Blackout loads. That's when I figured it out. The trick is that pressure isn’t just about how fast the bullet goes, it’s more about the force applied over time. A heavy bullet, like a 220gr, needs a lot of pressure to get going, but the powder charge is dialed in to keep it under the sound barrier. So you get this strong initial push, but not enough to keep hustling past that sonic threshold.

shrederic_ · Oct 28, 2025

I’ve been loading up some 220grain bullets for my .300 BLK, using powders like Trail Boss and Accurate 1680. The pressure was solid, but the velocity stayed around 1050fps, which is ideal for keeping it subsonic. It’s really about having the right balance between that initial pressure, the weight of the bullet, and the time it spends in the barrel.

Once I laid out the pressure curves next to the chrono data, it all started to make sense. It’s one of those things that feels off until you see it in action.

Question about ammos

Jeff543

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duraBrick

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shrederic_

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