Setting up an accurate lever action for subsonic loads

[bladeracer]

What's the auditory difference between ~1100fps and ~800fps? Is it a logarithmic or more linear decrease? Is there any actual data out there about this subject?

I haven't seen data, though I'm sure it exists. Go outside and fire a CCI Std Vel 40gn at 1080fps and a CCI Quiet 40gn at 710fps, the difference is significant. The CCI SV has 1gn of powder, I haven't opened a Quiet to measure it. It is probably a lower charge, but it could just be a different powder.

But I think there is some increase in noise when using larger charges to push heavier bullets, while still staying subsonic. I would have to actually measure the reports to be definitive. But they are still significantly quieter than even a .22LR going over 1200fps in my opinion, the sonic crack is very loud. I want to play with loading subsonic shotgun loads one day, a subsonic 450gn+ load should be getting significantly louder than a 40gn bullet at the same velocity, based on my experience, but would it approach the level of a sonic crack?

[bladeracer]

I'd have to google it in2anity, not sure of the figures. Its quite noticeable to me. The lightest loads of 38 which still exit barrels are burning less powder than a 22LR stinger for example, and without that supersonic crack (pulling stingers apart they average about 2.5 grains of an unknown powder).

That seems like a lot. I weighed the charges in WMR last year and I don't think they had more than 2.5gn in those. So I just pulled a Stinger - 2.6gn

[mickb]

Thanks for the comments Bladeracer. I might try TB again, found it a bit dirty and AS-30N gets more velocity per grain but worth seeing what accuracy I can wring.

As to WMR I dont use it, but data on the net suggests powder loads are up to 5.7 grains? With the case volume and velocity and same pressure rating as 22LR it would have to burning more powder to get all the extra velocity.

[mickb]

I want to play with loading subsonic shotgun loads one day, a subsonic 450gn+ load should be getting significantly louder than a 40gn bullet at the same velocity, based on my experience, but would it approach the level of a sonic crack?

Now that would be an interesting experiment mate. I have seen some sources on the Brits with suppressed shotguns.

[mickb]

in2anity, bladeracers analogy of 22LR quiet vs other 22 is a pretty good comparison. That even a 22LR match( 1050fps) has a lot more pop than a 22LR quiet at 700fps. The quiet is hearing safe.

[bladeracer]

Now that would be an interesting experiment mate. I have seen some sources on the Brits with suppressed shotguns.

Suppressors would be a nice option in the real world, but we live in fairyland.
I do want to put a brake on a shotgun though.

My current shotgun loads are actually faster than standard, though I've never bothered to run them over the chrono. I'm using bulk 1oz (438gn) field loads with the shot replaced with either a 360gn slug or 50 BB's (making 325gn - only 75% of the original load), so velocity is likely higher than the rated 1300fps 1oz loads of 7.5's they came loaded with. I'll have to have a play with the charge weights to bring them down to subsonic.