Thread: Subsonic 30-30

I've just been playing with this. Using trailboss and sierra 150gr round nose. 6.5g,7g,7.5g8g and 8.5 gr all worked well through marlin 336 15.5inch barrel 7.5 grouped reasonably at 50m. My shooting mate bailed on me last minute so I had no chronograph. It's only going to be a plinking round . What would the minimum velocity be to get reasonable expansion ?

The idea is to reliably get as close to supersonic as possible, without it going supersonic

7.5 grains of Trailboss is subsonic in my 16 inch M94 using 151gr cast bullets, using 8 grains I get some going supersonic.
I haven’t tried jacketed bullets, but I would assume they would have reasonable expansion at the velocity they are doing at 200m with normal loads, but this is probably well above subsonic.
I would try emailing Sierra.

The sierra's won't expand at subsonic velocity's . You will need to used either softlead hollow points or dedicated subsonic bullets which are real expensive

agree...use the 151 hps and if they arent giving you enough expansion......there are a few very basic "tweaks" tht can be made to ensure they will do so

Cheers guys thanks for the info. Wow $3 each is getting up there. But I kinda want to try them out

Cast lead flat nose or hollow point 180 grain bullets. Subsonic there is no need for a gas check and pure lead is soft enough to do quite a bit of expansion even if you don't hit bone.
Accuracy will also probably improve as there not enough pressure to properly set up a jacketed bullet designed for supersonic launching.
Trajectory is the same as for a .22 so it's simple to work out.
Rob walker (shooternz) would be a good place to start. Bullet casting though enjoyable is a whole new rabbit hole.

Originally Posted by Micky Duck

agree...use the 151 hps and if they arent giving you enough expansion......there are a few very basic "tweaks" tht can be made to ensure they will do soAttachment 128540

Your HP boolits are almost wadcutters. (-:

they arent mine, they are the ones mentioned above,Roberts...that was recovered from neck bones of head shot goat....so far the only one recovered.

Originally Posted by Cigar

7.5 grains of Trailboss is subsonic in my 16 inch M94 using 151gr cast bullets, using 8 grains I get some going supersonic.
I haven’t tried jacketed bullets, but I would assume they would have reasonable expansion at the velocity they are doing at 200m with normal loads, but this is probably well above subsonic.
I would try emailing Sierra.

Same for me with trailboss and 151gr 308 casts. We clocked them at 1050fps if I recall.

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