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1 Attachment(s)
Attachment 143104
I managed to get out to shoot some of my subsonic cast reloads today with some interesting results. The photo is of one captured in a milk bottle line up, from inside the 5th (2L) milk bottle. Speed 1120fps(just supersonic), 7.5 gr Trailboss, expanded to .453 dia., shed weight from 151gr to 97.3 gr
Todays Results: (all Trail boss @50M, COAL 2.450, Ave speed of 3 shot groups, 1.5-4x Leupold scope set@ 4x, dark marlin 30-30 DPT suppressor)
6.5gr 1042 fps, 50mm group
6.8gr 1070 fps, 35mm group
7.0gr 1098 fps ( one round supersonic) 50 mm group
7.5gr 1143 fps (all supersonic) 25mm group
Also shop a group of the longer rounds mentioned earlier that jammed into the lands somewhat COAL 2.500, 7.0 gr TB ave speed 1084, group size 50 mm. Effectively slightly slower, which was a bit unexpected as I would have thought there might have been a pressure increase.
Grouping was a bit average really but might be requiring some more work on my part and I wasn't set up on my normal(better) spot. I might play a bit more with those loaded at 6.5-6.8gr to see if I can improve accuracy. Interesting to compare with jacketed loads shot last week ( berry bullets 150 gr) which when loaded at 7.5gr TB were consistantly subsonic(ave 1060fps).
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Great data man. Thanks that's going to be useful going forward. My barrel is an inch shorter than yours so I'm interested to see what my speeds are. Cheers
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I am thinking about getting a mould designed specifically for the 30/30 one on the short list is 170-180 grains not sure if there is a HP option
The 151HP is designed for the .308 which the chamber is cut for the 168 gr Sierra MK in most cases in mine the 155 gr PALMA bullet, that is why it is a bit chubby
up front any one interested in a 30/30 mould let me know
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Good results there, personally I'm not a fan of trailboss, it has its uses but you seem to get some wide variations in speed with it. Admittedly I've never chased subsonic loads but the 14 to 1600fps region is where I "aim" for. You might like to consider a light charge of a shotgun or pistol powder if you are after better. Most cast bullet shooters will probably say if asked for a starting load in any calibre 10 grains of unique or equivalent ap70n
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You are right Trail Boss may not be the best powder for sub sonic loads But it is the easiest to get good results with, powders like Red dot AS30 N310 and other fast pistol / shot gun powders
can give better accuracy but are a lot harder to work with needing fillers to keep the small amount of powder against the flash hole, Trail Boss does not need that much fussing about wth,
Another good load besides 10 grs Unique is 13 grs Red Dot if you Google The Load it will pop up,
.30 cal cast bullets generally have their best accuracy between 1800 and 1900 fps using the soft lead that I use or wheel weights any harder won't expand or will shatter.
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Truth be told I used to use fillers but stopped years ago, never have had a problem with ignition or consistent velocity. Only thing I still fill for is light loads in black powder numbers and I've discovered rolled oats to be about the best,
