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Ford SD
06-05-2013, 01:56 PM
Help 300 Blackout cast reloading question

Built my first AR a 300 ACC Blackout build for cast, with A 16" Wilson ss 1:8 twist barrel
Brass is converted 223 to blackout (annealed)

Be cause of getting old ---->tried a Tasco red dot on top.
First rounds down the barrel was 150g jacketed reloads with a REM fmjbt and 5744 to get on paper.
Did 50 rounds of those reloads several-- 2"-- 5 shot groups at 50 yards
A different target might help, when I put the red dot on target my black dot on paper vanished

On to the Cast rounds

Lead Boolits
did some dummy rounds and the way to go with what I have in hand is
the rcbs 165-sil boolit. cast as 173g.

I only shot 10 rounds of cast after the 50 rounds of jacketed (without cleaning it)
165-sil 17.5g 1680 oal was 1.955+- primers were ok
Cast loads were a best guess of some data I found, I could not find data for the 165 sil boolit

the question is chamber was very greasy at the end of the day and cleaned up very easily with a dry patch pulled down the barrel-- no lead

I ran out of time and did not run any rounds over the chrony

What I think I need to do is load some hotter round and see if dirt is reduced in the chamber
I loaded 40 round of a lesser charge all ready

Question

Do I need a harder lube (home made Felix lube experiment) on the soft side but you need a heater to use it.
Do I need to seat boolit longer gc in neck/ 1st lube groove still in neck oal was 1.955+- go to max of 2.020
Less lube --Now I fill up the 1 lube groove and fill up above the gc
or
do you think pushing it harder will clean up the chamber

the last option is I put too much lube on the bolt -- but the jacketed rounds were not dirty like the cast brass

Note to other people using data off the Internet I used (found this data to be hot)
http://www.accuratepowder.com/wp-content/uploads/2010/09/300_ACC_Blackout_Data.pdf

150 SIERRA FMJBT 17.8 1,848 19.9 2,053 54,993 2.140-- from accurate web site
and what I started with was
150 Rem FMJBT 17.2--------19.8-----------------2.150 and loads were having flat primers (the 17.2 load was ok and got worse as charge went up)

So if you use that data don't make too many rounds

(Casting for about 20 years--still learning)

Thanks for reading and the help
this is the best site around

Gunnut 45/454
06-05-2013, 10:22 PM
I run the Lee 155 GC out of mine -I'd seat them out farther. My OAL for the Lee is 2.015" I lube by wipping some Alox in the grooves- zero leading and with 15.5 gr IMR 4227 they run at just over 1900 fps! Accurate enough to wack clay birds (3" target) at 180 yards, milk jugs at 250 yards!