Post by bluedot on Nov 29, 2021 1:43:44 GMT -5
I have a Kimber Mountain Ascent in .308. It's a 1:12 twist, 22" long barrel. It has a blind magazine, and I don't know yet just how long of a bullet/case it will feed. I can single round feed, but I'd prefer to feed from the mag. The barrel is threaded and I just picked up my can for it. I need to do some load development for both full speed bullets and subsonic bullets. It's strictly a hunting gun, and with the pencil barrel I can't shoot more than a few before it gets too hot. I have broken the barrel in, and now it's time to get busy.
The gun sans scope weighs 4.8 pounds. The can is a Dead Air Nomad Ti, 9 ounces.
I have downloaded the subsonic load data from Hodgdon. BUT they only list the 190g Sub-X bullet which I don't have any. I have a good feeling that I can play around with the Hodgdon data and shoot over the chronograph to get a handle on velocity/pressure with "off book" loads, but I'd rather start with known powder loads/bullet weights.
Here is a list of the .30 cal bullets that I am considering to use in the gun for subsonic hunting for whitetails, and I have them here on hand. I don't know if they will all work at subsonic speeds, if anyone knows please let me know yea or nay.
168g A-Max
176g Lehigh 300 ACC (750-1,200 fps)
178g A-max
194g Lehigh Max Expansion Subsonic (750-1,200 fps)
195g Sierra Tipped Matchking #7795
230g Sierra HPBT #2251
For full speed loads I have a boatload of bullets
130g Barnes TTSX
165g Sierra SBT #2145
168g Sierra MatchKings
175g Sierra Matchkings
180g Sierra Matchkings
168g Hornady BTHP National Match #30501
168g Hornady Interlock
The 168g and 176g Hornady A-Max listed above
168 Berger VLD Hunting bullets
165 and 180g Nosler Accubond
175g Lehigh Controlled Chaos (1,500-4,200 fps)
Various Lapua and Speer match bullets
Primers? I have enough. All Federal Large Rifle Primer variants, Win WLR primers, CCI BR-2.
Powders? Pretty much everything for a .308.
Trail Boss
H4895
H322
H335
CFE BLK
Lil' Gun
H4198
H110
IMR 4198
RL-7
RL-15
BL-C(2)
H335
Varget
IMR 3031
Win 748
I know RL-15 and 165-175g bullets work really well together for full house loads, but I am way more interested in the subsonic stuff. I have a Barnes Reloading book for the 130g Barnes. I also have books here from Speer, Sierra, Nosler and Hornady. Also have Ken Waters Pet Loads book and the updated addendum to it.
If anyone has any of the Hornady 190g Sub-X bullets, I'd trade bullet for bullet for up to 50 of any of the ones that I have listed above.
I don't know yet the base to lands dimension for the various bullets, but I have the modified case to start taking measurements.
I have a feeling that the 1:12 twist will be a limiting factor for the longer, heavier bullets, I thought it was a 1:10.
So, can anyone help with load data?
Thanks.