Post by bluedot on Dec 20, 2021 18:17:42 GMT -5
I will be testing some .30 caliber bullets for expansion. I will be using it for deer hunting, that's why the expansion thing. Shooting subsonic. I can taylor the fps to stay in the 1000 - 1025 fps MV range. I will be using Trail Boss Powder in the .308. It has a 1:12 twist so I will be limited in what bullets I can use, BUT I have found that it will stabilize a 195g Tipped Sierra Matchking at 1000 fps @ 50 yds so maybe this barrel isn't actually 1:12 like it is marked. I have to lower the powder charge than what Hodgdon lists for that caliber/bullet or I am getting a supersonic crack. Hodgdon shows a 10.5g powder charge of Trail Boss with a 190g Hornady Sub-X bullet is 1038 fps. (I have to drop the powder charge with a 190g Sierra Tipped MatchKing to 9.2g get 1050 fps.) Also, I cannot load bullets longer than 2.880" COAL or they won't feed from the blind mag. (Kimber Mountain Ascent rifle, .308 Caliber)
BUT I have a few questions before I start.
This pocketbook can't afford real Ballistic Gel, nor can I shoot in a temp controlled setting. So, with that said, what can I use and more importantly what size should it be?
I am only going to shoot one bullet at a particular "thing" to check expansion. I feel that shooting 2x into the same "thing" gives a false reading if the 2nd shot hits the wound channel created by the first shot. I will be putting the media at the impact yardage not some random yardage number.
The distance that I will be shooting subsonic is 15 yds to whatever distance the bullet stays stable and expands. Be it 100 yds or 300 yds, I have a place to hunt where I can't cover the whole area with the 7mm Allen Mag at warp speed, that's why yardage isn't important, bullet performance is.
Yes, I know that if the gun is accurate enough to shoot them in the head/upper neck I don't have to worry about bullet performance.
I have a shooting range here at the house so I don't have to worry about doing this at a public range. I have dirt backstops set up at 100, 200, 300 yds.
If and when I get a few accurate loads, I can move the chrono out to the target to verify impact velocity.
With that said:
1) What should I use to verify expansion?
2) What size should the "media" be that I am shooting the bullet into? i.e. 6"x6"x?" length? 1/2 gallon milk jugs backed up with multi layers of wet towels? 1 gal milk containers backed by multi layers of wet towrls? OR?? Should the 1/2 gallon milk jugs be laid on their side so I shoot into the bottom of them?
I will put up a list of bullets that the gun shoots accurately and stable. I talked to Speedbump and he suggested shooting at the impact distance to see if they retain their stability. Good thought!
Finding bullets to test is HARD!
Here is what I have found to be stable @ 50 yds at subsonic speeds. (I am shooting with the can NOT mounted on the gun until I can verify whether the bullets will be stable or not, then shoot with the can on to double check fps and accuracy).
50 Yds
195g Tipped SMK
175g SMK
168g SMK
These are the bullets I have yet to try:
190g Hornady Sub-X
Lehigh 194g Maximum Expansion Subsonic
168g or 176gr Controlled Fracturing Subsonic (I KNOW I have that bullet design here, just gotta find the box)
Hornady 168g A-Max Bullet
178g A-Max bullet
165g Interlock
Sierra 230g SMK
168g SMK
175g SMK
180g SMK
165g Gameking
I know the other bullets I have like Accubonds or Berger VLD's won't be worthwhile testing. A buddy might have some other .30 cal bullets that I can try, I haven't sent him a list of what I have yet.
O.K., your thoughts?