I just got it back from my gunsmith after he had to rechamber it following my handing my brother a 30-06 round to fire in it. (I posted this "dumb thing I've done" about a year ago. It really was a mess. Fortunately, noone was hurt, my brother still talks to me, and he does not have a permanent flinch.) We never could figure out exactly what was going on with it after the episode, but it just wasn't right. Eventually, the barrel was pulled; the was shortened slightly, and rechambered.
I loaded up some WW once fired cases with 71.3grs of H4831sc. Carefully measure the distance to the rifling, and seated a 180 Nosler Partition about 2/1000 off the rifling. Primed it with WW WLMR primers. This load is not as acc as my previous 180BT load. It shot a three inch group at 100yds, 200yds, and 300yds. (Several groups were shot at each distance. The groups were all three inches.) Velocity was 170fps faster than my previous load. The only change, other than bullet, from my 180BT load was primer. I used FC 215Match with the BT load.
Velocity was 3159fps. Friends this is flying. Bolt was easy to lift. Extraction was easy. No primer problems.
For those of you with a ballistic's program, this load essentially shoots 2.5"high at 100dys; 2.5"high at 200yds; and -2.5"low at 300yds. In sum, you put the pipper on the target and squeeze. Energy at 300yds is 2500ft#'s. This is a real "clean up" hitter. I wonder why I bother with anything else, but then where is the fun in that. Ku-dude
Is the 30-338 dimensionally equal to the .308 Norma Mag?? I'm thinking it is.
MM
The 30-338 is basically a 308 Norma Magnum, but with a wee bit more case capacity and they are not interchangeable..
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Ray Atkinson
No, DB, I meant three inch groups at all three distances. Go figure. I am certain some of it is operator error (after watching the parts fly everywhere, it is difficult to get snuggled in, don't you know?). I also suspect that at 100 and perhaps 200 the bullet has not settled in.
Regarding the increase in velocity, I called my gunsmith today and talked with him about it. It maybe a difference in primers (215M v. WLMR). It maybe a slightly shallower seating depth (less than a 1/100th of an inch though). It maybe a combination of those two factors and environmental factors such as temperature. (However, most of my testing is done in the spring and summer when our temps are 90F+.)
I know that I'd settle for 3100fps and 2"groups at all three distances. I will probably drop the load by at least the .3grs and see if the groups don't tighten up some. I noticed that my groups tightened up over the session. (100yds were fired first. 300yds last.)
This rifle was shooting one hole groups at 100, and gloverleafs at 200. It has shoot groups under 1/2MOA at 300. I hope that it will go back there. However, they were shot with Nosler BT's, and the partition is not quite as accurate. I figure half the problem is that alone.
I've got to help my wife with the groceries. Caio! Ku-dude
[This message has been edited by Ku-dude (edited 04-28-2002).]
Am I right in my assumption that the 30-338 is simply a necked down 338.
I agree though that the caliber is wonderful as it seems very forgiving.
On another note, I think ~71gr of H4831SC (for the 308 Norma anyway) is a bit on the light side based on my experience to date. I usually land somewhere between 72 and 74 grains of powder. Because I don't tend to shoot this particular rifle at high volumes (it's my deer rifle mainly) I weigh each and every round. I would agree that bridging can be a problem with this powder.
That's all that comes to mind.
Reed
Reed,
The .308 Norma case is slightly longer than the .30/.338, and won't chamber in the .30/.338.
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Phil- Life Member NRA & SCI
[This message has been edited by Phil R (edited 04-29-2002).]