I Did the initial velocity tests at the range yesterday. This is to determine the required velocity, before playing with seating depth for grouping. Everything was what I had hoped for. Even the groups were very consistent although for varying charge weights? Can anyone explain the pattern on the target for me.

The 1st four shots grouping ± 1/2". Charge 64gr-67gr.
And then going up in 1gr increments 2 shots still pair within 1/2".

Cheers
Johan

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The diagonal stringing is probably due to barrel harmonics and the associated increase in bullet speed leaving your rifle barrel. That'd be my guess anyway.

Looks to me like you'll find yourself a very accurate load for your rifle.

It shows that your rifle is relatively insensitive to changes in powder weights. And it shows you can pick any one of these and shoot very nice groups. I am sure you know this.

Quich question. Where do you get the targets with load data area?

Thanks
Jose

Your group is a typical pattern that is usually caused by the tang area being too low, and that causes the 3rd or 4th shot to be high and sometimes left probably from pressure on the left side of the tang. Your gun shows great accuracy and a desire to shoot, so load development is probably not your problem.

I would suggest that you check your tang bedding then place a shim under the tang being sure its not tight on one side or the other of the tang. If that works then glass the whole area lightly, usually just a paint coat of glass is all you need, or just leave the tang shim in it, if the shim works I have a policy, if it ain't broke, don't fix it.

While your at it check your bedding at the front of the forearm, sometimes, and more often than not, tang pressue moves the barrel in the opposite direction and many a rifle stock has been ruined by folks releaving the forend as opposed to the tang because inletting black indicates pressure there, and they end up with an ugly gap in the forend..The more wood they remove the larger the gap gets and when the inletting black no longer shows, total confusion and frustration abounds, they are giving it a haircut instead of wipeing its butt.

That "group" is from 8 different loads. Seven grains of powder won't make any difference?
Do you expect all 8 loads to go into the same hole from a 338 mag?
I don't see a problem.

quote:

Originally posted by mcvsbt:
Quich question. Where do you get the targets with load data area?

Thanks
Jose

I Made it myself, do you want it?

quote:

Originally posted by dpcd:
That "group" is from 8 different loads. Seven grains of powder won't make any difference?
Do you expect all 8 loads to go into the same hole from a 338 mag?
I don't see a problem.

No, no, too much to ask!!!! It was just interesting to see that two different loads grouped together at approx. every 2 grain increments. Next week I'll load the 69gr load at different seating depths and shoot for grouping. I hope to see tight groups from this!

Thanks
Johan

It was suggested that your rifle has an issue; I don't think it does and neither do your loads. Yes it is interesting how the different loads reacted. I would have expected far more dispersion.

Yes please. Can you send as a link I can print?

Thanks
Jose

johan,

Outstanding shooting. If you can do a group like that with a .338 Win Mag., you're shooter for sure, staying with the shot & following through.

Also a rifle, that with some tweaking is destined to be even better.

To your disappointment you'll find that superb diagonal group will look a lot more dispersed at 200 & 300 meters (remember field conditions).

I'm all over this with Ray Atkinson, who nailed this spot-on.

If the only thing you changed in this test was the was the charge in the cartridges, the group should be vertical; the rifle (barrel) is obviously a real shooter but you'll do alot better when the bedding issue is resolved.

At close range you can't count on the higher charges hitting higher, because the barrel whip can easily over-ride the influence of higher velocity. Or, to put it another way, a whipping free floated barrel doesn't know which way "up" is and can just as easily walk shots left to right as up and down. Sometimes shots will climb as the charges increase, stall out at a solid node and then start dropping again.

Thanks