Range session that puzzles me...

[tddeangelo]

Went to the range tonight, hoping to come away from the session with my 300H&H and pre-64 30-06 both dialed in and ready to hunt. Turns out neither is.

Here's the target pic:

Those are 2" dots, by the way.

Left column of targets are from the 30-06. Right colum is the 300H&H, except the bottom one (that was my dad's 243).

I shot top to bottom in sequence. Top target on left has two touching high, two touching lower. Made a scope change, as that group is around an inch. After letting it return to ambient temp, I shot Dot #3. There are 5 rounds there, two roughly centered in the dot, two at 12 o'clock, and 1 high. Sequence of those 5 was #1 to the right of the center of the dot, #2 was the highest shot, #'s 3 and 4 were at 12 o'clock, #5 landed on the black center of the dot. Then I shot Dot #5 with my last three shells. All were 57.0gr IMR4350 with a 165gr PT set at OAL of 3.230, which shot 0.7" in a nice triangle for me the first time I tried it. Obviously, it did not repeat. I am not sure where to go with this one.

The right side, Dot's #2 and #4, were shot with the 300H&H. That sure looks to me like something a seating depth change can fix, if I have enough latitude to vary it to find the "sweet spot". That's a 200gr AB on 65.5gr RL19, set to magazine length, roughly, they are doing 2700fps on Dad's chrono. Sure looks like it wants a different seat length...maybe deeper?

Wide open to ideas here, guys and gals. These rifles have me scratching my head.

 

[Oldtrader3]

Tom, I am not sure what your question is? To me, those groups look pretty much statistically relevent and are normally distributed. Maybe we need to talk more specifically? Just the way you are holding the rifle on the bench or whatever can walk groups that much.

 

[cloverleaf]

Groups 1-4 show "good to go" for hunting accuracy IMHO. Nothing shabby about those groups. "statistical variation" is what it is...CL

 

[tddeangelo]

On 1, 3, and 5, all the same rifle, all the same load. 1 shows about 1". 3 strings vertically over about 2". 5 shows a triangular distribution over about 1.5". I guess I'm expecting more from this rifle, so I'm not sure where to go next with it.

The 300H&H is on #'s 2 & 4.....seems to group and throw a flier. I've seen this before, and I'm thinking it might need a seating depth change? Any other suggestions on that one?

These are both pre-64 rifles. The '06 has the fore-end screw installed, the 300 does not.

I'd really like to see that '06 shoot at an inch reliably, not 1" - 2". I guess I'm looking for suggestions on tightening that group and making it throw repeatable groups.

 

[Oldtrader3]

Actually the groups look pretty coherent and I can not predict any randomness from what you have so far. I guess, considering how the .300 H&H came together and missing a front screw, I am surprised that it shoots as well as it does. It shoots really well considering! You may have a "node" affecting your groups just from the stock and not having the front screw? This all can be fixed of course.

Anyhow, today is not math day for me after last week and I will think about this some more from what you have shown here. A few more groups would make all of this data a little more congruent, me included.

 

[AzDak42]

When I get things wildly out of expectations, I start looking at the overall setup more than the load.

- I have a few rifles that have far different patterns depending on how I'm setup. (Bipod, versus bag. Front bag versus bag nestled into the trigger housing.) Did any of those things change?

- This is also why I bring a box of known factory loads along in case I need to validate whether it's my loads or something else gone awry.

- Check your scope mounts... did anything loosen up or shift? (If it had, I'd expect larger variation than this shows, but you never know.)

- Did you change your cleaning routine? How about your fouling shots? When you cleaned, did you nick or damage the crown at all? Shooting a dirty bore versus a clean bore can have pretty wild changes.

- Did you change up how shells were fed? Loading single shots can sometimes be different than magazine fed rounds, especially in an autoloader.

- How about you? Were you anxious? Sleepy deprived? Did you binge on coffee? (I hate the last one, on mornings I'm going for accuracy, I really have to skip my morning cup....)

- How were your personal ergonomics? Were you consistent every time you put your face to the stock? Were you getting the same eye relief? Same hold? Was your finger on the trigger in the exact same position? Was your body in the same position behind the rifle and sitting at the bench?

I know some of this seems silly, but I've found, at least for me, consistency is everything... When I write up my shooting notes when testing a reload batch, I take notes on all these things, so I can have some indicator of what's going on.

 

[SJB358]

I am with the others. I would reshoot them again Tom. Slowly as you can and as relaxed as you can, re shoot. Do three or four dry fires with your set up, between shots. That will really tune you into the specific rifle for that bench session. Overall though Tom, you could chase alot more accuracy for not alot of return on your investment. Your hunting accurate right now. I would just look and see exactly where you want your rifles zeroed, get them out there, verify your zero at that exact yardage and get em hunting. Sometimes shooting at 100 yards is frustrating. Stretch it out to 200 or 300 and see what comes out of it. That is a better test of your rifles/loads.. Might just surprise you too.

 

[Oldtrader3]

Tom, do you know or remember how to do "sum-of-the-squares" on these bullet holes? I would try to shoot maybe (5) 4-shot groups and sum the squares and look at them?

 

[tddeangelo]

Charlie, I think I'll need a lesson on that one....the term rings a bell, but I'm an IT weenie now, not a scientist.

 

[OU812]

I'm with Scotty and others. If it were me with the 06 I would load up a few more and shoot 3 shot groups. You said you made a scope change. Just cause you made the change to the scope does not mean the scope took it. Those other groups could be the scope settling.

The 300 H&H, I would seat deeper by 1/4 turn on the die and try again. Repeat until the group comes together, 2 touching 1 out is the reason.

That's what I would do.


Bill

 

[SJB358]

I was going to say that about the scope settling, but since it is a Minox/Swaro, I discounted it. Could be the rings are torqued a little too tight, as even the best scopes seem to take some extra nudging when the ring caps are tightened too much..

Yep, 1/4 turn on the seater till it pulls in. Might not take too much at all.

 

[Jerry 919]

Sometimes a change in primers call make a lot of difference.

Jerry 919

 

[Oldtrader3]

No sweat Tom. I am an old man who does nothing for a living. I had to do the stats for many years as part of my job. I still use them, not as an exercise, but to understand what I think I may know or not? Sometimes they help, sometimes they make it worse!

 

[OU812]

Sometimes a change in primers call make a lot of difference.

Jerry 919

Good call on a primer change.

Bill

 

[tddeangelo]

I loaded the 300H&H with Fed215M and the 06 with Winchester Large RIfle primers.

I guess I could load the 300H&H with the Win's.....

 

[Oldtrader3]

Tom, I have switched to Magnum Match Number 215 Federal in my 7mm Rem and my .340 Wea Mag. They seem to be hot and extremely accurate. I also use CCI BR2 in my .30-06 for primers with excellent groups. FYI.