.375W groups, puzzling and good

[3584ELK]

Okay, I went to the range today, and it was a bit gusty, but I tried to shoot when things were calm- that's variable #1. Variable #2 was shooting the best group at a 5" bullseye vs. an 8" bull for the 4.30" group. Here is where I am puzzled- from Ballistics 101, we learned that low Std. Deviation, Extreme Spread, and Ave. Deviation numbers indicate potential accuracy due to repeatability, etc.

The larger group was shot with a load chronographing 2076 fps, with SD, ES, and AD numbers in the single digits. Unheard of in my loadings! Then, one grain of powder more blows those numbers back up into the 20' and 30's and I pull off a 1.55" group! This rifle has never shot so well!

I know that a pair of 3 shot groups don't indicate anything other than a fluke, but it is interesting to me. What do you guys think? Thanks in advance for your opinions!

[Dale53]

Three shot groups can be VERY misleading. Your 4.3" group shows practically NO vertical. You mention a windy day and a good bit of that could have caught ONE bullet and made a decent group look bad. Shoot five shot groups and several of them in a row (three minimum and five is better). Then you can begin to judge.

I just think that you got caught in a reversal on one shot or maybe you zigged when you should have zagged on one shot:mrgreen: .

Easy solution, just shoot more:Fire:

Dale53

[waksupi]

The standard for testing cast bullets, is a ten shot group, preferable repeated at least three times, before a load can be really judged. Shoot more!:Fire:

[9.3X62AL]

I've gone to 10-shot groups to REALLY see what a load's potential is. For hunting load analysis, a 3-shot group from a clean, cold barrel might be a better way to see just what the load--rifle--and operator will do when the 5 x 5 shows himself in misty morning light.

[Harry O]

I use three shot goups, too. None of my guns are benchrest or varmint guns. After 3 to 5 shots the groups in every one of them begin to open up. In some, with light barrels, the barrel can get too hot to hold by the 4th to 5th shot. I am more interested in where they will hit with the first three shots. I probably won't be using more while hunting. If the first three shots don't hit at the point of aim, I try to cure it, but if I can't, I get rid of it.

BTW, every gun is a little different. My 9.5x57 MS will always shoot the first two shots within 1/2 MOA. The third shot is higher and to the right (1 MOA or a little more). Shooting more goes higher and a little to the right. My Browning BAR shoots the first three in a tight round group. More and they slowly start climbing. Some of my lever actions (like a Win 94 in .375 Win) will shoot 5 before they start climbing around.

There are a few guys at my range with similar guns who shoot 10 shot groups. However, they wait 5 or 10 minutes between shots. What will that tell them? They cannot do that while hunting and cannot do that in competition.

[versifier]

Harry, I think there are two different questions here involved here, not one. One way evaluates the load, the other the rifle. To evaluate the actual load/boolit combination, the more shots in the group, the better. Yes, you have to let the barrel cool, the stringing comes from the barrel heating. This is completely different than evaluating how a load will perform in a rifle in a hunting situation, which is what you are doing. I want to know what my hunting rifles will do, too, but before I check that out, I want to know exactly what the load is capable of. That to me means as many ten shot groups as it takes to clearly determine the differences in incremental charge increases: I want to know when the average group shrinks, when it reaches its maximum accuracy, and when the group begins to open up again. I have hunting rifles with very light barrels that are capable of 1/2MOA, but the barrel has to cool before I know anything meaningful about the load. If I were to crank ten rounds through them as fast as I can work the bolt, I'd have a nice tight little three or four shot group with a string climbing up and away to the right as I progressed. :rolleyes: All it would tell me is that the barrel was light and wasn't dissapating the heat well and I wouldn't have a clue what the load was capable of. I might be happy with that if all I wanted was a plinking load, but I want to know what's really happening with my loads, and it's no big deal to me to take the extra time to explore it, and it's likely no big deal to the other shooters you mentioned - they are trying to answer a different question than you are. The whole point of our hobby is to have fun, and that's a little different for each one of us. If you enjoy doing it your way and are happy with the results, that's good. As you say, every gun is a little different, but every shooter is a little different, too. ;)

[txpete]

I have a very early win 94 BB in 375 win.it is one of my fav. levers.
I use the lyman 264 gr gc sized .377 277 gr's my alloy.

I guess I am the odd man out here but I am more concerned about the placement of the first shot out of a cold barrel.I have taken my share of deer with my rifle and hadn't ever needed a follow up shot let alone3-5 or 9 more:-D .

[StarMetal]

Just do what Ross Seyfred suggested for a hunting rifle. After the barrel is foul, fire one shot from a cold barrel. Put the gun away till the next day. Go out and fire another shot at the same target. Same thing, put the gun away. Repeat this as many days as you wish. This will tell you where that rifle will shoot the first cold gun shot more then any other test will.

Joe

[txpete]

he nailed it.
pete

[3584ELK]

Three shot groups can be VERY misleading. Your 4.3" group shows practically NO vertical. You mention a windy day and a good bit of that could have caught ONE bullet and made a decent group look bad. Shoot five shot groups and several of them in a row (three minimum and five is better). Then you can begin to judge.

I just think that you got caught in a reversal on one shot or maybe you zigged when you should have zagged on one shot:mrgreen: .

Easy solution, just shoot more:Fire:

Dale53

I messed up when I scanned in that group- it was nothing BUT vertical stringing- so if you rotate it 90° to the right, that's how it appeared on the target. I pulled the target and scanned the backing for clarity since there were other groups on that target. My bad. Anyhow, thanks for the input.

I loaded another 20 rounds with both load recipess for further testing. It would be nice to be able to shoot one round a day, but the 60 miles drive each way to and from the range makes that a bit impractical. I have to make hay when I am there!