Barrel whip vs harmonics and timing question

[338 Ultra]

I have to agree with AS on the primer. I have seen combos shoot poorly with one primer only to shoot excellent with a different one. I don't claim to be really smart when it comes to any of the techie stuff but I think that the impulse of the primer firing causes a harmonic wave even before any amount of powder is burned. I know this is in fractions of milliseconds but it does make sense if you want to tear the whole consept of barrel harmonics down piece by piece. Even the firing pin striking is going to give you a shock wave of a minimal amount of measured force but it is still there.

 

[onesonek]

Just a quick note. Thanks for all the responses. I did try a slower burning powder as I usually would and conducted a ladder test. Using the 90% fill method mentioned below for a starting point, I was able to achive 1.08" spread on my last three rounds. That would be IMR4350 42.5, 43.0 and 43.5 grains with Nosler 90 Gr BT pushing just at 3250FPS. I still need to refine that load but still was amazed by the performance with the slower burning powder with more pressure and how it increased the accuracy. I have a good understanding of the harmonics, thanks to all the explanation and PMs.

Thats getting more respectable. Not dissing IMR, but more an observation,,,I have had better luck with H-4350 more often. You might want to give it a try. And then too, for a higher load density that I prefer, I would go with H-4831. While not always the case,(no pun intended), I generally have better results with case/powder/bullet combinations being nearly full, to lightly compressed.

 

[bullet]

Guys, the key word here is uniformity and consistency. Make your handload as uniform as you can make them. Eliminate or control as much variables as you can and you'll have no problem finding an accurate load.

Desert Fox is right on and if you do this and it still does not shoot well it is the rifle or your shooting skills or both. Show us some pictures of your good one hole targets and then some of the bad targets so we can get a better idea.

 

[Desert Fox]

I generally have better results with case/powder/bullet combinations being nearly full, to lightly compressed.

In my experienced, at least with my rifles, I found out that load density between 90 to 95% always is optimum for 30-06 and magnum class cartridges. Since I predominantly use boat tail and VLD bullets, I tend to stay away from compressed load to avoid problem with seating the bullet.

I have to agree with AS on the primer. I have seen combos shoot poorly with one primer only to shoot excellent with a different one. I don't claim to be really smart when it comes to any of the techie stuff but I think that the impulse of the primer firing causes a harmonic wave even before any amount of powder is burned. I know this is in fractions of milliseconds but it does make sense if you want to tear the whole consept of barrel harmonics down piece by piece. Even the firing pin striking is going to give you a shock wave of a minimal amount of measured force but it is still there.

338 Ultra, Of course it does. That's why accuracy enthusiast prefer shorter firing pin lock time for their rifle. It's part of the total sum.

 

[BalisticsNut]

Im sorry, forgot to mention in the previous post. The 4.14" spread was at 100 yards. My daughter wanted to go shooting so I let her shoot the ladder test at 200 yards. So, the grouping of 1.08" was at 200 yards and shot by my daughter. As stated in a previous post as well, the same rifle shot 3 rounds at 100 yards with less then a 1/4" group. So, I know the rifle shoot strait, I know that I shoot strait and I know my daughter shoots strait. Just need to refine the load. I have H4350 and H4831 on my list of powders to try. Honestly, if this round is sub MOA at 200 yards, I think its fine for a hunting load. Just need to refine the final measure.