30-06 stumpper?

[C.Smith]

I'm shooting a Tikka T3 lite in 30-06. I have been working on this years hunting load using RL 22. I shoot 165 grain Accubonds with Federal GM215M primers and 3rd time firing Nosler brass. I ran into an issue yesterday that I can not figure out.

I started off at 59.0 grains with an average velocity of 2702fps and it has steadily gone up as it should up to 62.0 grains the previous session with a velocity of 2828 fps.

The other day I went out and shot 62.2 grains and got an average velocity of 2763 fps. That through me so I came home and pulled some bullets and checked the weight, all was good.

Back out yesterday and same thing, with 62.4 = 2753 and finally ending with 63.0 grains (which is maximum) with a velocity of 2749 fps.

I'm completely stumped as to what is causing this? Any help or ideas would be greatly appreciated. By the way I'm still using the same 5lb jug of poweder.

Corey

 

[JD338]

A couple thoughts....

Different lot of RL 22?

Different lot of Primers?

Case neck tension?
Maybe the cases need to be annealed and FL resized.

JD338

 

[Antelope_Sniper]

Was it cold?
It froze here last night.
a 40 degree drop on the theomometer will drop you velocities about 100 fps. It's important to shoot the same load at different temperatures so you can adjust for temp variations.

 

[Big Squeeze]

If your bullet weights, bullets, powder charges and powder lots are all uniform, the one main thing that comes to my mind that could be a possible factor, is any outside air temperature differences between your sessions at the range.

Also, maybe some in-consistencies with your chrony?

I`d say, go through the same process again two or three times more with the RL22 and see if you get the same results. Make sure that the OA temps are as close as possible.

If you get the same velocity in-consistencies again and again, change the powder to maybe a faster burn for the `06. It`s possible that the RL22 just isn`t as consistent as you would like in your rifle.

Haven`t read of any velocity in-consistencies using the Vihtavouri powders. As a matter of fact, exactly the opposite. Very good consistencies, with lower e/spreads.

Something to consider trying later.

 

[DrMike]

Corey,

All the fellows have touched on issues that can and do affect velocity. Since you are using the same jug, it has ruled out lot-to-lot variation. However, temperature differentials can make quite a difference on a load. The actual differential in velocities that you list are not that great, and in the real world probably will not make much difference.

What is more worrisome is the trend to lower velocities with increased charge. A best-case interpretation of the data you present is that you have plateaued with the charge. Though the charge is increasing, velocity remains constant, which means that pressure is essentially unchanged. Whilst this may be observed in some instances, it should not be the case with ReLoder 22. The pressure curve is sharper than that.

It makes me wonder if your powder and/or primers have become contaminated with sizing lubricant, or some other material that is affecting the burn characteristics of the powder. Are there any solvents near your reloading bench that have been uncapped during the past several weeks?

This leads me to ask how many shots did you take to obtain the velocity reading? And what was the Standard Deviation? SD cannot be accurately calculated with less than ten shots, though if we see a consistent velocity and SD over a period of groups, we can speak with a degree of confidence about that particular load.

There is another point that occurs to me, and that is to point out that the charge increments are quite small. Though these may be beneficial in fine-tuning a load, realistically a 1 grain increase from 62 to 63 grains is 1.6% differential. A 0.2 grain change is 0.3% differential, which is difficult to measure accurately.

JD raised a good point is asking about case neck tension. Do you full-length resize? Or do you neck-size? You might find it necessary to mic the inside diameter of the neck to ensure that they are gripping uniformly.

When you reassess your loads, let us know what you find. This is interesting, to say the least.

 

[C.Smith]

Well it is the same lot of powder, primers and brass. The temperature was only differant at the most ten degrees. But I will try again and see what I get. I wonder if my scale has changed somehow, is that possible?

Corey

 

[DrMike]

Corey,

If using an electronic scale, you need to calibrate from time-to-time. I take the additional step of occasionally using a check weight to verify that the scale is still weighing correctly.

If using a balance beam scale, you need to tare the scale.

If the scale is slightly off balance, it will have a dramatic effect on the weights obtained.

Also, be aware that air currents can dramatically affect the balance.

 

[C.Smith]

Well I use a balance scale and I make sure it set at zero before I start weighing charges.

I usually shoot 3 shot groups, so it may be too soon to say. I have gotten fast velocities with this rifle and load before.

No contaminants around my bench, I try and keep it clean, especially since my wife let me bring it in the house.

Well I will load some more up and get a string of at least 10 shots and see. Should those be consistant shots or should time be allowed for the barrel to cool leaving the chrono on?

Corey

 

[DrMike]

Three shot groups are generally sufficient as a gauge for load development. Actually, we are watching patterns as we develop a load. If you shoot a three-shot group, let your rifle cool down after the group. When cool, shoot another three-shot group. Finally repeating the procedure, add a fourth shot for good measure. You will have a ten shot group, and three sets of groups for accuracy measurements on paper (two three-shot groups and a four-shot group). The velocity data generated will give you a more reliable readout in this manner. It is possible that your load actually has a standard deviation that is quite exaggerated, though in any given three-shot group you could possibly have a very good SD. However, that one group is essentially an artifact.

Something similar happens when people speak of a great load because they have a measured group of, say 0.25 inches. However, a ten-shot group yields 2.5 inches. Any three shots within the larger set can give a very small group, even though the load is not that great. This is the reason we are urged to shoot several groups before making a pronouncement on the accuracy of a group.

If you have some check weights, you can test your scale for accuracy. They are not expensive, and they will give you a degree of confidence in the weights obtained.

Some case lubes in the neck can have a dramatic impact on velocities. For this reason, I appreciate dry lubes (graphite or motor mica).

 

[YoteSmoker]

RL-22 is the most temperature sensitive powder I have used. It still works well in my 7mm for the time of year I use it mostly, but there is a noticeable change between shooting it in summer heat and now.

 

[Antelope_Sniper]

Actually I expect you did platue. With the 165's in the 30.06 you will plateau with Rl22/H4831. That's why many reloaders prefer something in the H4350, RL19 burn range when using 165gr bullets in a 30.06. Besides, the Tikka has what a 22"-23" barrel? The shorter the barrel the quicker you platue.

 

[C.Smith]

Would dropping the powder thorugh a drop tube help with the plateau effect? I used to use IMR 4350 but found I get better with RL 22 in my Savage I used to have. I guess each rifle is different. How is H4350 compared to IMR 4350?

Corey

 

[old #7]

Something else to consider is your chrony.
I had shot some loads and got different readings on the chrony and it turns out the crony wasn't open all the way in the locked position. The same load was shooting about 150 fps faster two weekends later. I was confused about the readings until I was packing up and noticed the chrony was very easy to fold up. I loaded up the same load again and made sure the chrony was locked and walla, I had the same results as I did the first time.
Don't over look the simple things.

 

[C.Smith]

Hmmm, I did not think it locked open, I will have to look into that. Thanks.

Corey

 

[DrMike]

Corey,

It doesn't "lock," but it must lie flat, or at least be so situated that it has the same distance between the photoelectric eyes each time. The velocity is dependent upon the shadow of the bullet passing over the eyes with a measured distance between. Occasionally, the Chrony (especially) is not opened fully. Set it on the shooting bench (or any flat surface) and verify that it is open all the way each time. I routinely do this as I place the guides in their respective slots. This gives me something to brace against as I seat the guides and it permits me to verify that the Chrony is fully open.

 

[C.Smith]

Corey,

It doesn't "lock," but it must lie flat, or at least be so situated that it has the same distance between the photoelectric eyes each time. The velocity is dependent upon the shadow of the bullet passing over the eyes with a measured distance between. Occasionally, the Chrony (especially) is not opened fully. Set it on the shooting bench (or any flat surface) and verify that it is open all the way each time. I routinely do this as I place the guides in their respective slots. This gives me something to brace against as I seat the guides and it permits me to verify that the Chrony is fully open.

Great idea and tip, thank you.

Corey

 

[Antelope_Sniper]

Once you've plateued with a given powder, that are three ways to fix it.
Faster Powder.
Heavier bullet.
Longer Barrel.

This is where longer barrels really shine. They don't pleatue as quick.

 

[30-338]

I'm shooting a Tikka T3 lite in 30-06. I have been working on this years hunting load using RL 22. I shoot 165 grain Accubonds with Federal GM215M primers and 3rd time firing Nosler brass. I ran into an issue yesterday that I can not figure out.

I started off at 59.0 grains with an average velocity of 2702fps and it has steadily gone up as it should up to 62.0 grains the previous session with a velocity of 2828 fps.

The other day I went out and shot 62.2 grains and got an average velocity of 2763 fps. That through me so I came home and pulled some bullets and checked the weight, all was good.

Back out yesterday and same thing, with 62.4 = 2753 and finally ending with 63.0 grains (which is maximum) with a velocity of 2749 fps.

I'm completely stumped as to what is causing this? Any help or ideas would be greatly appreciated. By the way I'm still using the same 5lb jug of poweder.

Corey

If you look at Alliant's data for the 30-06 using 165gr speer bullet max load is 62gr @2725fps.

If it was me I'd just use a different powder like IMR-4350 or H-4350. Nolser shows 57gr max with IMR-4350 with 165gr bullet and Hodgdon shows 60grs max. I workerd up to a max load of 60gr with 165gr bullet in a factory rem 700 24" barrel acouple years ago got 2940fps Hodgdon had max at 2934fps so I was pretty close. I have three 30-06 and that same load of 60gr/IMR-4350 with 165 Partition in the Bartlein barrel gets 3066fps,Shilen barrel get 3076fps,Lilja barrel get 3105fps. The only reason the Lilja is that fast over the others is 2" longer barrel.

 

[Antelope_Sniper]

In the past we've used slower powders such as H4831 with 150-165gr bullets in the .06. It's just too slow to get maximum velocity. Considering it's very similar to RL22 in burn rate, I wouldn't expect maximum velocities with the lighter bullets using RL 22 either. I would expect both to be perform better with a 180 gr bullet.

When it comes to 165gr bullets in the 30.06, I'd most of us on this site have had the best luck with H/IMR 4350, RL19, or IMR 4831.

Save the RL22 and H4831 for the 180gr bullets. :wink:

 

[old #7]

If you are looking for more velocity with a 165gr bullet A.S. is on the money with the faster burning powders.
Rl-19 is great in the 06