30-06 Velocity Question

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rayatphonix

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I'm trying to work up loads for my new 30-06. Tikka M695 with a 23 1/2" barrel. I'm using 150 grain sp bullet and H4350 powder. CCI LR primers (not match). I started at 56 grains and have worked up from there. Yesterday I went to the range with 60 and 61 gn loads. I used my chronometer to measure velocity on each shot. The 60 gn loads averaged 2766 fps and the 61 gn loads averaged 2667 fps. Any explantions?

Of all the loads I've tried, 60 grains seems to be the most accurate from my rifle and I'll work on refining that load. Thanks for any insight folks can offer.
 
The first question is how many shots you used for your average.

Sometimes with barrel heading and/or fouling velocity can decrease. Also, sometimes increasing a load causes diminishing returns as for a given powder/cartridge there will be a pressure where the load is most efficient. There are those who believe that velocity is a good indication of pressure and it isn't necessarily so.
 
No question is dumb, right? Here are a couple.

Does your rifle have a high rate of twist? Did you generate enough pressure with the 61 grain load that your bullet slipped through the barrel without grabbing the rifling? Likely not, but I ask anyway because I have heard of this happening before. Maybe the accuracy was off as well as velocity?

Or maybe at 61 grains your powder results in a packed case which altered the burn rate and lowered your velocity? With such a nice rifle, maybe this one is more likely.

Or like the post above, maybe you had a bit of fouling.
 
Your loads are way hotter than anything I will every use with a 150. I stop at 55 grains with a 175/168.

I get those velocities with my loads and you have five more grains of powder and a lighter bullet. Something is wrong.

I think it is more likely you are having instrumentation error. Misalignment on your chronograph.

I would cut your loads, if it were me.
 
+1

You reach a point of deminishing returns when the max load is reached.

You did.

Back off.

rc
 
Some answers...

First of all, the velocities are averaged off of 9 shots each; I shot a group of 3, let the barrel cool, shoot 3 more and let the barrel cool. You get the idea.

I believe my chronograph to be accurate; I can measure the speed of purchased cartridges and velocities are very close to what's on the box.

The Hodgdon site lists the maximum load for H4350 on a Nosler 150 gn BT at 62 grains... I'm not getting any signs of overpressure but I agree I'm at the very top end. 61 grains opened up the group so it's obviously not beneficial.

Slamfire, the 168 gn bullets use less powder than the 150's, so your volumes don't surprise me.


I had not thought of copper fouling. I looked back at my records and my highest velocities are always in the first group. Yesterday I'd shot 9 rounds before I chambered a 61 grain load. Next time I go out I'll clean the barrel after each group and see if that changes anything. This is a hunting rifle, so I shouldn't ever need to shoot a dirty barrel. I'll hopefully find with a clean barrel I can get repeatable strings with less powder.

Thanks for everyone for the advice. If anyone else has any ideas, please let me know.
 
Wow, your crony matches the numbers on the ammo boxes? It is definitely maladjusted...:rolleyes:

My first suggestion would be to listen to whatever rc said...

Or maybe at 61 grains your powder results in a packed case which altered the burn rate and lowered your velocity? With such a nice rifle, maybe this one is more likely.

That would be my guess.
 
You sure don't want to shoot it with a clean barrel if you take it hunting. You need to shoot several fouling shots before the rifle will shoot to poa. From a clean barrel you first 2 or 3 shots will be off. Similar results can be seen with pistols/revolvers.

Once my hunting rifle is sighten in I do not clean the barrel as fouling shots will be required to bring it back to zero.
 
Ray, what you just did was to interpolate velocity. It's a common mistake in judging rifle cartridges. More powder equals higher velocity? Not necessarily. A larger case with more powder equals higher velocity? Not necessarily. That's a trap that a lot of magnum lovers or improved cartridge lovers fall into. The 30-06 is a very efficient cartridge for the amount of powder burned compared to the velocity generated especially if you use the right powder with the right bullet. I got out of that discussion years ago when I started comparing the trajectory and accuracy of various loads out to 500 yards. Some powders just do better for velocity and accuracy. I agree with 4895, next time you reload work up to 51 grains of IMR 4064 with that bullet using a Magnum primer. Your recoil won't change much but your velocity will take a big jump and accuracy should be better. BW
 
That is a compressed load. And, even though it is on the Hodgdon site, it is about the heaviest load for a 150 gr. bullet in existence with H4350. I'd back off a few grains for sure. The anomalies in velocity might be telling you something is awry, I think.
 
Shooter, I think you pointed out my mistake/ignorance perfectly. I wasn't getting the accuracy I wanted and felt it was a velocity issue. I'll try the IMR 4064.

The funny thing is I have the same rifle in 25-06. I could load it with oatmeal and get good groups. It seems that no matter what the load, I can't go wrong. The 30-06 is more temperamental. Thanks again for the advice!
 
As already stated (thanks RC) slow burning powders reach a point in which increased charges will start to bring pressures down along with velocities. Go back to the starting charge and work up watching for the sweet spot.
GS
 
I'm trying to work up loads for my new 30-06. Tikka M695 with a 23 1/2" barrel. I'm using 150 grain sp bullet and H4350 powder. CCI LR primers (not match). I started at 56 grains and have worked up from there. Yesterday I went to the range with 60 and 61 gn loads. I used my chronometer to measure velocity on each shot. The 60 gn loads averaged 2766 fps and the 61 gn loads averaged 2667 fps. Any explantions?

Of all the loads I've tried, 60 grains seems to be the most accurate from my rifle and I'll work on refining that load. Thanks for any insight folks can offer.
You aren't the first one to see something like that, it has also happened to me.

When shot from a 26" barrel (1917 Enfield surplus rifle) I got more velocity from a 57.0gr charge of H4350 than with a 58.0gr charge under a 168gr Sierra bullet. That did not happen when I shot the same ammo through a 22" barrel Howa 1500 though... I also use CCI-200 LRP.
 
Re: 30-06 velosity

I used to struggle with velocity in my Win.670 /22 inch barrel. After trying several powder & bullet combos I suddenly realized I was addressing the wrong problem.
The question you need to answer is do you want your bullet to go fast or do you want it to hit where you aim it?
I have found that max loads are seldom accurate loads, especially with 4350 powder.
IMR says their 4350 is not reliable out side the start/max range in their published data. I found that to be true with my gun.
I found that loading lighter rather than hotter is a good thing with 4350.
The sweet spot for my rifle is a 150 gr. Hornady fmj over 54.2 grains IMR 4350.
This load gives me 2500 -2550 fps with 1.5" groups at 100 yd.
Recoil is very mild compared to the top end loads I had been using.
As for stopping power, I doubt if a deer or even an elk can tell the difference between 2500 and 2700 fps when the bullet hits.
Perhaps less is more. Try it. Your shoulder will thank you.
Good hunting,
dlw
 
Most reloading mauals from the bullet manufacturers (which are much more in depth and realistic, IMO) list 59gr as max for H4350, if I were you, I'd start at 56gr and slowly work up to 59 in 1/2gr increments.
 
Been loading 57..0 gr of 4350 under a 150 Ballistic Tip for a 700 for 20 years. It shoots 3 shots touching. I never felt the need to look any further.
 
I rarely load a 150gr bullet for the 30-06 but when I do I don't use H4350, it's too slow a powder for that light a bullet in the 30-06 IMO. If I did load a 150gr bullet I agree H4895, IMR4895, IMR4064 or even H414/W760 or BL-C(2) will work well.

When loading a 165/168gr bullet in the 30-06 I charge either 58.0gr H4350 or 57.0gr IMR4350. Those loads work very well for me.

I checked my notes and with a 150gr Hot-Cor bullet I would charge either 48.0gr IMR4064 or 49.0gr H4895. Neither are up near the top of the pressure range but were accurate for me.
 
I rarely load a 150gr bullet for the 30-06 but when I do I don't use H4350, it's too slow a powder for that light a bullet in the 30-06 IMO. If I did load a 150gr bullet I agree H4895, IMR4895, IMR4064 or even H414/W760 or BL-C(2) will work well.

When loading a 165/168gr bullet in the 30-06 I charge either 58.0gr H4350 or 57.0gr IMR4350. Those loads work very well for me.

I checked my notes and with a 150gr Hot-Cor bullet I would charge either 48.0gr IMR4064 or 49.0gr H4895. Neither are up near the top of the pressure range but were accurate for me.
i agree on this. i use a faster powder with my 30-06 in N140.
 
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