Home Forums Reloading Big Game Rifles us869 in the 264 win mag

I find that theory a bit suspect, and have never heard of it before. Cartridges typically reach full pressure essentially before the bullet starts down the barrel. By then powder temperature is in the thousands of degrees, and I can't believe significantly affected by the temperature of the barrel.

You have certainly fed those loads far more H4831 than I would be brave enough to try. If you can use 67 grains of H4831, then something is keeping the pressure down. Off the wall thoughts, but have you checked your powder scale? Tested velocity with a different chronograph? Also how many rounds have been down that barrel? Something does not seem right...

Still trying to figure out how Ron aka is getting a 300 fps increase with 4" of barrel.

It's easy to underforstand, it's the I-net baby people can say anything they wish and they don't have to back it up..

Dober

The scale is an RCBS 10-10. It has been checked and is right on. I have not cross checked velocity with another chronograph. Mine is an old Chrony, but data derived from it with various rifles, loads, and the 41 mag revolver suggest it is not suspect.

Rounds down the barrel? probably about fifteen hundred at that time. The barrel gave up the ghost on me a few years later at about 25 boxes of 100 bullets each.

On another thread, a while back was discussion of powder burn time, with data generated via electronic instrumentation. The consensus was, a fast burn rate powder may very well be consumed before the bullet has moved two or three inches down the bore. But some of our slower propellants will actually still be burning when the bullet has traveled a substantial distance.

Consider, the heat we can feel with our hand on the exterior of the barrel has little to do with the actual bore temperature, if shots are fired in rapid succession.

Of note is the FACT, the rate of any chemical reaction will double with every ten degree centigrade increase in temperature. With that in mind, one can understand that the rifle barrel acts as a dampener to burn rate by sucking heat out of the reaction.

If the bore temperature is still several hundred degrees from the energy of the last shot, it will not dampen the burn rate nearly as effectively as a cold bore.

It is worthwhile to note.

The Sierra manual shows 62 gr of H4831 as max load at 3000 fps with a 140 gr bullet.

Hornady says 58.8 gr at 2900 fps is max.

Nosler #4 does not even list H4831 as a suitable powder. Nor does my old Speer #10 from 1979.

When this data was collected, I was plotting charge weight vs velocity curves. The pierced primer and the flattening of the curve above 3000 fps suggests that the loads are well over maximum. The data was presented for informational purposes, not as a load recommendation.

There are far better powders for this application than H4831. But RL25 is not one of them.

"Rounds down the barrel? probably about fifteen hundred at that time. The barrel gave up the ghost on me a few years later at about 25 boxes of 100 bullets each."

My barrels died at about 800 rounds. I suspect a badly burned barrel even at 1500 rounds was a significant part of your issue.

and even more nonsense



and more nonsense

The rifle was still shooting right at half minute of angle with nearly everything I fed it: 100 gr BT, 120 gr Bt, 120 gr Rem CL handloads, and 140 gr Sierra's.

If you read my post carefully, you will see that I had no issue. The rifle was producing speed exactly in line with those predicted by the load manuals.

Sierra says 62 gr of H4831 should get 3000 fps. I was right there with 61 gr.

It is quite common for the charge weight/velocity curve to flatten as one goes above published loads, which is what happened in the sample above. More powder does not always yield more velocity in a linear fashion. When that becomes the case, you have already gone too far with the load.

If you want to shoot the 264 with 140's and H4831, shoot it at about 2950 fps and be happy. Of course a guy can do that with a 270 and about the same charge of H4831.

Yup, correctamundo Idaho, but we always knew that.

Ron should attach another 4" of barrel and get another 300 fps.

i think my barrel is very rough and that could cause slow speeds . thinking of lapping it to gain fps using the jb snake oil on it right now to try to polish her up a bit . never believed in this stuff but worth a try if it will not out run my 6.5x284 it will be a 28" barrel 338 edge by huntin time .

I tried US869 in the Model 70 I use to own. It was short throated so I was using some remington CL that would allow me to seat out farther. I had worked up to about max for the data I had at the time and the velocity was quite disapointing (24" barrel) . Now the old H-870...that worked really well in the 264.

looking to get my hands on some h870 to try . the retumbo is tops for speed and accuracy right now the max for the little data that i can find varries alot . their is not a lot of new data for the 264 wm even though their is a lot more suitable powders for it .

I've always thought N570, formally N170, would be the powder to try

There is something we can agree on without name calling.N-570

This is my second 264 barrel,the first one was both slow and walked.

In the first barrel;
-H-1000 popped a primer with the starting load,I ended up using H-4831 data.I'm distrustful of this lot.A 264 seems brings out the worst in powder.
-Also in the first barrel IMR-7828,was slow and had an open grouping.
-N560 was slow,but at least the holes lined up on three different targets,as I said, the barrel walked.

In the second barrel:
-N-560,slow,and topped out slow,even adding more powder.
-RL-25 see above
-Retumbo,didn't group
-Magpro,OK
-Magnum, 3150 with a 24" and a 1/2" group

I bought a rebarrel?? rechambered?? Husky 1600 6.5-06 it goes slow compared to what JB gets with his.That's why I suggest using Winchester 140 Powerpoints to get a base line.

My apologies, i'll work on my tone, and words.

I dumped my last charge of H870 about two weeks ago. I have been doing workups for a replacement. I was getting 3150 out of that load.

76.2 Grns US869 3040 out of my 24 inch Ruger with VLDs. I can seat them to max magazine length and that ups my capacity some. I hit a full case at around 78 Grains. I have not shot all the work up loads I made, so 76.2 is a far as I have gone.

I get 3100+ with 7878ssc. I started flattening primers at 64.8 grains and backed down. Extreme spread of 9. Maybe I'm wasting my money trying other things.

Magpro is looking promising, So far Retumbo is pretty erratic.

I use 57 grains of IMR 4350 in the two Sako's and two Westerner's. they all have 26 inch barrels. They chrono at 3025 fps. Kills stuff dead. I use Nosler ballistic tips.