here are some figures of today papaer punching session:

Hornady 95gn v.max 70gn H870
1. 2,832fps
2. 2,912fps
3. 2,863 fps
all bullets touching lans no extraction problems!

Nosler 140gn partition 65gn H870 ( 10gn under max).

1. 2,756fps impossible exraction flat primer expanded case, plunger indentation, scuffed head through bolt face rotation, only one shot fired..

Nosler 100gn partition 70gn H870

1. 3,023fps
2. 2,944fps
3. 2,939fps
4. 3,003fps
5. 3,056fps
all bullets touching lans,very difficult extraction. 5gns under max 500fps short of published velocity..

All loads are well under Max, Am I doing something fundamentally wrong or is this typical of this problem with the magnum cases?


Any thoughts on the problem would be very much appreciated..
should never of got rid of the 25!!!!

regards
griff

quote:

1. 2,756fps impossible exraction flat primer expanded case, plunger indentation, scuffed head through bolt face rotation, only one shot fired..

NEVER USE a significantly reduced charge of a real slow-burning powder in a case that has a large capacity in relation to its' bore diameter!!

Random, unexplained pressure excursions might or might not occur-in your case, I think it happened - rifles have been destroyed by this effect........

El Deguello,
tried 70gn H870 5gn under max, had to knock case out with cleaning rod!

regards
griff

Sorry forgot to say, it wasn't through choice that I arrived at 65gns, started at 72gn

regards
griff

If a rifle is showing signs of over pressure with starting loads, I'd say it's time to have it looked at by a knowledgeable gunsmith. I wouldn't shoot it anymore til it was checked. Out of curiosity, have you ever shot factory ammo through it?

olarmy,
shoot factory at $70.00 box no thanks!
but out of curiosity who knows!
regards
griff

Just my .02, but if I were you I'd:
1) Heed ElDeguello's warning!
2) Seat bullets .025" off the lands for a starting reference, then change seating depth according to what the targets tell you to do.
3) Consider VV N165 & N170 along with RL25 powders.
4) maintain proper case length.
5) verify your powder scale accuracy.
I know of no reason why the 264 with 140s won't run with the best of the magnum crowd, and in fact, haven't seen any of my loading buds get into trouble except when trying to launch 160s fast. Given 120s and 140s along with a 26" barrel, you 264 should be a death ray.

A reduced load sitting right aginst the lans can = pressure problems

quote:

factory at $70.00 box no thanks

ouch! perhaps you have a friend who will sell you 1 round for (gulp!) $3.50?

another thought: If you are using necked down 7Mag brass and your rifle has a tight neck....

olarmy,
new brass, trimmed to 2.494".

hunt-ducks,
will try seating considerably deeper and see what happens to the pressure. Is it your experience that the deeper the seated bullet the less the pressure?

time is 11.45 pm so forgive me if I do not respond till tommorrow..

regards
griff

Griff, I have never found anything that liked H870. I have just found some decent loads for a 264 Win that I recently had built. I am loading new Win brass with a Win LRM primer and 140 grain Hornady SST bullet with 63 grains of IMR 7828. These shot under an inch and think they'll do better than that on a good range day. My rifle has a 26" #3 contour Shilen barrel and it heats up pretty quick with this powder, all the way from the reciever to the muzzle. I have not run these over the chronograph yet but I am not hung up on speed too much anyway. I also have found that 60 grains of IMR4350 behind a 120 gr. Nosler BT to be even more accurate. I am not encroaching the lans very hard, but I don't know exactly how far I am from them. I set a slug in case just far enough that it would stay in the neck and then chambered the dumby round which gave me the exact length of the chamber then I put it in the seating die with the seater button screw way up, then I screwed the button down to where it contacted the bullet. I then removed the dumby from the die and turned the button in just a little so that the bullet would be set back slightly from the lans. The only thing about the 7828 that I don't like is that it leaves a lot of black residue in the bore of my rifle, but since this is a hunting rifle that isn't any big deal to me. This was my first time using 7828 but I have used the IMR4350 for many loads and really like it.

hey griff

if you don't take ELDE'S advice you may not be reporting on this forum much longer.

ELDE is right, you get a tutn around with the chemistry when you reduce to the extreme.

example-below minimum.

two canoes,
It wasn't through choice that I reduced the loads by 10gns, I reduced the loads in two grain increments from what I thought was a mediocre start load of 70gns when this showed signs of excess pressure..
I'm between the devil and the deep blue sea here: excess pressure from to much and excess from to little...
Will try seating further back by 10thou increments and see what transpires..

regards
griff

Hi Griff, according to Quickload 3.2, H870 powder is not a good choice for 95/100 g. bullets, since it's too slow. Both your loads seem to be at 2000-2200 bar that is too low, and even with your brass full and a compressed load you will not be able to acheive an optimal range of pressure. This could explain the high velocity spread you experienced; Hodgon website suggests to use H870 only with 140 g Nos. Part. that roughly corresponds to Quickload suggestions. You could try Vith. 560/160/165 that seem to be better suited to your needs.
Hodgon website suggests 73 g. of H870 as max for a 140 g. Partition. At 65 g. you were TOO low, and keep your bullets 0,4-0,6 mm. back from the lands as stated before.

H-870 has always been the "go to" powder for the .264. The results you are experiencing are NOT consistent with H-870, even if the bullets were JAMMED into the lands.

My suspicion is that you have been sold a mislabeled powder.

By the way, Secondary Explosion Effect (S.E.E.) is well known and demonstrable with stick powders like 4831, but is not generally seen in spherical powders like H-870.

My advice: See if you can access some RL-25 (or the Norma equivalent). Since it is made in Sweden, it may be available to you. Other possibilities for your 140 grain bullets would include Hodgdon's new US 869, the Vhita Vouri powders designed for the .50 BMG, or AA 8700. With your 95 grain bullets, good old H4831 should provide excellent velocities.

AGAIN: My 40+ years of reloading experience with the .264 in at least 5 different guns indicates that there is something amiss with the lot of powder you have.

One more issue: If this is a Winchester Model 70, it was chambered with practically no leade. For some reason that has never made any sense to me, the original .264 specs used a "two-diameter" bullet: The portion inside the neck was .264", but tapered sharply to .256" so that the protruding part of the bullet sat on, but not engaged with, the lands.

I would advise having the leade of your barrel extended so that you can seat a normal 140 grain bullet flush with the base of the neck and still not engage the lands with the nose.

Stonecreek,
thanks for the reply, I am trying to get a differemnt powder for the 100gn but would like to stick with the 870 for the 140gn as I have heard good reports about it.I bought the rifle so that I could use the 140's but his excess pressure is causing concern. I am going to take it to Border Barrels on Monday for them to check it over and see if it has an under sized bore or any other machining fault.


regards
griff

A Breakthrough.

Went back to basics as if new load. Started with new cases trimmed to 2.490" and LRM primer.Checked distance to rifling!!
That was a shock,3.230" had been reloading to an OAL of 3.340, so was seating 100 thou into the rifling.
Loaded 4 rounds started at 68gn finished at 72gn with an oal of 3.200" no signs of pressure and no difficult extraction, the group was about 3" and I couldn't chrono it as it was too dark for it to work, so now on the right track..
will play with seating depth later when I get to max load....
So when in doubt, go back to the beginning.
I also spoke to Les at Border Barrels, he explained how he had had difficult extraction through using cellulose to clean the lube off his cases, so I left a residue on the case and the extraction was slick.

many thanks

Griff

griff: glad you solved your problem, but wasn't it hard to close the bolt on a cartridge when the bullet had to be crammed 1/10" into the lands??

olarmy,
it was never hard to close the bolt,probably has a sloppy start to the rifling that was what was giving me a false indication of the bullet length.I was going by what others had indicated was their OAL and obviously every gun is different, definitely a lesson learned.

Stonecreek prompted me to look further into the freebore as he indicated Winchester have a habit of offering the reamer short thus causing the problem..

many thanks

griff

When Winchester designed the 264 in the late 50s,Olin didn't have powder like DuPonts 7828,so to keep the pressure from spiking they used a two diameter bullet.So as not to lose accuracy they short throated the chamber.This can and does play havoc.My life with a 264 got much simpler with a "normal" throat.The powder I use is Ramshot Magnum,it's made in Belgium,so you should be able to trace it's parent name.Vetcan? XXXX