I'm working up a .270 Win. load using 150 grain Nosler Partitions and H4831sc. Rifle is a Steyr Pro Hunter. Nosler lists a max load of 55 gr. and Hodgdon lists 55.7. I always start with a pressure ladder test and although I'm a firm believer in not exceeding published max loads, when I got to 55.6 grains I kept going in .2 grain increments until I hit 56.6 grains. Although there were zero pressure signs (bolt lift and extraction was smooth, primers looked the same as starting load and no ejector mark) I was almost a full grain over max and wasn't going any further.

.270 Win. with 150 grain partitions and H4831sc has to be a pretty common combination - was 56.6 grains way out of line?

To be clear, I was just running a pressure test looking for max and I'm planning to stick with Hodgdon's published 55.7 max load as the upper end for load development.

This powder is one of the great powders for reloading. Decades ago I was told you could just scoop the case full of powder and seat the bullet, that is almost the case. The .30-06 load with that bullet will hold at least 50 grains and be very accurate at long range.
The powder is temp sensitive and your safe load today may cause problems on a hot day.
I would load to most accurate load you have found. Mine are always about 98% of the max safe load. I only shoot long distant targets.

I load that very powder and 150g Partitions in my 270. I've been doing it since the early 1970s. I get 3000 fps out my BDL's 22" barrel. I neck size only fire formed cases (which increases their capacity) and use CCI magnum primers. I will just say my load is a bit hotter than yours, but in line with the reloading manuals back in the 70s. The reloading manuals are more conservative today. As always work up slowly and back off a grain or two with any signs of high pressure.

Down here we have the same powder but labelled AR2213sc. I have never run into over pressure signs with this powder used with suitable bullet weights in 243W, 270W, 300 WinMag. My belief is that you run out of case capacity before it's possible to load a charge that develops excessive pressure.

quote:

Originally posted by chuck375:
II will just say my load is a bit hotter than yours, but in line with the reloading manuals back in the 70s. The reloading manuals are more conservative today.

With a little bit of digging I found a post form 2010 that asked an almost identical question to mine:

https://forums.accuratereloadi...2511043/m/2041075131

Apparently (at least according to one of the posters) Hodgdon listed a maximum load of 58 grains of H4831 with a 150 grain bullet weight in their 1996 manual and lowered it to the current 55.7 gr. max charge in 2000.

EDIT: If I can hit 2,800 fps with reasonable accuracy I'll be a happy camper. At least now I know that the velocity part of that goal should be easily attainable.

quote:

Originally posted by belaw:

quote:

Originally posted by chuck375:
II will just say my load is a bit hotter than yours, but in line with the reloading manuals back in the 70s. The reloading manuals are more conservative today.

With a little bit of digging I found a post form 2010 that asked an almost identical question to mine:

https://forums.accuratereloadi...2511043/m/2041075131

Apparently (at least according to one of the posters) Hodgdon listed a maximum load of 58 grains of H4831 with a 150 grain bullet weight in their 1996 manual and lowered it to the current 55.7 gr. max charge in 2000.

EDIT: If I can hit 2,800 fps with reasonable accuracy I'll be a happy camper. At least now I know that the velocity part of that goal should be easily attainable.

Thanks and I believe Norma had 59g MRP load for the 150g Partition as well. Factory ammo is terribly underloaded. In the fall of 2010 I came down with CHF (much better now) so couldn't go with my youngest son on his first elk hunt. I had booked him a cow elk hunt with Kiowa Hunting in Northern New Mexico. I bought him some Federal ammo loaded with 150g Partitions chrony'ed them 2650 fps. So I said screw that and loaded him up 40 handloads. My wife went with him. He dropped his elk with one shot at a running cow at 150 yards. The guide said "Is that a 7mm Magnum?" All went well Here is is with his first elk and the 270 I bought in 1968. He wouldn't give it back lol

quote:

Originally posted by belaw:
I'm working up a .270 Win. load using 150 grain Nosler Partitions and H4831sc. Rifle is a Steyr Pro Hunter. Nosler lists a max load of 55 gr. and Hodgdon lists 55.7. I always start with a pressure ladder test and although I'm a firm believer in not exceeding published max loads, when I got to 55.6 grains I kept going in .2 grain increments until I hit 56.6 grains. Although there were zero pressure signs (bolt lift and extraction was smooth, primers looked the same as starting load and no ejector mark) I was almost a full grain over max and wasn't going any further.

.270 Win. with 150 grain partitions and H4831sc has to be a pretty common combination - was 56.6 grains way out of line?

To be clear, I was just running a pressure test looking for max and I'm planning to stick with Hodgdon's published 55.7 max load as the upper end for load development.

The original maximum loads given for the 270Win with the old ex military H4831 was 58.0grs with the 150gr bullet and 60.0grs with the 130gr bullet.

The modern maximum loads with H4831 or H4832SC (short cut) is 55.7grs/150gr and 60.0grs/130gr.

So the loading for the 130gr bullet remains the same for the old and the new H4831 whereas the load for the 150gr bullet has been lowered.

These are all book loadings but as we know, or should know, every rifle is a book unto itself.

You have hit 56.6grs with the 150gr bullet with no signs of excess pressure, if it were me I would have just kept going up until I saw more then one sign of pressure. Flattened primers do not always tell the full story but in conjunction with slightly sticky bolt lift or ejector mark, etc., then this is clear sign that you have reached higher pressures and need to drop at least a grain. Case life is something you will only know after sometime and may in fact choose to live with shorter case life to gain maximum performance.

I have, and still do, use books for reference but there is so much variation and that to stick with the idea of never exceeding published maximum loads is an exercise in futility. Your rifle does not recognise what is in a book. Only you know how your rifle is performing with any combination of powder and bullet and you should load accordingly.

I would be reluctant to go over book maximums no matter how normal the signs seemed, esp. if a chronograph said I was already getting the combined books' maximum velocities.

Personally, I've had several rifles where primers flatten with the base load and most factory ammo, even when the factory velocities are below what the box claims.

Therefore, I prefer to include case-head expansion in my judgements.

quote:

This powder is one of the great powders for reloading. Decades ago I was told you could just scoop the case full of powder and seat the bullet, that is almost the case.

There have been at least FOUR different versions of 4831, so referencing one of them (in this case the WW II surplus powder for the 20MM shell) provides no guidance on the others. There was (1) the original surplus powder sold by Bruce Hodgdon and stored in grain elevators and rail cars, (2) when that ran out Hodgdon contracted with ICI in Scotland to produce the next version of H4831, (3) DuPont introduced an IMR 4831 which is considerably faster than any other version, (4) and currently, Hodgdon sells an H4831 made in Australia. NONE of the above powders act exactly like the others.

But regarding "over book" powder charges, one has to remember that reloading manuals typically use pressure guns with chambers of minimum dimension to establish their "maximum" loads. No two rifles act exactly the same and identical loads rarely produce identical results in different rifles. Your factory rifle will typically generate less pressure than a ballistician's pressure gun.

It is the brass case, not the rifle's action or steel, which is the weak link in containing pressure. If there is no sticky bolt lift AND case heads do not expand after three or so firings (as evidenced by loosened primer pockets), then regardless of whether a load is "over book" or not, it is a safe and sustainable load (loads which expand primer pockets may not actually be "unsafe", but they are certainly unsustainable and shouldn't be used.)

I have rifles which exhibit unsustainable pressures with loads that are below book "maximum", so it is always appropriate to work up loads to suit your individual rifle, regardless of how that might relate to one or another printed reference.

Ive shot 57 to 58 grs of H4831 with the 150s AND 58 TO 60 WITH 130 gr bullets in all my 270s..Let the gun decide the best. I have used old surplus 4831 mostly but short core seems to work the same.

keep in mind your question is loaded!! You must load about 10% below all recommended loads and work up, firearms are an inity unto themselves.

Underloading 4831 is not recommended by some experts and loading books, and seems to be correct in my guns I begin at 57 and work up. Back in the day 1950ish we used a bucket and filled the case and seated a bullet and neverhad a problem with old world 4831 surplus. Jack O conner used 62 grs for 130 and 150s and had me do the same and told me you cant get enough of that stuff in a WW case to have a problem and he was almost correct but it pushed my bullets forward overnight and caused feeding problems so I cut back to 61, DONT TRY THIS WITH TODAYS 4831 YOU WILL STICK A CASE OR BLOW A PRIMER..