Home Forums Reloading Big Game Rifles Do I really have to start over???

Pet load in my 7x57 has been 48 grains of IMR 4350 with a 154 grain Hornady Interlock for years. I've tested it up to 50 grains with no apparent problems, but settled on the 48 gr. load a long time ago because it's well under max in my rifle, consistently prints nice tight groups, and been a stone-cold killer on deer, elk and antelope.

I haven't had to load for this rifle in a few years, but now I need to whip up a batch of ammo for the coming big game seasons so I bought a new canister of IMR 4350 to duplicate my old pet load. Thing is- I've read that burn rates can vary from lot number to lot number in any given powder, and it's wise to work up to an established load when using a new lot number of the same powder - in this case, IMR 4350.

Really? I've never done that. And I've never noticed any difference in pressure signs or performance. Have I just been lucky?

All things being equal - same brass, primers, bullets, charge weight, seating depth, etc., what risk is there in just loading up with my old tried and true recipe? I'm also wondering if I can substitute H4350 for IMR4350. They look to be interchangeable (the data looks to be exactly the same in all my manuals).
Brno is online now Report Post

Use your pet load and fill an ark.
As to substituting H4831, I'd start over again.
Though similar, checking my notes, some of my rifles like different charges of one than the other,

H4350 and IMR4350 are close, but not interchangeable. A max load with one can be too hot with the other....You need to work up when changing powders. As for changing lotts, I've never bothered working up when changing lots.

+1

Thanks, Everyone.

I reckon I'll just play it safe, and "re" develop that load. I'll start a few grains under and work back up to 48grs.

Better than wrecking a rifle... or worse, eh?

Thanks again for the input.

Depends on your comfort level and your rifle. I've used IMR 4350 and H 4350 in my 7X57 but work them up separately, but don't bother with lot changes, especially if my load is under book.

Book values for the 7X57 are usually very mild, usually well below loads for the same bullet in a 7mm-08 because of the variation in 7X57 rifles over the ages.

Years ago I used 50 g. of IMR 4350 with the 154 Hornady bullet and chronographed that load at 2849 fps . This is well above what most current manuals suggest. But cases lasted well and it seemed safe in my rifle and it did not show high pressure in two other rifles I tried it in.

That being said I would only use that load consistently in a strong action and check carefully for signs of pressure on the way up. (Mine is a FN made 98 Mauser action, with a Douglas barrel with a long throat -- I used that load as a "proof load" on an old neglected M 93 Mauser I resurrected - rifle tied to an old tire and the trigger pulled with a string!) Stopping at 48 grains would be prudent but each rifle is a law unto itself in my experience.

Brno,
What velocity are you getting from your 48 and 50 grain loads? I ask this as I am working up loads for my 7x57, and like you, want to use a 160gr bullet. A recent try with IMR-4350 yielded the following results: 48gr=2,520 and 50gr=2680. The 50gr load showed no pressure signs and bolt opening and ejection were normal. Some manuals list higher velocity numbers for these loads. While I am not particularly interested in velocity per sae, I am interested in how my velocities compare.
Thanks,

Same thing with IMR 4895 and H 4895. Which seems kind of funny, since Hodgdon owns IMR.

Correct me if I'm wrong, but I think IMR powders are made in Canada and Hodgden powders are made in Australia by ADI. Maybe Mule Deer cn jump in and clarify this mess.
Paul B.

Where did you get that? As far as I know Hodgdon Powder Company offices are located at 6231 Robinson in Overland Park, Kansas (even though the mailing address is Shawnee Mission, the destination of the central post office). The Powder magazine, packaging and manufacturing facilities are maintained about 140 miles southwest of the main office, in Herington, Kansas. Additional magazine space, located on a closed military base, is also leased from the City of Topeka, Kansas.

You are right about IMR, Originally, IMR powders were built in a facility at Carney�s Point, in New Jersey across the river from the black powder operations. This plant, built in the 1880�s, was a key provider of gunpowder to the U.S. military and its Allies during World War I. As the U.S. moved out of the Depression and headed towards World War II the need for increased capacity was satisfied through the construction of additional powder plants modeled after Carney�s Point. Amazingly, these plants in total shipped up to 1 Million pounds of gunpowder per day during World War II. In total, 2-1/2 billion pounds of smokeless powder was manufactured in these plants during the War. One of the locations of the newly constructed plants was Valleyfield, in Canada. This plant continues to be the primary supplier of IMR Legendary Powders today. ADI makes the Trail Boss powder IMR puts out, I'm not sure if they make others.

@Bruno one of my pet load's for my 30-06 uses 57.0grs of IMR4350 behind a 150gr Cup and Core. I couldn't get the same group using a range of H4350 weights. I called Hodgdon about this and got the answer I was expecting. My rifle just prefers the IMR4350 load. The technician I spoke with had better results with H4350. I don't know if its the difference in environments, rifles, shooters, all three or one of the many other factor's.

Powder consistency will vary from lot to lot. Competition shooters who live and die by the quarter inch, purchase large amounts from the same lot for their consistency. I would say for hunting, load up 20 pieces of brass keeping the consistency (there's that word again) as close as possible (brass from the same lot, powder from the same lot, primers from the same lot, bullets .. you get my drift). Go check your zero with 10 and save the other 10 for the hunt. but you should only need one ;-)

Have a great hunt, lucky you, I'm done for the year.

-HaYen

I read some where maybe Dave Scovill? That it is a good idea to load a middle of the road load and fire it over chronograph. Keep a few for reference. When you get a new batch of powder (new lot) load the exact same load and shoot over a chronograph. If the load is faster, the powder is probably a faster burning variation, if the load shoots slower then the powder is a slower variation. Load accordingly.