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Discussion Starter · #1 ·
I have a couple old bottles (about 4 pounds) of Hercules RX-7 (with the colored granules). Is there any diffence between this and the RX-7 powder Alliant has out now? I've noticed the powder dosen't have colored grains anymore. I'm looking to load some up in the 38-55.
Oh, while i'm at it. Old Hercules 2400 vs new Alliant 2400. Any difference? I tried calling Alliant trying to get some answers and left a message but no one ever called back. Thank you!
 

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The newer 2400 is supposed to be a little faster burning. At least that's what I've heard anyway.

Never dealt with RX-7, so I can't comment on it.
 

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I have used Rx7 for many years. Your 4#s are in the paper cans? The powder had red flecks (is that a word?) for identification. I was only loading 30-30 at the time and did not change the charge weight when the flecks were removed. As always, approach with caution, looking for signs of pressure.
The 2400 of yesteryear was reported as being slower than that of today to confirm 44-40 Willy.


Papalote
 

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Discussion Starter · #4 ·
Thanks guys. Yes, hercules RX-7 in the paper cans.
I will definitely start with a middle of the road load and work my way up. Maybe i'll have to get out the chronograph for this one. Haven't used it in years.
 

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RCHunter, when you get a chance, please publish your findings here.............I'm betting there is more of that powder lurking in a number of mancaves, and if there are any significant differences, it would be helpful to know. Thanks. 8)
 

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I've heard some say that in smaller cartridges that there is no difference in performance between the powders, but in the 45-70 there is a definite difference. If you look at the older data, say from the 3rd edition of the Lyman Cast Bullet handbook, and compare it with data for the same bullet in Lyman's 49th, you'll see that the data for the new powder is several grains less. For the 405gr 457193 I believe that the Charges were reduced by around 2.5gr or so with the switch to the new powder.

I can say from experience that the starting charge with the old data was reasonably close to max velocity when used with the newer powder. I wrote Alliant about that a few years ago and they said that what I was seeing on the chronograph was about what they'd expect.

Chris.
 

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On a similar note, the older Lyman manuals listed heavier charges for the old 2400 in the 44-40 that what the newer ones do. Not sure whether it's because the powder changed a bit, lawyers got involved or both.
 

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Both of the older stuff burns slightly slower, older data showed this.

Lot of the 45-70 shooters started getting pressure spikes in to end loads with RX7.

With the 38-55 I would just use current data for a starting point though it would be under in the older manuals.

I've found most 38-55s have several sweet spots, one is around 1100 - 1300 fps, the next is in the area of 1800.

Thing I've found that is the best part. When I started shooting cast in mine, 9gns of Unique pretty much duplicates the factory Winchester jacketed load in feet per second and accuracy.
 

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Discussion Starter · #10 ·
Swany, I have Lyman manual 47 & 48. They have RX-7 data for 38-55 in Lyman 47 but left it out of 48 and probably the newer manuals. So I will be refering to Lyman 47. The bullet i'm using is Barnes 255gr .377
Haven't started shooting cast yet. I will be using this Marlin 336CB mainly for deer hunting anyway so I probably won't shoot it a lot.
 

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The earlier Lyman manuals used the US manufactured Reloder 7. The later ones used the Swedish manufactured type, made by Bofors.

Ironically, despite the switch in manufacture, the recommendation for the powders did not change in many instances. I heard, but cannot confirm, that the Bofors manufactured variant was intended to replicate the old stuff as closely as possible despite the change in appearance, as the new does not have the multicolored granules.

In a modest amount of testing in determining the effect of the new versus the old I found they were pretty close, but of course I cannot speak for the cartridges I have not loaded. In 35 Remington the new is a little slower than the old, in that a bit slower velocities were obtained with similar charge weights.

In considerably reduced cast bullet loads there is relatively little difference.
 

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I know this is an old thread but I was looking for info on RX 7. In my Lyman 49th they list many loads for 45-70 using RX 7 but does not have it in their burn rate chart.
I have used Reloder 7 and thought that is what they were talking about. Is RX 7 the new RL 7 ??? I am trying to find a replacement for all my standard loads in all calibers because when my local shop gets powder it is what ever they send him.
 
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