Rx7 help

I went to load some Lee 457-405-F bullets (approx. 390 gr from homemade Lyman #2) for my 450 Marlin (1895M), but ran into a problem (potentially). I have never loaded this bullet before and bought some Alliant Rx7 to start with. Never have used Rx7 before, I doublechecked and reread the description of it in my Lyman 48th. It says Rx7 should have "a mix of red, yellow, and blue identifying granulations" (p67), but upon opening my bottle, I see no such granules. All I see are goldish tubular shaped granules. What gives? Has Alliant changed this since the 48th edition was published? A quick look at the Alliant website didn't help either -- they don't mention the colored granules.

Secondarily, has anyone have any experience with this combination?

Thanks,
Josh

Josh, if you don't get an answer here I would call Alliant before proceeding further.Maybe they put the wrong powder in the container and should know about it...Ray

I've used Reloader 7 from several lots and it is never anything but black short cut extruded grains.

0802 ... Got out my Lyman 48th manual and you are correct. Page 67 states about the color markers in the powder. I went to my powder cabinet and opened 3 containers of Rx7 and I can see no color markers. Either a microscope is needed to view these markers or something has been changed. I have used quite a few pounds of Rx7 in 45-70 with cast bullets and can never remember seeing the markers stated in the Lyman manual. If your powder came from a reliable source in an unopened container I would use it as Rx7.
Nighthunter

Reloader 7 from the last of several pounds I have burned:

http://mywebpages.comcast.net/imasho...res/rl7-sm.jpg

The best powder I've used for 7.62x39. I read the same thing and concur with nighthunter. I think Lyman dropped the ball on that one..........
Regards,
Jeff

My recently purchased can of RX7 appears exactly as you described. Short extruded black granules with a "goldish" hue to them. I have used this powder in the .450 Marlin cartridge with no problems at all. I agree with xring363, Lyman probably dropped the ball on the powder description.

Dutch
You suppose that Lyman was discribing the California, decorater varient of RL-7
Jim

When RX7 was made by Hercules it was colored as you described. When Alliant took over the Hercules powder line they had RX7 imported from Bofors which is a Swedish firm. The current Swedish version is a different powder than the original although it is designed to give the same ballistics for the saem weight.

I have several pounds of both versions and I much prefer the Hercules powder since it seems to give better accuracy.

Thanks -- I broke the seal on it when I opened it tonight and I bought it from my regular shop, so I have no reason to think it had been tampered with. It looks the same as what is pictured/described.

Quote:

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Originally Posted by unique

When RX7 was made by Hercules it was colored as you described. When Alliant took over the Hercules powder line they had RX7 imported from Bofors which is a Swedish firm. The current Swedish version is a different powder than the original although it is designed to give the same ballistics for the saem weight.

I have several pounds of both versions and I much prefer the Hercules powder since it seems to give better accuracy.

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How long ago was this change made?
I bought 20 or so pounds of RL-7 from a defunct gun shop ten years ago. The gun shop had the powder for how long is anybodies guess and that powder was black.
Jim

Don't know the exact date but it was in the 90's. Look at the label on the powder and if it says Alliant it will also say "Made in Sweden".

Older cans of Hercules powder will say "Made in USA" on them and will have the colorful grains.

There is an exception: you'll find a Hercules can with a sticker that says "Made in Sweden" that covers the the printed on the can "Made in USA". These came out around the time Hercules was bought by Alliant so it is not clear exactly when the transition occurred. What is clear is that Alliant RX7 is made by Bofors and is different than the original RX7.

While I am at it; the current version of RX7 has 7% Nitroglycerine. The 7% doesn't have anything to do with the RX7 name. RX7 works across a broad range and is extremely versatile. The reason I point out the 7% NG is since RX7 is doublebase powder, it keeps for a very long time and 20 years is nothing. I do not pass up an opprotunity to purchase the older RX7 whenever I can since I consider it superior to current version.

Yes, the RL7/RX7 "brand" has two formulas, one with circa 5 percent nitroglycerin, and the newer formulation closer to circa 10 percent. The older formula is slightly slower in speed from my experiments. Definitely, do not mix them because you will be throwing away this particular and beneficial asset. I like the powder, either formulation, specifically because each formula has a granule size close to that of the various 4227s. Both RL7 formulas are slightly slower than the majority of the 4227s which makes them very nice to have. ... felix

When the ReloadeR series first came out (late '60's?) with 7, 11, and 21, they each had identifing colored grains in them. My RL 21 has red and yellow grains but, I never used the other two. -JDL

Thanks for the help on this. Now -- a new question -- has anyone had a problem with Rx7 being dirty? More than a little unburned powder in the cases at the range today. I'm just getting into reloading in general, very new to cast bullets in 450 Marlin.


450 Marlin in Marlin 1895M
CCI large rifle primer
31.0 grains of Rx7
Lee 457-405 (about 390 gr actual) with a solid crimp

Suggestions?

I noticed my old batch being a bit sootier than similar level loads of IMR3031 in my .30wcf. The newer batch seems more like the IMR dirt wise. Your unburned powder may be because 31.0 seem like it would be a light load for a .45-70. The Alliant guide show 45.0s for a 385 gr. gc and 40.0 for a 400 Speer jacketed. Not the same as a .450 Marlin but should be in the same ball park. More powder will generate higher pressure and more complete combustion, thus less unburned and less soot. I noticed that effect with .45acp and Bullseye. Light loads dirty, hardball level ones clean.

Quote:

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Originally Posted by C A Plater

............More powder will generate higher pressure and more complete combustion, thus less unburned and less soot.

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That's exactly what I found when working up loads with RX-7 for the Lee 500 grn RFGC in my H&R Ultra Rifle in .450 Marlin. :)