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Discussion Starter · #1 · (Edited)
Just received my Rossi 92 .44 mag and was wondering what others are using for this particular rifle. I tried my pistol rounds-

Hornady 240 grain xtp (.430)
19 grains 2400,

and LSWC from Missouri bullet company,
.430 Brinell hardness of 18
over 9 grains of Power Pistol

Both rounds shot well, however the XTP round revealed signs of high pressure :confused::confused: and the LSWC managed to lead up the Rossi plenty good.

Sooo here's my thinking- I probably do not have an oversized bore because of the pressure signs revealed with the XTP at a load that's fully 1 to 2 grains under max. I also probably got the leading because I pushed the hardcast reasonably slow with the power pistol.

Up next I'm about to try Dardas' .431 200 grain RNFP with Unique powder at 9 and 10 grains, see how this does for the leading.

Anyone care to share what you use in your .44 mag leverguns? Does anyone know if Rossi has a reputation of making bores slightly tight or loose?
Much thanks for any input.
 

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Factory ammo is always good, but expensive. I use the same loads in my Marlin lever gun that I shoot in my Ruger Black Hawk. I use Winchester 296, 24.5 grains, or a max load, at 1400fps. AA #9, 19.5 grains for a reduced load, at 1250fps. Both of these loads are for the Hornady 240 grain XTP bullets. The Winchester 296 loads are max, and you should start lower with the Hornady manual, and work your way up to max. Every rifle is different! For lead bullets, I try to keep all loads down to 1,000fps, and will go to 1,200fps if I know the bullets I'm loading are really hard. And don't forget about the .44 special loads, they work well in the lever rifles also.
 

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Use of beveled base bullets of hard alloys may be you the root of your leading issue, especially if they are less than bore diameter. Their hardness keeps them from obturating at moderate pressure while the beveled base directs gases up and around the undersized bullet, the heat of those gases leave lead deposits. A flat based design of a softer alloy could likely ease leading considerably. Plain based designs overall should be held to 1400 fps or less for best results.

Slugging your bore could still be beneficial. In the past, some Rossi bores have been found to run .431 or even .432 inches. With straight walled cases, simply trimming cases to a uniform length has helped me to moderate pressure and increase accuracy in several cases.
 

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Discussion Starter · #5 ·
Well I tried the unique loads, 200 grain.431 rnfp with both 9 and 10 grains of unique. The 9 grains shot well with no leading, but the 10 grains did show signs of high pressure.:confused::confused:

It appears that I do need to slug my bore because I should not have had pressure signs with either of the loads that gave it to me. At this point I'm thinking my bore may be undersized. Anyone heard of this before?
 

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garydude,

Although I do not own a Rossi I do shoot a Marlin 1894 in 44 Mag and I use .432 cast bullets. 1st thing is to slug your bore with a soft lead fishing sinker (the egg kind) and measure the size of your rifling (dont know if Rossi uses micro groove or Ballard) but it should come out somewhere in the .430 range. What ever it is go .002 over and yes pushing a lead bullet to slow will also cause leading.


Doc
 

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What signs of pressure did those XTP rounds show? Flattened primers are a poor indication of pressures. You won't know what your barrel measures unless you slug it, no matter what you speculate by fired cartridge appearance. I have been reloading lead in my .44 Mag. Puma for 9 years and found two things; the gun will lead with any lead bullet less than .432" in diameter and my Puma won't feed SWC unless in Special cases. Many Rossi Pumas were manufactured with oversize bores (groove diameter up to .433") so the only way to know for sure is to slug the barrel...
 

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Discussion Starter · #8 ·
Well I slugged the bore and came up with.429. As to the signs of pressure what I was seeing was sticky extraction and a bulge right above the case web. I measured the bulge and a lower pressure round would bulge the case to (as memory recalls) .453 or so and the higher pressure xtp loads buldged the cases to.463 or so. It almost felt like a glock bulge. The rounds shot well and the primers did look fairly well. I'm thinking that i might have a loose chamber instead.

Any thoughts? I need to chrony the loads and see where I'm at, but the 9 grain loads are plenty potent for plinking and truth be told I didn't have huge expectations of the rifle to begin with. Oddly the lswc rounds from Missouri bullet co. actually feed just fine, but I did change out the extractor spring from the outset.
 
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