rossi 92 357 and full throttle 158 gc loads

[makicjf]

I just picked the little rifle up last night and cleaned it up. I cycled about 15 358429's in 38 cases over 7.5 of 4756 sized to .358, rebounded to .3585-.359 and they grouped well. Water dropped, traditional lubed( beeswax,lard, paraffin wax and a half bottle of LLA) and then tumble lubed in alox. My GP 100 loves them and this little rifle shows promise. I got 1400 fps with an sd of 10. I then ran some RCBS 150 ( weigh about 158-159) water dropped and lubed the same as above over 16.7 of H110 and got 2020 fps!!! That's a 30/30 with an 11 round capacity-- These loads will lead the end of the short 4 inch bbl in my GP100 a touch, so I only ran a few. I assume the gas cutting comes from a lack of a check. I have ordered the 358( the numbers escape me) GC'ed mold from Lyman and intend to work up some 30/30 level loads for the carbine. It will be the perfect companion for the GP 100, Vaquero and Blackhawk... in the woods, around the farm or in the truck. Does anyone have any thoughts/experience with full throttle 357 loads in a GC'ed water dropped dropped bullet in a 20 inch bbl?
Thanks!
Jason

[mnewcomb59]

My experience is that it doesn't need gas checks at all. The twist rate is super slow, so the drive bands have low stress and hold tight while the lube groove is deforming and pumping. Water dropped wheel weights at 1900-2100 fps shoot as good as I can. I'm using the Lee 158-RF, tumble lubed, sized 359, then tumble lubed again to half way fill the lube groove. Quick visual sort, no weighing.

I did have to firelap about 20 shots to get the leading to stop. The barrel had chatter marks from the bore being cut with a dull cutter. I also relieved the tight spot in the forearm (2 mins with 220 grit sandpaper) so that way it shoots to the same POA whether hot or cold barrel.

100 yards, discounting fliers due to my bad shooting will be 1 MOA with either 16.1 Lil Gun or 17.4 Lil Gun. 18.6 Lil' Gun (Brian Pearce data) shows promise. I had some vertical stringing, which is a problem when you look through a scout scope too low and the crosshairs aren't perfectly centered in the objective. I haven't tried 296/H110, but it LOVED 2400 in the low 14s charge weight.

I noticed that my Rossi has a large throat. .358 would give a few streaks of leading following the riflings for about 2 inches, but .359 shoots clean as a good .22.


133598

[makicjf]

That's awesome and promising. I don't mind using the GC's but would love to be able to load up some all out 357 loads with the 358429's that would fire from the carbine. I have yet to fire lap, ever. I don't know enough about the rifle to have any idea what it will do or if it will lead. I'll scrub it again this evening and fire it some more.
I have a full buckhorn on my 1895 Marlin cowboy 45/70 and my Rossi 92 in 45 colt, and just ordered one for the 357 rossi. They work perfectly as a ghost ring and are more than accurate enough. I went this route instead of a scout scope so I can use it in cowboy matches. The 45 will whack the 200 yard ram in the kill zone if I use the slight opening at the top of the buckhorn as a "pistol sight" and hold just below the top of the back. I have yet to get the set up dialed on the 45/70, but my hopes are the set up will work the same.
Thank You, Sir!
Jason

[mnewcomb59]

358429 is right on the edge of working in the slow twist. The reason is that it is really long compared to how much it weighs, which means it needs a faster twist than an equal weight RNFP would. This heaviest bullet this gun will shoot without tumbling is a 185 RNFP at max loads, and your bullet is probably just as long.

You might find that the bullets are yawing or tumbling until you really push it fast. I know that using a stability calculator, 158 RF at 1000 fps is 1.5 (perfect) but 158 SWC is 1.4 because the bullet is longer. 1.4 is marginal stability and could be why some people see bullets tumbling with standard 38 loads. http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

If I try to shoot any 158s at 800-900 out of the rifle, they don't shoot at all. My best 158 grain 38 load is 3.8 Tite Group, which is max standard pressure at about 1000 fps in the rifle. This will pretty much one-hole at 50 yards. 180s have to be shot above 1400-1500 to not tumble, and they shoot better and better up to max loads around 1600-1800 fps.


I'm not sure how long exactly the 358429 is, but if you measure it and put in the numbers you can see what the minimimum velocity would be to not have it tumble. Keep increasing the velocity until the calculator says 1.4 and that is where the bullets will start grouping. My guess is you won't see accuracy until 1600-1700 fps with that long bullet in the slow twist.

Also, the Rossi generally eats rounds up to 1.66", and will run the 358429 usually without modification like a Marlin would need. If it doesn't feed, the solution is to file a few thousands off the cartridge lifter stop until it does.

This "stop" is what the rim of the cartridge sits against when the lever is fully open and the cartridge is pointing at the chamber on a 45 degree angle. If your Rossi won't feed the bullet all of the way out of the tube into the action, I would recommend against just seating the bullet deeper and crimping on the drive band. If your bullets telescope into the case that is bad news.

The leading in your GP100 has to be because of a defect in the barrel. A gas check will help, but fire lapping 2 cylinder fulls would probably stop leading forever. Clean the barrel really well and run a dry patch. Then shine a good light from the forcing cone and examine the tops and sides of your riflings. Look for tooling marks that run crossways, or any sharp burrs on the corners.

Try that load again in your Rossi if you don't see any major leading from the first few shots. You might be pleasantly surprised. If you see lead the whole way down the barrel, bullet is too small. If you see a little lead at the beginning of the barrel it will probably will shoot fine after a few fouling shots, but if it bugs you, try 1 thou bigger on bullet. Any other leading means tooling marks, and that means you will have to firelap.

This rifling twist is so slow that you really can't shoot too soft of lead. I don't have access to pure lead, so my softest mix is 8-9 BHN air cooled range scrap with hard cast bullets sorted out before the smelt. I shot the Lee 125 grain RF from this soft alloy at well over 2000 fps with no leading. Accuracy was so-so like 3-4 MOA . Recovered bullets pretty much splattered but I could see the base cupped pretty deep and lube groove was completely gone. My guess is the accuracy was degrading because of the base being cupped so deep and the off center sprues made it cup unevenly. Even though the lube groove was gone, the Alox did it's job. I bet air cooled wheel weights would have been more accurate and would have deformed plenty from the velocity.

This spring I'm gonna work up the Lil Gun all the way to about 2100fps (16") and see what kind of accuracy I can get, then I'm gonna soften and soften alloy until accuracy degrades.

[makicjf]

That is a wealth of information! Thank you! I fired about 15 of the h110-150 rcbs last night and the only leading was at the end under the dovetail for the front sight. It was pretty minimal. I'm hoping that will wear in and go away. If not, I'll learn to fire lap! I think you may be right about the GP10 and tool marks. The same full bore load fired from a 5 1/2 inch vaquero runs clean. I have not checked the vintage Blackhawk 357 yet.
Thank you!
Jason

[mnewcomb59]

It sounds like you would only need a few firelapping shots if you don't have much lead. Leading in random spots is usually due to tooling marks, or sometimes a bore constriction if its near a dovetail.

[northmn]

As also mentioned, leading can be due to gas cutting on a too small bullet. There is a theory that if a bullet is properly fit lube is not needed (just a theory) the 359 was mentioned and may be a good answer. I also have been able to reduce leading using Lee tumble Lube. Some guns like it some don't.

DP

[fecmech]

Here are 2, 10 shot groups @100 yds. with a Rossi 20" carbine and 358429. The load was with 14.9/820/ACWW bullets. The 820 used here is a duplicate of 296/H110 as I get identical velocity and accuracy with identical charges. The velocity of this load was about 1650 fps. In the group on the right I wiffed one so it's 2.75" for 9 shots. I believe the load is just barely stable as these groups go to over 1 ft.@200 yds. The same load out of my Winchester 94 16" twist is linear to 200 yds. I don't hunt so most of my loading in Rossi's is with Lee 125 RF and 120TC bullets in the 1200-1400 fps range. Since .22 rimfire prices got stupid, this is now my main plinker. One 158 gr SWC that will shoot well in the 1000-1200 fps range is the Lee TL158 SWC. It is accurate and stable to 200 yds.

[Camba]

Good shooting!

[jamesgpobog]

I know that using a stability calculator, 158 RF at 1000 fps is 1.5 (perfect)
What calculator is that? Bergers gives that a 1.36 (BC .17, .358, 158gr, .645 long, 1000fps, 1:30, 59F, 0ft)

[missionary5155]

Good evening
Hard to beat having a revolver and rifle / carbine in the same caliber and especially that will shoot the same load reasonably well.
My .357 combination is a Marlin 1894 and a Dan Wesson 15-2 with a 4 inch barrel. Generally my shooting is well under 50 yards as I am mostly in thickets and river bottoms. If I have 35 yard groups of 1.5 inches or less that generally will take care of any ground hog, raccoon or other under 50 pound critter that fails to allude me.
I general shoot mostly with the Lyman 358429 over 5.5 - 6.5 grains of Unique. Has always served me well and easily fits my close in accuracy needs. Sized .360 from WW +1% tin or 50-50 (WW - range lead). I lube these with what ever lube is in the Lyman 450 "moderate velocity" lubber at the time.
Another favorite in caliber .357 is the Lyman 357446. Mine drops with 50-50 at 162 grains. This is my second choice as my DW likes the 357429 better. The Marlin shots both about the same.
If I need more thump I switch to a 180 grainer over 2400. But that load is seldom used any as I have larger bore rigs in calibers .41 mag, 45 Colt and 414 Supermag to handle tougher tasks.
I have 2 Rossi 92 carbines and they are good for the task. I would be sure all the burs and goo are well cleaned out if this is a newer model. Generally the older shot more 92's have been apart and cleaned but that is not a given.
Mike in Peru

[makicjf]

I fired a bunch last night of the 358429 wdww double lubed at.359 with enough h110 to get a very consistent 1805 fps avg with low teens sd. The RCBS 150 drops at .358 and averaged 1980, but was not as consistent in velocity (1900-2020) over ten shots. I was really just shooting to see if it would stay clean, but the groups from 25 yards offhand were really tight for both loadings, though to the left. I'm not going to bother adjusting until the full buckhorn arrives from steves gunz. The good news is the bbl stayed clean and shined like a new penny with a few dry patch runs. I'm wishing now I had been patient and not ordered the GC'ed Lyman mold and 1000 checks. I'm sure I'll find a use for them.
Ya'll were correct, the GP shows light marks exactly where the bit of leading will occur with full throttle loads. I'll need to sort out fire lapping.
Thanks Guys!
Jason

[357Mag]

MAKICKF -

Howdy !


I recommend 14.5gr WW296 ( H110 same stuff ) and SP Mag primer.


With regards,
357Mag

[makicjf]

357mag,
What oal are you running at that level? Are you crimping into the crimp groove?
Thanks!
Jason

[mnewcomb59]

What calculator is that? Bergers gives that a 1.36 (BC .17, .358, 158gr, .645 long, 1000fps, 1:30, 59F, 0ft)


I just ran the numbers at .64 long, 162 grains, 1:30 and 1000 fps. It is the JBM calculator I linked above. It just calculated out to 1.475 for me.

In all likelyhood, I am shooting them at 1020-1050 with my 3.8 load of Titegroup because it says on the bottle that 3.8 is 920 fps in their test barrel. I would imagine that I have at least 100 fps on their (7"?) test barrel.

[357Mag]

Makicjf -

Howdy !


I'll have to go check some of my rounds, once I return home tonight.

Film @ 11:00 ......


With regards,
357Mag

[357Mag]

Makicjf -

Howdy !

* My .357Mag's are set to a max c.o.a.l. of 1.615"..... a concession to their use in S&W "N"-frames.
This c.o.a.l. also worked just fine, through my M1894SC. No problems w/ feeding or cycling of the action.

Whether using the Lymans 158SWC or their 357446 162gr SWC, I crimp on the fwd driving band.
The 357446 has proven more accuarte for me over-all, than the lighter 158.

With the 14.5g WW296 & SP Mag primer load, I have been able to shoot non-GC boolits w/o excess leading ( my loads, my guns ).


With regards,
357Mag

[dubber123]

I see you are still considering firelapping at least one of your guns. It's not hard, and can work wonders. It's pretty near impossible to do any damage to a firearm unless you are a world class dufus :) To illustrate how much it can improve a gun, my Marlin 1985 Cowboy had a rough barrel that leaded with many loads. After firelapping, I can shoot a full 1.5 grains higher powder charge before I notice any deposits at all. Accuracy was improved with all loads. I have done primarily revolvers, and a 50% reduction in group size at 50 yds. is common.

[A pause for the COZ]

Hey good dope in this thread. I too have run into the tumble action using the heavies in the Rossi.
My intent when I purchased it was to load up 180's and use it as a brush gun.
I settled on a 300 Black Out as my Brush gun so I haven't played around with them for some time.

But I have happened upon a great match for this gun for small game and plinking.
Try LEE 125 rnfp's ahead of ether 4gr of Unique or 5 gr of Herco in 38 special cases.
I think you would be very very happy with the results.
These are at 100 yards. From a rest and a scout scope.
You can use 357 mag cases and I have tried upping the grains in the mag cases.
Good results all the way around.
Just not this good.
Well actually there is a reason I keep this image. Might not ever see that again.

http://i33.photobucket.com/albums/d66/Kelly2215/100_8371.jpg

[fecmech]

But I have happened upon a great match for this gun for small game and plinking.
Try LEE 125 rnfp's ahead of ether 4gr of Unique or 5 gr of Herco in 38 special cases.
I think you would be very very happy with the results.
The 30" twist loves the light weight bullets. The Lee 125 RF and the Lee or RCBS 124 TC with Bullseye or 231 in the 4.5-5.5 gr range runs roughly 1200 fps and less than 3 moa@100yds out of both my Rossi's.