GP 100 .357 loading, Where to Start?

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lowburb

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So, I have only shot factory 158 gr loads in my GP100 but I am ready to start loading. I'm not looking for max, just accuracy. What bullets should I be looking for? Lead, copper plated, wad, truncated, semi wad? What weight? Any suggestions as to where to start? Thanks!
 
My GP shoots straight with Cam Pro 158's. Light loads are with Unique powder, the heavy loads are with H110.( have to be near max ) All my reloads are 357 mag brass.
 
Haven't tried many different bullets in my gp100 but I run 124gr truncated cone bullets, campros so they are plated. Don't have a crony but have loaded some up with win 296 under them and sure makes a huge bang and flash and gun kicks more than factory 357 loads. Generally put like 4gr titegroup, not the best powder for this application but have tons of it, as paper or steel doesn't know difference and easier on me. Accuracy is good enough for me to hit plates reliably to 20 meters.
 
My two GP100 like 16.3grn H110 with magnum primer behind a 158grn campro. It's a full load but the felt recoil isn't really bad. It's more accurate than I can be without handrest. The blast is impressive to shooters in the lanes next to you, but for the shooter it isn't bad.
 
lowburb said:
... I'm not looking for max, just accuracy. What bullets should I be looking for? Lead, copper plated, wad, truncated, semi wad?...
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The Lyman Handloading Manual recommends the old standby, 2400, as a good starting point. Loads can also be adjusted up or down to suit, which is not recommended for H110/W296.

12 gr of 2400 under a 158 gr. lead/plated bullet should get you into "38-44" territory, ie around 1100-1200 fps. I've tried this in my GP100 (not chrony'd, though) and they are pleasant to shoot. 6-7 gr. of Bullseye should be around the same. According to a post on Castboolits, one fellow is using 6.2 gt of Unique in his GP100 with 158gr. SWC and gets 1100 fps. As someone else on that thread said, "Very accurate and just enough recoil to be interesting."

There's a good article on .357 loads by the late SkeeterSkelton here.
 
HI; Bullet weight 158 grain, will work for all types of shooting. Type; plated, campro, cost effective, available all over the place, no leading issues, no lead dust for indoor shooting.
Less lead exposure handling and reloading. Powder; whatever! used UNIQUE for silhouettes for years, like HP38 in the summer but too temperature sanative for winter cold. Tightgroup works but not for low pressure loads, winter loads. Heavy loads; old school, Alliant 2400, can go from mid to full hot loads.
Primers; Federal is first choice then what I can find.
Brass; One brand all the same length.
 
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Has anyone tried going above the max 5.5gr Unique loads for the Campro 158gr TC in 38spl? At 5.1 grains I'm getting no pressure signs and the bullets are shooting high from a 357 carbine. I'm thinking about stepping it up in increments to max and then going a bit over.

One of the bullets today actually didn't penetrate my green gopher target, it's stuck in the thing, can't even get it out with a pocket knife. Shooting into a rotten tree stump the bullets are barely penetrating in more than a bit, you can pull them out with your fingers. This load has to be going 850fps+ but i've never seen such lackluster performance before.
 
Once unpon a time a shooter overloaded 357 mag all the time because they were more accurate that way. The rear sight is still stuck in the ceiling and I have never saw him again.
 
lowburb said:
Lots of suggestions here! I think I will go with 158 cptc bullets. Now to decide on powder...
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Campro bullets are cheap and that's the end of it.
If you're looking for accuracy at 25 or 50yds look somewhere else.
Most people are shooting shotgun patterns at 10m and think 5" groups at that distance is accuracy (the correct word would be precision).
 
josquin said:
The Lyman Handloading Manual recommends the old standby, 2400, as a good starting point. Loads can also be adjusted up or down to suit, which is not recommended for H110/W296.

12 gr of 2400 under a 158 gr. lead/plated bullet should get you into "38-44" territory, ie around 1100-1200 fps. I've tried this in my GP100 (not chrony'd, though) and they are pleasant to shoot. 6-7 gr. of Bullseye should be around the same. According to a post on Castboolits, one fellow is using 6.2 gt of Unique in his GP100 with 158gr. SWC and gets 1100 fps. As someone else on that thread said, "Very accurate and just enough recoil to be interesting."

There's a good article on .357 loads by the late SkeeterSkelton here.
Click to expand...
Thanks for the article!
 
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