MGM 357 Max

[camotruck]

I need help from the brain trust. I just traded 2Amendmentnut for his 357 Max. Thanks again I love it.

Here's the issue, Maybe nothing but I'm sitting here at work and I can't stop thinking about it. I started working loads using IMR 4227 and the RCBS 35-200 GC. I started at 17 gr and worked up in .5gr increments until I hit 20. At 19.5 the group really came together 1.21 @100. With 20 I pulled the 2nd shot but 1 and 3 were within .75. I did the same with Win 296 Unimpressive. No pressure signs. I loaded up some more rounds for the next test. Started at 19.5 and went to 21.5. Two days later my first shot missed the target and hit the backing far left (8 inches or so) I looked down the barrel it looked good. I thought it was me so I loaded the next round it was closer but... So I grabbed the scope and fore end pushed , pulled twisted.. everything was tight. So I shot my next three shot string and felt something move. The butt stock was loose. I tightened her down and the next two rounds were in the dirt. the rest of the rounds were spent getting back on paper and now my scope is bottomed out. I still don't have any signs of pressure but am wondering if I might be pushing it too hard. No leading in the barrel.

Camo

[leftiye]

Contender? Encore? What forend? I'm at a loss, but I'd play with that buttstock. Try it loose, tight, moderate. It might like to be just tight enough to not rattle, and locktited down. It might need to be glass bedded.

[NVScouter]

complete disassembly/reassembly/cleaning. Dont waste anymore ammo until then. The scope could have blown up (I've had that happen a few times), a mount screw could have stripped/torn(ditto on that a couple times), or it could be shooter error (never....well maybe once....).

The point remains take out the guesses and you are left with known.

[badgeredd]

Camotruck,

Might I suggest you contact our own 357maximum for some advice/help. His MGM barrel shoots famously. He has worked up several loads with different powders, but if I recall correctly, his best powders and accuracy have been with 300MP and VV N120. Also BABore has a carbine length barrel that shoots very well and he has had good luck with 300MP. I use both powders in my my H&R Handi rifle and my converted Marlin 336 chambered in 357 Max with 1 moa accuracy. I can't address the Encore or Contender, but I believe both of the guys I mentioned earlier can.

Edd

[camotruck]

Sorry, it's a T/C Encore. I'm getting ready to tear it down now and start from scratch. The forend is ... well it's a standard walnut. I pulled the scope and rings off everything was tight. I've never had such a drastic poi change.

Thanks Camo

[Doc_Stihl]

Sounds like the scope gave up the ghost.

[Cosmiceyes]

Who made the scope? 357 Supermags with 200 grain boolits with a fast powder,can knock the guts loose.
Some Supermag links to follow.
http://www.sixguns.com/range/supermags.htm
http://www.danwessonforum.com/archive/history/elgin-gates-creator-of-the-supermag/
http://www.ihmsa.org/tom/techarticles/dan_wesson_414_supermag.htm
http://en.wikipedia.org/wiki/.357_SuperMag#.357_SuperMag

[camotruck]

The scope is a Nikon 4-12x40 Monarch UCC. My concern is the rings. I've never used bases and rings like these. I think they're Leupold quick detach with the pin that drops into the base and locks down. But once locked they feel solid.

[camotruck]

After taking it down and cleaning, I don't think it was equipment failure. (other than the loose butt stock) I think I may be pushing it too hard. I'll know more Sunday.

[Goatwhiskers]

Mine is a Cadet Martini, 24" barrel, shooting a RD357190 which drops at 195gr. I will suggest that you try A1680, had much better luck than with faster powders such as the 4227. GW

[357maximum]

after taking it down and cleaning, i don't think it was equipment failure. (other than the loose butt stock) i think i may be pushing it too hard. I'll know more sunday.


how long is the barrel???

[camotruck]

It's 22 inches. Any other recommendations on slower powders? I have the following powders available to me. Blue Dot Bullseye BLC(2) H335 H110 Reloader 10x HP38 Long Shot W296 2400 The rest of the powders I can use are rifle powders Rel 15, 17, 19, 22, Varget, H1000, IMR 7828, H4350 4891 maybe a couple others but like I said rifle powders. Dang, These powder companys need more sampler packs.

Like I said I'll see what happens tomorrow (Sunday)

[357maximum]

If you are still having issues after Sunday ....PM BaBore he can fix you up with an H110/W296 suggestion for your longer barrel length.

I prefer Vhit N-120 or Alliant MP-300 in mine, but I shoot mostly 180 grainers these days and my barrel is a mere 15 inches long.

[camotruck]

Thanks MAX I shot some W296 I felt it was dirty. As if it wasn't building enough pressure and expanding the brass to make a seal. I might try to anneal some of the brass and see if that helps. I was told the brass was new but with today's SS tumblers who knows for sure.

Camo

Been doing some more reading... I've been using Small Rifle Primers. With the W296 / H110 I read where some recommended using Small Rifle Magnum Primers for those powders.(I believe it was 44Mag speaking about 454 casull loads) I wonder if this could be part of my issue.

[Groo]

Groo here
After you be sure everything is mounted correctly and tight, load a standard 357max load with a 158gr jacketed bullet
over a book load of 296/h110, a good crimp and a sr mag primer .
Use a good rest and put the front bag as close to the action as you can.
Start with a bore sight at 25 yds and get it on paper .
Do not play with longer ranges,longer loads or heavy bullets till you can get a group at 25.
If you have a scope or even a red dot switch it out if the above does not group in 10 to 20 shots.
If all else fails, start with factory 357mag rounds and see how they group.

[camotruck]

[smilie=b::holysheep I think I figured this out. I've been loading 357 mag rounds for so long that I missed the Magnum part of this equation with my second group of loads. Thought I was too smart to bother looking back at my manual. Just grabbed a box of primers and loaded what I knew I wanted for powder charges. That's what I think anyway. And I know I loaded this group with Standard SR primers. Looks like I've got some bullet pulling to do. I just know those GC's are gonna be stuck in the case too, staring back at me.

All that being said If anyone else comes up with other thoughts or suggestions shout them out.

Camo

[357maximum]

I have found the Remington 7 1/2 primer to be top dog in my max as have many others....why I can only speculate, but they just plain work.

[camotruck]

I just picked up 12K CCI 450's I think I screwed up and loaded the second round of test loads with CCI 400. And I know I used 400 in the batch I have now. So I have to get to the bench and pull down what I have and reload using the correct primers. The first time out I watched the groups shrink to 1.25 inches with my last load. When I went back the following day I was all over the place. I think the reason was wrong primers. Another reason I never saw any pressure issues.

I'll update when I know for sure.

Camo

[LUCKYDAWG13]

why not try some 357 magnums in it and see how they shoot out of it
i had a Contender barrel 14" 357 max for years was just a PITA to find
brass for it.but it did shoot like a laser sometimes i miss it

[camotruck]

The barrel is throated for 357Max and heavy rifle bullets 180's and 200's I've shot some 357 mag in it, shot a nice pattern ... for a shotgun.

[357maximum]

**** be careful shooting shorter rounds like 38/357mags in a max......all is fine as long as you clean the "crud ring" from the chamber before touching off a fullhouse 357MAXIMUM....if you forget to clean...... it WILL slightly ring your chamber....ask me how I know.....it hurts nothing but esthetics in my case but it is a nice reminder of how stupid I can be each and every time I examine the chamber/throat of my gun. Mine will "loosely" group with 357Mags, but 38's are just plumb horrid.

[Cosmiceyes]

If you wanna do a funny,max out some 110 grainers.Then get down low enough to be a foot above grass head height.After you shoot at the target.Watch the air wave of the boolit. If you shoot a jackrabbit they exploded into tiny fragments that go everywhere! :)'s

[camotruck]

I don't want to do anything funny.

After some range time, Here's what I have. Scope is good. I'm back on paper, shooting what could be loosely classified as "groups"
Actually some aren't bad. I think my issues stem from these 1) Dirty chamber, after a few rounds I could wipe soot from the breach with my thumb. I could also feel grit in the chamber when thumbing in a round. Which brings me to #2) If the chamber is within spec It's on the large size of it. I need to dig up the SAMMI spec on the Max and check it against my chamber. 3) Not enough pressure to swell the case and seal the chamber. But a slower powder isn't going to help that. So I think I'm gonna anneal a few pieces of brass and see if that helps. Maybe some Mag brass loaded with a RCBS 35-200 seated way out.

Any other helpful thoughts welcome. A nudge in the right direction appreciated.

Camo

[Cosmiceyes]

My perfect powder for the Supermag has always been 5744! I achieve my lowest speed variables,and get the greatest accuracy!

[quilbilly]

I have a Contender 21" carbine in the 357 max and it is my most versatile carbine barrel. I use the 150 RNPB at 1200 fps using Unique, a 173 gr Keith style SWC-pb at 1400 fps with Unique, and a 160 gr swc-gc at 1950 fps with 2400. All have the same POA at 100 and all group under 3" at 100 with a Williams peep sight.

[Whiterabbit]

If you wanna do a funny,max out some 110 grainers.Then get down low enough to be a foot above grass head height.After you shoot at the target.Watch the air wave of the boolit. If you shoot a jackrabbit they exploded into tiny fragments that go everywhere! :)'s

If you want to do a funny, grab a ubiquitous SC steel mold from cast boolits as a sacrificial project mold to cast zing from. Ladle pour yourself some zinc bullets (new pot!) in a 158 grain mold, they come out about 96 grains. follow the load data and it's basically a case FULL of H110, you seat the bullet .1" deep on top of the powder and go.

The funny comes in when you get a muzzle flash so bright it looks like a camera flash in the middle of a bright sunny afternoon!

[Iowa Fox]

I have a Contender 21" carbine in the 357 max and it is my most versatile carbine barrel. I use the 150 RNPB at 1200 fps using Unique, a 173 gr Keith style SWC-pb at 1400 fps with Unique, and a 160 gr swc-gc at 1950 fps with 2400. All have the same POA at 100 and all group under 3" at 100 with a Williams peep sight.

quilbilly, If you don't mind my asking how much Unique are you using under the 173 Keith for 1400 fps? Thanks

[quilbilly]

8.0 gr of Unique with that 173 gr pb boolit. I found that to be maxed out for that pb boolit. Even slightly above that started to show signs of leading. I hope to do a terminal ballistics test on that boolit at 40 yards sometime soon and I bet it will be impressive even at an mv of 1400.

[camotruck]

Still working, Getting closer, Having trouble finding 1680

Camo

[Cosmiceyes]

If you want to do a funny, grab a ubiquitous SC steel mold from cast boolits as a sacrificial project mold to cast zing from. Ladle pour yourself some zinc bullets (new pot!) in a 158 grain mold, they come out about 96 grains. follow the load data and it's basically a case FULL of H110, you seat the bullet .1" deep on top of the powder and go.

The funny comes in when you get a muzzle flash so bright it looks like a camera flash in the middle of a bright sunny afternoon!

Since we at my gun club are member owners that would be a hoot after dark. Especially letting someone else shoot it first! ***** [smilie=p:

[Andy_P]

I use IMR4198 in my 357 Max chambered H&R Handi with good results. Not as high MVs' as the faster powders, but accurate in my gun.

You could have saved a lot of time and ammo if you had bore sighted at the first sign of a changed POI. Now that everything's tight, if your scope is still bottomed out, perhaps there's nothing wrong with it and you need to shim the front mount.

[lak]

Good thread, may explain some of my erratic accuracy issues. The barrel I have seems to prefer 24 to 24.5 grs of 1680. Also prefers the RCBS 200 over the 180 Sil

[camotruck]

Time spent dong something you love is not lost or wasted. And the ammo, well, it hasn't broken the bank. The rifle was bore sighted and on paper most of the time. I wasn't shooting at overly large targets, just 8x11. I print them at work. I had thought about the shimming but as I increase powder loads and decrease boolit weight it has come up. As far as shimming wouldn't I need to shim the rear ring?

[Cosmiceyes]

The fun is chasing the what! :)'s

[selmerfan]

When I was shooting my Max barrels they preferred Rel 7, 4227, and 1680 for heavy boolits with top velocity and accuracy. I was using the RD 359-190-RF and the Lyman 358627 GC for hunting boolits.

[Cosmiceyes]

When I was shooting my Max barrels they preferred Rel 7, 4227, and 1680 for heavy boolits with top velocity and accuracy. I was using the RD 359-190-RF and the Lyman 358627 GC for hunting boolits.

In Virginia I really enjoyed how the deer slammed the ground as if hit by a truck. I use the SAECO 180 grain truncated GC! :)'s

[camotruck]

Primers are becoming available, here's hoping powders are next to show up.

[camotruck]

My AA1680 finally showed up. And I was able to find some load data for some of the other powders I had on hand, BUT some of it is so far over published loads ,... Well, It's worrisome. The 1680 load data uses so much powder in the case (using max loads) I can't seat the bullet into the case without damaging the HP and it being pushed back out . Using starting load data I can seat the pill and crimp it in place but it collapses the HP as well (Hornady XTP) I haven't loaded my 180 gr NOE yet but I feel good about them. Sized .360 with my H110 load they shoot side by side lead and jacketed but my best groups with that is about 3 MOA. the 1680 jacketed shot just over 1.25 MOA.

I'll get picks from the range next time.

Camo

[Groo]

Groo here
One thing you will find with 1680 is that 100% load is the limit , it does not compress well.
I would be careful with the data, not because of pressure but bullet length.
Hp's are longer than Sp's. big Hp's longer than small ones. [weight for weight]
For the 357max I would look at 35 rem bullets or 35cal RIFLE cast.
The rifle bullets stick out of the case farther [more powder space] when crimped [ very good thing with 1680]

[TCLouis]

Goatwhiskers

How much 1680 are you stuffing in behind that RD 190 Boolit?

[uscra112]

I settled on Lil'Gun in my Max, but it's only a 12" Contender barrel. 2400 is way too fast. I had pretty good results with 1680, too.

There's a bunch of issues peculiar to the T/C breakopen that can clobber accuracy. One is the fit of the pivot pin, which I had to rework on mine. But that wouldn't account for wild shooting, just inability to fine it down.