Experiences with .357/45 G.W.M / .357/45 GWM / .357/45 L.A.R Grizzly

[de50ae]

Regarding OAL I think 40,3 to 40,5mm for flat point bullets is the way to go for the Grizzly.

I've shot arround 800 to 1000 rounds with 158grs (factory and reloaded ammo) and 180grs bullets this summer with the .357 Magnum barrel.

Won the national championship with the Grizzly by the way  

My experience is that with mild loads you could actually feel that with 40mm OAL the cycling was bumpy and with nearly 41mm it failed to feed.

So the sweetspot is inbetween.

 

Because of the same angle to the feed ramp I think that experience can be transfered to the .357/45 GWM too.

 

[Grizzly45]

Gongrats on the win

I bowed out of both relevant championships this year due to Covid. Do you have classes for "357 mag" type guns & "44 mag" type?

 

Here they're called Mag1 (Ø<=10mm, factor > 190) and Mag2, (Ø>10mm, power factor > 275)

 

Regarding feeding & length:

With FN bullets I frequently get cartridge 5 or 6 caught on the feed ramp, with a sad ending for that cartridge.

 

My cartridges (from number 2-3, are pointing downwards significantly. So - RN bullets, real jacketed so they don't deform, and now with an extra long OAL.

 

I fed atleast one 7 shot mag of these without fail.

 

With FP bullets & 40,3 OAL, 1-2 FTF per magazine.

 

I have new magsprings, but the magazines & followers have seen some use.

Edited October 18, 2022 by Grizzly45

[Grizzly45]

OK, I realize that this is mostly my own personal scratchpad now. But I now will draw the attention of the audience (mostly me) to the fact that I have tonight loaded 25 .357/45 GWM cartridges that have a 100% "plunk" rate when dropped into the barrel/chamber of the 357/45 GWM.

 

They also headspace correctly, and here was no "oh, that was odd". Only took two years.

 

The recipe is :
(thanks to @de50ae for the 8x33 idea) :
1) Buy the CH4D dies. Throw away a bit of the set, but keep the sizing & seat/crimp die.

2) Grid off a bit off the bottom of the size die. How much must be determined later

3) Get hold of a .357(8) rifle type expander die. I use a .358 Win die, with most of the body sawed off, so I can use the expander. I have ground the expander button down a bit.

4) Get some 8x33 Kurtz shells. This removes soo much hassle compared to .308 Win. .44 Automag might still work, though.

5) Expand the 8x33 shells on the die mentioned in 3), add primer, powder, shells. I ended up with a light bullet and a reasonably full load.

6) Fire. Go looking for the shells.

7) Here we're back to the "you need to grind off the bottom of the sizing die a bit". Grind until a fire-formed 8x33 plunks in the chamber, and then a bit more.

8} I then size the cases until they plunk, then a bit more. (Very important step :))

9) Expand the case necks, with the .357 expander ball, so you can seat the bullets

10) prime, powder, seat.

 

My 25 .357/45 GWM cartridges now "plunk", and headspace right.

 

I've found that seating the bullets long helps with feeding.

 

I also apply a hefty bit of crimp. The Grizzly is not kind on the cartridges, and because the .357/45 GWM tapers a lot more than the .45 Win Mag it actually was designed for, the .357's get a nose job every time they're fed. So heavy crimp   I feel this heavy crimp is a part of the "that's odd - some chamber, some don't". But is seems like the extra pushback from the sizer alleviates the possible bulges caused by the .357 flatbase brutally showed down + the rather heavy crimp.

 

The "then a bit more" seems to be the clue here. When the fireformed and sized cases "plunk" in the chamber, there is still a bit of room for trouble. And that has been nagging me. But adding a wee bit of extra case neck push back still lets them headspace right, after a .357 has been showed down the throat. This is of course because the CH4D dies are actually not .357/45 GWM sized.

 

But one works with what one has.

 

I will now epoxy down the position of the size, expander and seat dies, after I've made the journey from 8x33 to .357/45 GWM from fresh cases one last time. Then I'll quit posting here

Edited March 21, 2023 by Grizzly45

[spindrift]

Creativity, ingeniosity, persistence.

 

While your project has no direct relevance to my current shooting activities, I've enjoyed following this thread. Thanks!

 

[Grizzly45]

A few more comments:

1: The case necks are rather rough after sizing & fireforming. Neck chamfering is a good idea.

2: The Kurz cases give a little (~50 ft/s) lower velocity than the .308-cases, indicating that the case volume is a little larger. I've upped the load with 0.6 grains

 

I've just loaded 30 fireformed / fireformed + 1-time fired cases, and they all plunk.
I've loaded them with varying OAL from 39.9 - 40.6mm, to see if a particular OAL is better for loading/chambering from the magazine

Edited March 26, 2023 by Grizzly45

[Grizzly45]

OK, last update, promise. Almost certain.. (3 subjects in this post)

I was elated to have 25 .357/45 cartridges based on the 8x33 cases “plunk”, but unfortunately, the string was not consistent. I still had the occasional cartridge that would not plunk/feed. Diagnosis: Flat based bullets being showed down the throat of an insufficiently supported case neck sometimes would lead to a kink/bulge in the neck, causing problems.

 

New fix: A Lee Factory Neck Crimp die. This is the same type of die we know from rifles – 4 fingers come in to press the neck straight & tight. Wonderful.

Surprisingly, Lee has overlooked the .357/45 GWM, but they have made one  for .357 SIG. The .357 SIG is based on the .40 S&W case, about 10mm dia at the base, where the .357/45 is about 11mm. The SIG is also a bit shorter than the GWM.

The Factory Crimp Die (FCD) has a sleeve that impacts the shell holder, the sleeve then pushes the four crimp fingers together.

So. I drilled out the sleeve, and added a small extension to the sleeve, to compensate for the difference in case length.

And now, by Jove, I can consistently turn out 100’s of cartridges that actually chamber and go boom every time. Happy

 

OK, that was the plunking & FCD. I still had problems getting the cartridges to feed well, getting up the ramp without stopping.

 

Fix: Several deep breaths, get out some non-marring pliers, and carefully bend in the feed lips at the rear end. The “next” cartridge now pops up, and is kept in place by the indent in the feed lips, creating a good trajectory towards the chamber.

I can even load 110gr HP bullets without hiccups.

 

Those 110grs HP (Sierra something hollow cavity) brings me to the final item.  I was wondering if I could get them out at 2000 fps (610 m/s). The answer is no.

I can (safely) get them out at 1880 fps (573 m/s), which is an interesting experience (type: the fillings in your molars are shaking loose).  The loads at 1940 fps (591 m/s) showed an impressive range of indications that I’ve never seen in a handgun before: Primers backing out, cratered primers, bent rims from the extractor etc.

 

That’s not the actual third subject – the observation is that although the slightly smaller rim diameter of the 8x33 is a minor issue, of course the rest of the case head is similarly slightly smaller.

So if you go tickling the dragons tail by for example trying to push a 110gr at 2000 fps, the case (quite a bit ahead of where we go looking for the pressure ring), expands quite severely.

This is of course an indication that you’re in the red on this load, and secondarily, the cases needs to be discarded.

 

Calling it a night here, I may actually have beat this project

Edited June 3, 2023 by Grizzly45

[de50ae]

Thanks for constantly sharing your findings!
 

573m/s from a 6,5" barrel, Jesus!
This what I got out of my M1 Carbine with an 110grs bullet and this has a 18" barrel.

 

I haven't continued working on the 357/45 in the last year.

Only shot a few of those cartridges which came with the gun made from the WinMag cases.

Currently the Grizzly is at a gunsmith to modify my frontsight and optimize the .357 and the .45 WinMag setup for accuracy.

In fall I plan to continue to look for a nice 357/45 load for me.

Since the function already was pretty good with my loads the two things to be done are to fix that the cartridge is sometimes to big at the neck (would be hard to unload a chambered round) and to find an accurate load for the barrel.

I am not aiming for speed records

Pretty sure the big diameter can be solved by turning the case neck a little.

A friend of mine has a neck turner und a annealing machine.

So after fireforming the cases he will turn the neck a little and anneal the cases.
Then I should have a nice set of cases for my barrel

 

I will post here when I have found some nice loads and share my findings too

 

Regarding your question to my last post... (sorry forgot to reply at the time)
Yes we have dedicated classes for Magnum guns to .357 and over .357 bullet diameter.

And it's even devided in pistol and revolver, so quite a few classes to make use of ones Magnum guns

Edited June 3, 2023 by de50ae

[Carl Volt]

On 6/3/2023 at 9:29 PM, Grizzly45 said:

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Please keep going, it's highly interesting reading material when doing research on bottlenecked magnum pistol cartridges.