GM3 and 357 Mag reloading

This section is for reloading and ammunition only, all loads found in here are used strictly at your own risk, if in doubt ask again.
All handloading data posted on Full-Bore UK from 23/2/2021 must reference the published pressure tested data it was sourced from, posts without such verification will be removed.
Any existing data without such a reference should treated as suspect and not used.

Moderator: dromia

Forum rules
All handloading data posted on Full-Bore UK from 23/2/2021 must reference the published pressure tested data it was sourced from, posts without such verification will be removed.
Any existing data without such a reference should be treated as suspect and not used.

Use reloading information posted here at your own risk. This forum (http://www.full-bore.co.uk) is not responsible for any property damage or personal injury as a consequence of using reloading data posted here, the information is individual members findings and observations only. Always verify the load data and be absolutely sure your firearm can handle the load, especially older ones. If in doubt start low and work your way up.
Message
Author
User avatar
ovenpaa
Posts: 24689
Joined: Fri Nov 05, 2010 8:27 pm
Location: Årbjerg, Morsø DK
Contact:

GM3 and 357 Mag reloading

#1 Post by ovenpaa »

I was at the range for a local competition today and it turned out the vast majority of shooters have been moving to GM3 powder and they seemed to be doing OK. DOes anyone here have any experience of GM3 specifically for the .357Mag with 158 grn cast bullets?
/d

Du lytter aldrig til de ord jeg siger. Du ser mig kun for det tøj jeg har paa ...

Shed Journal
User avatar
bradaz11
Full-Bore UK Supporter
Posts: 4789
Joined: Mon Jun 02, 2014 1:23 am
Home club or Range: The tunnel at Charmouth, BWSS
Location: Bristol
Contact:

Re: GM3 and 357 Mag reloading

#2 Post by bradaz11 »

Not 357. But for 44 I've moved over to a1 as it's the same price and same weight but so much more consistent
When guns are outlawed, only Outlaws will have guns
User avatar
ovenpaa
Posts: 24689
Joined: Fri Nov 05, 2010 8:27 pm
Location: Årbjerg, Morsø DK
Contact:

Re: GM3 and 357 Mag reloading

#3 Post by ovenpaa »

It is GBP23.00 a tub (500g?) at the range so has to be worth a look
/d

Du lytter aldrig til de ord jeg siger. Du ser mig kun for det tøj jeg har paa ...

Shed Journal
User avatar
phaedra1106
Posts: 3429
Joined: Wed Feb 08, 2012 9:37 pm
Location: Just outside Sacriston (the nice bit!)
Contact:

Re: GM3 and 357 Mag reloading

#4 Post by phaedra1106 »

I've been using it in my 44's for quite few years, originally about £20/lb from Peter Lawman but I picked up 5Kg at £42/Kg (£19/lb) last year from a very nice man in Carlisle.

We had one of those "I'll meet you at 1pm under the train station clock" meetings, a bit like Brief Encounter but without the tea and tears :) I live an exciting life sometimes :D

Another powder to look out for is Maxam CSB-1, not found anyone in the UK selling it yet though. Load data is reported to be the same as Universal powder.
There's room for all Gods creatures, next to the mash and gravy :)
ukrifleman
Full-Bore UK Supporter
Posts: 757
Joined: Thu Jun 07, 2012 7:26 pm
Contact:

Re: GM3 and 357 Mag reloading

#5 Post by ukrifleman »

Ovenpaa wrote:I was at the range for a local competition today and it turned out the vast majority of shooters have been moving to GM3 powder and they seemed to be doing OK. DOes anyone here have any experience of GM3 specifically for the .357Mag with 158 grn cast bullets?

I no longer load .357, but got excellent results with my .357 Rossi lever action, with 5.8gn of GM3 behind a 158gn RNFP GM commercial cast bullet from Kranks.

The current owner of my rifle still uses this load and does very well with it.

I also use GM3 for my 44-40 Spencer carbine and 45 Colt Rossi lever action.

Disclaimer
This load worked well in my rifle but, use this load data at your own risk.

ukrifleman.
User avatar
bradaz11
Full-Bore UK Supporter
Posts: 4789
Joined: Mon Jun 02, 2014 1:23 am
Home club or Range: The tunnel at Charmouth, BWSS
Location: Bristol
Contact:

Re: GM3 and 357 Mag reloading

#6 Post by bradaz11 »

what sort of charge do you use for the 44-40 and 45lc?
When guns are outlawed, only Outlaws will have guns
User avatar
dodgyrog
Posts: 4103
Joined: Wed Jan 05, 2011 11:17 pm
Home club or Range: Three Counties Sporting Club & Gardners Guns
Location: Consett, County Durham
Contact:

Re: GM3 and 357 Mag reloading

#7 Post by dodgyrog »

I've used it for 38 Spl loads but not magnum loads.
Purveyor of fine cast boolits.
All round good guy and VERY grumpy old man.
ukrifleman
Full-Bore UK Supporter
Posts: 757
Joined: Thu Jun 07, 2012 7:26 pm
Contact:

Re: GM3 and 357 Mag reloading

#8 Post by ukrifleman »

bradaz11 wrote:what sort of charge do you use for the 44-40 and 45lc?
For the 44-40 I use 6.5gn GM3 with a .427 commercial cast 200gn RNFP bullet.

For the 45 Colt, I use 6.5gn GM3 with a .454 commercial cast 250gn RNFP bullet.

Disclaimer as previous, use this load data at your own risk.
ukrifleman.
lapua338
Posts: 521
Joined: Sat Nov 06, 2010 9:23 pm
Location: Surrey
Contact:

Re: GM3 and 357 Mag reloading

#9 Post by lapua338 »

I use GM3 in my Rossi carbine, Uberti 1873 and Taurus revolver (all chambered in .357).

As much as I like Unique the alternative is so much cheaper and the net result is the same.
User avatar
andrew375
Posts: 211
Joined: Sun Feb 28, 2016 6:29 pm
Location: Nottingham
Contact:

Re: GM3 and 357 Mag reloading

#10 Post by andrew375 »

I've used a lot of GM£ over the years It is exceptionally clean burning and well mannered. I put over 4 kilos through my .45; of course that was when law abiding subjects were trusted to legally own such nasty things. My main use now is for sub 2000 fps target loads in my .375 H&H.

There is loading data out there but you you have to go to continental practical shooting sites, specifically Italian.
"Consciousness is a lie your brain tells you to make you think you know what you are doing." Professor Maria Goncalves.

If liberty means anything at all, it means the right to tell people what they do not want to hear. George Orwell.
Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests