Gm3 powder.

[tim56]

Anyone using GM3 powder in .357 or .44 ? For many years iv stuck to Unique powder for my .357 Taurus LBR and my .44 Marlin lever action rifle with good results but iv obtained a couple of pounds of GM3 which im told is also good in pistol calibers. Am struggling to find any official load data though rather than just some blokes uncle twice removed who knew someone who may have used it type imfo. Tim.

[taz2]

I've been using GM3 quite successfully for many years in 44 Mag. Try 240 gn RNFP with 6.8 gn of powder. As to 357, if you want a plinking load, try 3 or 3.5 gn. I might add that the 44 load was nowhere near a full load, just the most accurate.
David

[tim56]

Many Thanks David, iv been using 6.2 grns Unique in the .44 mag and 5.0 grns in the LBR. Will give your loads a try. I payed £21 a pound for the gm3 compared with about £6 for the Unique so huge savings if it shoots ok in my guns. Tim

[Paul101]

I load 3.5grns of GM3 in a 357 with a 158grn bullet with ok grouping on 20m gallery and not too bad plinking on our 50m outdoor range today.
You've been to A&A ? he tricked up my marlin really well

Up your way tomorrow, mum lives in Ropsley.

[flanker]

I use it all the time, many of the guys in my club do.

Here is some load data for 44:http://www.frinchillucci.com/ricarica/11.htm and 357:http://www.frinchillucci.com/ricarica/10.htm

Some of these tables show the burn rate comparative to other powders to: http://www.tiropratico.com/htm/tabel...lveri_2011.htm.

It's in Italian, but you can work it out.

Cheap and effective.

[taz2]

I've been using GM3 quite successfully for many years in 44 Mag. Try 240 gn RNFP with 6.8 gn of powder. As to 357, if you want a plinking load, try 3 or 3.5 gn. I might add that the 44 load was nowhere near a full load, just the most accurate.
David

I use the same load in the 44 rifle and the pistol. I've found that ABOUT 6--7 gn of ANY pistol/410 shotgun powder works fine.....you may need to adjust a gn or so either side.

[norfolk shooter]

would you say that gm3 and unique are about the same burn rate??? by the way i use 3grns of gm3 in my taurus 357 with a lead 148gr WC and 6grns in my 44-40 with a lead 220grn RNFP

[taz2]

would you say that gm3 and unique are about the same burn rate??? by the way i use 3grns of gm3 in my taurus 357 with a lead 148gr WC and 6grns in my 44-40 with a lead 220grn RNFP

I'm sure someone will google this and come back with a definitive answer. BUT my experience tells me that,at the sort of load levels we are talking about (20-30 % full loads), as long as the case swells enough to seal the chamber,AND the load is accurate, what if it is a few percent faster or slower burn rate? The main difference with different powders seems to be the volume per grain. Most of the shotgun powders (.410) and pistol powders seem 'fairly' tolerant to powder load variations. I might add that this is only my personal view, I'm sure I'll get corrected on this, but I've been messing around with lever actions, and pistols both now and 'then' for a long time. After a long period of GM3 use, I ran out and moved to Vectan A1...for no other reason than I already had some...once again 6.8 grains, and no real difference in POA or performance........perhaps I got lucky?
I wouldn't say the same for CF rifle reloading, small load to case volume ratios are, generally a no no, except very small ratio loads for cast bullets, AND these are, generally, pistol powders, these seem to be tolerant of lots of air space in the case. I've never heard of the 'flash over' much described, rarely seen in low volume rifle powder loads, but I suppose they do exist.....
The short answer is that it's all about what suits YOUR gun.....any proffered 'magic' load is only 'magic' if it works !

[flanker]

If I'm reading this first table right, GM3 has a slightly faster burn rate than Unique but is very close to it. Mind you, my Italian is not to be relied upon: http://www.tiropratico.com/htm/tabel...lveri_2011.htm.

[Mike95]

A bit faster than Unique, meters better and not so smokey. Works fine in my 30/30 for reduced short range loads. Seems to work fine in all the pistol calibres. 357 loads per a 1990 magazine article...158gn bullet....6.8gns =1150fps......5.6gns=1020fps.

38 special 158gn bullet....4.3gns=1050fps.

Mike95

[norfolk shooter]

i have a loadish of it and only ask as im thinking about useing it for some cast lead 30-06

[taz2]

i have a loadish of it and only ask as im thinking about useing it for some cast lead 30-06

Look on Andy Allwood's site. He usually has some CF/cast bullet load data

http://www.tfsa.co.uk/reloading.htm

David