Microgroove in the Marlin M94

[FAsmus]

Gentlemen,

I bought a Marlin M94 in 357 magnum last week. Unfortunately I bought it sight-unseen through a friend.

This friend of mine didn't see the "Microgroove" stamped on the barrel, so I wound up with my first MG Marlin in about 30 years.

I once had a M336 in 44 Magnum and it wouldn't shoot cast bullets at all until in desperation I loaded the Lyman 429244 unsized. My mold casts this design at 0.434 and I loaded them as-cast. Loaded cartridges looked like a snake swallowing an egg but they did chamber and accuracy was outstanding.

Now, with this new 357 I skipped all the load work-up, went right to my oversize NEI 150-358-PB which casts bullets of 0.363, lubed them only in the 0.364 die, loaded them over Bullseye into unsized cases and went to the range for testing. Again, the MG rifling gave me outstanding accuracy with the massively oversize bullets.

All a fellow need do it seems is load big bullets for the Microgroove barrels. However, always make sure the cartridges so loaded will fit the gun's chamber before you load more than one!

Good afternoon,
Forrest

[haroldclark]

Don't let anyone tell you that Marlin Micro-grooved barrels won't shoot cast bullets.  I have two of the Model 1894s in 357 Mag and you can't have too many of them.

With a Saeco 180 RFN (round nose flattened) with 13 grains of H4227 and a Bushnell 3-9 Scopechief, it will shoot 20 consecutive shots into 1.5" at 100 yards.  Another 15 shot into 1.5".

I have A Marlin Texas 444 Marlin that shot .2" groups at 100 with a Saeco 245 grain RFN with 14.5 grains of IMR SR 7526.  I have a database with over 700 recorded groups and the first 4 slots were taken by the 444 Marlin with a micro-grooved barrel with a 1 in 38" twist.

My Marlins don't know that they are not supposed to shoot lead bullets and I'm not telling them.

I sold a Marlin 336 in 30-30 years ago that would also, print 1.5" groups or smaller at 100 yards.  I now have a Marlin Cowboy 336 in 30-30 and it has Ballard rifling.  It doesn't shoot any better than the Micro-groove.

Lots of luck with your 357.  It is a great little caliber  in the rifle.

Harold Clark

[haroldclark]

By the way, I size my bullets to .358 and the work just fine.  It doesn't lead or fould the barrel with 4227.  

H110 and Unique would cause leading at the throat and a few inches forward.

I use 3.5 grains of Bullseye and a 158 grain cast plain base bullet in 38 cases and that is a charm.

Harold

[Badnews Bob]

Yep mine shoots cast just fine. I also size to .358, I got one load of 2.8grs of bullseye under a 158gr RNFP Lee mould thats just to much fun to shoot. on a long shot with the light just right you can see the round going downrange. I luv .357s

[FAsmus]

Harold,

H:  I size my bullets to .358 and the work just fine.  It doesn't lead or foul the barrel with 4227.  

F: It is interesting that you don't need oversize bullets for your shooting.

I like the oversize bullets not only because they perform well but because I'm lazy: I don't need to size bullets at all and they are so big that I don't need to size cases either since the unsized bullets are a perfect fit in as-fired brass. Chambering is no problem even with such large cartridges and loading them is ever so much faster; important stuff since I'm using the rifle in Action shooting which eats up all my production quickly enough anyway!

Goo morning,
Forrest