'94 Marlin - .430 vs .431 Boolits

[Foto Joe]

I've got a '94 Marlin that I've had for years that has until now only been fed 44 Specials pushed by TrailBoss under 200gr SWC's or RF's sized to .429. A few weeks ago I ran into a guy out at the range who supplied me with some 44 Mag brass and I decided to start playing with them. My first attempts were sized to .429 and resulted in me digging around to find my ChoreBoy to clean out the barrel. After I got the lead cleaned out I did what I should have years ago and slugged the bore of the rifle only to find out that it's .430. My soft lubed low pressure undersized 44 Specials never bit me on leading but of course 44 Mag is a horse of a different color.

Since then I've run about a hundred .430's cast out of COWW's +2%sb at 12.5 BHN with 7.3gr 700X and 10.5gr AutoComp. The AutoComp loads chronographed out at 1,393fps with an SD of 7 with the 700X slightly slower and less consistent, both grouped reasonable at 50 yards with iron sights on a 16" barrel. Other lighter loads were tried but these were the two most consistent and accurate. Between each ten shot string I dry patched the barrel looking for little "sparkles" of lead and saw none. When I got home I pulled the bolt and patched out the barrel with Hoppes then had a look for leading. What I saw was a vast improvement over the .429's but I still had minor leading in the first 1/2" of the rifling, a few passes with some ChoreBoy and it came right out. Since "None" is better than "Some" when it comes to leading I'm still not happy with the results. Today I'm heading out to the range with some water dropped .429-200RF's (dropped from mold .431-.432 and sized to .430 lubed with Lyman Alox) that initially tested out at 18+ BHN using the above mentioned loads.

Now on to the question of the day:
For those of you who shoot '94 Marlins in 44SPC/44MAG are you sizing .430 or .431?
Any issues chambering the .431's?

[ballistim]

Sizing to .431 might help with a bore at .430, just a thought.

[ballistim]

Checked what I size to in my Ruger M77/44 & it's .431 with good results. I remember I made a dummy round to check function first before loading up a batch & usually do that.

[claude]

Marlins seem to like larger bullets, try .432 and you might like the results.

[Outpost75]

I use. 432 in my .44 Mags, and. 430 in my. 44-40s, Rugers and Marlins.

[TCFAN]

On my Marlin I have never slugged the bore. When I bought it I started with .429 then went to .430 .431 .432 and finally .433 where I found the accuracy I was looking for.As I went up in boolit size leading became less of a issue. COWW is all that I have ever cast with for this Marlin CB 44 Mag.All the boolits that I use are gas check...............Terry

[phaessler]

I use 0.432" regularly, no issues and excellent accuracy in my Marlin. Ballard rifling here, gas checked, at least 20bhn, and a stiff dose of 2400.
Pete

[Kraschenbirn]

.432 here...no chambering issues but mine's a microgroove and I get a bit of leading at 1450 fps with the 245 gr. RN (fairly soft and very blunt) I'm using. Accuracy is acceptable, though, and I don't mind cleaning after a trip to the range.

Bill

[LUCKYDAWG13]

same i size .432 for my 1894

[Foto Joe]

Interesting numbers.

I didn't expect responses to include the .432's. I went out yesterday with .430's that were 18+ BHN, I haven't pulled the bolt and checked the bore yet but with the almost invisible stock front sight on the gun I was printing about 6" at 100 yards. I'm not expecting any leading issues with those and the accuracy was within my acceptable standards for iron sights at that distance on a large bore short barrel guide gun.

I think what I'm going to do is order a .431 for now which will work for my 44-40 SAA as well as the Marlin. I'm also going to try and find a fiber optic from sight for this thing as the stock one is tough for my less than young eyes to actually see.

[longbow]

I have an old microgroove 1:38" twist Marlin with 0.4315" groove diameter and it had tight spots in the barrel under roll stamping and dovetails.

I got severe leading with Lyman 429421's which were casting at .429" so no surprise there. I worked my way up to 0.434" plain where accuracy was good and leading not much of a problem. I decided to lap out the tight spots and that about fixed it the rest of the way. Accuracy is good and leading almost non-existent even with max. loads.

I have several moulds and all cast 0.432" to 0.434" are tumble lubed then loaded without sizing. No problems chambering and accuracy is good.

Longbow

[dragon813gt]

SAAMI spec for 44 Magnum in a rifle is .431: http://www.saami.org/pubresources/cc...n%20Magnum.pdf

Microgroove Marlins tend to like fatter bullets. It would not surprise me if you ended up around .434 to keep it happy.

[Iowa Fox]

I got a .432 sizing die for my Lyman 450s from Buckshot. A 429244 checked & sized to .432 with Speed Green or LBT soft I get zero leading even pushing them hard. A guy needs molds that will drop @ 434.

[TCFAN]

I have 2 molds that drop .434+ one from Accurate http://www.accuratemolds.com/bullet_...=43-230C-D.png

And one RG4 from NOE http://noebulletmolds.com/NV/product...roducts_id=628
Got my .433 size die for my Lyman 450 from Lathesmith a member here................Terry

[bones37]

FWIW, my 1894 Marlin made circa early 80's, liked the .433" diameter best. Mine also had tight spots under the roll marks and dovetails like Longbow mentions in post #11. My rifle is also 'crippled' with that 1-38" twist, however a few years ago I had Erik of hollowpointmoldservice enlarge a RCBS 44-200-CM to .433 +" and the rifle shoots those very well.

bones.

[JohnH]

Several years back I had a Handi in 44 mag. It shot well with a Lee 310 mold, which I modified by machining the top of the mold off to remove the gas check shank, boolit weighs in a 250. But I couldn't get velocity greater than 1300 with any cast boolit. Jacketed it shot fine. Sold it to a friend. A while later I acquired another, and it exhibited the same problems. It shot fair to decent with a 200 grain boolit that drops out of round 431-437. Last year I bought a Rossi and immediately had the same problems the Handi's had given me. Had some extra cash at Christmas so I treated myself to an NOE 434429. Mold drops a near perfect 434. Handi will chamber the boolit without trouble as dropped, but the Rossi gets tight once in a while, so I run the boolit into my lubrisizer nose first and size only the front driving band to 431. The Rossi chambers the boolit so sized just fine and both rifles shoot it into 2" groups at 75 yards off a bench. It was during the lull over this summer/spring that I found that SAAMI specs for 44 Magnum pistol and rifle are different. Pistol barrel dimensions are 417 bore with 429 groove diameters while rifle barrel dimensions are 424 bore and 431 groove diameters. I could have saved myself a lot of trouble long ago by simply slugging the bore and/or making a chamber cast, but I'm generally lazy and like to have excuses to buy different molds There's lots of data for cowboy action shooting with 44 magnum for those like myself who have tender shoulders or just want inexpensive plinking. 5.5 grains of Red Dot in a magnum case gives circa 950 fps with 200 and 250 grainers is mild on the shoulder and sure to bring lots of smiles to all who shoot it.

[Slow Elk 45/70]

I have 2 marlin 44's with microgroove bbl.'s I struggled for a while before I went to .433-434 boolits , happy , Happy...this was years ago, so I have no info on the newer ones......but all of my marlins like FAT Boolits !!

[blackpowder man]

Another vote for the .432 same for the rossi .44 mag.

[nicholst55]

My W-W-W-Win-chester mikes at .432". Makes it near impossible to shoot decent groups with j-words. I run an NOE 434" boolit through it. I realize it ain't a Marlin, but then this phenomena isn't restricted to Marlins, either.

[dubber123]

If you want to try the larger boolits before coughing up the cash for a custom sizer, just hand lube enough of your .432" boolits and don't size them. I do it all the time.