Marlin 45/70 cast lead experiment a success! (with teething pains) (pics)...

[canoeguy]

Got my new Marlin 45/70 lever rifle out of layaway the other day from Gander Mountain. I loaded up some Missouri Bullet Company 405 grain cast lead flat point with Unique (16.0 grains, 1250 FPS), Trail Boss (13.0 grains, 1000 FPS) and 3031 (45.5 grains, 1597 FPS) and took the rifle to the range. Zeroed it at 50 yards with factory ammuntion, Remington 405 grain jacketed bullets, then tried my reloads...

Disapointed! All three loads key-holed or passed through the target sideways. Obviously, this rifle didn't like the Missouri Bullet Company offering. I contacted a friend who casts bullets for 45/70, shooting them through a Remington Rolling Block and a Browning single shot. He gave me three bullets to try, some Hornady 350 grain jacketed round nose, and two bullets he casts himself, a 405 grain lead flat nose gas check, and a 300 grain lead flat nose gas check.

I loaded the 350 grain jacketed Hornadys with 48 grains 3031 (1390 FPS according to my Speer manual), the 405 grain LFNGC's got 12.0 grains Trail Boss (971 FPS) and the 300 grain LFNGC's got 14.0 grains Trail Boss (1200 FPS). The rifle loved these bullets, putting them into less than 1" at 50 yards. I'll load some more and try them at 100 yards.

I am really loving this rifle, it will shoot factory jacketed ammuniton and mild cast lead (both 405 grain) to the same point of impact at 50 yards. What a hunting/survival rifle, being able to shoot small game or large with the same sight setting!

I'm thinking this rifle needs a gas check to stabilize the bullets. Anybody else have problems with 45/70 bullets loaded with no gas check?

My friend is going to introduce me to casting bullets within the next week, he has all the equipment and we'll walk through casting some of the 405 grain bullets.

Here's some pics of the rifle and targets/bullets, silver dollar shown to illustrate group size:

 

[epj]

You need to find out the alloy your friend uses. It sounds like the store bought bullets are too soft or too small and not grabbing the rifling. Cast bullets will work at 2000 fps and more with the right alloy and right lube.

 

[canoeguy]

EPJ,

I did try measuring the Missouri Bullet Company bullets with a cheap Sears micrometer, it was very coarse in measurement, I came up with .460 diameter. Since the bullets were advertised as .458 diameter, I assumed they were sized correctly. I fired about 15 rounds through the rifle with loads from 1000 to 1550 FPS, and they didn't lead the barrel, so I assumed they were hard enough. MBC advertises them as 18 Brinnel hardness, whatever that means. So, I'm thinking that leaves the gas check as the only difference.

 

[76 warlock]

My marlin cowboy does not need gas checks, I get very good groups at 50 yards [1"] with the 457122hp 330grns. I use very soft lead 16-1 and get no leading. I keep the velocity down though.

 

[epj]

EPJ,

I did try measuring the Missouri Bullet Company bullets with a cheap Sears micrometer, it was very coarse in measurement, I came up with .460 diameter. Since the bullets were advertised as .458 diameter, I assumed they were sized correctly. I fired about 15 rounds through the rifle with loads from 1000 to 1550 FPS, and they didn't lead the barrel, so I assumed they were hard enough. MBC advertises them as 18 Brinnel hardness, whatever that means. So, I'm thinking that leaves the gas check as the only difference.

I haven't cast any rifle bullets in a long time. Back when I did, I was loading a 30-06, and i was using straight linotype (very hard). At 1500 fps, you shouldn't need a real hard bullet, but you probably do need a gas check. Pose this same question over on Cast Boolits - Dedicated To The World Of Cast Bullets!, and you will get some real knowledgeable answers.

 

[epj]

It has occured to me that if your bullets are really sized .458, that could be your problem. The type caliper you are using is hard to read down to the .001 level. It's really meant to be read in .01 increments. I'm assuming the groove dia on the .45-70 to be .458. If that's correct, the cast bullet needs to be at least .001 bigger, maybe as much as .002 bigger. For one reason or another, your bullets are not grabbing the rifling sufficiently to get the proper spin. Too small, too soft, no GC, all possibilities. Once you figure out why the commercial bullets don't work well, then you know what to look for next time.

 

[Paul5388]

If that Marlin has micro groove rifling, that could be part of your problem. Micro groove is pretty shallow rifling, so you sometimes have to work at getting them to shoot cast bullets good.

The first thing I would suggest is, the Missouri bullets are too hard for the pressures you're developing. I shoot 12 BHN bullets in most of my micro grooves and get pretty good accuracy.

The bullet needs to obturate and alloy that's too hard just won't do it. A gas check would solve a lot of the problems, but they are also more expensive to make or buy. The reason they work better is mainly due to allowing the bullet to engrave without "skidding" on the rifling.

Most people recommend keeping cast bullets under 1600 fps in a micro groove barrel and I find that to be true also.

Here's a 100 yard group I shot with a scoped 22" Handi rifle in .45-70. It was a jacketed bullet, but a cast bullet will do just about the same.

The mid range trajectory is about 6" high with this 12.0 gr of Green Dot load, but it's only running about 1100 fps. 12.0 gr of Universal will shoot pretty close to this group, but not quite as tight.

BTW, H&R/NEF uses micro groove rifling on most of their newer guns.

 

[6GUNSONLY]

Sounds like you're on the right track now. Most Marlins seem to like .45s sized at least .460 rather than anything smaller than that. Next time you need powder, try some AA-5744. My single favorite powder for the .45-70. Oddly, and confirmed by other users, seems to produce less recoil for same velocities than 3031 and other appropriate IMR type powders.

 

[mkk41]

I have one of the mid-70s rifles without Micro-Groove rifling. Barrels were suposedly by Douglas. I shoot nothing but cast bullets. The RCBS 45-300 cast from straight linotype. Shoots great.

 

[Dale53]

My early Marlin 1895 with Ballard rifling shoots the plain base Lee 340 gr bullet well at 100 yards (1½" groups) with a four powered scope. I don't try to make a magnum out of this rifle but aim for black powder velocities using RL-7 for comfortable shooting.

I have the Lyman 457322 Gould Hollow point mould and wish they would allow deer hunting in my home state (Ohio) with a rifle. I would sure like to try that one out. I also have a Ruger #3 in 45/70 and am sure it would be the "cats meow" as a great deer rifle.

In the meantime, I guess I'll just have to be satisfied with my S&W Model 29 .44 Magnum. It is a certain deer harvester up to 100 yards or so.

Dale53

 

[LoboGunLeather]

Most Marlin rifles feature the Micro-Groove rifling. Extensive testing done by Col. E.H. Harrison was published in "Cast Bullets" by the NRA about 30 years ago (a very valuable resource for the cast bullet shooter). If you can find a copy you will have the answers to just about any cast bullet question in your hand.

Micro-Groove rifling generally requires a cast bullet with a long groove-diameter body, and high velocities/high pressures will cause the bullet to strip through the shallow rifling grooves.

Bullets cast of alloys in the range of 18 BHN should perform adequately within the velocity range of the .45-70. I use even softer alloys (straight wheelweight metal) in .45-70 with no problems.

My mold drops bullets at .459" diameter, which I run through the lubricator-sizer with a .460" sizing die (essentially lubricating only with no sizing, as any significant sizing always damages a cast bullet to some degree). This is a Lee 500-grain RN-FP gas check bullet. I have shot these with and without gas checks in my trap-door Springfield rifles with very good accuracy, and killed an elk with an angling uphill shot penetrating from behind the ribcage, through the lungs, and breaking the off-side front shoulder before exiting (about 4 feet of penetration at 70 yards in a large and tough critter).

General suggestions for the Micro-Groove barrels: 1. long bore-diameter body (short nose) bullets; 2. groove-diameter to + 0.001" diameter; 3. modest loads of powders in the medium burning rate range; 4. gas checks (I like the Hornady brand, as they crimp onto the bullet base during seating in the lubricator-sizer die).

 

[surveyor47]

Congratulations on your introduction to Joe Lewis. I picked up one of these rifles last year. Recoil is light with Trapdoor loads, which is where you should be with lead bullets. Recoil with Marlin loads is something akin to going a bout with a prize fighter. After 100 rounds of Marlin loads, particularly the 405 grain Remington bullet, my shoulder swells up.

My limited testing of this gun with 405 grain 459 diameter lead bullets indicates that accuracy falls off rapidly when you go above Trapdoor loading.

The 350 grain Hornady bullet you mention is not a deer round. It is intended for large game, such as elk, moose and bear. The Remington 300 grain JHP and 405 grain JSP are excellent cheap deer bullets. They work at both Trapdoor and Marlin velocities. The 405 grain JSP seems much more consistent at 100 yards than the 300 grain. My gun just seems to like a 405 Remington load that kicks the way Joe Lewis punched.