Marlin 375, Cast Bullets????

[GunnyJohn]

I have a Marlin 375 and have been trying to find a way to load cast bullets that will actually shoot acurately. I have used some laser cast bullets (plain based) at around 1800fps. To fast?? Would a gas checked bullet be better? Is the microgrooved barrel a hinderence? Is it possible? I really like this little carbine, it's my favorite saddle gun, and would like to shoot it more , but jacketed bullets are getting pretty expensive to use on coyotes and othe varmints. Any suggestions???? Thanks

[Trey45]

Firstly, welcome to the board, glad to have you here.

Have you slugged your bore? What are the dimensions of your bore? That dictates what size lead bullets to use. Gas checks never hurt, but if they're not necessary, why bother? 1800 is not too fast. Microgrooved barrels are normally no issue with lead.

If you haven't slugged your barrel, do so. If you have, post your results and we can go from there. A rule of thumb is to go .002 larger than you bore.

[Old Goat Keeper]

GunnyJohn also slug your throat! Most Marlins have generous throats. Don't know why but it is a fact of life with Marlins. Like Trey45 said fit is everything. Once you have your bore/throst measurements you can fit the boolit to that +.002. Then that microgroove should shoot just fine.

Tom

[GunnyJohn]

Thanks Guys, I'll get it done and get back with the results

[TomAM]

http://accuratemolds.com/img/bullets/detail/bullet_detail.php?bullet=38-250A-D.png
Here's a bullet I designed for the Marlin and Winchester 375s. Both rifles typically have over .300" of throat, and groove diameters of .378. The design is rather extreme, but I finally have a bullet that shoots 1.5 MOA in my 375 big bores, and feeds very smoothly.

[TomAM]

The drawing did not load. It's #38-250A in the catalog at Accuratemolds.com.

[GunnyJohn]

TomAM,

I just went on to the Accuratemolds site, and found the mold you mentioned. Neat idea. I saw ther that there were 1-3 cavity molds, and "Machine type molds". Whats the difference?

thanks GunnyJohn

[TomAM]

A different mold block is used for the casting machines made by magma and others.

[Ranch Dog]

I love my Marlin 375! I've actually owned three, one being a NIB that I was keeping squirreled away. I finally decided that I have so much hunting history with my "shooter" that I would never use the other two so I traded the one and sold the NIB.

Anyway here is a computer image made from a chamber cast taken from my 375 (http://www.ranchdogmolds.com/store/bin/TLC379235RF/chamber/chamber01.gif). It was identical on all three rifles.

The Marlin 375 has an extremely long and gentle step followed by a sudden throat down to the bore. This needs to be filled with lead. My TLC379-235-RF (http://www.ranchdogmolds.com/store/index.php?main_page=product_info&cPath=1_5_30&products_id=35&zenid=244350c23ec710e97a088b3fe1dd6801) does that while locating the center of gravity at the center of lift without taking up valuable space on this capacity limited case.

On my bullet I added two additional crimp groove to accommodate the 38-55 Win, these cartridges have nothing in common except the parent cartridge and bore, and this image dramatizes how much lead it takes to fill the throat and step of the 375 Win! If my bullet was just for me, it wouldn't have the additional crimp grooves.

http://www.ranchdogmolds.com/TLC379235RF/Images/TLC379235RF_Cartridge.jpg

If you don't fill that throat, you will have a poor shooter that cannot tolerate the high pressures this cartridge needs to perform. Remember that you are simply shooting a 30-30 Win with way too much bullet weight for the case capacity. It needs high pressure to perform! I get 2200 FPS with 40.0-grains of H322 (105% case density) at 43.2K PSI. I shoot

I'm casting with 95% WW, 5% tin, and 4 oz of #8 shot water quenched. I have some loads that are at 53.0K PSI, this is a 63.8K PSI cartridge. I shot a pressure trace session at the 53.0K PSI and saw no leading and here is what the alox "wax star" looked like from the Micro Groove rifling.

http://www.ranchdogmolds.com/TLC379235RF/actual_bullet_photo.jpg http://www.ranchdogmolds.com/TLC379235RF/Barrel_Wax_Star.jpg



I'm known as a 444 Marlin guy but in reality I probably kill more critters here on the ranch with the 375 Win than any of the Marlin I own, which is all of them except the 357 Mag and the 38-55 Win. I travel from South Texas each year out to West Texas for a bit of desert mule deer hunting and always take a load of manure from the other hunters as the Texas Big Bend is bolt gun country. I took my 375 Win two years ago and whacked this bad boy!

http://www.ranchdogmolds.com/TLC379235RF/Mule_Deer_01_350x263.jpg

The fellow that I was with was very impressed with the "fold" up. I had told him I would shoot the deer through both lungs and that it's front legs would collapse and it would go straight down and not move a muscle. My friend was most impressed as it did just that. I've seen that big flat point take the air out of too many whitetails and they go straight to the ground!