Does anyone know whether Lee 379-250-RF is a bore rider? Upon inspection of the bullet, I do believe it is, but not on the magnitude of other bore riders I have dealt with, mainly Lyman 311041. I am preparing to lapp the 375 Win bore with them, and know I should not use a bore rider. Lee does not know one way or another...Any help would be appreciated.

Thanks,

I would not call the bullet a bore rider. This is a poor picture of some recovered Lee 250 grain bullets shot from my .375 Winchester. I am having trouble attaching them although i think the picture is under size. I am also attaching a link to a photo album with the picture.

This bullet shoots well in my Winchester as cast (unsized) at all speed ranges using Javalina Alox.

http://www.imagestation.com/album/pictures.html?id=2131369383&idx=1

[Edit] I lost my mind and forgot to mention these bullets were resonably soft. Probably about 18bhn. Certainly less than 20bhn as all of my bullets are softer than 20bhn.

Thanks so much, William. My brother's Winchester shoots these well also. Marlin does not. I am going to smooth that bore out. Sizing this rascal should be done too. Mine is .380. Bore is .376.

When you run a tight patch down your barrel do you feel tight spots?
When you load up a dummy with the unsized bullets do you feel resistance when you chamber a round - just as the action closes - the nose engraving the rifling.

I would be more worried about how the bullet fits the throat than about the bore size. If the unsized bullets will chamber in your rifle it would be interesting to see the difference in accuracy and leading between the sized and unsized bullets.

You could call this a scientific experiment, conducted under controlled conditions!

Throat fits this bullet just fine. (to my suprise). I got about 3 inch groups at 75 yards last weekend, which is what my brothers Winchester will do at about 125 yards. This gun will shoot high velocity Sierra's and Hornady's at max loading of 1680 with ease. I have to admit that my first thought was that I already had enough cast shooting guns, but after spending for about 400 jacketed bullets, I am ready to start casting. Finding accurate loads was very easy. Coyote Hunter had done a lot of the work, and i just followed his notes. Cast is usually different,as we all know too well. I am impatiently awaiting some Beartooth bullets that should be here by the end of the week.

I definitely have tight spots. Dovetails are a problem, and the stamped area is a little tight. The gun probably has been shot more by me in the last 2 months than ever before. I tried some pistol loads from Greg Mushial, and tried some XMP 5744 as well. Any good loads for this bullet and regular Winchester 375 brass? My mic is broken, and my measurements may be off a bit. I am going to have to double check with a new one I will get. Any ideas to a lapping load? I have Unique, Titegroup, Universal, AA5, but no Bullseye. Thanks William.

David

I'd guess about 3 grains of Bullseye, maybe half a grain more. 3 grains worked perfectly in my .35 Rem, so that should be a close starting point.

" I am impatiently awaiting some Beartooth bullets that should be here by the end of the week."

You should find that the weight forward LBT designs work a little better.

"I definitely have tight spots. Dovetails are a problem, and the stamped area is a little tight."

Yes, the sight dovetail, where the word Marlin is stamped and on mine - where the front sight ramp attaches.
I would change powders and slow them down - although you have already done that with Greg's loads. Greg's loads work because the powder burns in the case and the bullet is in motion with only expanding gas acting on it.
Too bad you dont have a gas check bullet to try out.
Have you experianced light leading at the muzzle?

"My mic is broken, and my measurements may be off a bit."

Measure some jacketed bullets at the base and see how far your mic is off. You can then subtract the overage from the difference of your know dimension.
How hard are your bullets?

I would use Unique as it is easy to work with at the velocity levels we are talking about
Be sure to shoot your fireform loads at a target. You should begin to see a difference as you shoot.

Nothing like a cranky rifle to give you something to think about!

Ifen yer mic is broken, yer'll just have to sing louder!

Seriously though, I'm glad to hear from some other souls who have 375 Win rifles. I bought one a few months ago and haven't had a chance to shoot it yet. It is a Big Bore in great condition with a Lyman peep sight. I have a 45/70 marlin for bush shooting Sambar (aussie answer to elk) so I need the 375 like a hole in the head, but that never stopped me before.

I have a new RCBS 375 mould, I bought years ago, I knew I'd end up with a 375! Did that a few years ago with a 243 mould and viola! a rifle (two actually) ended up arriving.

I can't wait to get a week or so at home so I can cast a few boolits, load up this little beauty and go punch some holes in things. I'm currently posted to another town, a couple of hundred miles from home.

Mick.

I'm shooting a lot of that bullet in a 38-55, having cast up a thousand or so and measured more than a few, I can tell you that it is definately NOT a bore rider. Mine measure a consistant .3795 from base to nose, and they shoot very nicely as well. I find that this bullet is highly regarded by many shooters of the 38-55/375 all over the net. Try 7 grains of Blue Dot, it will give you circa 900 fps, is very accurate and with both lube grooves filled will carry lots of fire lapping lube down the bore, making short work of the task.