Cast bullets in a 300 win mag

I have no expertise with a 300 but I can't see any harm using cast in your rifle. I shoot cast all the time with really reduced loads. SR4759, Trailboss & 2400 all worked well for me. I get no leading in my rifles but I do keep my velocities down to about 1200 fps, this is without a gascheck. My accuracy is about 1" or less at 50 yards. I just strictly target shoot so I am happy with my results. If you want to shoot longer distances and push your bullet faster, you will need a gascheck.
 
Denny, my bible, the first edition of the Lyman handbook of cast bullets, doesn't have those new fangled magnums, of course, but it does show loads for the 300 H & H Magnum. That would be about the same, as far as cast bullet loading is concerned.
It shows a 190 grain bullet with loadings from 1585 to 2500 fps, with powders varying from 4227 to, would you believe, 4350!
 
Nothing at all wrong with shooting cast bullets in the big cases, IMR 4759 and XMP 5744 are your friends, it's just that the big cases/small bores are not optimum for accurate cast bullet shooting. There is alot of wasted space in the case and powder orientation inside the case can come into play. In my experience, even the .308 case is not optimum(too big) for accurate cast bullet loads, the 30/30 with it's capacity and long neck is about perfect. The darling of the cast bullet benchrest shooters is the .30br, the opposite end of the spectrum from your .300 Win. Mag.
 
"...shear the sides off the bullet..." Chamfering the inside of the case mouth fixes that. You should be chamfering and deburring every time you trim.
The Lyman manual has several cast bullet weights. Using pistol powders. Velocities run under 2000fps.
 
Jim Carmichael used to write for G & A or Shooting Times. He wrote lots of stuff on the 300Win Mag(his fav). I sorta remember him pushing gas checked HARD cast boolits quite fast....I won't quote #'s, 'cause I think they were in the '70's or early '80's?....and 'membering those years are tough. I still have the rags, so if I come across the articles, I'll pass them along.

LeRoy
 
Be aware that with the bullet extending below the neck, as it likely would in a 300WM, the gas check could fall off. Not entirely sure just what the result of a loose gas check in a case might be when you touched it off, perhaps nothing but increased leading and bad accuracy from the subject round. If it increased pressures, it should easily be contained by the safety margin you would have at cast bullet velocities, and pressures in the 300WM.
There are a number of newer powders that might prove beneficial to try, Trail Boss for one, and SR4759. Sorry, my manuals are not up to the task.
You are aiming for velocities in the 2000 FPS range, accuracy will probably be better if you can get in the 1900 to 2000fps range.
If you need a bit more speed, look into paper patching. Labor intensive, but it will allow much higher speeds.
 
Accurate lists a couple of reduced 150 and 165 gr L GC loads with their 5744 powder. I tried some tests in my .300 RUM a while back.
Here is a (broken)link to .300 Win Mag Data
h ttp://tinyurl.com/3qht5o
 
Thanks for the tips guys. It sounds like it can be done as long as I can get a load that doesn't punch it too hard. Sunray....when I said shear the sides off the bullet, I meant ripping the sides off the bullet with the rifling in the barrel due to too high a velocity for a lead cast bullet. I just whipped off about 500 200 grainers and gas checked them, so I've got lots to experiment with. I'll go and pick up some 4759 powder next week and give it a try. I'll post my findings once I've had a chance to go out and play with some different loads.

Thanks again.

Den....
 
Den; I like you wanted to try cast bullets in a mag., a 375HH in my case.I have just fired about 125 rds off with great results.I used 265gr. Gas checked bullets from The Bullet Barn.I got the load from Ken Waters Pet Loads Manual. 44grs. of IMR 3031 Win lg. primer I used a Lee collet and factory crimp die to put them together.You need to get a Lee universal expanding die it will save you a lot of grief seating the bullets without scrapeing them. I,m getting 1800fps and 1.5" groups at 100m. a ragged hole at 6om. Recoil is about like a 30/06 which is good I did not want a recoilless load but something with a little bit shove. I just finished fireing 50 rds today with out cleaning. I pushed 2 wet patches through followed by a few passes with a bore brush ,no lead, no problems. A great way to practice with a big rifle I wished the Bullet Barn had a 416 cal but they do have a 358 cal I will try in my 358 Win. I just took a look in the Pet Loads Manual and he lists a load for 300 win mag with a 175gr GC bullet with 24.5gr 4198 Win-120 1750fps.
 
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Do you guys use any kind of filler when putting such small amounts of powder in large magnum cases?

I've heard that using the granulated plastic stuff designed to buffer shot pellets in magnum shotshells works well for this purpose.

Anyone with experiences in this area?
 
P17; I did not use any filler in my 375HH loads but I thought about it as that 44grs of 3031 looked out of place in that big case. When I loaded the first few rds the cases were already primed with mag primers CCI 250,s. I did get what felt like a little delay in ignition which went away when I elevated the muzzle before firing. I then remembered reading some where that you should only use std. primers. Switched to Win 120,s everything works great.A primary purpose for this load for me was to practice rapid fire and reloading under pressure and shooting offhand. It feeds properly has a bit of recoil ,groups really well so I,m very happy with it.
 
Here are some loads for a 200gr bullet (all under 2000 fps):

Unique - 18.0 grs
2400 - 20.0 grs
H4227 - 31.0 grs
H4895 - 40.0 grs
IMR4064 - 44.0 grs
760 - 52.0 grs

None require filler. A gas checked bullet using Wheelweight alloy, properly sized (at least 0.002" over groove diameter) and using a good lube should leave no leading.
 
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