I test fired some 500 gr Laser Cast bullets in my Marlin 1895 and some of them keyholed.
I'v since used only 405 and smaller bullet weights, but also notice many on here do shoot the heavier bullets with good results.
What is the secret, dia. or powder type. I believe the dia of the laser cast were .459.

Twist rate (1:20) is too slow on the 1895. You can probably run up to a 420gr but to keep it short enough the nose will need to be wide and stubby which may lead to feed problems.

You need a twist of 1:18 or faster to run the heavier weight bullets.

Actually, it may be a little more complicated. The 20" twist will theoretically work with 500 grain bullets 1.8" long or shorter traveling over 1400 fps. Slower or longer, and you get into trouble. I don't know the length of the Laser Cast?

The trouble you get into occurs mainly when the velocity drops into the transonic range, where the speed of air over different parts of the bullet are both above and below the speed of sound, and shockwave formation shifts location or ceases. The drag forces increase significantly in this range and many bullets are caused to begin tumbling and keyholing by them. You need extra spin to get through it.

Naturally, as you start to work a load up with a bullet that heavy, you will have rounds that are right in the transonic range. Stay below it (say, 900 fps or less at sea level, or above it (say, 1400 fps or more at sea level) all the way to the target, and you will have less stabiltiy trouble than when the bullet passes through the range at some point in its flight. The width of the transonic range depends on bullet shape, so I can't give you exact numbers.

When they come out the end of the barrel at 1400 + fps of a Guide Gun they're not fun to shoot. I have a few and they just sit in the box. The 350 grain family over a full case of Varget is a great load, plenty of speed, highly accuracte, and it doesn't beat me up.

I think you'll find the Laser-Cast 500 gr bullets tend to be inherently unstable. I'm not sure why, but I bought a box of them (.459 dia) for my .45-90, and found I couldn't hit the broadside of a barn. Using every accuracy technique I could think of, I obtained 20 (!) minute of angle groups (6.5 inches at 30 yards). The entry holes told me the bullets were unstable as they penetrated the target. I was so frustrated I was actually contemplating sending my rifle back for a replacement, but my dealer/gunsmith slugged the bore and found it to be excellent (no high points, very smooth, .4576 dia., 1/18 twist). I later read in the product reviews at Midwayusa.com that others have experienced the same phenomenon.

http://www.midwayusa.com/eproductreview.exe/GetReviews?productid=816014

On the plus side, they didn't lead at any velocity I tried, up to 1900 fps...

I will probably try some Beartooth bullets in that weight range next and see what kind of results I get. I'm also toying with boring the back of these bullets out a bit in my drill press and seeing if I can get them to stabilize by changing the balance and increasing bullet expansion to the bore.

If you are having stability problems with this weight bullet you need to look elsewhere than twist for the solution. The standard US Infantry bullet was a 500 gr. RN that is well replicated by the Lyman #457125, which is slightly longer than the bullet you are using. The twist for the 1873 Springfield series refles was 22", which is where this twist rate came from that became standard for the caliber.

The problem could be bullet fit or design. Try something else.

My .45x2.1 had 1:18 twist and the best accuracy was produced with 450gr bullets, didn't matter the shape nor style. I got "half decent" accuracy to around 200 yards with bullets over 450gr but nowhere near as good as with the 450's. Granted, I was running primarily black powder loads which may be a different issue I never used the Laser-Cast bullet either, could be a design/alloy issue involved as well?

If you are having stability problems with this weight bullet you need to look elsewhere than twist for the solution. The standard US Infantry bullet was a 500 gr. RN that is well replicated by the Lyman #457125, which is slightly longer than the bullet you are using. The twist for the 1873 Springfield series refles was 22", which is where this twist rate came from that became standard for the caliber.

The problem could be bullet fit or design. Try something else.
I've had less than favorable results with any lead cast bullet except for the laser cast 350's with very fast powder. I just wanted to get some idea's from some of you.
I figured it would most likely be caused from a non compatable bullet diameter.
This same rifle has often grouped under 1" at a hundred yards with Speer 400 gr jsp bullets, and also does very well with Rem 405 gr jsp's. Glenn

I've had less than favorable results with any lead cast bullet except for the laser cast 350's with very fast powder. . .

That sure sounds like you are needing a bump-up from your powder. It suggests you might have a constriction where the barrel screws into the frame. You need to slug it with pure lead before going further. Firelapping may be the cure.


Alk8944,

The information on the original army load is confusing. The rifle is 1873, but the original .45-70-500 load is dated 1881 (here (http://www.riflemagazine.com/magazine/article.cfm?tocid=1094&magid=78)). Others state the .45-70-405 was the first load. I don't know the history, so someone else should step in who does. I always assumed the 405 grain bullet started out to be about 1 oz. (437.5 grains), and lost metal to make the paper patch twist recess. I gather there was some fiddling with the load in early years. Regardless, the article says the rifling twist is 1 in 18", not 1 in 22". There is a carbine version with 22" barrel, but that's as close as they got to that number in the course of the article.

I only fired two of the 500 gr cast bullets out of my Ruger #3 in 45-70. Those chunks of lead out of that little lightweight, plastic butt plated, straight stocked thing called a rifle almost killed me. I only fired it the second time because I could not believe the first one kicked so bad. The second one made a believer out of me. Sold that rifle to an exbuddy of mine. :p

I only fired it the second time because I could not believe the first one kicked so bad. The second one made a believer out of me. Sold that rifle to an exbuddy of mine. :p

I know a fellow who put together a 9.2 pound .50x3.25, after sending a couple 680gr bullets down range, he put 5# of lead in the stock.

I had my Siamese Mauser built with a 1:18" barrel specifically for 500 grain bullets using a straight taper 26" barrel. It will shoot jacketed 500 grain bullets into one ragged hole at 100 yards. Same with cast bullets although the groups will open to 1.5". However, this action (Rockwell tested for safety at an industrial heat treating company) will take about half-again as much pressure as the Marlin, allowing maximum loads and velocity. So, the advise about your barrel twist and lower velocities is correct, the longer, heavier bullets won't stabilize.

I use a 430gr paper patch bullet over 52gr of AA2495 in my 1895g. Groups 1.15 to 1.75 over cross sticks with a Lyman peep sight. Good enough for me anytime.

I noticed that Midway is closing out the 500 gn Oregon Trail Laser-Cast.