Imr 4831 in 308 cast loads

[Old colt]

Did a little testing this weekend using IMR4831 and the NOE 188gr hunter mold. Shot 20 rounds, no leading. Since it was blowing 40mph here, I had to shoot at the indoor range with a crappy rest. Most stayed inside an inch at 35 yds, can't wait to try the hundred.

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[blue32]

That shows a lot of promise. I used IMR4831 extensively in 260 jacketed loads but never thought of using it in cast. I know its unpublished, but would you mind posting load data?

[runfiverun]

44-47grs in a ladder test with a well or decently fit bullet will get you there.
usually water dropped ww's and some soft with just enough tin for decent fill out is all you need.
that hunter mold shown above will get you there, as will the XCB design from NOE [it generally like a bit harder alloy] or the 165-A from Accurate.
a lyman design will usually peter out in the 21-2200 fps area.

[Old colt]

It water dropped ww with a bit of tin, seating deeper than I like as my rifle has a pretty tight throat. Have loads from 42-46 that was the 42. I'll chrono them the next round

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[Old colt]

That shows a lot of promise. I used IMR4831 extensively in 260 jacketed loads but never thought of using it in cast. I know its unpublished, but would you mind posting load data?

That was 42gr.

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[tomme boy]

That mold is made to top out at 2200 fps in a 10 twist

[Old colt]

That mold is made to top out at 2200 fps in a 10 twist

Thanks for the heads up. Hoping for 2000-2100. Just starting to work up the loads

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[glockky]

If it were me I would just shoot it and let the bullet tell you when the load has topped out. Don’t let preconceived notions build a wall in your head when working up a load.

[HangFireW8]

If it were me I would just shoot it and let the bullet tell you when the load has topped out. Don’t let preconceived notions build a wall in your head when working up a load.

This. Careful attention to boolit quality, moderate neck tension, low runout, and quality lube and you'll never know how high you can go until you try it.

[Old colt]

This. Careful attention to boolit quality, moderate neck tension, low runout, and quality lube and you'll never know how high you can go until you try it.

No walls just setting a goal, I know the bullet will run at 1900 with no leading, but my rifle didn't like the h4895 as well as I hoped. It loves it with jacketed bullets. Using white label 2500+. Sized .0025 over the bore

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[runfiverun]

shoot your rifle and see.
it will do what it does, I seen a recent test with 4350, and this bullet where 2500fps seemed to be the better accuracy node.
the groups blew up, come together, blew up again, then come right down to about an inch, all from just powder steps.

[glockky]

Here’s my post using IMR 4350
https://www.artfulbullet.com/index.p...-hv-cast.3546/

[geargnasher]

They're all good powders, you just need to experiment some if what you try first doesn't work out. With the bullet shape and alloy I tend to use most, H4350 never would get good groups in one of my .308s. I switched to H414, and hit money right at 2200, then it fell apart when I pushed it faster, but not completely apart. I had plenty of pressure headroom, so up I went and suddenly I get a vertical string...bump the powder one more tick and bingo! Tight groups again, a couple hundred FPS on up. That's the thing to look for on your targets, the patterns of your groups will tell you a story.

I could have changed the alloy a little, or the bullet shape, and accomplished the same thing. The trick is to get the powder and alloy working together in a happy zone..and make that coincide with a barrel harmonic happy zone. Sometimes it falls together, sometimes the math just won't give you a common denominator and you end up changing one of the major components.

Gear

[tomme boy]

I designed this mold to shoot 1" groups at 2200 fps and no more. While yes it can and I have pushed it faster but the amount of bearing surface is a little low for going much faster. The tapor is also made for a standard 308 win throat but it does well in a 3006 throat as well.

I pushed it to much faster but I am not that good of a caster. And that is where you are going to gain your most accuracy. That was why I always had some bullets go off in never never land. Well part of the reason anyway.

This mold does extremely well under 2000fps. I shot just about every load under an inch and most were under a 1/2" . I borrowed ideas off goodsteels xb bullet and help from Larry. It was not meant to be a speed demon

[geargnasher]

Isn't it odd that taper-matching .308 Winchester bullets often shoot as well or better in the long, gentle leades of the '06.....and that the opposite is also true, such as the XCB bullet in a .308? The XCB bullet is designed to exactly mimic the SAAMI '06 throat angle used in the XCB rifles, yet it shoots very, very well in the parallel freebore and abrupt ball seat angle of the SAAMI .308.

Gear

[tomme boy]

Fill the throat right with the least amount of distortion to the bullet. I always felt that the more the bullet does not fit the barrel the more the lead has to move and can move to a place you don't want it to move to. That's also to reasoning behind the small lube gives as passed to the one huge one that was originally planned like was on 45.1 sil bullet. That thing was a complete failure because of that lube grove. And mihec not knowing how to cut a mold did not help

[runfiverun]

the original lube groove for the XCB was just that one groove it was never supposed to be a large one.
the idea was to give about 68-% drive band length after set back from firing.
the area above the gas check was also supposed to be a bit taller to take up the displaced alloy from the rifling impressions on the bottom band to help the check not gave to try and scrape excess lead.
moving to more lube grooves is of no concern and splitting the one into 2 would have been a bit better idea rather than 3.
three just gives the bullet a little too much unsupported wall for compression on a hard launch especially when it's not filled with lube.

[tomme boy]

But the large single one gave too much of a chance for the base to not be cured before coming out of the mold and having a tilted base. Or one with fractures in the stem. That was the main reason for me to switch to the smaller lube groves.

I know if someone like Larry, gear, run, and a few others that are very meticulous in how they cast, this could very well be pushed fast. But how fast is the question. It will not be as fast as the xcb as there is a bit of unsupported nose, but it should be close with a hard alloy.

I know Waco has this mold. Maybe we can talk him into making a vid of this bullet too!

[35 shooter]

The noe 188 hunter was an easy to work with .30 cal boolit in my .308. I had about 50 of them gifted to me and hit several accurate loads between 1900 to 2200 fps. With just those few. I definitely want a mould for it to do further testing.
It fed slick as butter in my Mauser. I was using IMR 4350 powder.

[runfiverun]

correct Tomme.
I don't think people pay enough attention to the wall angle of their lube grooves when they have a mold cut.
they also have a tendency to put too much lube groove in them.
especially a single groove boolit.