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Question about H4831sc in 243 Win.

I'm working up a load for my 243 Win using H4831sc and the Hornady 90gr CX. Working up from 42.8gr to 46.2 in .2 increments. I noticed at about 45 gr or so when seating the bullets I could hear some crunching as the seater bottomed out. I expected the upper charge weights to be compressed but I was somewhat surprised to hear powder crunching so early in the load range. I noticed the COAL and OAL to ogive both increased slightly at the last 3 or 4 charges. My COAL goal is 2.71" but the 1st 14 or 15 rounds settled at 2.708-2.709. I think the ogive number was about 2.15 and ended up at about 2.17 at the upper charge weights. Is it unusual for a compressed charge to resist the seating depth of the uncompressed charge weight? I have seen some folks loading as much as 48gr of H4831sc in 243 win, but I don't see how. My powder at 46.2 was at the top of the neck taper.
 
I'm working up a load for my 243 Win using H4831sc and the Hornady 90gr CX. Working up from 42.8gr to 46.2 in .2 increments. I noticed at about 45 gr or so when seating the bullets I could hear some crunching as the seater bottomed out. I expected the upper charge weights to be compressed but I was somewhat surprised to hear powder crunching so early in the load range. I noticed the COAL and OAL to ogive both increased slightly at the last 3 or 4 charges. My COAL goal is 2.71" but the 1st 14 or 15 rounds settled at 2.708-2.709. I think the ogive number was about 2.15 and ended up at about 2.17 at the upper charge weights. Is it unusual for a compressed charge to resist the seating depth of the uncompressed charge weight? I have seen some folks loading as much as 48gr of H4831sc in 243 win, but I don't see how. My powder at 46.2 was at the top of the neck taper.
Also, if anyone has any load data for this combination it would be helpful. I have not found much information for this bullet. 45.5gr is the max book charge I've found, but for similar monolithic bullets, I've seen somewhat higher. I don't fully expect to shoot up to my 46.2, but if I don't see pressure signs I will test up to there.
 
Try using a 6" drop tube on your funnel, or tapping the charged case to get the powder to settle. Also, what brand of brass? Internal volume makes a difference.
I don't have a drop tube, but I did tap the brass to try to settle the powder. Its Federal brass once fired. I've kept all my brass over the years. FWIW, this bullet this bullet may not work in my barrel as it is a 1:9 twist and recommended twist is 1:8. But I want to try it out to see how it performed. Also not sure how much difference it would make, but I incorrectly bumped the shoulder a taint too far to 1.622 instead of my desired 1.628. Wouldn't figure this to be a significant impact on powder capacity. This brass was sized from my old barrel from my Rem 600. When I put my new barrel on, I disassembled the bolt and tested I took measurements from a fired round on the new barrel. If anything good comes from my test at least it will fireform the brass to this chamber. I will shoot these rounds this afternoon or tomorrow.
 
A cheap cordless toothbrush. You can use it to vibrate the case and settle the powder more tight.
 
I do use 4831sc in a 6mmSLR - a shortened 243 case. 43.5 will push a 107 around 3000fps, I don't need any more. The obvious answer is that it's not the powder for the 90g in your brass - go look at a faster burner or one with less bulk - say H4350.
 
I do use 4831sc in a 6mmSLR - a shortened 243 case. 43.5 will push a 107 around 3000fps, I don't need any more. The obvious answer is that it's not the powder for the 90g in your brass - go look at a faster burner or one with less bulk - say H4350.
You're probably right. I have worked up a load with a 100gr Sierra SBT I like using H4350, and I may very well end up using it for this bullet too, but for curiosity I wanted to try a slightly slower power for better case fill.
 
H4831sc is great for the 6mm heavies 105 - 107 grain bullets. Works great from my 1-8 twist Brouthon barrel. And I think I use 40..5 grains
 

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