Low pressure loads for 243?

coyoteking

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I’m in need of education on this topic. I’ve been researching and have come across H4895 as being recommended for reduced loads, as much as 60% according to Hodgdon.

I don’t have H4895 on hand, but I do have IMR4895. I’m finding conflicting information on whether the IMR can be substituted for the Hodgdon. Have any of you done this and had good results?
 
Hodgdon specifically says to NOT use IMR 4895 for reduced loads. Only H4895. Or look in a Lyman manual for the powders that they use for reduced cast bullet loads. H4895 and IMR 4198 show up in there for 243 cast lead.
 
Hodgdon specifically says to NOT use IMR 4895 for reduced loads. Only H4895. Or look in a Lyman manual for the powders that they use for reduced cast bullet loads. H4895 and IMR 4198 show up in there for 243 cast lead.

I don't know why they would say that since as far back as the '60s Dupont declared that IMR 4895 could be safely reduced to 2/3rds of the maximum charge. I'd be willing to bet that like IMR 4350 and H 4350, or H414 and Win 760, or H-110 and Win 296, the only difference today between IMR and H 4895 is the label on the bottle. If there is a difference its very slight, as there can be in lot to lot variations of any powder, and certainly not in the same way that IMR 4831 differs from H-4831.
 
" Modern Reloading " from LEE has charts and information on pages 156 to 159 that gives a very good idea as to which powders can be reduced , and by what percentage . Hope this helps a bit...catnip.
 
" Modern Reloading " from LEE has charts and information on pages 156 to 159 that gives a very good idea as to which powders can be reduced , and by what percentage . Hope this helps a bit...catnip.

Thanks, I’ll look into that. I don’t own a Lee manual but should be able to find something online.
 
I’m in need of education on this topic. I’ve been researching and have come across H4895 as being recommended for reduced loads, as much as 60% according to Hodgdon.

I don’t have H4895 on hand, but I do have IMR4895. I’m finding conflicting information on whether the IMR can be substituted for the Hodgdon. Have any of you done this and had good results?

I have reduced IMR4895 using the same formula as H4895. I think I remember a time IMR did publish reduced IMR4895 load data before Hodgdon started marketing the IMR powders.

This is a good article for reduced loads and talks about IMR4895: https://www.handloadermagazine.com/reduced-rifle-loads
 
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The published START load is probably a low pressure load in your rifle.

What are you trying to do?

Click the link I posted in post #7 and scroll down to addendum. It’s a firelapping/handlapping process using 5 rounds at reduced pressure. The author used 5 grains of red dot in his 308 to lap his barrel, but the only pistol powder I have on hand is Titegroup which I don’t think is suitable for the task, which is why I’m hoping to use the IMR4895 I have on hand.
 
I have reduced IMR4895 using the same formula as H4895. I think I remember a time IMR did publish reduced IMR4895 load data before Hodgdon started marketing the IMR powders.

This is a good article for reduced loads and talks about IMR4895: https://www.handloadermagazine.com/reduced-rifle-loads

That’s the first article I read when I started researching this subject. John claims the IMR and H4895 are both suitable for 60% reductions.

I’m thinking I’ll try a 50% reduced load with my IMR 4885, it’s only 5 rounds and then I’ll be done with this experiment.

How did your reduced loads of IMR work for you? No pressure signs I’m assuming?
 
Might want to re-read that - it is to reduce "to 60%" of a published maximum load for that bullet, not reduce "by 60%". Not certain what you mean by "50% reduced load" - but whether you mean "by 50%" or "to 50%", you will be going down below the published information.
 
Might want to re-read that - it is to reduce "to 60%" of a published maximum load for that bullet, not reduce "by 60%". Not certain what you mean by "50% reduced load" - but whether you mean "by 50%" or "to 50%", you will be going down below the published information.

Yes that’s what I meant. 50% below max.
 
You are not following - reducing to 60% of the max load gets you to 60% of the max load, not 50% - take the max load and multiply by 0.6 - that is what you are going to go down to - the published stuff says to the 60% level, that is a 40% reduction - as far down as you can safely go. 50% below max is further than they recommend...
 
You are not following - reducing to 60% of the max load gets you to 60% of the max load, not 50% - take the max load and multiply by 0.6 - that is what you are going to go down to - the published stuff says to the 60% level, that is a 40% reduction - as far down as you can safely go. 50% below max is further than they recommend...

Yes. I understand. I’m going to use 70% of the max load, not 50%. Obviously math is not my strong suit. Lol.
 
That’s the first article I read when I started researching this subject. John claims the IMR and H4895 are both suitable for 60% reductions.

I’m thinking I’ll try a 50% reduced load with my IMR 4885, it’s only 5 rounds and then I’ll be done with this experiment.

How did your reduced loads of IMR work for you? No pressure signs I’m assuming?

It's 40% reduction leaving 60% as the minimum, not a 60% reduction. Max load gr. x 0.6 = minimum load.

I've used 70% with jacketed bullets ok, haven't tried going lower. Shot a lot of cast at 60-65%. Reduced velocity no pressure signs. Smokey necks.
 
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