IMR 4198 And Confusing (to me) Load Data

Ammunition, reloading, shooting, etc
MosbyRidge
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Joined: Mon May 30, 2022 2:45 am

IMR 4198 And Confusing (to me) Load Data

Post by MosbyRidge »

Speer has load data for 30-40 Krag. For 130, 180, and 200 grain bullets they have listed IMR 4198 for reduced loads. Why in the world would it work for the extremes, but not in between?

I have 147 grain .308 bullets and IMR 4198 that I would like to use, but I do not intend on experimenting myself as I have no idea what I don't know.

Does anyone know why this is the case?

Thank you
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butlersrangers
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Re: IMR 4198 And Confusing (to me) Load Data

Post by butlersrangers »

'Mosby Ridge' - I shoot some reduced loads in my .30-40 Krag rifles and carbines. I like that Speer includes such loads in their data.

I believe, they vary the 'reduced' data a bit and also include IMR-4759 for some bullet weights, just to offer an alternative powder.

I have been shooting 152 grain .30 caliber projectiles, using 26 grains of IMR-4198, W-W cases & LR Primers.

(Since the 26 grains of IMR-4198 powder charge is safe with 130 grain and 180 grain projectiles, there would be little concern using it with 147 grain projectiles).

The Krag that I have mainly used, when shooting reduced loads, has a 3-power Weaver scope. This greatly helps with sight picture and group sizes.

Be advised, not all Krags will like lighter bullets. Some projectiles will not allow feeding through the magazine and will require single loading.
Different bullet weights (and styles) with reduced loads, will likely have very different points of impact.
I usually use a 'clean' cardboard backer with one precise "aiming point". I use one point of aim and shoot groups, without changing sights.
This lets me know how accurate my loads are, without a lot of squirreling around.

I find it a lot of fun shooting reduced loads and they are economical.
I weigh each charge and take extra precautions to avoid loading errors, especially, with very fast powders that can be double charged!
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Parashooter
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Re: IMR 4198 And Confusing (to me) Load Data

Post by Parashooter »

Looks to me like Speer authors arbitrarily chose to use 4759 for the mid-weight projectiles and 4198 for the "extremes". Could simply be what was handy that day. Either will work, as seen in this "maximum load" data from IMR (columns are: powder ID, grains, velocity, pressure in CUP) -
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butlersrangers
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Re: IMR 4198 And Confusing (to me) Load Data

Post by butlersrangers »

Thanks 'Parashooter' for that pressure data!

I appreciate 'MosbyRidge' admitting this is new to him and not wanting to do anything bonehead.

No one wants a 'Detonation', that can occur with a reduced charge of certain 'Slow Burning' propellants.

MosbyRidge
Posts: 40
Joined: Mon May 30, 2022 2:45 am

Re: IMR 4198 And Confusing (to me) Load Data

Post by MosbyRidge »

Wow, asked and answered!

Glad to see that someone else is using this setup of powder, bullet, and gun!
I don't know that I'll be able to make groups that tight with irons, but at 26gns a shot I should be able to make plenty of practice rounds.

Good to see max load with pressure. I could not find that online.

I feel confident to use this powder now, thank you both.

Hopefully after my sight parts come in I can post some groups.

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butlersrangers
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Location: Below the Bridge, Michigan

Re: IMR 4198 And Confusing (to me) Load Data

Post by butlersrangers »

About 10 years ago, a co-worker gave me some powder canisters, primers and lightweight .30 caliber projectiles,
from a deceased relative's estate. It was stuff I had no use for.
When a lot of ammunition and components came to be in short supply, during Covid, I looked at these odds & sods with renewed interest.
It's fun to have some almost free ammo and cheap shooting!

MosbyRidge
Posts: 40
Joined: Mon May 30, 2022 2:45 am

Re: IMR 4198 And Confusing (to me) Load Data

Post by MosbyRidge »

I only started reloading during covid because I couldn't afford to shoot my .308 as much as I wanted. Now I'm realizing its potential in less common cartridges like the Krag. I think 30-40 krag is 3 to 4 dollars a round some places. I'd have to quit.

Anyways, I don't plan on being caught without components next shortage. I am glad that the powder I have available will work!

Doubly Reincarnated
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Joined: Sat Jul 17, 2021 1:51 am

Re: IMR 4198 And Confusing (to me) Load Data

Post by Doubly Reincarnated »

SR 4759 is far too valuable to waste on low-pressure loads with jacketed bullets. The single shot & lead bullet guys will be glad to trade in exchange for more suitable powders.

MosbyRidge
Posts: 40
Joined: Mon May 30, 2022 2:45 am

Re: IMR 4198 And Confusing (to me) Load Data

Post by MosbyRidge »

I just looked up that powder. I wonder why they discontinued it? Its seems like there are already a million powders for every purpose. What's one more?

donki1967
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Joined: Thu Apr 14, 2016 5:05 pm

Re: IMR 4198 And Confusing (to me) Load Data

Post by donki1967 »

@butlersrangers:
What die you use to seat the 110 grain RN bullet please?

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