Min Max loads for unlisted powder

[Nvhunter92]

I'm loooking to start reloading for a 300 winnmag that I recently got. I'm
Primarily going to use it for elk hunting and a few deer possibly. I want to start with 180 gr accubonds and I'd like to use H4831SC to keep it consistent with my other rifles. The problem is that on nosler's website they don't list H4831 as a tested powder for that bullet. I found on hogdons website that for a 180gr E-tip the starting is 66.8gr and the max is 71.8gr, for a SPR MT SP the starting is 69gr and max is 73gr. How should I go about determine a good min max range to start off with for load develeopment? Is H4831 a good powder for my intended use? Thanks

 

[gohring3006]

I personally look at the COAL I'm going to run at, and what the manual says. I will also look at the brass that was used in the manual data. If my brass is of a different make and my COAL is different, i always start at the minimum load in the manual that has the lowest charge weight and work up to the highest charge weight of the manual that shows the highest weight.
I might only load two cases at each charge weight just to determine pressure, then once I dertemine my max, I work back from there with three or five shot groups depending on the barrel diameter to cartridge size..

 

[el matador]

Data for Barnes bullets is usually a few grains lower since the solid copper generates higher pressures. Also, the Speer Mag-Tip is not a boat tail bullet, and would give you higher pressures due to the longer bearing surface.

Comparing data for bullets similar to the Accubond:

Hornady data for 180 grain Interbond and SST: Min 61.9 grains (2500 fps) Max 74.3 grains (2900 fps)
Hodgdon data for 175 Sierra boat tail: 72.0 grains (2843 fps) Max 76.5 grains (3006 fps)

Based on this data I'd anticipate a max load right around 75-76 grains, depending on your individual rifle and the seating depth you choose. I would start around 70 grains and work up.

H4831 is a good powder for the 300 WM and 180s. I've used it for target shooting with 168s and had good success.

 

[Nvhunter92]

Thanks el matador that makes total sense! But it does bring up another question; since seating depth affects pressure is it better to test seating depth or powder charge first when developing a load? It seems like most articles I've read test powder charge before seating depth, but if you find an accurate powder charge then change seating depth wouldn't you have to retest the powder charge after?

 

[el matador]

Good question. The pressure will rise when you get close to the lands or when you seat the bullet very deep, reducing case volume. Between about .030" and .250" off the lands there won't be a huge difference in pressure.

There are many ways to develop your loads and no single method has been proven to be the best for all rifles. So basically you have to choose a route and try it. Here are two methods I've used that work for me:

1 - Find the Optimal Charge Weight first, then change seating depth to find best accuracy. There are plenty of write-ups on the OCW method if you're not familiar with it.

2 - Use Berger's seating depth test to find your OAL, then tune your accuracy with powder charge: http://www.longrangehunting.com/for...accuracy-berger-vld-bullets-your-rifle-40204/ As an example for doing this test, you could load 1 round at 70.0 grains and 1 at 71.0 grains, and use these 2 shots to get your scope on target. You'll be watching for pressure as well, just in case you max out sooner than you expect. Then run your seating depth test at 72.0 grains.

 

[Bullet bumper]

H4831SC is ballistic equivalent to H4831 it just meters better through a powder measure .

 

[Lonewolf74]

Thanks el matador that makes total sense! But it does bring up another question; since seating depth affects pressure is it better to test seating depth or powder charge first when developing a load? It seems like most articles I've read test powder charge before seating depth, but if you find an accurate powder charge then change seating depth wouldn't you have to retest the powder charge after?

I'm not an expert and haven't been doing this very long but put in a ton of research before I ever started reloading so I like to think I started in a little more advanced state. Any who what I do and what makes the most sense to me is starting out finding your charge weight at the longest OAL you will possibly use. For me this means starting with the bullet touching the lands because I don't want to use jam in a hunting rig. But if my bullet combination is too long to fit in the magazine then I would start at the max mag length cus I don't want to single feed my hunting rifles. This way I can find max pressure and work my way backwards to fine tune seating depth and not worry about running into a pressure spike at the charge weight I found.

 

[Rich Coyle]

I'm not an expert and haven't been doing this very long but put in a ton of research before I ever started reloading so I like to think I started in a little more advanced state. Any who what I do and what makes the most sense to me is starting out finding your charge weight at the longest OAL you will possibly use. For me this means starting with the bullet touching the lands because I don't want to use jam in a hunting rig. But if my bullet combination is too long to fit in the magazine then I would start at the max mag length cus I don't want to single feed my hunting rifles. This way I can find max pressure and work my way backwards to fine tune seating depth and not worry about running into a pressure spike at the charge weight I found.

Bingo! Winner!

 

[CogburnR]

If you are using these loads for Elk hunting then loading them for reliability is important.

I would load them at the recommended coal. Often cartridges loaded "at mag length" can easily hang up at a bad time. Always allow for a decent amount of clearance for reliable feeding under hunting conditions.

I looked at Noslers Data and while they do not list H4831 they do list IMR4831. You can use that data by reducing it 5% for manufacturer differences in this powder, then reduce that charge by 5% for starting loads. In my experience many times the powder from these two manufacturers is within 3% of charge weight at max charges. IMR4831 is definitely a faster burning powder though-they are not exactly the same(you may find the H4831 may need a couple grains more powder for max than the IMR).

When working up loads remember that a "max load" may not be best for hunting. A load reduced at a minimum of 2% from the working max should be considered a hunting max. Conditions such as the box of cartridges or the rifle warming can create problems. Of course H4831 is pretty stable but a max load that was developed on a 50 degree day could be a little hot when the rifle or cartridges are 100 degrees. Often times accuracy may be quite different over the charge range and the more accurate load should be favored unless it is at absolute max. A couple grains of powder less can make a difference in feeding and accuracy but not much in yardage.

 

[Rich Coyle]

Often cartridges loaded "at mag length" can easily hang up at a bad time.

A couple grains of powder less can make a difference in feeding

If one spends the time with the load prior to hunting season mag length problem would already be solved.

How can "A couple grains of powder less can make a difference in feeding"?

 

[CogburnR]

Take a box off the dash that has been cooking on the defroster then shoot them. You may find out(then you may be looking for a mallet to beat the bolt open also).

Cartridges loaded long are more likely to wedge between the bolt and chamber when cycled with some excitement.

I've seen both of these things happen.

 

[CatShooter]

Take a box off the dash that has been cooking on the defroster then shoot them. You may find out(then you may be looking for a mallet to beat the bolt open also).

Cartridges loaded long are more likely to wedge between the bolt and chamber when cycled with some excitement.

I've seen both of these things happen.

Please explain "A couple grains of powder less can make a difference in feeding".

What is inside of the case cannot effect how it feeds out of a magazine

 

[CogburnR]

The bolt being stuck shut effects the feeding. The number of grains is what effects the bolt being stuck or not. When the bolt doesn't move it is hard to feed in the next cartridge. And this happens quite a lot.

 

[CatShooter]

The bolt being stuck shut effects the feeding. The number of grains is what effects the bolt being stuck or not. When the bolt doesn't move it is hard to feed in the next cartridge. And this happens quite a lot.

"When the bolt doesn't move it is hard to feed in the next cartridge. "

REALLY???

"And this happens quite a lot" Are you KIDDING??? Do you actually reload and shoot rifles??

This is silliness at the extreme.

If the load is a few grains less, it cannot cause the bolt to stick, and a stuck bolt does NOT effect the feeding of cartridges from the magazine.