Mixing and Matching

[dross]

I'm new to reloading.

I've read the cautions that say you should use the exact powder, bullet and primer recommended in whatever manual you're using. Yet I know people are mixing these components.

For instance, I have some Nosler ballistic tip bullets, but the Nosler site only lists four powders for use and doesn't mention primers. I have some IMR 4894 powder, but I can't find this combination.

What is a safe procedure to build loads when you don't have the exact components?

 

[ghitch75]

go by know load data for the rd you want to load.....only time you might get in trouble if the powders get mixed....

 

[Robert Richardson]

Load by bullet weight not bullet maker.

 

[45fan]

Usually you will be fine by loading by bullet weight, and starting at the bottom end of a load, and working your way up. As long as you are careful, and watch for signs of pressure, you should be fine.

 

[red_zr24x4]

Load by bullet weight not bullet maker.

^^^^this^^^^
And if you're not using the primers they list, start at the lower end of the powder charge and work up.
If you switch primers in the middle of your loading, reduce powder charge by 10%

 

[Yeah]

Bearing surface and obturation tendencies matter every bit as much as bullet weight. I'd not throw a 100 grain Nosler Partition on top of my 105 Amax load and expect it work. It would overpressure significanty due to the former's generous bearing surface as compared with the latter. Same with a moly load versus not.

There are several reputable sources of load data outside published manuals. 6mmbr.com has a variety of verified loads. So does reloadersbench. Stick to the places that actually verify loads rather than just compile lists. Check several sources for common charge weights with your components, start around 20% low, and work up a round at a time.

Or ask someone with Quickload to run a pressure curve and start equally low.

 

[shibumiseeker]

Bearing surface and obturation tendencies matter every bit as much as bullet weight. I'd not throw a 100 grain Nosler Partition on top of my 105 Amax load and expect it work. It would overpressure significanty due to the former's generous bearing surface as compared with the latter. Same with a moly load versus not.

^ This. Dross, in general if you are loading conservatively you can use the numbers as a starting point by reducing the charges and working up carefully. But if you are running hot loads or hot rounds, then you are best off starting with the manufacturers recommendations.

This is more important with rifle rounds than with pistol rounds since there's a lot less variance in the amount of rifling engagement involved with pistol rounds and the pressures are generally lower.

As with any of these things, when you are working up a charge, a chronograph and careful attention to pressure signs on brass (which are NOT reliable indicators) and a "feel" for how a round is shooting compared to a known round, all these things will serve you in good stead.

 

[kludge]

Since you are using IMR 4895, go to the Hodgdon online loading guide and see what you can find.

Unless you are using military cases, the biggest factor is the bullet. Weight, length, and bearing surface all make a difference when comparing pressures. The next biggest factor is the chamber (your gun) that it is fired in. Your chamber will never be the same as the one the powder/bullet company is using.

It's best if you use the same bullet as the data, especially when approaching max loads. When data for the exact bullet and powder isn't available, then look for similarly constructed bullets using that powder.

Primers, variations in powder lots, case capacity, brass thickness, etc. can make a difference which is why you always start 10% low* and work up. The primer brand/style will have an effect, but not the largest effect.

Keep an eye on primers and case heads (flat primers, craters, flow into the ejector groove) and note how hard it is to lift the bolt. If you get any signs of pressure, then stop. And IMO my chronograph is as valuable a tool as my press, so watch your velocity. When you get to max velocity, chances are you're at max pressure too. I also have a 0.0001" micrometer that I got cheap at Harbor Freight. When I am working up a load (especially if it's something I can't find data for) I measure the case head diameter right at the web. If I see any difference before and after firing it means stop. You don't want any case head expansion.

* Does not apply to H110/W296 magnum pistol powder.