Factory load development

[vonn]

How does the factory determine a load for all the different brands of rifles in a certain caliber? My rifles definitely prefer certain factory loads over others, I sometimes try 3 or more loads to determine the best load for that rifle. Federal match ammo in 308 is the only factory ammunition that shoots well in most rifles I have tried it in. All opinions wanted

 

[Univibe]

What's the specific question?

The factories try to make a SAAMI-spec, cost-effective round that can be marketed to shooters and will provide acceptable performance in any rifle it's likely to be used in. It's inevitable that some brands of rifles, and some individual rifles, will "prefer" one load over another, or one ammo company's load over another.

Handloaders, by contrast, can experiment with various bullets and powders, and various powder charges, to optimize performance in their specific rifle.

Major brand ammo is actually very good, all considered. But it's all a compromise. That's why with no trouble at all, the handloader can exceed the performance of ordinary factory loads, and with maximal effort can produce truly phenomenal accuracy.

 

[Nevada Ed]

When you think about it..........
each comany has it's own powders that it uses......
plus their bullets may be differen in many ways from the other companies.

Each brand of ammo HAS to be fifferent in your rifle, just due to these differences.
Take a look at these .308 hunting bullets and think where they will end up on a 100 yard target
just out of the same rifle.

 

[ArchAngelCD]

Clarify ammo is not loaded with the canister powders we can buy. They blend their own powders to meet their specs for that round.

Just a note, I have taken several different Speer handgun rounds of the same type apart and the powders were different in the ammo made in different years. (very different) So like I said, the factories blend the powders they use to meet their specs.

That said, sometimes they will use a powder that is very close to the canister powders we can buy.

 

[Univibe]

One thing some folks think is that reloading powders are dregs or rejects that the commercial ammo makers don't want.

Not so! Canister powders are the best there is. Ammo makers have labs that can test the lots of powders they make or buy. If it's a shade off spec, they know how to adjust it.

But loaders depend on published data. We can't do pressure testing or other types of analysis. Every pound has to be in spec.

 

[vonn]

I know that I can build a load that will shoot as well or better than factory loads just wondering what the factory priorities are when they build a load. Pretty sure cost,speed, accuracy,and pressure are considerations . Wonder how they arrive at the mix they sell. Got to thinking about it because of trying to build a load for four 270 rifles. Haven’t seen any factory deer hunting ammo for this season for over a year around here . Thanks for your replies.

 

[ReloadforFun]

Factories are trying to load acceptable ammunition at the lowest cost they can. Using non-canister powders is lower cost than using canister powders. The non-canister powders will arrive in drums with 50 or so pounds per drum. I'm not aware of any ammunition companies making their own powder at this point (in the US, at least). Even situations like Vista that has both ammunition companies and a powder company in the portfolio, it's not a given that the Alliant powders will be lower cost than some others, and they will go for the more economical, assuming ballistic performance is maintained.

Bullets, like the powder, are bought or made. They are bought, or made, in large quantities and the price per bullet will be less than we, as reloaders, will be able to buy them. Unless we're buying 50 - 100 thousand at a time. Then we can negotiate prices too.

Not all that many ammunition companies make there own cases either. Obviously, Winchester, Remington, Federal and CCI-Speer do, and some others, but many are buying their cases.

Then, of course, there are primers. Even fewer companies making primers than cases. Again, the ammo makers have some leverage by buying in large quantities.

So - first consideration is cost.

But, within that cost they are looking at reliable ballistics meeting the criteria initially set for that cartridge/bullet.

Each new lot of powder, being non-canister, must be tested to develop the load to be used in production. There was testing of powder samples before a quantity of powder was purchased.

While many will test ammunition in actual guns after developing the load in the pressure gun, there is no way the entire spectrum of models can be tested. They will use some of the more popular models. In semi-autos they are trying to ensure functional reliability and may use several different models.

Accuracy testing is more commonly from the pressure gun as it eliminates the additional variable of the shooter and whatever model gun is used.

They will try to deliver the ballistic performance at the lowest pressure they can. Sometimes that pressure is at SAAMI MAP. Others, preferably, will be comfortably lower.

 

[glenwolde]

At this point in time, they must have a tremendous amount of data about what works and doesn't work for a given cartridge. I imagine they start there and make minor adjustments. The .308 is over 70 years old.

 

[jcelect]

Accuracy

All these post about powder, primers, different guns of the same caliber, bullets, etc. and no one has mentioned the twist rate of their rifle! Twist rate has the same effect on accuracy as any powder, or maybe more! The weight of the bullet you use must be compatable with the twist rate of your gun!
jcelect

 

[Nevada Ed]

All these post about powder, primers, different guns of the same caliber, bullets, etc. and no one has mentioned the twist rate of their rifle! Twist rate has the same effect on accuracy as any powder, or maybe more! The weight of the bullet you use must be compatable with the twist rate of your gun!
jcelect

Most rifles have a "Standard" twist rate that was set in the early 1900's.
Today's custom barrels might change as have the old "Nam" rifles
with the heavier bullets and rifle designs, of today.

However there is always one standard barrel twist, that the industry uses.

If your rifle is different, you need to adjust.