What Powder??????

[veteran]

Anyone know what powder Federal uses in the Gold Medal Match 69gr hpbt
load?

Gerry

[longranger]

Most likely a proprietary powder not available to the public.Those loads can be bettered by handloading.What they do for "match" ammo is having consistent powder charges with good componets.Maybe or maybe not having prepped brass such as the Nosler,Norma or LaPua.

[Teuthis]

They blend and change their powders and have access to things we could not imagine. Get a manual and see if you can safely duplicate the claimed velocity of that round. One cannot, through handloading, always equal the velocity of factory rounds but sometimes it is possible. Good Luck and be safe.

[Mike Irwin]

It's power that you can get, only not in a formulary that any of us can get.

Unless it's something totally new in the industry, it's a non canister powder, meaning that the powder, be it 231ish, 296ish, Vargetish or what ever, generally comes from a single lot, whereas what we can buy commercially is blended from multiple lots, the intention being preservation of the expected performance curve year after year.

[Jim Watson]

It is whatever they got a good deal on.

Glen Zediker wrote about one of the service teams pulling a bullet from a round in every new shipment of match ammunition. If it contained Ball powder, they shot it for 200 and 300 yards; if it was loaded with extruded powder, they kept it for 600 yards because they had learned to expect better accuracy from such.

There was a gunzine article recently about a police department that was unpleasantly surprised with the amount of muzzle flash from ammunition under a new contract. Pulling bullets showed it was loaded with an entirely different powder than the previous order. It met all specifications as to pressure, velocity, and bullet design; but nobody there had thought to quantify muzzle flash and write a specification for it.

Otherwise, Mike is right. Bulk lot powder used for factory loads is tested and loads worked up for that lot. That does not mean it is some mystery magic formula, it is just powder that did not meet the specs for retail sale.
Or maybe it did and they had more orders for bulk powder than they did pound cans. A gunzine writer was surprised to find early production 7mm 08 ammo loaded with something that looked a lot like Win 748 instead of some IMR. Handload development of the then-new round revealed that it WAS 748, load for load.

Long ago, Phil Sharpe wrote that WW II powder lot numbers were assigned to cover 50,000 - 60,000 lb carload lots. Not because there were differences in production over the time it took to make 30 tons, but because they could not be SURE that the next shipment would be the same.

[veteran]

I guess I'm a little confused.

If I use the same case,
same sizing,
same primer,
same bullet,
same seating depth.

Then loading for velocity
should give me the same results
regardless of which powder I use.

As long as it is in the family of powdeers recommended for that
caliber.

Right?

Gerry

[Demaiter]

Different powders will give different velocities. They will be close but not the same. They have different burn rates and different pressures associated and therefore velocities will vary.

You could match powders to a certain velocity with different charges of powder to an extent... however you should really be adjusting the charge depending on accuracy.

Hand loading will probably give you better accuracy then matching their load specifically anyways.

A lot of people use a charge of varget with rem brass, 69 grain sierra match kings, and 7 1/2 Remington small rifle bench rest primer with great success.

[Mike Irwin]

"That does not mean it is some mystery magic formula, it is just powder that did not meet the specs for retail sale. "

Actually, not the case.

Ammo companies have certain specifications that they need to meet for each cartridge. Powder manufacturers will test lots coming off the production line until they find one that matches the specs laid out by the manufacturer and then tag it to fulfill the ammo company's order.

Generally a powder that won't meet specifications for blending into canister powder for retail sale will either be surplussed/wholesaled or destroyed.

[Magnum Wheel Man]

I'm in the powder business ( sorry, food ingredients, not gun powder )... each lot / batch / run of powder is going to varry slightly in "moisture content" & thus bulk density, & ever so slightly in burn charictoristics... they likely have a spec, that offers a range of readings...

just like I blend several powders together in my factory, they likely do the same at the ammo factorys perhaps their load reciepe might have 3-4 different powders to choose from, or a blend of those powders that result in proper density, burn rate, & resulting velocities...

just like your soda can might say sugar & or corn sweetener, they use what ever is available or at the best price, that can match the "flavor & sweetness" they are after... same with ammo

[Jim Watson]

Ammo companies have certain specifications that they need to meet for each cartridge. Powder manufacturers will test lots coming off the production line until they find one that matches the specs laid out by the manufacturer

But how tight are those specifications? Does the ammo company management care whether they get a truckload of of Powder A which requires 51 grains to produce 2930 fps at 48,000 CUP in .30-06 or Powder B which requires 53 grains for the same ballistics, assuming the price PER ROUND is the same?

We used to be told that the ammo company bought powder of a suitable burning rate RANGE and did their own testing to determine actual loads. Is it now the case that the powder mill maintains a pressure gun and set of barrels?

I was in a bulk product business, too; fertilizer R&D. We did little if any back blending to try to achieve an exact analysis. We produced a tank or bin of material, analyzed it, and furnished that analysis to the user. Always thought that was what the powder mills did.

[Mike Irwin]

Althought it's a lot less common today than it was in years past, the simple fact is that some powder lots, for whatever reason, can vary significantly from the expected or anticipated norms.


"Is it now the case that the powder mill maintains a pressure gun and set of barrels?"

You don't need to maintain a pressure gun and barrels. There are numerous ways of testing the burning rate and pressure progression of a lot of powder without actually having to fire a bullet out of the end of a gun.

As for how tight the specifications are, you'd have to ask the individual ammunition companies themselves. I would suspect that they all have very different parameters in what they want/expect and what they're willing to accept as deviation from that.

[Unclenick]

As Mike says, powder lots do vary. The processes are temperature and time and contaminate sensitive. Just changing which tree or cotton crop the cellulose came from can affect it, and you can't refine those raw materials to chemical purity if you don't want to pay $200 a pound for powder.

It seems like two different bits of information are getting crossed over. Canister powder blenders keep aside especially fast and slow lots of each powder they sell for blending into new lots to adjust their burning rates to match that of previous lots. That is thought to give adequate protection to recipe loaders who don't rework their loads for new powder lots. It doesn't always work out, though, so the warning and recommendation to work loads back up from a 10% reduction with any new powder lot still stands. I have seen 10% peak pressure variation, lot-to-lot, with 296 in .44 magnum loads, for example, but haven't measured any others. Both peak pressures were within SAAMI peak limits.

Prospective loads of non-canister grades of powder (powder not blended for uniform burning rate) for commercial ammunition manufacture are tested by firing ten rounds in a pressure test barrel and ensuring the mean pressure and extreme spread do not exceed those of reference loads for the round fired in that same test barrel. The loads of the new powder lot are adjusted and retested as needed to meet that criteria, then the successful load is used just with that powder lot. The testing starts over with the next lot. (I had a discussion about the way proof and reference loads are managed with SAAMI's technical director, Ken Green, earlier this year. For more detail on how SAAMI proof and reference loads are determined and handled, see my post #34 in this thread.)

The military is a little different. It not only has pressure limits, but also has performance requirements. A prospective lot of powder for the military is loaded to meet a ballistic performance requirement and is tested to see that it accomplishes this without producing either too little or too much pressure for operating automatic arms safely and reliably. A lot is rejected for a particular application if it can't produce a load meeting all those requirements.

Originally Posted by veteran

If I use the same case,
same sizing,
same primer,
same bullet,
same seating depth.

Then loading for velocity
should give me the same results
regardless of which powder I use.

Nope. VERY DANGEROUS assumption. Take the .223 for example: If I load it for a 20" M16 barrel, I can drive a 69 grain match bullet to 2,800 fps with Hodgdon BL-C(2) powder loaded to a peak pressure of 50,000 psi. Good pressure and performance levels. But if I am foolish enough to try to load it to 2,800 fps with Winchester 231, I get a gun and shooter damaging 123,000 psi peak pressure.

The 231 is a much faster burning powder used in pistol target loads. It makes all its gas at the beginning of the bullet travel before the bullet has moved down the barrel very far at all. Thus that total gas volume needed to reach 2,800 fps is confined to the volume of the case plus an inch or so of barrel, which is small enough to make for that very high 123,000 psi peak pressure. The slower burning BL-C(2) lets the bullet get well underway before it has burned completely and it keeps burning and making gas the whole time the bullet is in the barrel. Thus the gas from the slower powder is gradually paid out into the much larger volume of the case plus the longer barrel volume behind the bullet all the way down the tube. This makes for much lower peak pressure. Thus: for any given chambering and barrel length and peak pressure specification it is only safe to get to a certain velocity with powders that fall within a certain burning rate range.

Stay safe, and limit yourself to the powder recommendations in the manuals.

Nick