How do the factories load "universal" high performance cartridges??

243winxb

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Are there indeed SAAMI velocity standards for the various cartridges?
I guess "pressure standards" is essentially equal to "velocity standards."
I've never seen reference to "velocity standards" before,
SAAMI posts velocities. May not be a "standard"?
Screenshot_20200918-112442.jpg
 

antelopedundee

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Oct 14, 2018
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Iowa
I bought 2 boxes of Hornady Outfitter 300 Win Mag 180 GMX to shoot in my new to me Blaser.
It shot 1/2 moa to 400 yds (as far as I've tested it) and the cases came out "snickety - snick"
Unfired ammo has a rounded face primer like a Winchester. After firing, the primer is flat against the bolt face. Too hot, nope as cases fall out, head expansion is a non event and the Blaser has nowhere near the primary extraction power of a Mauser.
And the nickel cases are soooo pretty !

Speakin a pretty nickel cases!

 

The Java Junkie

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Sep 13, 2020
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Vermont
Went to a Hornady reload class , a while back , when they had the "light mag" ammo. I asked what powder they used, as I wanted to purchase some for reloading , I was told by the rep. that its a proprietary blend , and wasn't available to the public...!
 

SheepSeeker

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No factory ammo is loaded with any standard cannister powder. The ammo company draws up a spec and the powder company builds to that spec. This is not "new" knowledge. It has been true as long as there has been factory ammo. Once in a while the custom made powder "bleeds over" into commerce like 4895 and 4831 that TONS of which were made for the 30-06 and 20mm respectivly.
 

MagnumManiac

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Not wise to shoot MK248 mod 1 ammo in guns not chambered for it. Its loaded for 68k psi in their chamber. You probably hit 75-80k.
This is false. I run the A191 chambers, they have SHORTER throats than SAAMI chambers, therefore a SAAMI chamber produces LESS pressure.

To the OP, the reason the factories produce loads that work in almost every gun is because they use a few techniques that are known to produce high start pressures with a fast powder that produces a flatter curve.
They blend several powders to get a pressure within 10,000psi of max at the VELOCITY they determine to be optimum.
The biggest trick they use is crimping, this raises the start pressure significantly and flattens the curve somewhat. The rise over time is short, because the powder used is on the fast side.
I compared Winchester loaded ammo in 300WM loaded with 785, Winchester’s equivalent to 780, and my own 780 loads.
I could not come close, without excessive pressure, to their velocities. Over my pressure trace, my loads were over 75,000psi, proof loads actually, to match their velocity.
So their tricks in formulation, crimping and blending is what makes their loads safe.
The maximum pressure from any load in that factory ammo was only around 56,000psi, now I know my pressure trace isn’t calibrated to SAAMI reference ammo, but that is quite low for the 300.

Cheers.
 
Last edited:

C.C.W.

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Sep 13, 2020
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So we've all seen it advised a bazillion times; "....work up a load slowly in your gun, watching for pressure signs". And, "If you change any component, start over on load workup with a reduced charge".

Now sometimes it is difficult when reloading to match the performance, at least in terms of velocity, of factory loaded ammo. To be competitive, and keep the buying public happy, (and brand loyal), factory ammo has to have relatively high velocity performance for each given cartridge.

So how do they do it? How do they make rounds with respectable velocity, that are safe in "any gun of modern manufacture in good condition"??

I realize they use powders that we don't have access to, but where's the "magic"? High performance loads, that work in ANY gun, (and are safe) ,with no gun specific load workup.

What am I missing here??

Vettepilot
What a great question. By the way no; I have no clue but hopeful that someone will chime it with the magic bullet
 

Tulsa Reiner

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Tulsa, OK
This is false. I run the A191 chambers, they have SHORTER throats than SAAMI chambers, therefore a SAAMI chamber produces LESS pressure.

To the OP, the reason the factories produce loads that work in almost every gun is because they use a few techniques that are known to produce high start pressures with a fast powder that produces a flatter curve.
They blend several powders to get a pressure within 10,000psi of max at the VELOCITY they determine to be optimum.
The biggest trick they use is crimping, this raises the start pressure significantly and flattens the curve somewhat. The rise over time is short, because the powder used is on the fast side.
I compared Winchester loaded ammo in 300WM loaded with 785, Winchester’s equivalent to 780, and my own 780 loads.
I could not come close, without excessive pressure, to their velocities. Over my pressure trace, my loads were over 75,000psi, proof loads actually, to match their velocity.
So their tricks in formulation, crimping and blending is what makes their loads safe.
The maximum pressure from any load in that factory ammo was only around 56,000psi, now I know my pressure trace isn’t calibrated to SAAMI reference ammo, but that is quite low for the 300.

Cheers.
This answers a question I've had for some time: why does Hornady factory ammo for a given caliber and bullet weight exceed the maximum MV published for the same combination published in their reloading manual?
Thank you.
 

DJ Fergus

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Dec 25, 2015
Messages
2,118
I have more than once seen ejector marks on factory loaded brass. I would assume that factory rifle makers are mandated to stay within a set dimension for SAMMI and if the cutters go outside of that, they are changed out. With that they can take their "high performance" load at either end and if no signs of pressure are noted, there good to go. Now do rifle manufactures hold true to that limit?? I dont know, seeing ejector marks on factory loaded ammo leads me to believe, no.

Maybe Im WAY off, if so I too have always wondered that.
I've saw plenty of factory rounds with ejector marks as well.
 

Tripodmvr7

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Sep 17, 2020
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South Africa
In an ammo plant that is starting off, the normal proviso of start with safe low charges would apply. Once you have a list of bullet weights, propellant and cases that shoot well in the test barrels then any change in components can be overcome with mild reductions in existing loads and then going up slowly to again get accurate loads. This is the way I explained that PMP used to get accurate ammo. Persistent combustion and sound reloading procedures produce low ES rounds that ensure accuracy in numerous different rifles.
 

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