Compressed Loads...Bad Juju?

O

oneshotonemiss

Guest
I posted the following on another shooting site and got many comments. I'd like your opinions, since this site has an entirely different orientation on shooting.

Thank you!

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As handloaders we strive for consistency. We try very hard to have each and every round just like the round before it and as close to perfection as we can achieve.

So much for the obvious.

Every powder no matter what shape it is is coated with chemicals that effect the burn rate.

Compressed loads cause individual particles to break. Some types such as extruded will break more readily than say a flake powder. The breaks expose non-coated surfaces and makes them burn differently (usually faster) than intact ones. The particles are also pushed together more tightly.

Under compression, this breakage and compaction cannot be predicted, controlled or consistent. It is chaotic.

Burning powder under such circumstances cannot be the same from round to round as there is no way to control the compression and breakage.

This is the very definition of inconsistency and should be avoided.

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do you have any scientific data to back up you hypothesis ( ie chamber pressure readings, etc)? i'd be very interested to see your data, otherwise it would seem your just blowing smoke!
 
Compressed Loads

One shot,
If you were to go to the centerfire benchrest and ask this guestion you would get an answer that would surprise you .
Almost every load with every powder combo you will find that all of the BR cart. use a compressed load ,it doesnt matter if it is a 6PPC,22PPC,6BR,or 30BR or any other true BR round.
Nick
 
I've found that about any powder I find useful needs a tap on the head to let it know whose boss, that is a serious 100% loading density.

Now if you leave the realm of short range benchrest, I believe that you'll find that this issue, rather than being related to how many kernels you crack as you seat the pill, is how far & how irregularly they back out when you exceed the limit of common sense. Here in Australia, the somewhat eccentric displine of match rifle necessitates you getting a projectile in the 200-220 grain range to 1200 yards supersonically out of a standard .308 Winchester case. Most of us have accepted that VV N550 is the most reliable path to go, given that the loads really require cases of the integrity of Lapuas to avoid backfiring. That works. The disbelievers (we call them stubborn pigheaded buggers) use Winchester cases & load them with a truckload of AR 2209 (I forget what the big H calls it stateside). If they use a heavy enough engineering arbour press, the necessary compressed load hardly backs the projectile out of the case & while they're willing to hire their own personal firefighters to quench the burning embers shooting from the muzzle, it works - but why bother?

Use enough of the right powder & you, your cases & the environment will be hunky dory.

John
 
Your theory sounds reasonable but reality proves it wrong. Accurate compressed loads are common and quite often the best.
 
The main reason I avoid compressed loads is that my base to ogive measurements seem less consistent. Has anyone else noticed this phenomenon?

I've also heard that compressed loads can potentially damage Redding Competition seaters. I haven't actually bunged up mine yet (as far as I can tell), but I'm not going too far beyond 100% full when I do compress.

Disregarding the potential damage to the seating die, would more neck tension be the cure for the inconsistent length measurements?
 
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Compression is not a fixed number.... obviously at some point it will become a problem...

Slight compression has never been a problem.
 
I used to have a 7x57 hunting rifle WAY BACK, and after Norma 205 was discontinued found that a caseful or MRP worked fairly well with a 140 gr bullet. When the bullet was seated it sounded like someone dancing on peanuts on the floor. It shot great.

More inconsistency is produced by the powder charge being able to move around in the case and thus be ignited less consistently. Some of the old "experts" viewed compressed loads like a little kid does the monster under his bed, but they have mostly been shown to be at least misguided if not entirely wrong.

Theory is great, but it's the practice that matters. Compressed loads work well if they're properly developed - just like any other loads.
 
Life behind the trigger has proven otherwise. The proof is on the paper. Compressed loads should be what the first poster theory says, reality rears it's ugly head and shows you why this theory does not prove it's self true and causes the theory to prove itself untrue.

The thing about theories that is true, it's easier to come up with a theory
about a seen phenomena than it is to put the cart before the horse and not find the effect.:D
 
Big Al said:
The thing about theories that is true, it's easier to come up with a theory
about a seen phenomena than it is to put the cart before the horse and not find the effect.:D
Click to expand...

Put a little differently, I think scientific principle for the empirical world dictates that you first notice a phenomena and then look for testable theories to explain. The original poster has a theory and is now looking for the phenomena that it explains.
 
Where does this get started?

Is there some old, widely circulated manual that spouted such BS about compressed loads?
 
Engines loooove compression so. . .

My Palma rifle really likes 47 grains of Varget (new Varget) and trying to stuff that into the case can be a bit daunting.

My drop tube is 28" long. I made it from an old Easton arrow shaft. It has a delrin adapter that screws into the top of my press. That gets me "almost there". From there I have loading blocks glued to a little vibratory table that I made. (Got the idea from a buddy who talked of locating one of them ol football board games from the 70's) and it shakes and rattles that powder down nice and neat.

No more crunching kernels.

Hope this helped.

C
 
BottleBaby said:
Where does this get started?

Is there some old, widely circulated manual that spouted such BS about compressed loads?
Click to expand...

Some of the old timers, Ken Waters is a prime example, seemed to believe that a compressed load was the work of the devil for some reason. I've never read any explanation for his belief, but modern target shooters use compressed loads with good success and they're being listed more and more in loading manuals.
 
BottleBaby said:
Where does this get started?

Is there some old, widely circulated manual that spouted such BS about compressed loads?
Click to expand...


It used to have me just down right afraid back in the 60's until I bought a couple of hundred pounds of 4831 and got used to shooting compressed loads in the .30-06. It was a common warning about compressed loads from the old "Shooting Times" reloading paper. Carried on to "Reloader" magazine.

I to was and ardent reader of the late KEN WATERS. Even after all these years of using the compressed loads, I still am a little
uncomfortable.

It was vary common t see dire warnings about compressed loads in magazines of the 60's and 70's. The one thing you can be sure of, is that is sure made for a large dose of skeptiseum on my part.:confused:
 
Never thought about it....

oneshotonemiss said:
I posted the following on another shooting site and got many comments. I'd like your opinions, since this site has an entirely different orientation on shooting.

Thank you!
Click to expand...

I use 43.8gr of Vit 135 in a 30X47HBR Rem (shortened Sav 300) case. The powder comes within 1/16" from the top of the neck. Then I stick a 136gr BIB bullet on top with a Lee bullet seater and the rifle shoots great @ 3020fps velocity and great groups.

virg
 
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