One of the most accurate loads I ever had was 40gr. of 4350 in my 22 varminter( later to become a 22-250)This load completly filled the neck before the bullet was PRESSED in.
There is documentation available that shows that in many compressed loads the pressure is LOWER than that same powder in the same cartridge uncompressed.
When you compress ball powder not only can you swell the case you can move the primer out. I'VE DONE THIS.Shine it on when someone tries to tell you it's OK because ball powder has an elastic component. Mox Nix roger
Posts: 10226 | Location: Temple City CA | Registered: 29 April 2003
Quote: It will logically just depend on the extent of the pulverizing or fracturing.
Bottom line, if you are going for extreme accuracy and consistency, changing the propellant by cracking it, can't be beneficial.
I notice your handle. Any experience with loads for 160g bullets in a 7STW? What propellant and approximately what range of charge?
This is an awesome thread. I can see now how that breaking the grains could make a difference, although i still dont think that uless your going extreme, not much is going to change. Like stated above, its having the same amount of breakage in each case that would be the biggest deal. this would be near inpossible with stick type powders though. We are talking perfectionist talk here though LOL.
Unfortunatly I havent tried any 160's in my STW so i have no info for ya. I have been using 140Gr Ballistic Silvertips with 84.5 gr of H1000 till now but I am not at all happy with the bullets performance on game. I am trying the 127gr Groove bullets and the 120 gr Lazzeroni XXX's in the gun next. I want fast and flat for heart lung shots as I am not a shoulder buster although I have no doubt that the 120gr XXX will do a serious number on a shoulder bone at 3600+ FPS or so. I will more than likely end up with Reloader 22 as my powder for these. In the Nosler manual they hailed the H-1000 as a great podwer in the STW for the 160gr and heavier bullets. Might want to give it a try.
Another trick I've heard of (not had to use, thankfully) to get a case full o' powder is to use a tube to get most of the powder in, and then hold the case head against something like a running tumbler for a few seconds, to vibrate the powder to cause it to settle. Not sure how much it actually helps, but I've heard people swear by it.
Monte
Posts: 341 | Location: Wenatchee, WA | Registered: 27 February 2002
Seems to me it would be pretty easy to test this theory. Take two identical loads, pulverize and/or crush the powder in one loading and not the other. Shoot and see what happens. If I were to do this I would be sure to use the old tire and long string method. Besides, I don't have a donor rifle. Maybe we could get Clark to try it, it seems like he likes to do stuff like this.
Posts: 8169 | Location: humboldt | Registered: 10 April 2002
Quote: as an example...lets say you wish to load 100 grains of powder.....you first load 50 grains and using a probe you compress it. Then you load another 50 grains and compress that and finally install the bullet.
Something like that appears to be done by the factories selling "Light Magnum" type ammo. There was lots of discussion when they came out about them using "special powders unavailable to handloaders" and having "special loading techniques" which no outsiders were allowed to observe. Several folks reported having to dig the powder out of the case with a tool after pulling the bullet, and that it would not fit back in.
Posts: 1325 | Location: Bristol, Tennessee, USA | Registered: 24 December 2003
Ball powders can compress somewhat, as the nitrocellulose colloid is a plastic (remember that celluloid was originally developed for billiard balls) and the spheroids will deform elastically when pressed against each other. They flatten out where they're in contact under pressure and bulge in between, like mashing rubber balls together. But they won't compress a lot.
I had to pull some bullets back out of a load I'd compressed a little too much with a long stick powder the other day. The grains right under the bullet bases were mashed flat and bent. I haven't been getting good accuracy with those loads either, and will back off so they're only slightly compressed. I think the damaged grains have been erratically affecting the burn rate and pressure. It's safe to shoot, but not the best load.
With very heavily compressed loads you can see deformation of the BULLET from the seating die pressure (which has to mean the powder's getting deformed), bulging cases as previously mentioned, and the elastic powder will often reexpand and push the bullet back out of the neck, making seating to a consistent desired overall length difficult.
Posts: 1325 | Location: Bristol, Tennessee, USA | Registered: 24 December 2003
When you drop a charge of stick powder, there are a lot of air holes left between the sticks. Usually you are just packing the sticks a little closer with a compressed load. Any change in burn rate because of broken sticks would be insignificant. Do not try a compressed load with ball powder as it can't compress and will bulge your case walls.
Posts: 2037 | Location: frametown west virginia usa | Registered: 14 October 2001
Depends on the type of powder it is and the degree of compression. I've compressed powders that are up to the neck, making it difficult to even get the bullet started. When I've examined the granules after pulling the bullets there was no evidence of fractures. In the case of the larger and longer stick powders you'll find some of the sticks have broken. Fracturing the granules alters the burn rate and therefore makes them less consistent. Powder "burns" from the outside in and fracturing the granules alters the rate.
The compression itself has no effect on burn rate. The pressure is affected by the burn rate of the powder and the volume of it and not by the compression itself.
You usually compress powders that are slower for the application. This tends to make them burn more consistently if they are ignited uniformly by the proper primer. The evidence of this is in lower standard deviations and extreme spreads in the velocity. Faster powders that don't fill the case tend to burn less consistently because of the air space and they may give large SD's and wider extreme spreads.
Posts: 1261 | Location: Placerville, CA, US of A | Registered: 07 January 2001
I've got a couple of ball powder loads with the case shaken down full right up to the mouth and fairly long bullets pushed down inside, that shoot well. Haven't bulged a case or pushed a primer out yet, but there's always a first time. My most compressed load, though, is with a ball powder full right up to the base of the neck in a 7mm Rem Mag and a 175 grain SP seated to the cannelure. There's a lot of bullet poked down in that powder space!
Posts: 1325 | Location: Bristol, Tennessee, USA | Registered: 24 December 2003
When i need max loads in my long wildcats,I compress powder when I seat bullets, with a shaker attached to press.Using higher energy ball powder that is slightly slower for the bullet and volumne,that is compressed, gets more energy, and with most of the ball the peak pressure is later on the curve thus putting less stress on the brass, giving many more reloads and longer case life.Ed.
as an example...lets say you wish to load 100 grains of powder.....you first load 50 grains and using a probe you compress it. Then you load another 50 grains and compress that and finally install the bullet.
Of course you use a powder a little too slow for your intended cartridge...it's just another way to attain more powder capacity or in other words a larger case.
Posts: 28849 | Location: western Nebraska | Registered: 27 May 2003
roger
