Which powders are position insensitive ???????

[Willyp]

Which powders are position insensitive ,for loading of cast bullets,in a 308 Win. or a 30-30??

[geezerbiker]

So far I've used IMR3031, red dot and unique and not had any problems.  I haven't tried any others for this purpose...

Tony

[Swampman]

I use Unique for everything.
 

[Land_Owner]

For the two rifle calibers you mention, use powders that nearly fill the case (>75%) before stuffing the bullet.  There will be little or no "sensitivity" when the case is over half full.  Just Google the issue then read some of the posts.  Position sensitivity is more closely associated with handgun cases where the powder charge can be less than 1/2 of the case volume.

[Larry Gibson]

Any appropriate powder (there are many powders not appropriate for those 2 cartridges) that occupies 80% or less of the cases powder capacity will be "position sensitive" to one degree or another.  How much depends on the ease of ignition of the powder and the actual loading density.

You can easily test for position senstivity with a specific load by shooting a 10 shot test string at a 100 yard target and chronograph the test. Keep the rifle level during the test and load the cartridges in the normal manner.

Then do the same with another test string only raise the muzzle to vertical after loading to position the powder to the rear of the case.  slowly lower the rifle to the level position before firing.  Shoot that 10 shot test at the same target.  Chronograph that 10 shot test string as well.

Then shoot another 10 shot test string but this time lower the muzzle to at least 45 degrees down to postion the powder at the front of the case.  Gently raise the rifle to the level position before firing.  Fire at the same target and also chronograph that test string.

You will probably have 3 sperate groups with vertical stinging between the groups.  The 2 test strings with muzzle raised and lowered will probably have a considerably different average velocity than the 1st test string.  They will probably also have lower ES and SDs.  Additional the ES between the slowest shot and the fastest shots of the 30 shots will be very large.  All this indicates the powder is "position sensitive" with that load. 

I have run this test many times and have found several inches of vertical stringing between the shot group centers and also upwards of 250 fps variation between the fastest and slowest shots. BTW; the use of a dacron filler where appropriate will negate "powder position sensitivity" because the powder will be held back against the rear of the case regardless of how you handle the rifle or when shooting up or down hill.  That is one of the very real advantages with the use of the dacron filler with reduced cast bullet loads.

Larry Gibson

[kynardsj]

Red Dot and Unique. I've used them both in a 308.

[Dinny]

Trail Boss 

Thanks, Dinny

[mauserand9mm]

Actually you can use Trailboss with jacketed projectiles too, although would be a waste of a (relatively) expensive projectile.

[Dinny]

Actually you can use Trailboss with jacketed projectiles too, although would be a waste of a (relatively) expensive projectile.

That really depends on the use. I have used TB with great success in developing subsonic loads with heavy jacketed bullets. Personally, I have not tried a better powder for that specific use...

Thanks, Dinny

[mauserand9mm]

I couldn't think of an application for hard (constructed) bullets at low velocities, but not to say there are none.
 
What was the application?
 
(I have heard of sub-sonic loads in 45/70 for the quiet taking of deer but the projectiles are usually selected as soft to ensure some sort of mushrooming.)

[Dinny]

I have found heavy slow moving bullets very useful for dispatching pesky varmints around suburban areas. They don't necessarily need to expand to do their job well. A poke in the CNS area seems to work quite well for most all animals.

Thanks, Dinny

[budman46]

in rifles, red dot and 2400 are the two powders supposedly unaffected by position; after thousands of rounds in various calibers,  i'll testify to 2400.

budman

ignorance is fixable...