IMR 3031 and 4064 safe to compress?

[Exposure]

I was putting together some new loads tonight for my .223 bolt rifle.

I used both IMR 3031 and 4064 at 25 grains. Both of those filled the cases to the brim of the case mouth. However, multiple sources listed 25 grains or MORE for a .223 round. I don't know how you could get any more than 25 grains of these powders in there!

When I seated the rounds I heard the powder go "crunch"

I searched and searched but couldn't find anything saying it was OK or not to compress these powders.

Any advice is welcome.

 

[Galil5.56]

Perfectly OK, and have been doing it forever, just not in .223. Only "problem" you may run into depending on compression level, and if/how much crimp is applied is the bullet not wanting to stay fully seated (popped out a bit). Tapping the case, using a long drop tube, etc can help pack the powder prior to seating.

My old DuPont manuals will place a "C" for compressed next to a charge weight, some may use a symbol and place it in the notes, and perhaps some say nothing. Irregardless, aside from hearing/feeling disconcerting "crunching", all is well.

 

[loadedround]

I second Galil's comments....been doing it for 40 years.

 

[243winxb]

Compressed Loads

Use a drop tube. I see it this way, a little compression is OK., but can be over done as in anything. http://www.fbi.gov/hq/lab/fsc/backissu/april2002/mccord.htm#table1

another important characteristic is its morphology. Shape and size have a profound effect on the burning rate and power generation of a
powder (Meyer 1987).

and the resulting mixture is shaped by extrusion and cut into specified lengths. The granules are screened to ensure consistency,

 

[ants]

Good advice in first three replies above.

Yes, compressed loads are OK with those powders as long as you follow published data. Drop tube helps, but not always necessary.

Given the hundred (or thousands) of different 5.56/223 brass manufacturers, I have measured great variance in case volume over the years. Some brass has more volume and can take more powder, some can not. Just stick to published data and go by the book. You'll be OK.

--Compressed load of IMR3031 in 223: I don't find those near-max loads to be the most accurate with that powder. You'll have to find out for yourself. With light bullets and low to mid loads, when each powder charged is carefully measured on the scale, 3031 yields very highly accurate mid-velocity ammo for my 16" AR carbines. 3031 doesn't always meter very consistently in many powder measures, so the charge has to be measured very carefully for accuracy. Your experience may be different. You'll have to find out for yourself.

--Compressed load of IMR4064 in 223: Works OK, but I've never had luck with this powder. You certainly can make good ammo with it, but it has never been an accuracy stand-out for me. Your experience may be different.