Compressed loads?

[Ammo Junky]

I genraly try to avoid compressed loads. However heavier bullets need slower powders and that where the trouble starts. 165 3006 load with 57.5 h4350 is great, but when I switch to 180gr and 56.0 H4350 I get compression. I have a similar situation whith 175gr bullets and varget in 308. I guess switching to the next faster powder would relive the compression, but I cant see using a faster powder with a heavier bullet and slower with the lighter bullet. What is the concensis?

[cheygriz]

Most of my very accurate loads are compressed. There's no reason to avoid compressed charges.

[Crosshair]

I use compressed loads all the time. Nothing wrong with them. Sometimes you need to use a magnum primer to get the party started. Most load data will tell you when to use a magnum primer.

I use cheap surplus H870 powder in my 6.5x55 to great effect and I am developing plinking loads for the 7.5x55. Both use compressed powder charges.

[ligonierbill]

Crosshair, what are you loading in your 6.5x55? I've got H870 that I use for heavy bullets in 7 mm Mag, but I have only used IMR 4350 in the 6.5. I was about to load some 140 gr with Reloader 22.

[Shoney]

I’ve used compressed loads in many rifle cartridges with great success.

I have a friend who loads 338 Wim Mag by filling the case to overflowing with IMR XXYZ, then leveling it off with a knife, then crunching a bullet home. His accuracy is very good. One summer he decided to hunt the wild and elusive prurient prevaricating pusillanimous prairie poodle with the 338 (Some professional guides consider this cartridge to be the minimum necessary to stop the charge of an enraged bull prairie poodle.).

It was 90-100+ degree weather, and after a series of thundershowers, it became very humid and muggy. He discovered that the cartridges in the magazine were wedged in and the others would not chamber. Hot humid weather can swell powder, and on compressed loads it may push the bullet forward. Many hunters going to Africa with Big Five legal weapons have experienced this. So BEWARE when using compressed loads in hot humid conditions.

[Ammo Junky]

I have have seen compressed loads give much less consistant loaded oal. This is during pressuar workups where loads start out not compressed and go up. The oal was measured with a coparator, before anyone asks.

[crowbeaner]

The only compressed loads that I use are in the 22-250 and 243. The powder in the 22-250 is Imr 4350 and in the 243 it is Imr 7828. Neither is "compressed" all that much, and I prefer to have some airspace in the case to allow for temperature variation. If you use IMR 4064 in your 30-06 with the 180 grainer, you'll have just about the same velocity:2700 fps. Loads with 4350 might do a little better, but not much.

[amamnn]

If you use a drop tube, a lot of compressed loads are no longer really compressed. In BR competition it can make a difference to lay the powder with a drop tube so that you avoid broken grains and oddities in the powder column durring ignition. For most other uses I don't see a need for a compressed load; the slight velocity gain is far outweighed by the accelerated barrel errosion in factory rifles. Trajectories don't change all that much with a slight boost either. An elk won't know the difference between a 2950 fps bullet and a 2750 bullet.