Pressured or crushed loads

C

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Hi every one,
I was wondering what every ones thoughts are on reloads that are very full of powder and get crushed or pushed down when seating a bullet.

I use an old Nosler reload Manual, My favorite over the years for a .308 win is IMR powder 4831 with a 165 gr. Nosler partition.

we have taken all North american game with these loads excluding Bison.

What happens is when reloading, I have some Federal brass, Imperial and Winchester. The Imperial is loaded right up the neck to almost the top, but the Federal is near the shoulder top.
I do keep them seperate from one another and have noticed no difference at the range.
Any thoughts on this as a possible problem or trouble??

Thanks in advance

CT
 
How much powder is in this load?

What is the water capcity of the 3 types of brass you have mentioned?

What is the final OAL
 
Ordinairly, I'd say that was cause for caution -- but with IMR4831 in a 308 Winchester, I doubt you could fit enough powder in the case to make over-pressure if you tried. If QuickLoad is correct, you'd need well over 52 grains of powder to get into any kind of possible over-pressure situation (and in my experience, 50-ish grains of stick powder is all you're likely to fit in a 308 before it starts running over the neck).
 
hey folks,
thanks for the replies.

Ok, bad by me to not state load capacity ... oops

I have had zero signs of pressure or over expansion ..... over hundreds of rounds over several years with various rifles.

My favorite load and best group of 1 1/4 inches at 100 yards 5 shots, (years ago, old and shaky now ) with 47 grains of IMR 4831, Federal Brass. 165 grain Nosler Partition Spitzer
I have used 49 gr. also but that over flows the Imperial brass I have.

I have never had any incident but sure don't like the full load casing look compared to down the shoulder area.

Just wondering what this does???

Thanks CT
 
With IMR4831 and 47 to 49 grains of powder, you are actually loading pretty light in terms of pressure. As I said, assuming QuickLoad's calculations are vaguely correct (and they usually are), it would probably take you 52-ish grans of powder before you could even get close to a 'max load' of 4831 -- and that probably wouldn't fit in a 308 case, no matter what you did. Generally speaking, most of us would think you'd want a faster burning powder in a 308 Win (Varget, Reloader 15, BL-C(2), or the like), but if you're getting accuracy you're happy with and knocking em dead with that load -- then there's no real reason to change I reckon.

So long as you're not seeing some kind of problem result from it (bullets working their way forward from the pressure, pressure signs, etc), having powder compressed isn't a bad thing at all. I actually kind of prefer it, since it means a perfectly full case, which for (possibly not rational) reasons seems better to me than having air-space in there.
 
The only powder I can think of that would have issues with compressed loads is IMR Trail Boss, which is designed to give burn rates similar to Bullseye while mostly filling cases like .38 Special or .45 Colt. With this powder, compressed loads run the risk of breaking the doughnut-shaped kernels, which can cause a dangerously high burn rate.

Otherwise, compressed charges are fine, so long as pressure isn't excessive.
 
It's called a compressed load. Nothing to worry about, but something is screwy with your powder charges. Check the lengths of your Imperial brass. It's old to start with and may have been trimmed too much at some time. The Trim-to length for a .308 case is 2.005". The case shouldn't be shorter than that.
 
Length is good, thats not it, I've had some of this stuff for many many years, kept it well and will likely discard after these rounds are done fireing off.

CT
 
When I was working up loads for my 9.3x62 using Barnes 286 TSX I couldn't get the 2400 FPS they advertised with boox max loads, only 2000. I tried going to a load of 4350 that was listed as the max with the old X bullet (remember, they were shorter and had no grooves). The load was so compresssed that when I tried to fully seat the bullet it stubbornly refused and the bullet stuck in the seating stem in the die! And I mean STUCK. It pulled the bullet back out of the case with it and I had to remove the stem from the die and pop the bullet out of it! :eek: I ended up seatign the loads using my 416 Rigby dies and the RN bullet seater (it stuck in the spitzer stem - even the 416 stem!) I was so nervous that I took a buddy to the range with me (I abhor shooting with people on the range) because I didn't knwo what might happen and I didn't fell like lying there waiting for someone to come along (could be a long time at the Inuvik Shooting Range). As luck would have it they were fairly sedate loads around 2300 FPS. That was when I realized a couple of things. First - I had a large chamber that was lowering my pressures and, second - I really didn't want to use the 286 Barnes TSX anymore. I switched to some 286 Norma RNs that Why Noy? graciously passed on to me and have been running a grain over max and 2350 FPS ever since. The only downfall is the damned thing kicks WAY harder at 2350 than it did at 2000.
 
I've done up compressed loads before. Nothing spectacular about them. Many manuals show them as knowingly being compressed. Just use your head. If the sides of the case starts to bulge or you have to stand on the handle of your press to get the bullet to where you want it.......well........like I said. Use your head.
 
Compressed loads provide more consistent powder burn. Like gatehouse says just make sure COAL doesn't grow. Measure them, leave them overnight and measure them again to be sure. Or use a jiffy marker on the ogive/neck so you can see if it moved.
 
curly top said:
Hi every one,
I was wondering what every ones thoughts are on reloads that are very full of powder and get crushed or pushed down when seating a bullet.

I use an old Nosler reload Manual, My favorite over the years for a .308 win is IMR powder 4831 with a 165 gr. Nosler partition.

we have taken all North american game with these loads excluding Bison.

What happens is when reloading, I have some Federal brass, Imperial and Winchester. The Imperial is loaded right up the neck to almost the top, but the Federal is near the shoulder top.
I do keep them seperate from one another and have noticed no difference at the range.
Any thoughts on this as a possible problem or trouble??

Thanks in advance

CT
Click to expand...


You cannot get enough 4831 into a .308 to cause a problem.
 
i think the original question was asking what happens when you hear that crunch.
Yes, you are damaging powder granules, and that will change the burn rate of the granules that are broken, by exposing more surface area, and reducing the coverage of the retardant coating. However, these are most likely just the top few in direct contact with the bullet base.
Too small a difference to be noticed over a full load of granules that are burning properly.
As mentioned above, the major problem with compressed loads is cartridge growth.
It's really only going to happen on severely compressed loads, and is more likely on un-crimped loads.
This may happen right away, but it's been my experience that it's more likely to happen after the cartridges have been handled a bit.
For the inexperienced, cartridge growth can mean that your bullet is jammed into the lands, raising pressure, or, that it locks up a tube fed rifle, because it's too long to feed.

If you experience difficult feeding with compressed loads, start measuring the case. You may find you've expanded it outwards.

Now with all those problems to watch for, I use compressed loads periodically. Just be aware.
 
Heavily compressed loads can normally be matched with lighter charges of slightly faster powder and still produce the velocity sought after and the accuracy desired. I dislike investing in the time it takes to make good consistent ammo when the powder charge is heavily compressed requiring a drop tube to get it all in the cartridge case.
 
The older load books do tend to give a few "C" Compressed Loads that you don't see in the newer ones.
Personally; I don't recommend them due to the nature of physics involved but wildcatter’s and the cannon group like to conduct their experiments, with a reverse onus to those scientists.
There are hotter powders available out there if the need for speed with kinetic energy is more desirable.
Whether you using a volumetric measuring or weighting to a 1/10 of a grain, it’s generally accepted to stay within the case dimensions and avoid the crunch.
I taken lumps and flames here for stating that in the past, but with any incidents hitting the media, almost always get sensationalized, or blown out of proportions, hurting our image, as a safe hobby practice.

Driller
 
Driller said:
The older load books do tend to give a few "C" Compressed Loads that you don't see in the newer ones.
Personally; I don't recommend them due to the nature of physics involved but wildcatter’s and the cannon group like to conduct their experiments, with a reverse onus to those scientists.
There are hotter powders available out there if the need for speed with kinetic energy is more desirable.
Whether you using a volumetric measuring or weighting to a 1/10 of a grain, it’s generally accepted to stay within the case dimensions and avoid the crunch.
I taken lumps and flames here for stating that in the past, but with any incidents hitting the media, almost always get sensationalized, or blown out of proportions, hurting our image, as a safe hobby practice.

Driller
Click to expand...

Thanks everyone for your opinions.

CT
 
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