Home Forums Reloading Big Game Rifles Ever had ammo "grow" on you ?

I had some 30'06 loads do just that on me.
I had prevfiously tested some 58-59 gr. charges of H4831SC over the 200 gr. Nosler Partition. Having found that both are pretty accurate on consistant basis, I decided to see how hot they were. Since my usual procedure is to load them until I get any kind of pressure sign on a hot day, then back off a full 5%, I loaded up some 60-62 gr. loads. All of which I tested at 3.32 inches COL.
My first surprise was that they didn't come out at that lenth when the powder is compressed much. But eventually I did get them to that lenth by setting the die shorter than the non compressed loads needed. Only to have to redo the 61 gr. loads even more.
Two weeks later, they'd grown again. Managed to jam a bullet in the throat so bad that I needed a block of wood to open the action. Out came the case and the loose powder, but no bullet.
Good thing I didn't try to shoot the gun clear with the bullet jammed in the throat. I understand guns have blown up under such conditions. Furthermore, I was informed that if I insist on shooting heavily compressed loads, I should load them the night before because over time they will grow. Sure enough, my 61 gr. loads had gone from 3.320 to 3.326 inch loads.
The moral of this story is no more heavily compressed loads for this shooter. E

what powder was you using i would guess one of the 4350 how fast was the 200 gr bullets going with 58-59gr

Oops, I forgot to mention that. I was using H4831SC. H4350 won't give me 2650-2680 fps. E

E--- have experienced the same problem with "partitions" and "triple shocks" in compressed loads for the 260 Rem. .Tried polishing the expander ball to clean up any residue and also double cleaned case necks to be sure no sizing lube was lurking. All to no avail.

Have you tried, or thought about trying, the Lee Factory Crimp Die?

Had the problem using RL22 in one of my sons' '06. Had his formed brass, carefully put loads together for great accuracy with about .002" shoulder clearance and shipped the reloads to him. The bullets didn't come out but the shoulders swelled where they wouldn't chamber. They did before I turned them over to him but they "grew". I've also had the bullets push out. In every case it was with RL22. Incidentally, that was 62g of powder. Pretty compressed.

I've also found that heavily compressing loads is often bad for runout as well.

If you're having to compress that much try a few charges of 4350 instead.

If you want to use loads like that, one way to get the powder to fit is to begin seating the bullet into the neck; then holding the case against the side of a vibrating tumbler for a few seconds to help align and settle the powder before fully seating the bullet. I've built loads which were so compressed that the case was swelled by the seating of the bullet (and had trouble with growth after seating). I've been able to assemble the same loads by vibrating the powder after partial seating so that the loaded cartridges easy fit the chamber (no case swelling) and the case length on the leftovers has not grown even after several years.

I will not hunt with ammo whose bullets are very close to the lands or has cases which have anything even close to a slight crush fit. There are way to many other things to worry about without worrying about ammo not being reliable. YMMD.

Had some 308 loads with moly'd 208 AMax over compressed W760 grow overnight, from 2.95" to 3.00". The moly will let that bullet move much easier.

I quite agree. No compressed loads and I'm going to seat these bullets a little deeper as well. I'll also recheck any loads I do for both lenth and function.
I used to run every round I'd take into the field through the action. Got lazy and started just spot checking them. Maybe I should go back to doing that as well.
Thanks for the feedback guys. E

If you're gonna compress the powder so much, you're gonna have to start crimping your bullets.
According to Lyman's 48th, you can get 2600fps with 4350???