Seating long bullets deep?

[Dave R]

Help me understand any risks associated with seating long bullets deep.

I loaded some .223 last week with 55gr. Nosler Trophy Grade bullets. Used 24.2gr of H335. That's 1.1gr under the max load listed on Hodgdon's website. Shot great in my rifle, but I had seated 'em too long to fit in the magazine. No pressure signs.

I ran another short batch today, and seated 'em short enough to fit in the mag.

OAL of the round is 58mm.
Bullet length is 21mm
There's 13mm out of the neck so...
There's 8mm in the neck.
That puts the base of the bullet about 1mm above the start of the shoulder.

Its about 2-3mm deeper than the 1st batch. Do you think I'll have any pressure problems at that depth, being 1.1 gr. under max load?

 

[P95Carry]

IMHO ....... with a sub max load ..... very unlikely to have pressure problems ......... the performance of the round will tho be slightly altered .... but probably at a subjective level difficult to see. A chrono might show a marginal change.

Bearing in mind the capacity of a bottle neck case, even small like .223 ... the small difference in ''free space'' is in percentage terms very minor, relative to the powder charge which probably all but fills the case. Theory would dictate a marginally higher pressure peak ..... but as said, I'd doubt very much here you'd see any troubles at all..... certainly nothing there that smacks of risk to me at all.

Inspect cases however as soon as fired ... just to be safe.

 

[saands]

Not that it is always a perfect predictor, but the QuickLoad simulator shows a bump of only 2000 psi as a result of seating 2mm deeper with that load. If you were nearly filling the case with the first load, it might be more drastic, but it looks like you are not. Small volume, straight walled pistol cases are a LOT more picky about changes like this one ... for example, my 200 grain 45acp load doing 1000 fps at a predicted 20,200psi jumps to a predicted 31,800 psi if I seat it 2mm deeper ... and I'm sure it is even more dramatic on the smaller pistol cases that are even shorter.

Saands