Can deeper bullet seating comp. for case over max. length?

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Why aren't we allowed to correct typos in titles?:scrutiny:

My Lee-Enfield .303 cases have a max. length of 2.22.

About twenty accidentally 'got through', were accidentally primed with a length which is up to 2.35 or so. Some are only 2.25 or 2.3.

Would it be safe to seat the bullets in these cases a tiny amount deeper than usual, or does this increase case pressures about the same extra amount, just as with having cases a little too long? My powder loads (IMR 4065) are at the minimum suggested: 38 grains for 147-grain bullets.
 
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Back to your cases.
So they are primed, can't you trim them anyway?
I've already trimmed the length of primed cases on my Forster Case Trimmer.

If pressure spikes are going to occur because your cases are too long thus wedging in the throat or forward chamber, you will get those spikes in pressure regardless of how the bullet is set, as we are talking a wedge-effect which is holding the bullet from freely moving out of the case mouth and into the barrel, if in fact, there is that problem.

Find a case that is longer than your longest case and try chambering it. Then pull it from the chamber and see if the mouth of the case has marks in the brass like it was jammed in place. If not, then most likely you are safe.
 
I personally wouldn't take the chance. Pull the bullets and start over.
If they are not loaded just go ahead and trim them. It's also possible
for a round to become stuck in the chamber without fully chambering
and of course that's when the extractor slips off. Then you have a live round stuck in the chamber. Don't get in that situation.
 
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As mentioned above it could be a problem. Your chamber dimentions might allow it, but why take the chance? Primed cases can be trimmed in the lathe-type trimmers. If you use the Lee trimmer you will have to deprime them. Just wear your eyes and ears (PPE) and go slow. I've re-used live primers that were removed this way, but only for range fodder.
 
Usually the Enfields have generous chamber dimensions, so you might be OK.
But on the other hand the Enfields aren't a really strong action(bolt with rear locking lugs), designed about 100 plus years ago.
To keep me on the safe side of things, I'd be willing to push out the primers and trim 'em.
 
The longer cases won't make pressure go up because the bullets are not "deeper" in the case in comparison to what counts, only "deeper" in relation to the case mouth. It hasn't changed the internal capacity under the bullet. The only issue is if the case moth is long enough to get into the throat/lands area and not have enough room to expand and release the bullet properly. Probably OK with generous chambers, but you don't know either.
 
" When an overlength case is chambered, the mouth or edge of the neck will come up against the throat before the bolt has fully closed or the case shoulder has contacted
the chamber. The camming action of the bolt is so powerful that it will actually crimp
the case mouth fully into the bullet.and wedge the case so solidly between the bullet and the throat that the neck cannot expand to release the bullet. Chamber pressures in
this situation can and MOST CERTAINLY WILL go dangerously high." Quote from
Joyce Hornady ( From Hornady Handbook #3 and #4 )
 
The longer cases won't make pressure go up because the bullets are not "deeper" in the case in comparison to what counts,
Click to expand...
+1

This is exactly right.

OAL or seating depth has nothing to do with short or long cases, as the OAL measurement is not taken to the case mouth. It's taken to the bullet tip or ogive of the bullet, depending on how fancy your OAL measuring equipment is.

As several people have pointed out, a too long case is a danger only if it hits the rifling leade at the end of the chamber and can't expand enough to release the bullet.
Seating depth has nothing to do with that.

rc
 
OYE said:
" When an overlength case is chambered, the mouth or edge of the neck will come up against the throat before the bolt has fully closed or the case shoulder has contacted
the chamber. The camming action of the bolt is so powerful that it will actually crimp
the case mouth fully into the bullet.and wedge the case so solidly between the bullet and the throat that the neck cannot expand to release the bullet. Chamber pressures in
this situation can and MOST CERTAINLY WILL go dangerously high." Quote from
Joyce Hornady ( From Hornady Handbook #3 and #4 )
Click to expand...
+1
In total agreement here.
Everyone else as well, it's just that this points out where there could be a catastrophic problem.
 
It may be useful for everyone to review a picture of a rifle chamber, with particular attention to the "step" in the chamber where the brass case mouth would end.
 
Thanks very much.

I'll certainly deprime them in order to grind the case mouths with the hand trimmer.
This bag of somebody's very old cases (of mixed origins) is the only/last group for me-no more.

Along with problems such as breaking two deprimer spikes etc they were not worth it, compared to boxes of new Prvi Partizan .303 ("PPY").
 
"I'll certainly deprime them in order to grind the case mouths with the hand trimmer. "

Decapping cases to lathe trim is not necessary nor even helpful unless you have a Lyman Accu-trimmer.
 
I agree. Just keep them level while trimming, and then tip them down to shake out anything laying in the neck. Same with deburring/chamfering, just keep them tilted and give them a tap or two when finished. You could always use some compressed air to blow them out as well.
 
I'm guessing you use a Lee trimmer or similar which necessitates an unprimed case.

Me? I'd take a sharp, flat file & trim the cases to just below 2.222" then chamfer & load.
Unless you're looking for ultimate accuracy I doubt you will notice which are the "hand trimmed" ones.
Just remember to check ALL your cases for length next time & trim them to 2.212".;)
 
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