Dents in cases


Well-Known Member
Morning all,

Through experience can some explain to us novice reloaded why cases slightly dent in the full size die when to much case lube is present? Will very all dents make that much of a differents? Should they be discarded or fired ?

Regards as always



Well-Known Member

I have dented a few shoulders. It is air pressure that causes the dents at the end of the downstroke. As the shoulder of the case closes against the shoulder of the die, the excessive lube stops the air escaping and dents the shoulders. I tried various lube methods and have returned to the RCBS lube pad. All I did with the dented cases is fired them off for practice and once fired, I couldn't tell them apart from any other case.

Good luck. JCS

Treacle Trackpad

Well-Known Member
Not quite correct JCS. One of the basic laws of hydraulics is that a liquid cannot be compressed, it is therefore the actual lube that dents the case, when it is under pressure from the die; it has nowhere alse to go and the brass is softer than the steel die so it's the case that gives.I would say that minor denting can be sorted by firing the load and will have no noticable effect on your accuracy, but you have to judge which are minor and which you are not happy with.


Site Staff
What i was told when i started reloading was that so long as the dent is not so large it will have an effect on case capacity (may affect pressure/rate of burn) or serious enough that the brass is 'creased' (could be fatigued) then they are safe to fire and the dent will pop straight out


Well-Known Member
well i have changed to a spray lube

now this will cause some raised eyebrows.

i use a silicon based spray and it works very well, in fact it is all i use now, the problem is its from lidls and every time i go to the shop and its come in someone has got the fin lot, so i found a replacement, that being 3 in 1 spray silicon based oil, works well but not as well as the lidls one.

i used the RCBS lub and mat and no matter what way i lubed the case i always ended up with the small indents to the shoulder of the odd case, since using the silicon oil based stuff all seems to be fine,

now i will wait here and see just how many people have thoughts on the oil im using.



Well-Known Member
Also to add remember to clean the inside of your dies occasionally which also helps remove dents as dies will start to build up with gunk/lube


Well-Known Member
Thanks for all your sound advice lads. I stripped down the dies today and gave them a good clean which i think will help. I used a cotton ear bud to coat the inside of the neck, this action helped with the press action. I think i was using too much Lyman lube on the RCBS tray in the end.

Any cases with very small dents in will get fired off and hopefully return to the correct dimensions.

Treacle Trackpad

Well-Known Member
TT. You're havering. The excessive lube traps the air in the shoulder section of the die.

Regards JCS
Havering??? Had to look that one up. Suppose we'll have to agree to disagree on who's babbling about this one. Excess lube causes the dent, not the trapped air.

Excess LubricantA common and obvious cause of shoulder denting is the application of
excessive lubricant before the case is run into the sizing die. When using a
high-grade case lubricant, such as our "Imperial Sizing Die Wax" or "Original
Formula", a light, even coat applied to the body of the cartridge case is all
that is necessary. The lubricant can be applied using your fingers or our
lubricant pad. Be sure to wipe the excess lubricant off the case shoulder and
neck area, leaving only a thin film remaining.

Lubricant can also build up over time in the sizing die body. Each time the
die is used, a new layer of lubricant is added. The lubricant then hardens
during storage and gradually builds up until the accumulation starts denting the
cartridge cases. Clean the die using the above recommended procedure to restore
the interior of the die.

Excess Sizing

...A popular misconception is that sizing dies need a "vent hole" to release air
or excessive lubricant. It can be easily demonstrated that a vented die will
also dent cases if excessive lubricant is applied to the cases, case dimensions
are not compatible with the sizing die or the case shoulder is being bumped


Well-Known Member
Whatever - whether it's lub build-up or trapped air, we've all experienced it (if you do enough reloading). I personally get round the problem by using a PTFE spray. I no longer get any dents and i can't remember the last time i cleaned my dies. I just load up the tray and then give the batch a light spray.

If i'm feeling anal, i may even give them a wipe with a rag afterwards.

I use this one:


Well-Known Member
There was a time when RCBS used to put a vent hole in their dies. I haven't bought any new RCBS dies so I don't know if they abandone3d the practice or not. I quit using their "case honey" lube years ago.~Muir


Well-Known Member
I use the wax lube and found a little goes a long long long way.Never had a problem yet. (Touch wood)
Yes done the messy lube thing years ago - now use Imperial Sizing Wax, had my small tin years and it is bearly half empty. Besides when wiping the wax off with a cotton cloth it actually shines up the cases - another reason why I never bother to tumble my cases.


Well-Known Member

The RCBS 25-06 dies I got off E-Bay USA has the vent hole but they were used. Now both dies are marked "91" so could that be 1991?

204 Ruger

Well-Known Member
I use a very thin amout of lube and rarely geta dent. If I do I flatten it and put it in my waste brass tin. Not worth re-using for the price of brass.