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Forum Index > Rifles general discussion > inside case neck too clean?

inside case neck too clean?

08 Oct 2012
@ 04:01 am (GMT)

jason brown

iv brought an ultrasonic cleaner.
im using a product that is free to me, in the industry i work in, where the active ingredient is lactic acid.
iv tested it on twice fired brass and after four or so full cycles, im happy with how clean they are. (i really just went this way to be able to clean the insides, without tumbling)
iv rinsed them in dish water after, and havnt seen any ill effects/reactions feel free to comment...
anyway... iv heard that these can leave inside case necks too clean?
as in dry and maybe inconsistantly hard grip on a projectile. and lube was recomended. just not what to use.
which makes me wonder wouldnt using a bore brush in the necks be a similar situation...or maybe solve mine...
would powdered graphite be good to use in the necks, with no problems reacting with powder. or maybe use it to lube the projectile before seating?

any comments on cleaning etc welcome.


08 Oct 2012
@ 08:51 pm (GMT)

Jim Moseley

Re: inside case neck too clean?
Clean is fine...dry is not. When sizing the case you need to use something like Imperial die wax or you can use ONE Shot Lube. I use a Q-tip to put the lube in the case neck for sizing and for bullet seating. If using a Lee Collet Die, no lube is need for the neck sizing. The Lee Collet die is cheap and very accurate. Mine runs about .0015 runout which is better than my Reddening Competition die. Hope this helps.
10 Oct 2012
@ 01:06 am (GMT)

jason brown

Re: inside case neck too clean?
are you saying you lube for sizing, and reapply for seating. or.. the lube you use for sizing leaves enough left after sizing, to assist seating as well.

10 Oct 2012
@ 03:44 pm (GMT)

Nathan Foster

Re: inside case neck too clean?
Hi Jason, what you are talking about can become a very indepth subject. What we are primarily concerned with here is neck tension.

Increasing neck neck tension generally helps lower ES (extreme velocity spread from shot to shot) which can aide performance at long range a great deal. There is no point having a .250" load with a 100fps ES as in some instances, this will result in a vertically strung group of around 1 yard at 600 yards- ugly.

As we introduce lubes such as powdered graphite, we decrease neck tension. It is therefore important to make sure our reloading dies are set up in such a way as to mechanically increase neck tension in order to control the powder burn and keep ES low.

It is worth noting that if the case necks are lubed with graphite, this graphite will be transferred to the throat after ignition, helping to minimize friction and wear.

If you tumble the projectiles in graphite, you will achieve the same results as tumbling in moly. The two compounds are so similar, honestly, graphite is really just a cheaper, readily available compound.

If you tumble projectiles in graphite, you may have to do this continually because the reduced friction will effect hand loads entirely, reducing velocity, changing the POI. Throat life will be increased through this process, thereby increasing barrel life. But this does not mean it is a magic fix. The graphite (or moly) may have a negative effect on accuracy in your particular rifle. So whatever you do, make sure you do the same thing every time you reload ammo.

Both graphite and moly are also hydroscopic so you will also need to be vigilant about bore protection, even though you have a stainless barrel.

You will be able to tell if your clean dry brass has too much friction as seating projectiles will be very difficult. The seating process may shave copper from the projectile and marr its surface. Much will depend on your current reloading dies versus the diameter of the expander button.

I have really only touched on the subject here. Its one of those things where you could expend a couple of hundred rounds performing experiments to see what works and doesn't work. Hopefully the above info is straight forwards enough to offer simple solutions.

When we neck size using graphite, it does tend to put a partial coating of graphite on the projectile and has a positive effect on throat life and in some cases, an improvement in accuracy. I believe some of the accuracy increases we see with neck sizing, especially in rougher factory rifle bores, comes as a result of the graphite, not the concentric alignment of neck sized ammo versus full length sized ammo.
10 Oct 2012
@ 06:14 pm (GMT)

jason brown

Re: inside case neck too clean?
ok, i see where your going. and it does start to get technical.
i think i will just keep it simple and after cleaning cases use a bore brush to even them all out. then just seat them as normal, unless seating gets hard.

when you work a load for someone, what do you do to clean the inside of the necks?
as in what should the customer do when he copys that load you have made for him/her...

the problem is i have too much time on my hands to think about these things waiting for my barrel, haha.
10 Oct 2012
@ 07:06 pm (GMT)

Nathan Foster

Re: inside case neck too clean?
I don't do any case cleaning inside the case. I simply do not have the rifles here long enough to have any problematic build ups inside the cases.

If I am neck sizing, I use graphite and leave surplus graphite in the case neck- then inform the client that I have used this process.

If FL sizing, I lube with lee on a cotton bud, then swab dry afterwards.

In my .308, I am on my 4th barrel, using the same batch of brass I started with few thousand rounds ago. the cases have never been cleaned on the inside, I really 'should' do something about this one day. No doubt my ES will go out the window one of these days due to carbon build up.
10 Oct 2012
@ 09:29 pm (GMT)

Jim Moseley

Re: inside case neck too clean?
Interested in the negative side of moly coating bullets. On the Hart barrel site, they state that if you use moly, they will no longer warranty the barrel. Just curious.
10 Oct 2012
@ 10:13 pm (GMT)

jason brown

Re: inside case neck too clean?
well nathan, you sure got your moneys worth out of that brass.
i think i remember you saying something along the same lines with 7mag brass.
it does go to show cleaning and the little extras in reloading can be over rated.
a little bit of topic, but i read somewhere of a guy making a case neck length gauge...
he took a fired case, squared off the mouth. then cut the neck in half... so hes left with a case with a short neck and a ring looking piece. (the other part of the neck)
he then used something, i cant remember what, maybe it was a projectile backwards.. and sliped it into the case, with the ring part on the outa end of the projectile.(or whatever he used)
he then chambered it into the rifle. as he did this the ring part slides back when it hits the end of the chamber.
so when he ejects the made up round, he has a measurment of max case length.
so once the measurment is sorted he can possably leave the necks to grow, and can trim at a longer, closer to his chamber specs length. (he subtracted some amount off the measurment, so it was still safe to fire)

i cant remember what he was trying to prove, but we do seem to taylor every other measurment to our own rifles. maybe he was trying to help with contricity. or work the case less.

is this something to play with on a rainny day, or just another thing that doesnt really prove much... ?
11 Oct 2012
@ 07:10 pm (GMT)

Nathan Foster

Re: inside case neck too clean?
Hi Jim, moly has two problems, the first is that it is hygroscopic so it will grab any moisture in the air. The second problem is that its a sulphate (salt). Put the two together and there is a risk of corrosion in both chrome moly and stainless bores. Bore preservation is a key factor here. Light oils in the field (to be shot over), heavy oils during storage. You can see how Hart don't want to go down that route, its impossible to control maintenance procedures once the barrel is sold.

Powdered graphite is also hygroscopic but does not contain a sulphate. This lowers the risk of corrosion slightly.

Jason, you could play with that if you want to. For me, using my .308 as an example, I fire so many rounds that I don't want to have to muck around with case trimming on a regular basis. To this end, I simply trim my cases shorter than normal trim specs. This allows me to use the case several times before re-trimming. Accuracy is uneffected.

You can just get away with this with your 7mm RM, even though the neck is already very short. Going the other way, if you took the time to measure your chamber as you described, you could save trimming operations if you find out that the chamber is quite long. The premise is very sound. In a long chamber, it would help optimize concentricity for accuracy, minimize carbon caking/fouling in the chamber (area of the case mouth) which helps lower ES and save time reloading over a long term.
12 Oct 2012
@ 12:14 am (GMT)

jason brown

Re: inside case neck too clean?
ok. im not sure if im going to get that carried away. but you never know one day. i was mostly interested in what you thought.
i do remember now. it also said something along the lines of... if you do the extended neck thing, you need to be careful your chamber is allways very clean. as if it got too dirty, it would be like having too longer case, once the case was chambered against the crud, being unsafe.


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