OzFclass

Hi
Im quite new to the sport and looking for some information on the KM arbor press force indicator.
Im using 308 bullets with 2 thou neck tension.
Do i need to use the low force indicator or the standard indicator with the press?
Also what are peoples thoughts on using the arbor press to seat bullets and sort them in seating pressure. Im currently using a standard Redding Seating die in my press.
Thanks in advance

Way back now, I corresponded with a gut who designed a jig to measure unseating pressure. He figured that it might be more pertinent to seating.

I do have a K&M seater with the force dial but it doesn't get used very much. I found the springs were too weak for seating 7mm bullets, but does work well enough with 6mm bullets which are slightly easier to seat. I usually prefer a regular press now as I neck turn and anneal pretty much everything. Unless these presses are now coming with firmer springs, I dont think the will work so well with a 303 bullet.

Just some loose general advice for ya mate re this type of measuring and it's effect on your groups : I would consider it way down in importance. Yes it may help, as with MANY other small things a shooter can do but if you say spent a relatively small amount of money on a bore scope like a "Teslong" ( $50US ) so you could keep an eye on your cleaning regime and what is happening in your guns bore then that would help you a hell of a lot more.
It's a matter of working through what is most important to be focussing on ......

Are you new to shooting or new to fclass? If new to shooting in general, 90% of the accuracy can be had with simple lee equipment, spend every spare cent on ammo and optics until the equipment is limiting you, all the minutia is for refining the very last points to be had and increasing the numbers of mental asylum inpatients (don’t ask me how I know this ) take the low hanging fruit first
Charge weight consistency, consistent primer seating and seating depth will get you most of the way, that being said I totally understand how enticing the catalogues are, just get one of everything

Thanks very much everyone for the advice, much appreciated. Ill definitely save some money and not go down the rabbit hole lol I was just worried with my Redding seating die I wasn't getting the accuracy I needed because its not a micrometer type. Ill definitely look at getting one of those borescopes though. Will be very interesting to see if my cleaning regime is up to scratch. Thanks again

If variable seating force is bad enough to be a serious problem, you'll definitely notice it with a standard arbour press. What you do about it is the same. You look for the problem and fix it, or if its not really bad you might just put the abnormally light or heavy seaters aside, and use for sighters/foulers (or short ranges ).

chinga wrote:Thanks very much everyone for the advice, much appreciated. Ill definitely save some money and not go down the rabbit hole lol I was just worried with my Redding seating die I wasn't getting the accuracy I needed because its not a micrometer type. Ill definitely look at getting one of those borescopes though. Will be very interesting to see if my cleaning regime is up to scratch. Thanks again

micrometer dies are no aid or otherwise to accuracy.
they do however make adjustments easier.
do not however think that 0.001 on such micrometers is in fact 0.001".
they are not very accurate.
they will however get you close easier than a non micrometer.
bruce.

i have often wondered how much difference seating pressure affects accuracy on paper.
the reason is that differences here might well be negated by case neck obturation on firing.
unless the primer overrides this?
the same suspicion goes into measuring release force.
you might be measuring something that is irrelevant.
here we go back to the old jam the bullet method having advantages, even though it has gone out of fashion in certain circles.
even there, usually a good load will shoot well with anything from say 0.008" to 0.015" jam
bruce.

My suspicion is seating pressure really effects really come down to projectile deformation, better finished neck internals mess up the projectiles less, I personally like the sliding chamber seaters, not so much the micrometers, however they tend to go together

Rich4 wrote:My suspicion is seating pressure really effects really come down to projectile deformation, better finished neck internals mess up the projectiles less, I personally like the sliding chamber seaters, not so much the micrometers, however they tend to go together

I used to think just the same way but after a few stuffups in the loading room, pulling projectiles, reseating them, sometimes re neck sizing sometimes not, and seeing absolutely no difference on the target, I changed my mind.
I don't think much of it matters any more. The bearing surface gets a pretty hard time running down the barrel. I wouldn't go at it with a dremel or anything, but a few scratches?
Damage to the boat tail, that's a different story.

chinga wrote:Thanks very much everyone for the advice, much appreciated. Ill definitely save some money and not go down the rabbit hole lol I was just worried with my Redding seating die I wasn't getting the accuracy I needed because its not a micrometer type. Ill definitely look at getting one of those borescopes though. Will be very interesting to see if my cleaning regime is up to scratch. Thanks again

The key to seating is not pressure but ultimately consistency of seated depth....you can measure that...micrometer dies make it easier to nudge bullets in.
Basically when seating you have two v shaped surfaces pushing against each other, they have a tendency to slide over each other rather than come to a fixed point every time.. This coupled with any change in friction or speed of movement, dwell time or ogive shape will give you small but important differences in one bullets seated depth to another.
I'm not saying that seating pressure consistency isn't important. I do think it has a lower impact on precision than seating depth consistency. I would put my money into measuring depth...this is what I have done anyways.

wsftr,
you raise a good point.
when seating bullets with an arbor press it is easy to feel differences in seating pressure, and batch the ammo into harder to seat and easier to seat lots.
you don't need a gauge to do this.
invariably, the harder to seat lots have a slightly longer coal.
maybe 0.001" to 0.002".
i was putting this down to the possibility of the cases springing at the shoulder more when you seat the tighter ones, and then springing back for a longer coal.
your explaination of how it could happen is a more plausible one.
this is not a big problem when (if?) you discover it, as you can then do something about it.
those who prefer light neck tension will notice it less than those with more neck tension.
i am lucky with a current barrel, in that anything between 0.008" and 0.015" jam piles them into the same group given a correctly fouled barrel.
here we come to another issue, namely barrel cleaning.
sooner or later you are going to have to deal with carbon fouling or you will have a monkey on your back like you would not believe.
keeping these things all in balance can be a challenge, but a worthy one.
bruce.