No.do i actually need a head space gauge??
Fast forward to 00-47:
K
No.do i actually need a head space gauge??
Chelmsford EssexWhere?
All H and h tolerances nowadays.
I have lent my set to a toolmaker here who is just starting out to make himself a copy of my set, he has 3 cnc high end lathes and millers etc so knows his stuff, would there be a market for a cheaper knockoff "asking for a friend"not feeling clever, or brave enough to be poring anything into my chamber
i will just order the OAL gauge and bullet comparator then, watched a few youtube videos on them, i recon i can make good use of them, thinking of buying the flat anvil too to make the measure easier, only £20![]()
No.
Fast forward to 00-47:
K



Length of the trimmed brass won't change COAL, it only changes how deep the bullet is seated in the case, which changes the pressure, velocity and the POI.my trouble is i want to know everything on day one, i do absorb some of the info and advise im given, and it does come back to me at certain times when needed, and its all here in black and white for me to revisit when i need to, im just trying to stick to the fundamentals at the moment, today iv been making another 40 round up with the N-133 powder, id trimmed my cases a few days ago, got the trimmer set up and trimmed them all all , set my seating die on the first one but after that was getting inconsistent measurements, so started checking my brass and it was all over the place, some 1.750 some 1.740 and 1.760, iv also had problems with the powder measurements, this time i did it on my digital scales, did all the different charges, and when i was done i tested some to see if they were the same, not one was the same, and measured something different every time, so i emptied all the cases and used the balance scales, then when to check each one on the digital scales, all between 0.1 and 0.6gr difference, so just stuck with the balance scales, yet the digital scales were always at zero when i put the powder on, got done in the end though, and hoping to test them tomorrow.
theses are then changes i want to avoid, so i need to get my CL right so everything else can be right, comparator and OAL gauge ordered, should be here for my next concoctionLength of the trimmed brass won't change COAL, it only changes how deep the bullet is seated in the case, which changes the pressure, velocity and the POI.
If your using soft points the length of the tip varies, hence my point about using a comparator.
Beam scales are the way to go initially, cheap digitals drift.
Interesting and thought provoking,So I've just measured some 6.5 bullets for accuracy of o/a length:-
Accubond with a polymer tip, max variation over 10 bullets of .0025"
Yew Tree with an aluminium (I assume) tip, max variation over 10 bullets of .0005"
From the quick drawing I've done to approximate a 6mm Nosler BT, with an eccentric bullet of only .002", means a contact variation at the ogive of .013"
Loading with decent kit, RCBS and good brass, Norma, using good bullets, Nosler, I found that eccentricity up to .003" or even .005" was common. I concluded that when the bullet leaves the case and moves down a degree of free bore, eccentricity of these dimensions are irrelevant with the bullet eased into the rifling in a short distance and then travelling down a long barrel. Eccentricity measured at ogive will always produce bullets further from the land than planned, therefore you could say safer as athough the bullets I measured for o/a length are quality and therefore accurate, maybe there are bullets out there that are not so good.
This was the reasoning that although I have a precision mic for measuring to the ogive, I no longer bother as hunting ammo is more than capable of being produced by measuring the arguable more accurate o/a length. The OP I believe was interesting in loading within a budget and hence the reason I do not believe he needs to invest in precision micrometers.
Just answered you on Niche reloading topics to avoid derailing this one. Yes, there is an interesting tolerance stack here.Interesting and thought provoking,
Query is that SP are far less uniform than BT, and even those can vary, I've had some Nosler BT that varied by 0.01" bullet length and A Max that varied by 0.015".
if the COAL length to the Ogive varies due to runout variation, surely the further from the neck the greater the variation?
Compounded by the lack of consistency in bullet length, the length at the tip will vary even more according to the orientation of the the base of the cartridge to the tip of the bullet when measuring COAL, so if the cartridge is rotated through 360° the length will surely change even more?

well at the moment im leaning more towards the V-max, and i am going to get some blitzkings and try them, what were your findings with the soft point?i gave up on soft point bullets thirty years ago a waste of time and energy, i use berger bullets they are so consistant, but its a pity tikkat 1x cant find someone where he lives, to show him the ropes, but he will get there in the end we are all with you matey, but i will say one thing if you are going to measure a bullet or loaded round measure from the ogive![]()