Interesting finding with Hornsby elec scales

[TassieTiger]

So, I’ve been talking behind the scenes Re some strange anomalies I obtained from some recent 300win FPS results and after getting to the bottom of the issue, thought it might help others - thus this thread.
Recently, I tested a few 300 loads - 4gns over max book recommendation and I used a calibrated and working chrono. Thing was, 69gns was sometimes reading faster than 72gns and well - you can imagine accuracy was a bit hit and miss as a result.
Now marksman showed me a brilliant video RE case pressures that might have explained some of the strangeness but we both agreed that scales needed checking.

I recently dropped off my scales to a pro weights and measure service and I explained my issue.
Long story short - these $398 elec scales have a .4gn PLUS or MINUS variance at the approx 70gn measuring point. This tolerance lessens with smaller quantities and increases with larger weights...
As explained to me - the issue is a basic design flaw in the way there is stiction points across 2 difference paths before the scale (cup plate slides into a holder and then pressure plate itself can hang up), and this stiction will change depending on temperature etc.
This means that if I was reloading over say two days, of diff temp, I could be .8gns different...at 300win loads, not really good enough in anyone’s book.

The pros recommended that if I wanted to continue using “these” scales (they really didn’t like them nor their design and said this is far from unusual with reload scales)), then I should employ balance scales as a check, or a calibration set of weights that are utilised regularly while reloading or purchasing a proper set of top end scales that are checked professionally on a regular basis (they showed me a Set, can’t recall name, but were $1400, so I drifted off lol)...

I naively thought $400 was a decent spend for elec scales, especially when you can buy pretty accurate drugiie type units for $30 - but apparently not.
I’ve a cheap calibration set of weights coming and the pros are going to check weigh down to .1gn free of charge so I’ll know within reason how far out my scales are reading...
FYI.

[sungazer]

Yes IMHO scales are the most important part in the reloading system. I now have a set of those high end professional type scales but before I had these, I bought a set of Chinese electronic 1mg resolution 0.02grn. That 1mg is of course the resolution and not the accuracy. I ended up having about 3 check weights 2 of those were just projectiles but those two projectiles lived with the scales and I knew the weights of them. They were also in the range of loads that are normally dispensed. for example a 40grn 22 cal is about 2.6 grams 60 grn 3.9 grams and a 155 grn 10.052 grams and a standard 100 gram weight.
You need to learn a bit about your electronic scales as well for instance the sampling time/ averaging and as Tassie said Stiction, liniarity and sensitivity which is not resolution in some digital measuring devices extra digits can be added to make them look better than they really are in reality you are better off putting a pice of paper over the last digit or digits.
I found that by trickling up and always up not taking grains off that by going very slowly and always stopping at the point when the last digit increased I could get good results. Provided that I carried out the calibration often and corrected zeros for drift often. This is what you dont have to do with more expensive name brand scales.

I would still have the cheap $60 Electronic scales over the medium priced balance scales used for reloading anyday though both for speed and accuracy.

The balance scales are not free from their own sources of error Stiction being one of those as is temperature the list is quite long for both electronic and balance depending on the accuracy you wish to achieve.

[SCJ429]

Even if your scales were out plus or minus .4 of a grain Tassie, it still does not explain why 69 grains was faster than 72 grains. When you do a ladder test you can plot the increase in speed even with small 0.2 grain increases. The speed always rises.

Best advice is to resize your brass as little as possible. Use a balance beam scale if you are looking for nice consistant powder charges. Remember that seating depth also changes the available space inside the case. This will also effect the speed obtained.

[Stix]

Interesting...
Ive not spent money on scales for that reason--i just use cheap beam & elec scales & double weigh each charge while continually zeroing the scales through a session.

I too constantly get stupid differences in velocities & dont know why...i have no doubt my scales dont help here, but i get the impression neck tension is my biggest enemy..

What is the video Tas...?--the same one you put in the brass thread i posted or a different one...?...(just finished watching that...thanks)...

[sungazer]

Actually I should qualify my previous post. I think you really need to think about what you want to achieve. To the point of perhaps putting it on paper just so you can see it think about is that what you really need. If possible even quantify if it put down some specs that will suit your needs.

On Tassies case I have seen from working up loads there is a point when the fps gained per grn of powder is no longer linear and you can end up trying to squeeze quite a bit more powder in for little gain in fps.

What can also occur is if you seat the bullet lower into the case on a 69 grn load than you do on a 72 grn load the pressure may be greater in the 69 grn load resulting in a higher velocity. Once the bullet starts moving forward the pressure drops and if there is still powder to burn getting pushed out with it even if it burns way down the end of the barrel you probably didnt get any fps for it.

[TassieTiger]

Interesting...
Ive not spent money on scales for that reason--i just use cheap beam & elec scales & double weigh each charge while continually zeroing the scales through a session.

I too constantly get stupid differences in velocities & dont know why...i have no doubt my scales dont help here, but i get the impression neck tension is my biggest enemy..

What is the video Tas...?--the same one you put in the brass thread i posted or a different one...?...(just finished watching that...thanks)...

Yes mate - same video. I’ll link again for others - I can’t take credit, MM sent it to me. It’s bloody good.
On the same day as the 300 weird happenings, I watched 223 development, slowly increase FPS per .2g as per SC advice.
This is why the 300’s were so confusing - but it’s a sliding scale of inaccuracy. Loading 120gns would be 1gn error...

This video helps explain some differences in FPS if everything else was ok...and has really opened my eyes.

https://m.youtube.com/watch?v=Md50fFCeQJE&t=316s

[marksman]

I'm very glad you got a result Tassie sounds pretty farked that does doesn't it sry

IMHO consistency is everything when you want precision
so you want everything exactly or as close as you can the same, I believe there is always a fudge factor but try and minimise it

consider .8 gr powder different as well as internal volume may be different because sizing is erratic or the cases are not fully formed to your chamber and the bullets may not be the exact same form so they do not seat exactly the same depth
each of these things will cause different pressures so different velocities which means bigger groups, no consistency pressure is velocity
I think the challenge is to become proficient at all different stages of reloading, every step

in the vid Tassie has posted up the guy shows the difference in velocity when he sizes one of his chamber formed cases down 5 thou and records velocity, this round even though only bumped 5 thou shot 30 or so fps faster than the cases that were internal volume sorted, at 100 it probably would not matter but take it out a bit further and it really does

I like the balance beam scales and really you can check the calibration yourself by weighing a bullet but put that one aside and only weigh that one

at least now you can correct that

[SCJ429]

I think the challenge is to become proficient at all different stages of reloading, every step
drinks:

I am learning every day and still manage to stuff things up, so I am not any sort of guru. To become proficient at every stage you should first try to limit your input into the process. If you are worried that you are bumping the shoulder inconsistently, try not bumping the shoulder at all. If it is hard to apply a large amount of neck tension consistently then try a die where you can adjust the tension. It is easier to apply low amounts of tension than large amounts consistently.

I do not like expander balls in sizing dies, they often increase neck runout.

For Stix, try reloading your Nosler brass without sizing at all. Once fired brass will have enough residual neck tension from spring back, to hold the pill. See if you get better groups from no sizing. If you do the resizing process is costing you accuracy.

[Stix]

I think the challenge is to become proficient at all different stages of reloading, every step
drinks:

I am learning every day and still manage to stuff things up, so I am not any sort of guru. To become proficient at every stage you should first try to limit your input into the process. If you are worried that you are bumping the shoulder inconsistently, try not bumping the shoulder at all. If it is hard to apply a large amount of neck tension consistently then try a die where you can adjust the tension. It is easier to apply low amounts of tension than large amounts consistently.

I do not like expander balls in sizing dies, they often increase neck runout.

For Stix, try reloading your Nosler brass without sizing at all. Once fired brass will have enough residual neck tension from spring back, to hold the pill. See if you get better groups from no sizing. If you do the resizing process is costing you accuracy.

No sizing---you mean on the first firing of the brass...?...or subsequent firings...?... ...because the neck will need sizing after the first firing...

[SCJ429]

After you have fired the new brass, it will come out of your chamber nice and straight. It should still have enough neck tension, just pop the primer out without sizing the case and reload. This will only work for one or two reloads and the brass will work harden and not have enough spring back to hold the pill.

[Stix]

After you have fired the new brass, it will come out of your chamber nice and straight. It should still have enough neck tension, just pop the primer out without sizing the case and reload. This will only work for one or two reloads and the brass will work harden and not have enough spring back to hold the pill.

I fail to see how this will help me...?
Im not being smart...rather, i guess im asking...

Here's how i see it...
To my mind, the very first firing will for sure have different neck tension between cases due to out of round necks...
The subsequent firing will possibly have a more consistant neck tension,, but there after (the following load) it will change again (from having to be sized)...so i wont get any conceivable consistancy until the third firing & after...

Again, im not being diffucult, im just not sure what, & want to know what you're suggesting this will acheive...

[sungazer]

Sorry for off topic this really should be in the resizing thread rather on a Scales thread. Plenty of discussion on scales can be had.

Depending on what cartridge you are reloading you may need to employ different process. The brass is typically the most consistent for neck tension and all other parameters after the first firing. This is as long as the brass was actually smaller than your chamber (the other thread on fire forming) you can not bump a shoulder back by fire forming. With you firing pin removed and you ejector removed your bolt should drop freely on an empty case or just stop at the very last part of closing.

After the second firing you have options to neck size or FLS and depending on brass and the cartridge (some cartridge sizes seem to work harden much quicker) you may need to anneal no matter which way you resize the brass.

if you are able to adjust your FLS die either by screwing it out or using a thicker shell holder you can minimize the amount you resize the brass again aiming for the bolt just to stop short of freely dropping all the way closed or all the way if there is a very small increment from not dropping to dropping. This will mean you are not working your brass to much and the FLS depending on die not working the brass too much.

A FLS die that has an expander ball tends to work the neck more than a well sized bushing die.

Hope some of that makes sense. There is certainly a lot of options on resizing all with pros and cons. Hence all the different equipment and opinions.

[SCJ429]

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I fail to see how this will help me...?
Im not being smart...rather, i guess im asking...

Here's how i see it...
To my mind, the very first firing will for sure have different neck tension between cases due to out of round necks...
The subsequent firing will possibly have a more consistant neck tension,, but there after (the following load) it will change again (from having to be sized)...so i wont get any conceivable consistancy until the third firing & after...

Again, im not being diffucult, im just not sure what, & want to know what you're suggesting this will acheive...

Your brass came out of your chamber perfectly straight, no sizing ensure it is still straight when you put the loaded round back in.
The no sizing of the neck ensures very light neck tension, if the tension is different between cases it will only be slightly so. These things gives you the best chance of shooting a decent group. Only the variation of the brass will add to your Standard Deviation.

[Stix]

.

I fail to see how this will help me...?
Im not being smart...rather, i guess im asking...

Here's how i see it...
To my mind, the very first firing will for sure have different neck tension between cases due to out of round necks...
The subsequent firing will possibly have a more consistant neck tension,, but there after (the following load) it will change again (from having to be sized)...so i wont get any conceivable consistancy until the third firing & after...

Again, im not being diffucult, im just not sure what, & want to know what you're suggesting this will acheive...

Your brass came out of your chamber perfectly straight, no sizing ensure it is still straight when you put the loaded round back in.
The no sizing of the neck ensures very light neck tension, if the tension is different between cases it will only be slightly so. These things gives you the best chance of shooting a decent group. Only the variation of the brass will add to your Standard Deviation.

I get that part of it--that will be good for that firing......but what are your suggestions for the subsequent loadings...the cases have to be sized at some point which will change the neck tension, which will change everything...
Am i missing something obvious...

[SCJ429]

If the no sizing shows improvement then I would go with a bushing neck die or a collet die. If you see no improvement, then I would look at the bullet, try batching them.

What size scope are you using on your 204? What bullet are you using? What groups is it producing?

[marksman]

it really depends on the neck size in your chamber if you could seat a bullet without sizing, some are ridiculous in being oversize and the bullet would drop through the case neck in these
I have 2 fitted neck custom chambers that do not require sizing for reloading but they are not for the faint at heart,
if I do not do my job correctly pressures will be high but the benefit is perfectly straight cases for that chamber, no runout

where you get crooked neck's is from sh!t made brass that is way thicker on one side and stays bent like a banana, expander dies pulling or pushing necks crooked when sizing, seating bullets that need too much force to seat and dies that are not set up correctly
this is why I look for good cases and go through a lot of prep to make good cases, even the expensive ones, I dont like expander buttons but if I have to use dies that have them I do not lock the lock ring on the die so that it can wobble straight when sizing, I polish the inside of my case necks for a smooth entry and exit as well as have no more than 3 thou neck tension, usually 2 thou or less so no crooked necks from seating bullets and a clean release

by shooting a hard to chamber round in your chamber you dont bump back the shoulder, it makes the case form to the chamber so it will fit easier
try a round that is not fireformed to your chamber and the bolt is hard to close then after firing try chambering the same case, you will be surprised it will fit easy

these are things that work for me anyway, it's not for everyone OCD

[Stix]

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I

:

Thanks for the input gyts...
Not really sure how this morphed over into this thread...

If the no sizing shows improvement then I would go with a bushing neck die or a collet die. If you see no improvement, then I would look at the bullet, try batching them.

What size scope are you using on your 204? What bullet are you using? What groups is it producing?

Righto...now i getcha...

Firstly...the rifle is new & unfired...

a 5-25x50 is the plan for glass--although i suspect that scope to be faulty so ill probably start with a 4-16...then switch back to test the 5-25...

Bullet...ive got 32 Zmax, 34 Nos shots, 32 Nos Varmegeddon, & 40 Vmax...
I may buy the Speer 39's, but probably not just yet...ill see how these others go...

The 40gr Vmax shoot very well in my other one...
But Im thinking ill start with the cheapest first--the 34gr Nos shots...

Think i should just get a collet die actually...i forgot to ring around today to see if i could get one locally, or who interstate has one & how far away they are...

[marksman]

as you know Stix I am a big fan of the lee collet dies

https://www.ozgunmart.com.au/lee-collet-2-die-sets

[SCJ429]

I am betting that if you grab those 40 grain Vmax and 27.5 grain of 2206H give or take a couple of tenths you should get a pretty good result. Using a16x scope is going to make it more challenging and be gentle with those collet dies.

[Stix]

I am betting that if you grab those 40 grain Vmax and 27.5 grain of 2206H give or take a couple of tenths you should get a pretty good result. Using a16x scope is going to make it more challenging and be gentle with those collet dies.

You know ive got a bottle of 2206h & have not had good results with it in the other 204, a 222, & 2x 22-250's...

So i got myself a bottle of the 8208 for thjis rifle...i figured ill go for full cases & try get some serios speed out of this one...as the other one is loaded so very mildly...
I want to join the Marksman & SCJ speed demon club...

Dont bother talking me out of it--its getting stuffed with BM 8208...!!...& if the rifle doesnt like it, its gonna be your fault...!!...

[SCJ429]

You can get some more speed with 2206h with more powder than with 27.5 but I didn't bother chasing the next node.

You should get some pretty good results out of 8208, speed should be similar to 2206.

What make is this rifle?

[Stix]

You can get some more speed with 2206h with more powder than with 27.5 but I didn't bother chasing the next node.

You should get some pretty good results out of 8208, speed should be similar to 2206.

What make is this rifle?

Same as yours...

[Stix]

as you know Stix I am a big fan of the lee collet dies

https://www.ozgunmart.com.au/lee-collet-2-die-sets

Yes Marksman...

Hopefully ill get some time to get these collet dies happening...

Have you used those guys before...?-(Oz Gun Mart)-?...

If so, any good...??

Ive contacted them over a week ago about something else & again about these dies & not had a response , so i ordered the dies from someone else...
I ordered something small from them to see if they are any good--hopefully they are more responsive with money in their account...we'll see...

[marksman]

I have and it was ok but I would not buy off anyone who did not respond to an email, they dont want your money

ebay is more secure https://www.ebay.com.au/itm/Lee-Collet- ... ctupt=true

[Sergeant Hartman]

I have bought off him and midway on eBay. Both no issues.

But he always is slack with replying when i have asked a Q... usually with an excuse that he was sick or similar