Accuracy Loading - Primer Selection

[ELR LVR]

Wouldn't differences in weight of just the cup be more than the variations in amount of primer material?

No Sir, there is no differences in weight of just the cup...
...Out of the Primers I prefer to use and weighed for this test
I weighed some of the spent primers afterward
In the sample lot I weighed there was NO VARIATION WHATSOEVER in the spent primer
that Being the Cup and Anvil
the primer cups and anvil - all weighed the exact same - down to the milligram.
One primer kept flicking between .313 and .314, then back to .313
That was the only variation
The rest were all .313mg Empty
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Therefore we can determine that any variation in Primer Weight is due to variation in primer compound only
So within weight sorting I know I am sorting according to primer compound weight only and can ignore any possible variation in brass weight of the primer. (Since there is none)
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It is definitely a good question and a factor to consider and weed out.
If the brass varied at all - that would throw a whole new complicated variable into the equation
And IF, that were the case, then guys would start reloading there own primers as well.
Some people do actually, as there are kits for this, Home recipes for the compound etc.
I am not at that level of "Anal-osity" with my primers yet
Only with my machining

 

[Straightshooter1]

Yesterday I sorted a brick of CCI 200's The lightest was 5.12 gr and the heaviest was 5.36 gr. Of course, these are at each end of the spectrum were the outliers and very few of them. But it's good to identify them as they will have an effect on paper. . . especially at distance. Just in one of the sleeves there was one at 5.14 grs and a couple at 5.32 and 5.30 grs. The majority of them were from 5.24 to 5.26 grs, where you really don't want both those few 5.12's or 5.36's nestled among them.

 

[ELR LVR]

Yesterday I sorted a brick of CCI 200's The lightest was 5.12 gr and the heaviest was 5.36 gr. Of course, these are at each end of the spectrum were the outliers and very few of them. But it's good to identify them as they will have an effect on paper. . . especially at distance. Just in one of the sleeves there was one at 5.14 grs and a couple at 5.32 and 5.30 grs. The majority of them were from 5.24 to 5.26 grs, where you really don't want both those few 5.12's or 5.36's nestled among them.

As I was informed and now agree with...
best to sort weight according to milligrams or even on a finer unit of measure
as this scale will give you better resolution on the weight
as opposed to grains.
(Your weight difference will be more defined )
Since your priming compound is approx 40 milligrams this equates to .6173 grains
You are seeing a difference of 16 milligrams
which is approx a 40% difference in priming compound weight
I am seeing as much a a 50% difference in priming compound weight from one extreme side to the other
which to me, is a "Whole Bunch" of difference if we can experience that from 1 primer to another
you may not see the differences in a few milligrams when using grains
But at least weighing them in grains is a good start
and grouping them together in their similar lots is better than not at all

 

[Fast14riot]

As I was informed and now agree with...
best to sort weight according to milligrams
as this scale will give you better resolution on the weight
as opposed to grains.
(Your weight difference will be more defined )
Since your priming compound is approx 40 milligrams this equates to .6173 grains
you may not see the differences in a few milligrams when using grains
But at least weighing them in grains and grouping them together in their similar lots is better than not at all

Lol, I saw this as you posted it and am glad you edited the conversion!

~0.02gr resolution scales are pretty common and are normally mg scales since 1mg = ~0.015gr they just convert for the output. Its why a single kernel doesn't always roll it over to the next 0.02gr.

 

[ELR LVR]

Lol, I saw this as you posted it and am glad you edited the conversion!

~0.02gr resolution scales are pretty common and are normally mg scales since 1mg = ~0.015gr they just convert for the output. Its why a single kernel doesn't always roll it over to the next 0.02gr.

Lol yeah I was using the google quick conversion thing on computer when I posted and just went with it
when after I posted ...
I was like
Nawwww, that aint right!
Be sure you know if you want it converting from Grams or Milligrams before hand
.040 grams is OK, but .040 Mg is not good
----
That reminds of the Whole Spinach makes popeye strong thing
Some Scientist calculated the (amount of whatever mineral/vitamin, I believe it was iron) is in spinach that improves muscle strength
and put the decimal point in the wrong place
I guess everyone believed it until it was corrected

 

[JFrank]

I haven’t tested primers since they’ve come back down in price so it’s on my bucket list of to do’s, however when I did test br-4 against 450’s a couple years ago I did it with weight sorted primers in a ladder format judging how well each came into tune and overall small group in tune.
It wasnt the best data that day but I felt the Br-4 edged out the 450’s although the receiver would perform well with either one.

(1000 yards with a bit of breeze)

 

[ELR LVR]

I haven’t tested primers since they’ve come back down in price so it’s on my bucket list of to do’s, however when I did test br-4 against 450’s a couple years ago I did it with weight sorted primers in a ladder format judging how well each came into tune and overall small group in tune.
It wasnt the best data that day but I felt the Br-4 edged out the 450’s although the receiver would perform well with either one.

(1000 yards with a bit of breeze)

Good stuff man,
I am baffled at the variation in some of these different primers. Considering the small amount of compound they have to begin with.
Must be hard for them to get consistency
Wonder if they weigh their consistency as we do to consider them Benchrest primers
or monitor the volume of compound used in each primer
The BR primers should edge out the others, and it looks like you have proved that in your load as well

 

[JFrank]

I’ve tested primers at 200 yards using one powder charge, they all looked about the same until I moved out to 550 yards, than one was real bad but that’s the point of post #24, ya gotta look at them over a few different charge rates to not get fooled. In the case below fed might have been great with another 1/10 powder ( up or down )

 

[ELR LVR]

I’ve tested primers at 200 yards using one powder charge, they all looked about the same until I moved out to 550 yards, than one was real bad but that’s the point of post #24, ya gotta look at them over a few different charge rates to not get fooled. In the case below fed might have been great with another 1/10 powder

Interesting - the 450's look very close to performance with the BR-4's
Likely as with the CCI200 = BR-2
The 450 may be the same primer a the BR-4 , just more closely sorted
yet the 450's may not start off bad to begin with
That one low drop in the second pic of the 450's ?
...could that have been simply an outlier primer? Not as closely matched in weight to the others?

 

[NZ_Fclass]

I recently loaded 50-odd rounds of 308 Win 175gn / StaBALL Match over eight primer makes. Single charge weight only and all components / details identical bar the primer. This wasn't done to show up different performance / precision, but for a different purpose entirely.

Previous wider range tests showed that the rifle doesn't like this bullet-powder combination at all and that groups would be large. I used it again as it was a) a stiff load pressure-wise, and b) I had the powder and no other use for it.

I shot a single 5-round group for each model (plus some 'foulers') and chronographed everything just out of interest. Only a single group for each, so a tiny sample, but a near 4 to 1 discrepancy in the resulting group sizes from just over the half-inch to 2-inches at 100 yards off the bench. Moreover, the 2-incher wasn't of the 4+1 flier, or even 3 + 2 fliers / split group, rather every shot spread out over the four corners. Also, interestingly, to confound the small ES/SD fanatics, the primer that produced the smallest ES value (by far) also produced the largest group, the two-incher. Not that that is unusual!

That seems correct - but Staball Match! Back in the days of yore- well, the 80's - it was a "well-known-fact" that ball powders always needed a "hotter" primer. We used to even joke that the best load of W748 needed a few match heads in the bottom to get it going. This was a time when the NRANZ were almost the only supplier of powder - and they would buy bulk amounts of one type. Mulwex AR2001, the most temperature unstable powder to find it's way into military ammo was common, then Win748, followed by AR2206, a forerunner of AR2206H- now sold in the US as H4895. Thankfully, we now get all the AR powders and a better selection of primers.

Whether the old adage was factual... I do get better results in my Dasher with CCi450's than "cooler" ( is that that a thing?) primers using Staball Match - and good velocity with that powder too. The Dasher isnt so fussy with Varget/AR2208 and I have been using RWS/RUAG primers to good effect.

But the most finiky cartridge that I use is the 223. If ever a cartridge needed good primers - I only use Federal Gold for matches and Ginex/Reminton 7 1/2 for practice. I'm currently working on an H4895 load to reduce the fill level, as I have had some "growth" with the 100% plus Varget load. Maybe the H4895 load won't be so picky - I'm using the Ginex for testing/tuning - just as a cost saving exercise - I will see how it goes at 600 next weekend.

 

[Fast14riot]

Good stuff man,
I am baffled at the variation in some of these different primers. Considering the small amount of compound they have to begin with.
Must be hard for them to get consistency
Wonder if they weigh their consistency as we do to consider them Benchrest primers
or monitor the volume of compound used in each primer
The BR primers should edge out the others, and it looks like you have proved that in your load as well

In short, no, they do not weigh a single spec of priming compound. Often BR primers just come off the line of the most experience worker.

[Youtube]

 

[Straightshooter1]

Good stuff man,
I am baffled at the variation in some of these different primers. Considering the small amount of compound they have to begin with.
Must be hard for them to get consistency
Wonder if they weigh their consistency as we do to consider them Benchrest primers
or monitor the volume of compound used in each primer
The BR primers should edge out the others, and it looks like you have proved that in your load as well

I've seen a couple different YouTube videos showing how primers are made and the method is pretty universal as far as I know. There's no weighing for consistency and it's up to the skill of the worker who fills the cups with compound that determines how uniformly the cups are being filled. And that's why it's the more skilled worker being assigned to do the match grade primers. It's probably just too labor intensive to check the consistency like we do when sorting primers. If they did and you think primers are high priced now . . .

 

[ELR LVR]

I've see a couple different YouTube videos showing how primers are made and the method is pretty universal as far as I know. There's no weighing for consistency and it's up to the skill of the worker who fills the cups with compound that determines how uniformly the cups are being filled. And that's why it's the more skilled worker being assigned to do the match grade primers. It's probably just too labor intensive to check the consistency like we do when sorting primers. If they did and you think primers are high priced now . . .

Looks like they're just frosting a cake
No wonder there is so much variation

 

[marchx]

I found the thread very interesting. Thank you for bringing this up. Without extensive testing I have been using BR4 and BR2 in my competition loads. For my hunting loads I use gold medal match. I will participate in a tactical match in 2 weeks where l cannot use a rear bag. I have to stabilize the rifle with my body which I am not very good at. My tested ammo for the match was giving me yesterday .4 10-shot group at 100m, but frankly if I lose that match it won’t be because of primer weight variance.

 

[ELR LVR]

I found the thread very interesting. Thank you for bringing this up. Without extensive testing I have been using BR4 and BR2 in my competition loads. For my hunting loads I use gold medal match. I will participate in a tactical match in 2 weeks where l cannot use a rear bag. I have to stabilize the rifle with my body which I am not very good at. My tested ammo for the match was giving me yesterday .4 10-shot group at 100m, but frankly if I lose that match it won’t be because of primer weight variance.

Thanks, The Br-2's are very consistent primers
Another thing to consider, even if one certain primer may be consistent
Different primers have a different AMOUNT of priming compound, as well as dif characteritics.
This would be another reason to try various different primers since...
Some powder may like a slightly lighter primer while another powder may react better to a primer with slightly more compound
Also, 2 different primers may weigh similarly, but behave differently in the vessel.
We are talking 10 milligrams difference in some case for a primer switch.
One of my guns loves F-210 which are very consistent in it.
While another LR rifle using a different powder is more accurate with the BR-2's
I wish this was not the case, since I would like to simply use 1 primer for both of the 2 guns
But this is simply not the case
Both Powders are RE-22 and H-1000, so are not too far apart on the burn rate chart
Yet each behave best with their own primer.
It may not be critical to use the BR-2 in the one gun and I could use the F-210 in both
, but the targets speak the truth and I .....like most people
have my own acceptable requirements for certain rifles.
--------------------------------------------------------------------------------
So just to see if I understand your grouping correctly?

You are shooting --- 0.4" for 10 shots at 100m ?
Sounds like your rifle driving technique is very good
---
When you say stabilize your rifle with your body
Do you mean to say, prone with no rear sandbag or monopod to help stabilize the butt?
Perhaps I can inform you of a technique to try which has proven to be very consistent for me.
For prone using a bipod and shouldering with no rear bag...
If this is what you are doing PM me
John

 

[marchx]

Yup. This is the technique. You are shooting prone, off a bipod, no rear bag. My rifle is like 19lbs and with x50 magnification and adrenaline I see my pulse impacting heavily the reticle movement. With a rear bag I shoot free recoil, but during this particular match it’s impossible.

 

[Coonman300]

Interesting thread…thanks for the info. I’m having some issues with a gun that routinely shoots sub MOA and now it has opened up. It’s a heavy barreled Remington 700 in 300 WM and as I’m getting ready for deer season the groups are 1.5-1.75. I historically used the old orange box of Winchester magnum primers (30 years old). Bought some of the newer Winchester mag primers. I wouldn’t have thought it’d made that much difference but your pics certainly show it can. Fortunately, I did find a brick of the old orange box Winchester primers and have already loaded some more to test this weekend. Hopefully the answer is that simple. Thank you!!

 

[Straightshooter1]

Looks like they're just frosting a cake
No wonder there is so much variation

I just got to thinking about my ES of .24 gr on those CCI-200's I sorted the other day and how acceptable that might be for my powder charges. For me, .24 gr variation in my powder charges is just not acceptable for my .308 or my 6.5 PRC and I can't think of any good reason why that variation in the primer charges should be acceptable. Though I know for many people, that variance in their powder charge just doesn't matter.