Can primers reduce E.S.?

[Kennibear]

Canadian Bushman

Yes, sort of.....
Primers are icing on the cake. Gotta have a good cake recipe first. I start with a good primer and vary the powder charge to find my best load. I try several powders and choose the best from that test series. THEN I try different primers.

Just an aside, if your load is holding a good group out past 400yds or so and then suddenly burps up to something greater (1/2 minute jumps to 1 1/2 minute) you may have stability issues. The bullets may be Lurching to conform to aerodynamic pressure. Trying a different bullet can help. I try to stay at the heavy end of what the barrel twist will stabilize.

Try your primer change on your best load and see if it gets better. But don't discount a different bullet of the same weight. Lots of testing, but its lots of fun to pull that trigger.

 

[BountyHunter]

BountyHunter,

I know you have useful knowledge but...

Why is it that you never miss a chance to blag off on technology?

Tools are tools and it's not the fault of the tool if the user are inept.

Did you have a failed experience with QuickLoad or some other tool and now feel it's your duty to disparage it at every opportunity?

As far as I'm concerned it makes you look like a whiner.

I love new technology and I am probably one of the first to look to get and use especially IF it checks out. Probably spent 2-3x of anyone else here buying and testing new things.

I have Q load and use it to validate some things. However, I learned its limitations first by spending several hours a day over a couple weeks with the techs learning how they derived their algorithms by testing only standard SAAMI chambers and twists and what it really can do and cannot do and how to try and make it work best for what I was looking for! I even ran some of my loads tested with strain gauges against what Q load said and they is why I view it no better than a computerized reloading manual in reality. ie start 10% below and work up.

It is often not just that the user is inept either as you state. It is the fact that too many think Q load is "THE answer and manna from heaven".

I have seen Q load touted here especially, as the "know all, end all" to especially novice reloaders as the "definitive answer", not a tool. You have supposed competent reloaders and smiths here posting print screens of what someone's PSI will be or is and they do not have a clue what the chamber dimensions are, how far off the lands etc etc. but Q load says...... so it must be gospel.

I have personally seen the same Q load disciples provide given "recommended loads" to a new shooter that locked up a gun tighter than a jug, because difference in chambers, air density, temp and what ever else, but Q load said it was good to go.

It cannot tell you what the pressure will really be by changing primers etc BEFOREHAND for example and Q load did not even test for that.

You are right it is only a tool, and not an end all as too many people try to make it.

 

[Kennibear]

In support of Bounty Hunter:

1) In setting up a Pressure Trace II for four different rifles w/ attendant strain gauges, chamber measurements, case wall thickness @ the strain gauge location , ad infinitum I can tell you the data collection for just AS MEASURED chamber pressure is overwhelming. God forbid someone without some technical measuring skills try it without help. How are you going to measure the actual functioning volume of your chamber? It is not liquid tight so how do you get a volume with the leaks around the standing breach and the front edge of the chamber?
2) How can we assess, for data purposes, the very primers on our loading bench? The lot of powder currently in your possession? Have you measured any bullets lately? Bullets are easy because great strides have been made in recent years by Makers in very consistent product. How do I know? I measured the bullets. Compared them to old examples or older notes.
3) How many data points entered to achieve your computer's educated guess?

All these programs are a best guess safety net and they still get it wrong once in awhile. I am very thankful they are there and they are an improvement over Homer Powley's slide rule load estimator- but only slightly. Too many variables and the programmer is forced to make a lot of basic assumptions.
I use these programs too but I do not assume any accuracy in their computations. It's a starting point only, albeit a dam good one.
But the starting load screams over the chronograph and I stare into a Netbook screen to see what's really happening. Theoretical meets reality. Reality always wins.

And the Programs? They are pretty close but never spot on.

 

[eddybo]

In support of Bounty Hunter:

1) In setting up a Pressure Trace II for four different rifles w/ attendant strain gauges, chamber measurements, case wall thickness @ the strain gauge location , ad infinitum I can tell you the data collection for just AS MEASURED chamber pressure is overwhelming. God forbid someone without some technical measuring skills try it without help. How are you going to measure the actual functioning volume of your chamber? It is not liquid tight so how do you get a volume with the leaks around the standing breach and the front edge of the chamber?
2) How can we assess, for data purposes, the very primers on our loading bench? The lot of powder currently in your possession? Have you measured any bullets lately? Bullets are easy because great strides have been made in recent years by Makers in very consistent product. How do I know? I measured the bullets. Compared them to old examples or older notes.
3) How many data points entered to achieve your computer's educated guess?

All these programs are a best guess safety net and they still get it wrong once in awhile. I am very thankful they are there and they are an improvement over Homer Powley's slide rule load estimator- but only slightly. Too many variables and the programmer is forced to make a lot of basic assumptions.
I use these programs too but I do not assume any accuracy in their computations. It's a starting point only, albeit a dam good one.
But the starting load screams over the chronograph and I stare into a Netbook screen to see what's really happening. Theoretical meets reality. Reality always wins.

And the Programs? They are pretty close but never spot on.

H2O volumes of actual fired cases are about as close as you can get to measuring volume, you can adjust for that in QL. I find it to be w/n 10% and usually much closer. I have pressure trace and played with it a great deal when I first got it several years ago. It sits on a shelf now, while QL keeps generating load estimations that are very accurate if all things are considered.
The bigest weakness in QL IMO is the lot to lot variance in the powders we buy.

 

[Mikecr]

QL is better than manuals in that you can calibrate it to your barrel/chamber/load based on good chrono data & ambient temps.
As a predictive tool, sometimes it's great, sometimes not so much. As mentioned, there are so many variables, from barrel to barrel, lot to lot, etc, that nothing will ever be able to predict big changes(like primer changes). Also, you need to watch the default numbers in QL(there are errors), and you need to learn how to calibrate it.
But once it's dialed in, you can run relative 'what-ifs' with it.

I can't imagine someone would purely predict loads with any source and go right to max with it.

 

[Kennibear]

This thread is cascading off track.
The primer question is not answered in any of the ballistic programs that I am aware of. But help from threads (read: experience) like this can keep the the beginning reloaders out of trouble.
This is where our collective experience is more than the sum of the programs. Pretty much those on this thread have the same experience. Time to share. But the efficacy of ballistic programs is another thread.

eddybo
Very interested in your Pressure Trace experience. Just starting and it has delivered data that corroborates some of the manuals. A 300WM load showed the beginning of an after shock pressure increase that is mentioned in the literature. The time stamp on the wave is after the bullet exits the barrel. Nothing major, and it did not rise above about 5kpsi.

 

[eddybo]

This thread is cascading off track.
The primer question is not answered in any of the ballistic programs that I am aware of. But help from threads (read: experience) like this can keep the the beginning reloaders out of trouble.
This is where our collective experience is more than the sum of the programs. Pretty much those on this thread have the same experience. Time to share. But the efficacy of ballistic programs is another thread.

eddybo
Very interested in your Pressure Trace experience. Just starting and it has delivered data that corroborates some of the manuals. A 300WM load showed the beginning of an after shock pressure increase that is mentioned in the literature. The time stamp on the wave is after the bullet exits the barrel. Nothing major, and it did not rise above about 5kpsi.

Like you stated, it is getting off topic. I went out in the shop and knocked the dust of my pressure trace ii last night. someone else playing with it got my interest back up. I had planned to strain gauge my 338AM but my glue was too old. Feel free to PM me or start a thread on pressure trace. It is a nifty tool, but I feel Ql is more practical for a reloader, of course there are always safety protocols everyone should follow with any reloading information.

 

[al308]

Here's a article on primers may shine some light on the subject...Al


The Rifleman's Journal: Primers - Small Rifle Primer Study

 

[Canadian Bushman]

After reading that i return to my previous conclusion. Black magic!

Al308
That was s good find and an informative article. Thank you for finding that.

 

[Kennibear]

Canadian Bushman

For your consideration;

Perhaps the confusion or perplexity of the primers vs. ES can seem overwhelming. It is not. Sometimes a different primer helps, sometimes not. But it is one avenue we use to fine tune a load. The key is - "Fine Tune". If a subject load show a high ES and/or SD (>150fps ES or >50fps SD) a switch in primers will not correct it. But if you have a promising load, emphasis on "promising", it may be possible to eke out the very best performance by trying different primers. Stay within the basic rules of safety when changing primers as laid out in this thread. But changing primers will not correct a poor load.

Not to add to the confusion but maybe as a help, some powders seem to be primer picky and some powders seem primer tolerant. As examples:

H322 I have used a lot in 223/556. This powder doesn't change no matter what primer I have used. Every load I have tried from 223 to 45/70 shoots very consistent and is insensitive to primer type.

H4895 This powder is used by DCM shooters and every one of them I have talked to says it is tolerant.

WW 680BR. Older Winchester powder not available from them any more. It magically appeared the same time WW/Olin got a huge order for 7.65X39 for use in captured AK's in Viet Nam. Just a coincidence. My reloading friends and I used it in 357Mag and 44Mag for Max loads (16.2grs - 172gr Lyman 359429 - WW 357 cases cut back to 1.224" trimmed length). CCI 550 SP Magnum primers work, nothing else did. Ditto WW748. A good load in 223/556 requires tweaking the primer (I use CCI 450 SRMag). AA2460 is intolerant. WW 760 seems tolerant.

H335 has produced good groups for me in 223/556 no matter what primer.

IMR 4350 has good performance as a general rule but it will hone to a fine point by finding the right primer. Different loads will prefer different primers. I use it in 30-06, 300 WinMag and 375 Ruger. Different primers in almost every load. Go figure.

All this to say that talking to others can help as you take advantage of the collective experience. I would hope this thread will motivate others to relate their findings in powder vs. primer to help others like yourself. But don't throw up your hands in defeat. This is a fascinating journey your are about to take!

 

[Canadian Bushman]

Kennibear

Thats makes sense. Its just that it seems there is a lot of trial and error to finding the perfect primer. Is there any sort of way to predict what primer might be good for a given load?

For example: Ive heard slow powders in long cases work well with magnum primers. So could i assume a short case with fast powder prefers a smaller or less aggressive primer?

 

[tbrice23]

This is a post from another member. I tried some of his combinations with dissimilar results.
I've been looking for a Unified Primer Theory for years. I dont think it exists.

 

[tbrice23]

Sorry my reply sounded like there is no hope but I pray to God that im wrong.
I try at least 3 different primers per powder unless I get lucky. It seems im never satisfied until im sure I've reached the maximum potential of the rifle , which is about 80% of my barrels life. I think sooner or later ill stop reaching for the stars and become more complacent. But that doesn't seem to be a pattern that I frequently exhibit.
Dont let me discourage you and please if you find a Unified Primer Theory let us know!

 

[Canadian Bushman]

Sorry my reply sounded like there is no hope but I pray to God that im wrong.
I try at least 3 different primers per powder unless I get lucky. It seems im never satisfied until im sure I've reached the maximum potential of the rifle , which is about 80% of my barrels life. I think sooner or later ill stop reaching for the stars and become more complacent. But that doesn't seem to be a pattern that I frequently exhibit.
Dont let me discourage you and please if you find a Unified Primer Theory let us know!

Many of reloders seem to carry the same sentimint. I think there are others like kennibear who have a good knowledge base of the primers and powders that work well together in the cartridges they use and things make a bit more sense to them. I still consider myself to be in the dark as far as achieving very low E.S. and S.D.