After reading the replies in this thread I thought it would be interesting to construct a test to try and measure large rifle primers and magnum LR primers to see what (if any) differences one might be able to measure to conclude some differences of them.

Frankly, I'm not even sure what it is that one wants to measure as temperature might be extremely difficult to measure.

Any ideas?

vapo

It's just my ignorant farm-boy opinion but I think it would be very difficult and time consuming to try and conduct such a test. Why? because I think all of the answers you read on that other thread (and countless others on other threads) are probably valid. In other words, observed differences in primers depend on the particular circumstances. Every one of us can cite examples of actual experiences where results were contrary to what we've been told. I'd be hard pressed to explain why primer X Magnum gives lower pressure signs, better accuracy, and lower velocity than does primer X Standard, in my 30-06, while my shooting buddy Tom gets just the opposite results.

Now, all this is not to say that you cannot see and measure differences in primers. We've all seen the photographs of primer flash and you can certainly measure primer temperature, speed, and energy with simple devices. But what it all means and how that information can be used in every day load development is something else.

I'd sure be interested in reading the results of any tests. But I would file it away like all other information of this type and put my faith in my chronograph and, even more importantly, where the bullet meets the paper.

Again, JMHO

Ray

I seem to recall a guy posting a while (year or two) back about a simple jig for testing primers. It was based on a swing arm that would be displaced by the primer blast. Is that the kind of test you are referring to?

Sealing them in a bomb calorimeter would tell you the total energy released, but the speed of release would be just as important IMO.

quote:

Originally posted by CDH:
I seem to recall a guy posting a while (year or two) back about a simple jig for testing primers. It was based on a swing arm that would be displaced by the primer blast.

Gussy over at Cabintree actually did that test. I don't have his web site handy, but it might be castingstuff.com or something like that.

Personally, I think 10 shots over a chronograph provides a useful primer comparison. Usually my only choice is between a magnum and a standard of the same brand, and the chrono will quickly reveal which produces the more consistent velocities.

As far as brands ago, CCI is widely available in my state, so that's what I usually shoot. I also like Federals, but they have to be ordered. Remmies are hard to find here, and have no known advantage except that they have a reputation for being easier to ignite. Winnies are hard to find here, and they have a reputation for increasing pressure.

In my younger days, I did some accuracy comparisons with every brand and type of primer that I could get my hands on, and thought that I discovered something of importance, but now I realize that I didn't shoot enough groups to prove anything.

I own reload and shoot a large number of different CF rifles (33) I have two chronographs a Oehler 43 W/strain gage and a Chrony MB.(the oehler now collects dust)

Over the years I have seen no set reason which is better Std. or Mag. they all shoot different in every Cal. every gun, depending on powder, bullet outside temp, here are some of my results.

22-250= H-380 Fed match mag(FMM) primer it will shoot on average 80FPS faster with this primer then Std.+ accuracy is better.

243= H-380 55gr bullet FMM 100gr bullet 4350 Std. Rem. 9.5

260= RL-15 100gr & 120gr FMM.

6.5 Rem.Mag= IMR-4064 100 & 120 Rem 9.5 Mag

270= WMR or H-4831 130gr 150gr Rem 9.5

7x57= H-4895 139gr 165gr Win.LR

7MM-08= H-4350 115gr 140gr 160gr Win.LRmag

30-06= RL-19 165gr&168gr FMM. FPS increase over 100 with this primer.

300WM=RL-22 180gr 200gr 220gr Rem. 9.5mag

I have found a FPS increase almost always using Federal match mag primers, but a few cases only 10-20FPS or less and others accuracy drop off.

I'll stop there but as you can see everything depends on what your gun digest best to me accuracy is the deciding factor I put it head and shoulders above FPS but when you get both THAT'S GREAT.

Ok i got curious a bit ago & tried it. I took an old 8mm loaded a bullet in an empty case and fired it. knocked the bullet out and did the same thing with a mag primer & measured how far down the barrel the bullet went. - didn't measure any diff. probably not technical enuf to satisify most, but it did me.

Cheechako gave you the right poop, IMHO.


I once helped a fellow re-loader reduce his extreme shot-to-shot variation in a .340 Weatherby Mag from 200+ f.p.s. to less than 30 f.p.s. just by switching from CCI Mag to RWS standard primers. Everything else was EXACTLY the same.

On the other hand, I've seen some really, really small groups shot with CCI's in other guns and cartridges.

Ray said it all. The best test is to shoot them in your rifle. It will tell you loud and clear what it likes.

Much as we all like to have explanations of what works and why, we still don't really seem to have that when it comes to primers. Neither do the manufacturers, or they would all perform as well as each other in every gun.

The problem w/ any testing is that primers perform differently in different cartridges. I did a vel. only test using diff. LRP in my .260ai. Then again w/ my .338-06. Primers that showed higher vel. in one did not neccesarily show higher vel. in the other. At the least I think you would need a chronograph & pressure trace or sim. devise for measuring chamber pressure. There is some good reading in the A-Square manual about diff. primers in the .30-06, vel. v chamber pressure.