TRBLSHTR wrote:

tried the benchrest primers-blew my groups,and on the chrony-the deviation was 100 to 200 fps!!!!!!!!!!!

Did your average speed go up or down ?
Did you adjust accordingly to obtain the same velocity window ?
Or did you just swap primers to see what would happen ?

stovepipe wrote:

Cuz you use them in connection with BR reloading recipes and methods and components. For standard target and hunting loads dont even bother. Just buy standard, easy to find primers and get back on with life.

Stovey.....remember this group ???
7mm08, 120gr B-Tip Hunting Load

It uses a Federal 210M (Match)

Chuck Hawks on primers !!! Here

Ominivision1 wrote:

Geland: When you tried those magnum primers, were they on the same day as you tried the standard primers? Weather has a lot to do with overall performance.

Omini,
the tests was on different days, however, as I said it is consistent no matter when the day was. And I have tested this many times.
And I test both the same brand and different brand of primers.

My theory is that the fact that Magnum primer with its larger fire, saturated the whole (small) case of the 300Whisper, thus rises the pressure early in the ignition time and expend most of the energy in raising the pressure, and thus left little energy to propel the projectile downrange in the barrel.

The effect is similar to the fact that, if you use faster burning powder your MV would be a tad slower than if you are using slower burning powder in the same case.
Slower burning powder would keep on accelerating the projectile while it is still within the barrel, whereas fast burning powder would have expended all the energy.

Mind you I am talking of using LOW powder charge loads in SUBSONIC MV range on a small-for-the-projector-weight-caliber.

Have you ever considered that the intensity of the magnum primer may be moving the bullet prematurity creating more air space ???

chambered221 wrote:

stovepipe wrote: Cuz you use them in connection with BR reloading recipes and methods and components. For standard target and hunting loads dont even bother. Just buy standard, easy to find primers and get back on with life. Stovey.....remember this group ??? 7mm08, 120gr B-Tip Hunting Load It uses a Federal 210M (Match)

Didnt say they dont work as intended. My point is the majority of non-BR reloaders use normal primers with great success w/o resorting to BR prep and methods and recipes. Some recipes it might help with, know of some shooters it dont. They are also not as readily available here. None of my recipes call for them either so I use common and readily available components. I'd also need a lead-sled to hold that tight- whatever primer was in the case.

And the Hawk's article mirrors what I said earlier.

gelandangan wrote:

My theory is that the fact that Magnum primer with its larger fire, saturated the whole (small) case of the 300Whisper, thus rises the pressure early in the ignition time and expend most of the energy in raising the pressure, and thus left little energy to propel the projectile downrange in the barrel.

Yup, I also read about this at one of the bullet manufacturers web sites and they stated that using lower powder loads with mag primers causes flash over in which the powder in front (behind the bullet) ignites at the same time as the powder at the rear. They said that when using low powder charges, the flash hole is not completely covered and the sparks from the primer is all over inside the case causing multiple ignition points instead of a gradual burn.

Also they stated that since the front and rear of the powder are burning at once, going in different directions in the case colliding with each other, instead of a uniformed burn, its chaos inside the case.

OV1 wrote:

...Also they stated that since the front and rear of the powder are burning at once, going in different directions in the case colliding with each other, instead of a uniformed burn, its chaos inside the case.

Sounds an awful lot like my guts after a big night on the turps.

I remember back in the day when loading for pistol, there was an article in the AmericanHangunner called The 2.8gn Bullseye Surprise...story goes that igniting small charges of powder that lay along the bottom of the case could cause the powder to act like a cutting charge because the primer would "flash" across the top of the powder, igniting it all in one go causing it all to burn almost instantly. It was also believed that a magnum primer would exacerbate the problem. I regularly used loads of this size without problem, but I admit it certainly had me thinking.

Cheers, Vince

Vince wrote:

Sounds an awful lot like my guts after a big night on the turps. :wtf:Cheers, Vince

Hmmm, "turps" Ok, I need a translation for that word.

Thats just another Aussie pet name for grog. What else did you think Vince would be talking about

Vince wrote:

OV1 wrote: ...Also they stated that since the front and rear of the powder are burning at once, going in different directions in the case colliding with each other, instead of a uniformed burn, its chaos inside the case. Sounds an awful lot like my guts after a big night on the turps. I remember back in the day when loading for pistol, there was an article in the AmericanHangunner called The 2.8gn Bullseye Surprise...story goes that igniting small charges of powder that lay along the bottom of the case could cause the powder to act like a cutting charge because the primer would "flash" across the top of the powder, igniting it all in one go causing it all to burn almost instantly. It was also believed that a magnum primer would exacerbate the problem. I regularly used loads of this size without problem, but I admit it certainly had me thinking. Cheers, Vince

Your age is showing Vince, so's mine I remember that article.
Was probably the reason I used 3.0 grns of bullseye and std pistol primers.
Over 20,000 rounds without a problem.

Ominivision1 wrote:

Vince wrote: Sounds an awful lot like my guts after a big night on the turps. :wtf:Cheers, Vince Hmmm, "turps" Ok, I need a translation for that word.

As Camel said OV1..."turps" is a slang or pet name for booze, grog, alcohol. The term turps originates from the painting thinning product called Mineral Turpentine I think...although I couldn't be 100% sure.

I know that when ya have a bellyful of the wallop (another slang term from booze), the next morning you feel like you have been drinking turps the night before. A nasty hangover is cruel...makes me feel like I'm recovering from an autopsy.

Anyway, back onto topic. I found this article on the net. It may have been posted here some time in the past, but for the sake of the info contained within, I'll post it anyway.

Primers, the Sparkplug of Centerfire Cartridges

Cheers, Vince

First let me say thank you all for your input. My example was just that an example... however let me get a little more specific on my load I'm working..

I am working a load for my 204, I have been using a Berger 40gr BT and I haven't really gotten out to shoot much yet but was curious... here is the specific load and "recipe" from Berger:

40gr Berger BT H414 powder
start load 26.0 gr (3225 approx fps)
Max load 28.8 gr (3610 approx fps) 101.7% fill ratio

They do not specify magnum or standard primers...

Here was my thought and I could be all wet... but I have "heard" in the 204 partially compressed loads preform better with a magnum primer and that the 204 seems to just like partially compressed loads. So I specifically started working with a load that once worked up to max (as long as no over pressure signs where present) would end in a 100% plus fill ratio. My current test loads are with the standard CCI 400 primer. With that in mind I was thinking that a magnum primer would work better to fully ignite all the powder, thus giving better performance...

Am I on the right track?

FYI, I will also be testing the 35gr Berger and the 32gr Hornady V-max

Thanks

Dave

Warnberg-This may/may not apply to your situation...but with the 204(of which I do not own one)However a couple of my shooting buddies do,and I am impressed whith the ballistics.That being said;I would hesitate to go maximum loads all at once as the 204-which as I recall was derived from necking down the 222 rem magnum,and the 222magnum was not adopted by the military for being hard on the throat of the barrel.Now if barrel prices are no object to you-then full speed ahead.I have found that most of (my) reloads work with the most accuracy between starting loads and max(never max).YMMV!One othe example;a lifetime shooting/hunting reloading bud of mine was starting to reload for a .17 remington that his father gave him,absolute tack driver-an original rem 700 I think,but he was loading with somebody else while I was out of state,(and their may have been some of Vince's "turps" involved),but when we took his gun to the range all it did was key hole every bullet @100yds.We took the loads home and out of curiosity pulled a couple and weighed the charge against the listed book load and found that they were all over max by a half a grain.Small cases seem to develope exponential problems with a little more powder.He lowered the powder and took it shooting again but it would not stabilize the bullets any longer.He sent it back to remington and they confirmed that the throat was "washed" and charged him and installed a new barrel.The gun shhots like new again. That is why I personally did'nt go with light speed cartridges like the 204 or 220 swift.I like to shoot more than replacing barrels.

Don't get me wrong, I work toward max load, rarely do I find that a max load provides best performance/accuracy...

This particular caliber I am starting at minimum... 26.0gr and step up .3 grains at a time...

i.e. 5 @ 26.0, 5 @ 26.3, 5 @ 26.6, 5 @ 26.9, etc.... ending around 28.5gr provided I do not see any signs of over pressure before then, if I do I stop and call it a day pulling the rest of the test loads...

I was just curious as to what a magnum primer would do to my results of my load, performance, accuracy, etc.... Again I have heard that this particular caliber likes full cases and magnum primers but I have not confirmed that hence the question and the test loads....

FYI... this was my brothers gun, he suggested a particular load all within specs for the reloading manual, he lives at 5500ft, those same loads at sea level showed cratering primers, typical over pressure signs.

Thanks