Primer flame size?

[Blancoalex]

Have primer technical question. How far does the the primer fire reach thru the .060-.080 hole into a case and what is the size of the ball of fire?
My guess is 1/2-3/4 inch reach and and the fire ball being size of inside of case. Thanks

 

[milboltnut]

what matters is you try it and see how it performs. I wouldn't concern my self about what it looks like.

 

[MagnumManiac]

The primer releases sparks and flame and it pressurises the case. How far a primers flame enters the case depends on how compactly the powder is and it's type.
Loose loads, which I call fluffy, will allow the flame to run over a portion of the powder instead of into the powder column…this is bad for uniform ignition unless some other mechanical solution is used to make start pressure rise uniformly, such as a crimp.

Cheers.

 

[Blancoalex]

MagnumManic, I ask because trying to create Subsonic loads using flake powders in small (223) to large (308) cases. Powders I have on hand to try are Blue Dot, Green Dot, Win. WST and Trail Boss. I do have both Standard and Magnum primers to use. I am currently getting more vertical shots than I like to have. Thanks

 

[codyadams]

There was at one time a thread, article or some other informational post that I saw that illustrated the flame created by a some of the popular primers, showing the difference in the flame. It was rather interesting but I do not know if I can find it again, if I can I will link it.

 

[Chuckrub]

https://www.6mmbr.com/PrimerPix.html

 

[codyadams]

Yup, that one ☝

 

[Dean2]

Use Trail Boss, a heavy for caliber bullet, and a standard primer and you will get less vertical. Depending on how far below 1,100 fps you are trying to get, put a small crimp on the case for lower speed loads. The pistol and shotgun powder loads have very little powder in them are easy to double charge, which puts them way over pressure, and need a wad and corn meal or some other filler to get them to group at all. Before Trail Boss these were our only choices for sub loads, now that TB is out it is all I ever use.

 

[Coyote Shadow Tracker]

https://www.6mmbr.com/PrimerPix.html

WOW! Make you think about what primer to use. Looks like CCI has a more uniform flash.

 

[Lefty38-55]

FWIW the 'power or strength'of a primer is called brisance - the measure of the rapidity with which an explosive develops its maximum pressure.

Here's but one test: https://castingstuff.com/primer_testing_reference.htm

I myself, for my Schuetzen loads in a 38-55 Winchester single-shot black power cartridge rifle (using smokeless loads to duplicate BP velocities), will use a large pistol primer in place of a large rifle primer. Others are known to put a piece of toilet paper between the case and primer prior to insertion (or over the flash hole inside the case) ... to 'tame down the flame'. I only report this as supplemental info and am not advocating that you do this, nor am I responsible for your actions.

 

[Chuckrub]

Here is another article.
https://fliphtml5.com/bmca/rben/basic

 

[Blancoalex]

Thanks , just what looking for to help deciding on what to use for low powder charge subsonic loads.

 

[Blancoalex]

Dean 2, so what I have been finding on line is that I need a magnum primer. Your recommendation of standard primer caught my attention.
Thinking about it the 6mmbr works so well with Sm Rifle Primer.

 

[cohunt]

Primer brisance

Try using a magnum primer and enlarging the flash hole -- works for me in 308w sub loads with green dot powder