Flash hole sizes

Get or give advice on equipment, reloading and other technical issues.

Moderator: Mod

Walt
Posts: 97
Joined: Fri Feb 17, 2017 10:25 am
Location: Shoalhaven
Been thanked: 19 times

Flash hole sizes

Post by Walt »

Recently I had occasion to notice the difference in flash holes between 284 cases in Lapua and Bertram brass. I should qualify this by saying the Lapua brass was a necked up 6.5 originally. The Bertram flash hole is significantly larger than Lapua, at least 30% larger.
I am curious to know what impact this would have on the ignition process and thereby any differences in bullet performance, given all other components (other than the brass composition) are equal.
Academic question really, because I certainly won't be mixing the brass in competition.
Comments invited.
AlanF
Posts: 7532
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic
Has thanked: 229 times
Been thanked: 936 times

Re: Flash hole sizes

Post by AlanF »

Walt wrote:Recently I had occasion to notice the difference in flash holes between 284 cases in Lapua and Bertram brass. I should qualify this by saying the Lapua brass was a necked up 6.5 originally. The Bertram flash hole is significantly larger than Lapua, at least 30% larger.
I am curious to know what impact this would have on the ignition process and thereby any differences in bullet performance, given all other components (other than the brass composition) are equal.
Academic question really, because I certainly won't be mixing the brass in competition.
Comments invited.

The size of the flash hole would I believe affect the shape, power and duration of the ignition flame, so it could mean that your favourite primer goes out of favour. And if the Bertram flash holes are at least 30% larger then you won't be able to uniform them with a standard uniformer.
Post Reply Previous topicNext topic