Primers - Hard Primer Cups

[gruntus]

Hi All,

As per a previous thread, I have a straight pull SVD which has a significant inertia effect when the bolt is "let go" from the locked back position.

I have noticed in the past some light witness marks on primers from the firing pin (floating) when unfired rounds have been unchambered. I understand it isn't uncommon in some semi-auto service rifles (M14's etc).

See Slam Fires in the article: http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

"Virtually all U.S. military Service Rifles utilize firing pins that rest freely within the bolt. Referred to as a floating firing pin, it will actually strike the primer lightly when the bolt is closed. This results in a slight dimple in the primer, which is plainly visible if the unfired round is extracted. This isn’t a problem with military ammunition because they use primers with thicker cups specifically because of this. However, it can be hazardous with the more sensitive commercial primers." 

I would obviously like to add some additional margins of error for reloading and certainly want to prevent a potential Slamfire.

Has anyone seen this behavior before in their own straight pulls/semi-autos before? 

Does anyone use specific large rifle primers with harder primer cups for their semi-autos/straight pulls? 

Is there any information on which primers are "hardest"?

Thanks in advance.

All the best.

G

PS - A stronger firing pin spring may assist with alleviating the risk. Will need to investigate what options are available. 

 

Edited September 3, 2019 by gruntus
PS note added for a firing pin spring

[Catch-22]

Generally speaking, ‘magnum’ primers of the small and large variety have thicker cups than standard primers.

[gruntus]

Thanks Catch, I do have some magnum primers I can try and will see if there are any issues with using a magnum primer for the 7.62 x 54R round.

I havent started to develop a load yet so will be starting from a low load initially regardless.

Cheers

G 

[Ballistol]

[gruntus]

3 hours ago, Ballistol said:

Thanks Ballistol, I have some CCI200s I can try.