What about using a primer pocket uniformer on your brass before loading?
This way you can get the primers to sit about 0.005" or so deeper in the pocket. That should help to keep the firing pin from coming into contact with the primer when the bolt goes forward.
I saw that idea floating around on a M14 forum, and it is bogus as can be. If the firing pin can rebound off the primer, than its seating depth will not prevent ignition, if the primer is sensitive enough.
Primer sensitivity is what prevented this primer from going bang!
Now, if the pocket is reamed so deep, than misfires can happen, as happened to me:
I snapped and snapped these rounds at a match in my M70, and while the primer dented, it no go boom bang. And it was due to reaming the pockets too deep. However, they all went bang during slowfire prone in my M1a!
Rifle primers should be set below the case head, I set mine from 0.0 to 0.003", but no deeper, as deeper caused problems. There is a chance that a high primer will ignite, the anvil has to be firmly set on something, and the bridge distance between anvil and cup has to be set to the proper distance. Given the combination of those two things, a high primer will go bang if hit by the bolt face. So, I do recommend reaming pockets for gas gun ammunition. But not excessively deep.
There are two primary ways to reduce slamfires. The first, is to reduce the inertia impact with a spring.
Murray's sells a
spring loaded firing pin for the SKS.
The Italians installed a spring in the Garand bolt
The AR10 firing pin is heavy compared to the AR15, and removing the spring will cause slamfires
Another way to reduce firing pin inertia impact is by lightening the firing pin
A titanium firing pin will reduce the risk of a series 70 1911 firing when dropped. Titanium is lighter than steel, and Drakes found it takes more height to cause a series 70 M1911 to fire when the pistol is dropped on its muzzle.
And the last way I know of, is with a less sensitive primer. Of the American primers on the market, only CCI has made its military primers available to the public. These are the CCI #41's and CCi #34's. I heard Federal offered mil spec primers, but I have never seen one, and I don't know anyone who found them. The military primers are less sensitive by virtue of increasing the distance between anvil and cup, and per one book, altering the shape of the anvil tip. To what shape, I don't know. Primer manufacturer's don't like to change their mixtures, so I have been told that primer mix is the same between commercial primers and military primers. I do know primer cup thickness and hardness will change the sensitivity of a primer, and that CCI customer service told a caller they don't recommend bench rest primers for gas guns, because the primer cup is thinner. Maybe it is.
The idea of burying the bunny deeper in its hole, will not prevent slamfires unless the primer is so deep, the firing pin can't set it off.
The first thing to do, is clean out the firing pin channel, so there are no rat's nests, or grease/oil to gum the firing pin in a forward position. Then, use the least sensitive primer you can find, which are the CCI mil spec primer.
Always feed the weapon from the magazine, don't drop a round in the chamber, or point the muzzle at the ground, and release the bolt. That little extra speed due to gravity is why the NRA changed the standing position loading rules. Used to be you could load on the shooting stool, and if you had a Garand or M1a, you had the muzzle up, round in the magazine, and tripped the bolt. Then came AR15's, and shooters placed the muzzle on the shooting stool. Dropped a round in the chamber, and once in a while, the rifle slamfired a round through the shooting stool!
The change upset me when I shot a bolt gun. There is zero chance of a round slamfiring when the bolt is closed, and it was easier to press a round in the chamber with the rifle butt on the shooting stool. Now I have to hold the rifle up, get a round in the magazine, and close the bolt, while not sweeping the firing line.
And, never trust a weapon with a free floating firing pin to never slamfire. Primer sensitivity varies by lot, and within the lot. You can't trust the little buggers, even mil spec primers slamfire. They are on average less sensitivity, but, nothing is perfect!