To drill or not to drill flash hole? :)

[shangai]

Hi, guys!

I am new here, and new in loading cast bullets.

I want to reload ammo as safe as it is possible. I wonder, is it necessary to "drill the flash hole to 3.5mm (9/64") to allow all the primer flash to enter the case and ignite the powder completely"? It is recomended for subsonic ammo. I want to reload moderate loads - about 1600-2000fps, with fast pistol powders, that is similar to subsonic loads...
I plan to have load density about 50%, and never below 40%...

Thanks!

[leebuilder]

Hey, never drilled any flash holes yet, but have expeienced unpredictabe stringing in groups and different amounts of report in my "mouse phart and cat sneeze" loads below 6grs of Red Dot and Unique loads.
Never used fillers and stopped crimping my loads. Lots of experience here i am sure someone will chime in with more info.
Lots of fun shooting the light loads, i have no croney and assume they are around 1000 f/sec.
Be safe

[Outpost75]

It isn't necessary to enlarge flash holes with the easily ignited, fast burning pistol or shotgun powders and there is no benefit to doing so. If you are trying to load slower powders such as 4198, RL7, 3031, 4895, 4064, RL15 or Varget at less than 60% of case capacity in cases such as the .303 British, 7.62x54R, 8mm or .30-'06, there is some benefit, but you are walking a tightrope between improved ignition and weakening the case, which could cause a burst if the modified case is inadvertently used for a full charge load.

I would limit the use of enlarged flash holes to light Cowboy loads, blanks and shotloads in revolvers, to prevent, case heads from setting back against the recoil shield, using them only when necessary with very light loads under 10,000 psi.

With reduced charges in which there is a great deal of free airspace in the case, ballistic uniformity is better served by using Winchester primers, which have added aluminum metallic fuel, intended to aid ignition in cold conditions. The desired product of an efficient primer is HEAT, not explosive force. Winchester primers are more effective in reduced loads than enlarging flash holes or using magnum primers of other brands.

[Shooter6br]

According to most articles you get shoulder backset if primer holes arent drilled out with bottle neck cases http://home.comcast.net/~gavinsw/guns/castbulletmilitaryrifle.pdf

[shangai]

...

With reduced charges in which there is a great deal of free airspace in the case, ballistic uniformity is better served by using Winchester primers, which have added aluminum metallic fuel, intended to aid ignition in cold conditions. The desired product of an efficient primer is HEAT, not explosive force. Winchester primers are more effective in reduced loads than enlarging flash holes or using magnum primers of other brands.

Winchester Magnum LR primers, or standard LR primers?

[Larry Gibson]

If you are using a push feed with a plunger type ejector in particular then, with really low pressure loads, the rifles cases can develop headspace problems. That can lead to miss fires in as little as 3 - 4 firings. I use well fire formed cases that take LR primers with the flash holes drilled out with 28 - 31 drill bit sizes.

I have thoroughly pressure tested such cases in the .308W using 4895 under the 311291 to 28,000+ psi with no indication of pressure problems. I have also found with the very light low density loads using the fast pistol powders that ignition is more uniform and powder position sensitivity is greatly decreased.

Larry Gibson

[Digger]

If you are using a push feed with a plunger type ejector in particular then, with really low pressure loads, the rifles cases can develop headspace problems. That can lead to miss fires in as little as 3 - 4 firings. I use well fire formed cases that take LR primers with the flash holes drilled out with 28 - 31 drill bit sizes.

I have thoroughly pressure tested such cases in the .308W using 4895 under the 311291 to 28,000+ psi with no indication of pressure problems. I have also found with the very light low density loads using the fast pistol powders that ignition is more uniform and powder position sensitivity is greatly decreased.

Larry Gibson

Fast pistol powders ... like WST maybe ? , in a 308 ... intriguing !
but do not want to hijack the thread here ...

[bangerjim]

All the load data books I have show TiteGroup and other fast powders with loads for 223/30-30/30-06 (tel:223/30-30/30-06) with loads of around 3-4 gns. And no drilled primers! I load and shoot those all the time with various boolit weights. They simulate approximate 22LR's but are faster.

I have never had any primer problems. I only drill out ( AND MARK CLEARLY!) any brass I do drill out for shooting HMG boolits and primer-only loads.....especailly in revolvers.

banger-j

[Outpost75]

Winchester Magnum LR primers, or standard LR primers?

They are nominally the same, Winchester magnum primers are not dedicated production, but simply sorted.

[Outpost75]

Fast pistol powders ... like WST maybe ? , in a 308 ... intriguing !
but do not want to hijack the thread here ...

WST works fine, about 8.5-9 grains in the '06 with 160-grain plainbase.

[Larry Gibson]

Fast pistol powders ... like WST maybe ? , in a 308 ... intriguing !
but do not want to hijack the thread here ...

How about Bullseye (WST works well too) with 90 - 200+ gr cast bullets in the .308W and even the 30-06?

Larry Gibson

[bangerjim]

They are nominally the same, Winchester magnum primers are not dedicated production, but simply sorted.



Last couple of 1K cartons of Winnies I bought said "for standard OR magnum loads".

go figger!

banger-j

[sthwestvictoria]

The OP does not state what cartridge they are using - if is a rimmed case with headspacing on the rim then there is not going to be any need to drill flash-holes.