Powder Stacking in Subsonic Non-compressed Loads

[BoomerVF14]

I heard about an interesting concept today involving a study on the effect of "stacking" the powder in subsonic non-compressed loads.

The idea: prior to firing the shooter lightly (and safely!) taps either the muzzle or the buttstock on the ground three times to stack the powder at one end inside the cartridge. Forward-stacking would involve tapping the muzzle, back-stacking the opposite.

The study examined both methods against a control group (no tap, normal chambering process), and even shot a group in which a supersonic cartridge was fired before every sub in order to burn off any powder residue in the suppressor.

Bottom line, the back-stacking method was shown to have the best accuracy and lowest muzzle velocity variance (100yd target).

Unfortunately, that is everything I know about the test and I don't expect to be able to get any more information about it... I don't even know if it was .300BLK (my semi-informed guess). My Google-fu isn't dredging up anything useful.

Was wondering if anyone else has tried or considered this, or what your thoughts are. It's certainly not a tactic one would want to include in a home defense plan, but it may have application in the next round of the .300BlkTalk 200-yd sub contest...

[dellet]

I heard about an interesting concept today involving a study on the effect of "stacking" the powder in subsonic non-compressed loads.

The idea: prior to firing the shooter lightly (and safely!) taps either the muzzle or the buttstock on the ground three times to stack the powder at one end inside the cartridge. Forward-stacking would involve tapping the muzzle, back-stacking the opposite.

The study examined both methods against a control group (no tap, normal chambering process), and even shot a group in which a supersonic cartridge was fired before every sub in order to burn off any powder residue in the suppressor.

Bottom line, the back-stacking method was shown to have the best accuracy and lowest muzzle velocity variance (100yd target).

Unfortunately, that is everything I know about the test and I don't expect to be able to get any more information about it... I don't even know if it was .300BLK (my semi-informed guess). My Google-fu isn't dredging up anything useful.

Was wondering if anyone else has tried or considered this, or what your thoughts are. It's certainly not a tactic one would want to include in a home defense plan, but it may have application in the next round of the .300BlkTalk 200-yd sub contest...

I'm guessing that you missed the first 10 seconds of the video where the host said "howdy UTOOBERS hold my beer and watch this"

What he was trying to do was determine if his load/powder is position sensitive and unstable. Which it probably is or he would not have been offering the wonderful advice and test process.

Method "A" is just plain stupid and probably was very erratic in the test.
The cartridge system was designed to have the powder sitting on the primer and for the fire to burn back to front, having the pressure build the same direction. The flash of the primer moves through the powder. Stacking all the powder at the front end in short terms changes the the way the pressure travels and also the curve. This is where a lot of talk about reduced loads going kaboom come from.

Method "B" is trying to compensate for the problem that might occur in a condition where the load is not quite all the way forward, or the erratic behavior of the primer flash going over the powder instead of through it.

Research Secondary Explosion Effect, and Powder flashover. These are the conditions he is trying to compensate for. Right amounts of the wrong powder and things can get interesting doing that.

Basically someone has a crap powder/bullet combination that he is trying to make work.

Lots of controversy as to whether loading too light can make things go kaboom, but something that is not controversial is using the right combinations keeps you safe.

[Jim Timber]

People have been using case fillers to resolve this for as long as people have been making cartridge ammunition.

Use different powder, or use a filler. No need to tamp the charge in hopes it'll stay put before you get back on target and pull the trigger.

[Dolomite_Supafly]

People have been using case fillers to resolve this for as long as people have been making cartridge ammunition.

Use different powder, or use a filler. No need to tamp the charge in hopes it'll stay put before you get back on target and pull the trigger.

Better yet, use a bullet designed specifically for the 300 Blackout and the powders normally used.

[L1A1Rocker]

Basically someone has a crap powder/bullet combination that he is trying to make work.

THIS!!!

10-15 years ago getting sub-sonic loadings in 308 was difficult, and dangerous if not done with extreme care. The powder industry just did not have any good offerings for it. As mentioned above, Secondary Explosive Affect, and Detonation were very real possibilities.

Today with the popularity of silencers, and the demand for sub-sonic loadings, we now have some very good powders for the job - although there is still the odd duck that has "special needs". What this guy is doing, need not be done any longer.

[hardcase]

I heard about an interesting concept today involving a study on the effect of "stacking" the powder in subsonic non-compressed loads.

The idea: prior to firing the shooter lightly (and safely!) taps either the muzzle or the buttstock on the ground three times to stack the powder at one end inside the cartridge. ...

I would not want to be around anyone who tried to shoot a gun after poking/taping the muzzle into the ground.

[dellet]

I heard about an interesting concept today involving a study on the effect of "stacking" the powder in subsonic non-compressed loads.

The idea: prior to firing the shooter lightly (and safely!) taps either the muzzle or the buttstock on the ground three times to stack the powder at one end inside the cartridge. ...

I would not want to be around anyone who tried to shoot a gun after poking/taping the muzzle into the ground.

The trick is to add taps until you get bolt hold open, then two more for reliability