Sub-Sonic Loads for 7.62x39 and 300 Blackout:

My mate "Cutters" has been busy lately working-up sub-sonic loadings for his Saiga Semi-auto 7.62x37mm and for his Remington 700 B/A rifle chambering the .300 Blackout. - Both of these particular rifles are 'A-Cat' firearms here in NZ.

Along the way he has responded to a Remington factory re-call notice that required the fitting of a replacement trigger assembly to the 700s action for safety reasons.

The sub-sonic loads for the Russian Saiga mean that he is permitted to use it on our pistol club range. - Our range site is certified for use with all New Zealand legal firearms - but out of consideration to neighbouring properties we have restricted to use of centre-fire rifles (supersonic) and shotguns.

'Cutters' Silenced Saiga 7.62x39mm Russian.

And 'Cutters' - like me - fully appreciates the use of  a silenced firearm with its obvious benefit of causing much less disturbance to hunted game, pests and neighbours.

It needs to be said that there is no such thing as a silent firearm - all those movies showing a revolver fitted with a screw-on "silencer" that goes "phttt" when the trigger is squeezed are total works of fiction. - However a generously sized well-made sound-moderator can be very effective in taking the BANG out of bang when fitted to the most suited firearms action.

 Revolvers are not suitable because of the leaky cylinder gap - and semi-autos have actions that cycle open before the gas pressure has dissipated allowing noise to escape (unless you lock the action shut).

For best effect with a conventional moderated firearm - select a manual or bolt-action.

  - All that being said is as a general rule - However there is a system (Russian) that uses 'captive-piston cartridges' that is very close to silent for covert use.( See my post 10 July 2014).

Sub-Sonic 7.62x39mm:

 - Cutters has worked-up a satisfactory load that works in his Saiga when fitted with his 'silencer'.

First drill-out the flash hole from the primer pockets to 9/64 of an inch (and de-burr) keeping these cases solely for sub-sonic loading. The cases are primed using Large Rifle Magnum primers. He is using cast-lead gas-checked flat-bottomed projectiles with a pointed nose weighing 186gn that he buys for 27cents NZ each. He applies a light taper crimp.

The bullets are seated in front of 11.5gns of AR2205 powder (as thrown) and this loading - in his gun - works well and cycles the action when the silencer is mounted. - It does not cycle the action if the silencer is removed.

 - Warning: This is an example of a safely developed hand-load - do not copy it and presume that it will be safe in your rifle.

Photo Shows Standard Cartridge & pulled Bullet then Cast Lead Projectile & Subsonic 'Russian' (- .22R.F Long-Rifle for comparison.)

Here in New Zealand this load works-out cheaper than imported Chinese military surplus ammunition.

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.300" Blackout Sub-Sonic:

'Cutters' .300 Blackout gun is a pre-owned Remington 700 'SPS Tactical' with 5R rifling in 1:7 twist suitable to stabilise heavier bullet weights.

'Cutters ' is developing loads using a range of projectiles for the 300 Blackout all intended to make sub-sonic velocities (as well as normal super-sonic loads). He has a selection of bullets weighing 120gn, 150gn, 166gn, 186gn, and 235gn .

Cutters comments that the limited case capacity of the 300 Blackout suggests that there likely would not be any issue with too much air-space behind the loaded pills - as the cases are roughly similar in size to a .357 Magnum pistol round - but may be fitted with larger/longer pills.

300 Blackout Case compared to .357"Magnum Revolver Round.

You'd best be warned that fitting "silencers" to guns is not always a simple job - Cutters has an issue with deflection (alignment) on one of his after-market fitted moderators - and I have a semi-auto .22" pistol that tends to destroy silencer baffles repeatedly (that's again & again & ..)!

Note: Rod (gundoc@xtra.co.nz) says that misalignment problems are readily corrected by a decent gunsmith - even my sloppy muzzle thread issue on my Browning Buckmark can be resolved.

- It all adds "spice" to life eh!

Marty K.

P.S. I've just viewed my "Audience Stats" and for the first time ever the American readers have been exceeded by France  - Wow - Bonjour mes amis.

After researching & writing 1,036 blogs I've got something NEW to try .. I've signed-up to Patreon. - In over five years I've not made one cent from this .. NOW you can send me a wee support $ - starting from $1. to get all this stuff from New Zealand - over a year that's nearly the price of one Shooting magazine. - Am I worth it?

https://www.patreon.com/user?u=16618870