what do you look for in sub sonic loading

[love2shoot]

While I am not loading for a Whisper.......maybe you could call it a mini whisper ......it is a 7.62x25 tokerav loaded with 180 to 220 grain projectiles.

Just wondering what people are looking for on there reloading of subsonics.....

100% powder burn?
Case Capacity fill?
chamber/port pressure
or mostly on what will get you velocity.

Also, what kind of a difference are finding using magnum over standard primers? or has anyone checked the difference to se if it gives a more effective powder burn?

I have also found that for me, with the heavier projectiles Quickloads is a couple hundred FPS high on the velocity then what I am actually getting out of my 12.5" barrel.

I did load up some with Lil' gun powder for this round of reload testing/chronoing.

[Titleiiredneck]

I use match primers, better concistency, i look for vertical stringing and speed under 1045 fps. Better to stay away from magnums since they can increase pressure to get you above subsonic during temprature change.

Usally just set up a chrony and go from there, once i get a good spread of fps i then check for vertical stringing and then i stick with that load until winter/sumer change and do it over again.

[i8asquirrel]

I look for accuracy. If I cant hear a sonic crack I figure thats good to go. But I want it to shoot under 1 moa.

[buffetdestroyer]

One issue that you need to look into is consistency within a wide range of temperatures. Otherwise you can end up going over the sound barrier (when hot), under the cycle pressure (when cold in an AR) or potentially squib and ruin a good barrel (too far under the cycle pressure that it doesn't exit the barrel).

A Chrony doesn't lie and picking something between 1,000 and 1,050 fps that consistently cycles your action (if on an AR platform) is ideal.

I found a load that worked with 2400, but switched to Vihtavuori N110 because it is more consistent for me. 8.1 grains of N110 works subsonic with and without the gas block turned off for maximum quiet and versatility.
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Granny blowjob

[Hoser]

I look for accuracy. That is all.

Single digit ES is key.

Trying to hit small targets past 200 yards is tough when your velocity is all over the map.

For my bolt gun I shoot Sierra 220 SMKs that I point up using a Whidden Pointing die. I also use Lapua brass, Federal primers and N-110.

[love2shoot]

I do not quite have the case capacity that ya'll do, and so far with 3n38 and 2400, the velocities were lower then QL predicted. atleast with the heavy projectiles. it is real close with the lighter projectile. I do not have the case capacity that ya'll have. but the 300 whisper is the closet thing to what I have am doing. so I came here to get as much knowledge as I can to apply it to my setup.....that and I eventually want to 300 whisper bolt action.

Using N110, 6.7grn for 99% case capacity, quickloads shows I'll have 1063 velocity, but if it holds true with other powders so far, I expect that to be about 800fps range in actuality with 200grn SMK. pressure at the gas port looks like it will cycle unsurpressed........

This is a fun project, sometimes I think a 300 Whisper AR would have been an easier build for subsonic shooting......but then I would not have the supper cheap plinking ammo.