Subsonic Creedmoor

[Too Deer]

Does anyone have any load data for 6.5 Creedmoor subsonic ammo, using Vit N310?

I see that @phaedra has posted previously about using 150gr cast bullets but I'm planning to use 140gr or 160gr jacketed bullets.

Any assistance will be gratefully received!

 

[phaedra]

5gr or N310 will happily work with both of those weights, obviously chrono your loads to get an exact velocity.

 

[Too Deer]

5gr or N310 will happily work with both of those weights, obviously chrono your loads to get an exact velocity.

Thank you!

 

[NullMac]

Is N130 very low density ??

 

[Foxyboy43]

Is N130 very low density ??

N130 or N310??
Be careful - the 100 series is generally for rifle whilst the 300 is for pistol!
My own powder of choice for .308 subs is Titegroup but I afraid I have no load for bunworrierwearers.

 

[petlowe]

There will be a lot of rattle room in that case, people tend to put wadding in to stop migration, the question has to be asked why. Even a 300BLK isn't a clever load for subs without a >200gr pellet.

 

[One on top of two]

Your get it stuck take a push rod with you .

 

[Ciganka762]

I've just had a look at some figures on Strelok as I also have a CM and have considered experimenting with subs.

Even with a 139g scenar (what I happen to have set up at present) Strelok suggests a 70m zero with a MPBR of 82m given an 8cm diameter target. Thats assuming 1050fps.

Logically 160g is going to take a further toll on those ballistics.

Is anyone using 6.5cm as a subsonic in the field that can say how their getting on with it?

I'm assuming the 'use case' is relatively close range foxing in areas where you don't want any disturbance?

 

[Smellydog]

I'm assuming the 'use case' is relatively close range foxing in areas where you don't want any disturbance?

Like where you could use a 22 maybe.....

 

[Foxyboy43]

Dunno about a 6.5 but a .308 165 gns trundling along at 1050 fps delivers just north of 400 ft lbs so would definitely sting! For short range 50/60 yards they are certainly very accurate too - see my avatar - Mosin Nagant subs at 50m but at 100 - nah…..

 

[User00044]

I ran this , simply out of interest .
Having never loaded subsonic , is it normal for such a low load/fill ratio ?

22.6% with 6 grains of N310 , ELD-X 140 grain , 22" in barrel. Predicted velocity 1142 fps , 5 grains = 1042 fps , 19% fill .

 

[Smellydog]

I ran this , simply out of interest .
Having never loaded subsonic , is it normal for such a low load/fill ratio ?View attachment 340856

22.6% with 6 grains of N310 , ELD-X 140 grain , 22" in barrel. Predicted velocity 1142 fps , 5 grains = 1042 fps , 19% fill .

Well I'm shooting 9 gn of Herco and just going super.
I started at 6gn.
30-30win though.
Low case volume with the RIGHT powder isn't a problem. The problem is choosing the right powder!

 

[jthyttin]

Your get it stuck take a push rod with you .

This. And 140-160gr jacketed bullet will be VERY stuck, you will ruin a cleaning rod trying to tap it out. I can imagine 5gr of N310 works with cast bullets, but quite confident it won't work with jacketed.

Recipe for subsonic loading in rifle cases is to start high and work your way down. And you must really make sure the bullet exits, since recoil will be negligible.

You must be patient in developing the load, since muzzle velocity will vary greatly (tens of meters per second) depending on shooting cadence, bore condition and probably also powder placement. Up to 50m or so, the velocity variation won't play a big role in POI/POA but at 100m you can expect at least 10cm vertical spread if you don't get the variation in check. Bullet weight / length is kind of paradox, you don't gain any terminal performance (unless you get consistent tumble) and interior ballistics is a wash with largish case capacity and longish barrel. Yes it's easier to get consistent burn and engraving with heavier / longer bullet, but other interior ballistics is playing against you.

 

[Foxyboy43]

See attached - same load of Titegroup works really well in .308 and 7.62x54R.

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