Thread: 308 subsonic trail boss projectiles and loads

Im wanting to put together a subsonic load for my 308 using trail boss.
Just want it to be able to knock over hares quietly for my dogs dinner each day while on multi day trips ( and maybe a goose for a change of diet for me ).
But don't want to make a lot of noise and scare the deer and pigs.

So weight of projectile not important as it will be just punching through and have a good GWP to find the runners.
308 has a gunworks suppressor on it and 16" barrel so should be reasonably discrete.
Have dial up Zeiss on it with zero stops so should be easy to dial in the sub load in the field when needed.

Would prefer to stick with conventional copper jacket as don't want to upset the usual full power load with different fouling.

Thoughts and experiences appreciated.

90gr xtp is made for you, will expand at sub velocity.....very quiet due to low powder load.

I was at around 5. something grains from memory(trailboss) start high and work down.

Originally Posted by veitnamcam

90gr xtp is made for you, will expand at sub velocity.....very quiet due to low powder load.

I was at around 5. something grains from memory(trailboss) start high and work down.

That was what I was thinking ... just wanted to see if anyone else had it in use.
Will get some 90 grain XTPs next time Im in town and as you stated work down.

Did you use standard or magnum primers with the trail boss in the 308 ?

I have used trail boss heaps in the 44 and it fills the case reasonably well ... but never in a big case so need to check about the primers etc.

Only need standard primers with Trail boss ignites real easy

I used mag primers but only because that was what I had.

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Originally Posted by veitnamcam

90gr xtp is made for you, will expand at sub velocity.....very quiet due to low powder load.

I was at around 5. something grains from memory(trailboss) start high and work down.

what kind of accuracy can you expect at 50yds . . . and how much do you have to dial up from your full power load to get 50yrd zero . . . . cheers

Originally Posted by rossi.45

what kind of accuracy can you expect at 50yds . . . and how much do you have to dial up from your full power load to get 50yrd zero . . . . cheers

Two inch groups at 100yrds

Dial 15 moa for 100yrd zero

Originally Posted by rossi.45

what kind of accuracy can you expect at 50yds . . . and how much do you have to dial up from your full power load to get 50yrd zero . . . . cheers

Originally Posted by 7mmsaum

Two inch groups at 100yrds

Dial 15 moa for 100yrd zero

I dont recall dial but an inch at 50 should be well achievable, annealing the neck is a huge help in consistent velocity's with subsonics.

I use 200gn Lapuas and they shoot under an inch at 50m. I wouldn't recommend them for what you are doing though as they ricochet terribly.
I have found that I can use the top point of the heavy post of the reticule for my 50m zero so no dialling needed. I just have to remember to have the scope on 3 power.

Originally Posted by Shearer

I use 200gn Lapuas and they shoot under an inch at 50m. I wouldn't recommend them for what you are doing though as they ricochet terribly.
I have found that I can use the top point of the heavy post of the reticule for my 50m zero so no dialling needed. I just have to remember to have the scope on 3 power.

How much powder are you using?


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Originally Posted by Manu

How much powder are you using?


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10.2 gns.

Finally got around to sorting this load.

308 with Hornady 90 XTP Subsonic with Trail Boss.

Worked down from 10 grains in one grain increments to 7.0 grains when it went subsonic and reasonably quiet.
Then tried 7.5 grains and plenty of noise again.
So 7.0 grains is perfect in my 16" Blaser 308 / Gunworks suppressor.
Then tested for grouping and drop at 50m on the target low vertically but well centered. Rapid fire group 25 to 30mm 5 shots.
Wound in 5moa on the elevation dial and it was absolutely perfect for dead on hold at 50m. Slow fire 25mm group.
Nice and easy to remember and with zero stops also easy to go back instantly to zero for usual full power supersonic load.

Will need to check dial up at ranges out to 100m but its pouring with rain ... hence being able to finally have time to sort this out.

Nice.
Will be interested to hear how they work on game.

I got so excited that I put on a rain coat and a target on the 100m range.
Have the luxury of shooting out of the gun room on own 100m range so very quick and easy to do load development and hold overs etc.

Took my time to dial up and confirm 16moa is perfect dial up for the sub sonic load at 100m.
And shot this 25mm 3 shot group while aiming at the small marker 'V' on the arm of the red cross.



So need to work up a chart from the known 5moa @ 50m and 16moa @ 100m and have 17moa available on the Zeiss 3-15x42 HD5.
This will be perfect to quietly shoot small game to feed my dog while away in big game / trophy hunting areas.

Now the hares around the farm are in a whole lot of trouble.
Haven't been shooting them at all for the last year so there are plenty around for a 'proof of concept' shoot up.
Also good for shooting the pesky hut possums who keep you awake at night but don't want to shoot due to the noise of using the full power ammo.

Originally Posted by akaroa1

I got so excited that I put on a rain coat and a target on the 100m range.
Have the luxury of shooting out of the gun room on own 100m range so very quick and easy to do load development and hold overs etc.

Took my time to dial up and confirm 16moa is perfect dial up for the sub sonic load at 100m.
And shot this 25mm 3 shot group while aiming at the small marker 'V' on the arm of the red cross.

Attachment 57636

So need to work up a chart from the known 5moa @ 50m and 16moa @ 100m and have 17moa available on the Zeiss 3-15x42 HD5.
This will be perfect to quietly shoot small game to feed my dog while away in big game / trophy hunting areas.

Now the hares around the farm are in a whole lot of trouble.
Haven't been shooting them at all for the last year so there are plenty around for a 'proof of concept' shoot up.
Also good for shooting the pesky hut possums who keep you awake at night but don't want to shoot due to the noise of using the full power ammo.

Looking good