.243 subsonic loads Tikka M55

Hey all I gave my brother my .243 and then realised there was a .243 sized hole in my gun safe so got myself another rifle and am after some load development help.

Im after some info/starting point on a subsonic load for a Tikka M55 .243
Also after suggestions on a hunting load out to 200m. I was using 2209 to good effect on my other .243 but when it ran dry I got a bottle of H414 and set about developing a new load for my Tikka .243. I have tried a heap of different projectiles and powder weights but have not found anything that looked particularly promising. Im loading to 15 thousanths of an inch off the lands.

I have spent quite a lot of time and money on the development already and I am almost at the point of giving the rifle to someone and paying for the load development and load blueprint. If there is anyone in Canterbury that can provide the service id be keen to hear from you.

Cheers
Strider

I use H414. Loaded it to 2.710 overall length to the ogive.

My howa liked 41.5 grains and a Federal Primer. S&B brass.

I was loading 95 grain targex. I have some flat base pro hunters for when I want to experiment.

What projectile are you reloading with?

I should be getting in theory around 2900 fps which is slow but it was accurate for me.

Not sure sub sonics would be easy. May have to pack the case with a case filler.

And finding a 6mm projectile which would expand may prove difficult

Trail boss?

So far I have tried the following: All with 414

Using Federal LR Primers and R&P Brass on its second trip around.

Sierra - 85gr HPBT with 43-44 gr
Hornady Vmax 75gr 40 - 42 gr
Sierra - 90gr TGK 42 - 43.5 gr casing had circular scuff at 43 gr so stopped there
Hornady 87 gr SP 40-43gr

I have worked up a few loads for seveal different rifles without too much difficulty but this one has been somewhat problematic.

The 90gr eld-x works well for me, doing 3140fps. The Sierra 85 hpbt and Hornady 87 sp shoot well too, as does the Sierra prohunter 100gr.
I haven’t tried subs in the 243. In the 308 a full load of trailboss is about 15gr, subsonic is 7.5gr in the 1:12 twist and 8gr in the 1:8 twist using Robert’s 151gr cast bullets, I think he does a 6mm cast as well (shooternz on the forum).