Hello all,

My PH in Namibia has a .375 H&H with a suppressor installed. He uses it in culling operations. He is having a terrible time coming up with an accurate subsonic load for it, probably because of the low loading density with the powders available to him. Do any of you have experience with this? He would like to shoot 300 grain bullets at speeds just below the speed of sound.

He's tried Kapoc and corn meal over the powder without much luck.

Thank you for any advice that you can offer.

Lyman shows a load of 11.0 grs of PB under a 265 gr cast bullet that runs 1075 fps out of a 24'" bbl. Their data does not mention the use of a filler with this load.

Unique, or Red Dot or Green Dot, 700X and 800 X would be some good powders to try.. Blue Dot is actually listed in some load data in cast manuals...


these powders shouldn't need any filler, and are going to be fairly accurate..

I am also interested in all loads for subsonic cast and jacketed bullets in .375hh!
I have a suppressor and thought of developing a load for roe deer with a 300 grain or heavier bullet.
Any data with Norma, Hodgdon, vihtavuori powders?

Sincerely
Daniel

Huglu,

Contact DUK..he is a German member of the forum, but he has done some loads with N110 in ther 338 Win Mag,.. he might be able to give you some points of reference....

ya think that a 300 grain bullet is big enough for those roe deer???

I use both N110 and Blue Dot for the .338 and the 9.3x74 R, both at around 720 m/s and 670 m/s and thus, twice supersonic.

Powders of this range are most likely too slow to reach sonic speed with heavy bullets for this caliber. As stated, faster powders like Unique, N320 or Red Dot would do the job better. A calculation with Quickload indicates that 10 grain of Red Dot should give 340 m/s or slightly above sonic speed with a 300 grain bullet. 10 grains N320 ought result in 323 m/s from a 600 mm barrel.

However, I'd presume that for this extreme load QL is not totally precise, I'd just give it a try, as Seafire recommended, without any filler. Big handgun cartridges contain lots of air, too.

The most likely powder he can get is Somchem's S265. I don't think Rosenthal's has stuff like Blue Dot etc. He can try 27gr of that and a 265gr RCBS Cast Gas Check bullet which will be subsonic. No need for a filler.

I've not experimented with 300gr jacketed bullets. He should try Sierra 200gr bullets though, they are pretty good for this kind of app.

Thank you, all, for your suggestions.

Daniel,

for a good roe deer load I would not necessarily goe subsonic. Use the 200 grain SP bullet from the .375 Winchester mentioned here, ought to be available in Sweden as well, load it to about 600 to 700 m/s with N110 and whack them good. I'd bet you will have them drop like hit by the Hammer of Thor, no meat wasted, either.

This load would, I bet, kill a moose as well.

Gents,
Thanks for all suggestions so far!
It is really interesting to see if it is possible to get an accurate subsonic load.
I do have the Sierra 200 gn FN bullet, but it just does not want to perform in my rifle. It makes 3-4" patterns at best at 100 m, this is regardless of velocity. At higher speeds it is a varmint bullet, it fragments and lacks penetration, furthermore it fouls the barrel incredibly fast. (It´s excellent for seals, beavers or other head shot candidates though.)
For moose and brown bear and other larger animals I have either the 300gn Norma ORYX (-useless crap! too soft!!!) or the renowned 300gn SAF which does the work always. Those are supersonic. But, since I do have a suppressor installed, I would like to have a "silent" load as well. It is no problem for me to shoot a roe with a 300gn Swift, but if I could do the same thing and still be within the legal requirements of atleast 800 joule at 100 m it would be more fun to do it without the neighbour hearing it.
I think that it would be easiest to achieve the legal energy requirements with a bullet that is as heavy as possible. Therefore, 300+ gn.
Thats partly what handloading/reloading is about, to make things that factories cannot/do not want to do for economical or other reasons...
Why do I want a subsonic load? because I CAN.
There are factory loads to cater for every hunting situation but I would like to try something different. Not only to try to get a good DG load, but also to make it a silent but deadly stalking load, these are just end members of the calibre loading spectrum.

I would on the other hand not have any SE-effects or lodged bullets in the barrel, so I will take it safe and sound, but without any noise please...

Sincerely
Daniel

Daniel,

Still try Blue Dot if available in your 375 with the 200 grain Bullet...

Blue Dot has tightened up a lot of rifles that grouped very poorly, but did some pretty darn good accuracy with Blue Dot...

maybe if you have a friend who has a little you could try out.. instead of purchasing an entire pound...

I have one 243 that is terrible with almost any loads.. especially factory loads.. however Blue Dot and SR 4759 both turn it into a half inch shooter at 100 yds... I don't question why.. it just works, and saved the gun from getting rebarreled.. or replaced...

cheers
seafire

Greg Mushial has a bunch of 240gr cast bullet data on his web page.

http://www.gmdr.com/lever/lowveldata.htm

I use a lead bullet and 9 gr of Red Dot for about 1000 fps in my .375 H&H.

I stocked up with Red Dot a few years ago when I heard rumors that the Swedish distributor was going to stop carrying it. Don't know if this happened or not though.

Note however, that cast bullets may give poor accuracy in a suppressed rifle, and the lube may be hard to clean out of your suppressor (depending on its construction).

The 200g jacketed bullets mentioned above work fine for practice (all I've used them for, so far).

John

Thanks for ideas again!
I just checked the maths on the 200gn bullet, and at speed of sound it gives a muzzle velocity of ca 750 joule, which would disqualify it as a roe bullet for hunting by legal reasons. The gas checks and cast bullets seem interesting though.
I dont know how to clean the suppressor, it is in one section and cannot be opened in any way. It is just to screw it on and off, but no moving parts since all is welded.

Would not just 9 grains of red dot leave a lot of space in the cartridge and the risk of inconsistent ignition? or is it any kind of filler involved. I have never seen red dot in sweden, nor have I seen the grainsizes of the powder.

I am more and more thinking about getting some mold to cast my own plinking bullets. It is getting too expencive to practice with the gun.
As of now it is heavy bullets thats most interesting, since the sfn 200gn is still somewhat reasonable in price.

Sincerely
Daniel