Is it possible?

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Dehan

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I am shooting a 7x64 and use it mainly for bush pigs here in South Africa, I got it silenced but now i want to know is it possible to load a sub sonic round? what is the in's and out's of sub sonic rounds?
 
Probably. A main issue will be finding a right bullet weight that will stabilize in that barrel with reduced velocity. Don't stick a bullet!
Hopefully this'll be moved to the handloading section. Good luck.
 
Dehan, were I to try to do what you are trying, I'd consider "The Load".. however, your 7mm is less than the slightly larger .30 or larger commonly recommended. People (and me) have been using/doing this for many decades.. I've only used heavy cast lead out of my 30-06 though. A chronograph might come in handy. Be careful and good luck once again.

http://members.shaw.ca/cronhelm/TheLoad.html
 
7mm subsonic screams cast lead- and a heavy for caliber bullet, too.

I'd try something in the 180- range- but I have no idea what your twist rate is on your rifle.

Finding a subsonic load is primarily a math problem- making one thats accurate, and accurate in your rifle is going to be the quest.
 
If you can find any sub sonic load data for .280 Remington or 7mm-06, those may be safe data. Or if you have access to Trail Boss you can follow IMR/Hodgdon's guidelines for creating light loads with it. There's just not much data out there for the 7x64. There isn't any sub sonic data here but you might be able to use this someday http://petloads.com/members/search.cfm?CFID=28735236&CFTOKEN=73542278
 
subsonic rifle loads

Have a look at these 3 WEB pages.

http://guns.connect.fi/gow/arcane1.html
http://guns.connect.fi/gow/arcane2.html
http://guns.connect.fi/gow/arcane3.html

The articles describe using a variety of powders, including Unique to achieve subsonic loads. Unique was originally developed as a reduced load rifle powder in the late 1890s. The history is particularly fascinating.

Fairly heavy for caliber cast loads are the thing to use.

I have another article that I will try to find that has some more specific data.
Here it is:
http://www.gmdr.com/lever/pistolpowi.htm

It is imperative that you check after each shot that the barrel is clear before firing another.
 
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So the main idea will be to find a heavy projectile with low velocity? According to science then, a projectile with a round nose and 175gr will be a good starting point? well here in south africa we only have access to our somchem propellant which differ from your American propellant in burning rates but i have compared my propellant to the IMR4850 which is more or less the same. At the moment i load 150gr projectiles with 52,5gr of powder. Still have a lot of research to do on sub sonic rounds.
 
Fast powder like is used in handguns is going to work the best for subsonic loads. Careful to use small amounts.
 
well here in south africa we only have access to our somchem propellant which differ from your American propellant in burning rates but i have compared my propellant to the IMR4850 which is more or less the same.
Click to expand...
Are you saying in SA, you only have one powder with which to load all ammo? How in the world does that work?

EDIT: Oh, I found more info: http://www.jjwapens.com/somchemballisticdata.htm

Looks like Somchem has a pretty decent variety of powders to choose from, including one (MS200) that is listed as equivalent to Red Dot, which is used in "The Load" (http://members.shaw.ca/cronhelm/TheLoad.html).

Unfortunately, experimentation is a dangerous and tricky business.
 
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If this http://www.reloadersnest.com/burnrates.asp burn rate chart is correct, you'd probably have the best results with S121 or MS200. MP200 may work as well but it's a little bit on the slow side. I don't think I would ever attempt it with any Somchem powders besides those three. Going by density, volume, and burn rate, I believe my choice would be MS200 if I were limited to Somchem powders. It appears to be pretty close to Red Dot in all aspects and Red Dot is pretty popular for this type of purpose. 13gr of Red Dot is supposed to be a good load in most .30 cartridges. Taking all of that into consideration I would probably start with 8.0gr of MS200 and slowly work my way up until I found an accurate load or see signs of over pressure.

After typing all of this I found http://people.ru.ac.za/ccfj/shooting/load-dev/subsonic.txt

Hope that helps. After doing a little research on that caliber I think I'd like to own one someday. What type of rifle will you be using? A Mauser?
 
Sam i meant that we only have one manufacturer which is providing us with propellant. KansasSasquatch thank you for the useful info!! I own a Musgrave 7x64. Is a company in South africa. but yes its a mauser action. I sure as hell not gonna test the first bunch i load in my rifle, will build myself a mechanism to set off a few to see how the ms200 react in the brass. I can highly recommend the caliber above a .270! and as for the 7mm projectiles i love having high BC values. As far as I know its only Tikka that still develop a 7x64 caliber.
 
No problem, my google-fu just happened to be strong this morning. The second link I provided ( http://people.ru.ac.za/ccfj/shooting/load-dev/subsonic.txt ) actually suggests MP200 would be better than MS200. Try your best to get your hands on the Lyman Cast Bullet Handbook. The 4th edition is the most current but I've read many complaints that it lacks a lot of data that was in the 3rd edition. The 3rd edition seems to still be available straight from Lyman (I don't know if they'll ship internationally) http://www.lymanproducts.com/lyman/publications/cast-bullet.php . Once you do that you should consider using any data they have for .280 Remington (aka 7mm Express Remington, NOT 7mm Remington Magnum) and reducing it slightly. That link suggests that S121 is a poor choice because it's a fine ball powder. MS200 is close to Alliant Red Dot, MP200 is close to Alliant Unique, and S265 is close to IMR 4227. Just look for data using your bullet style with one of those powders, start at minimum charge, and work up slowly. Since you'll be using it for hunting you may really want to consider using an inert case filler between the powder and bullet, just in case Somchem powders are position sensitive. That's about as much data as I can give you for a cartridge I had never heard of until yesterday. Be safe and have fun. If you have any doubts about data you find, it may help to contact Somchem directly and see what they have to say. Let us know how it turns out.

Edit: and if you can ever manage to get your hands on some IMR Trail Boss, snatch it up.
 
Dehan said:
Sam i meant that we only have one manufacturer which is providing us with propellant. KansasSasquatch thank you for the useful info!! I own a Musgrave 7x64. Is a company in South africa. but yes its a mauser action. I sure as hell not gonna test the first bunch i load in my rifle, will build myself a mechanism to set off a few to see how the ms200 react in the brass. I can highly recommend the caliber above a .270! and as for the 7mm projectiles i love having high BC values. As far as I know its only Tikka that still develop a 7x64 caliber.
Click to expand...
Lots of manufacturers produce the 7X64mm.

The Somchem S365 is close to IMR4350.

What is the reason for the sub-sonic loads?
 
P1110403.jpg

P1110399.jpg

this was the last pig i shot before i had to come back to university haha but atleast its almost holidays again!!
 
Andrew its for hunting bush pigs at night and at times i got to a sounder of about 30 pigs on one maize land.. so would like to take out as much as possible
 
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