Subsonic Reloading

[tau_1point618]

I have been considering getting into reloading subsonic rounds for a few reasons:

1) I want to test out the no gas selection on a rifle I recently purchased.
2) I would like to become more knowledgeable in this area, with the expectation of eventually purchasing a suppressor.
3) I would like to use the reduced recoil to improve my shooting technique, while also developing muscle memory with this rifle

With that said, can anyone point me to a GS, site, etc. where I can purchase subsonic .308?

Does anyone have a website, book, person, where I can learn some more about working up a subsonic load?

Any tips, recipes, knowledge is appreciated. Thank you in advance gents -- Rich

[338RemUltraMag]

It is a good thing for us to know what you are shooting, subsonic reloading is easy enough, but you always work DOWN, beating or D/Ting a stuck jacketed bullet out of your bore is a real pain in the ass.

I assume you are using a 300 BLK? If so I think Reloader 7 will go subsonic but still give enough gas to cycle an AR-15

[tau_1point618]

Brain Fart,

Shooting LWRC REPR in 7.62x51 I have a 20" Barrel with 1:10 twist.

[mtntroll666]

http://http://www.imrpowder.com/PDF/Trail-Boss-data.pdf
Try this.

[338RemUltraMag]

For a 308 start with 10 gr of unique (about 1400 fps) and work down in .5 grain steps, you need a chrono for this but you can safely go subsonic.

[Toxicodendron11]

Not .308 but this my experience on the subject.


http://forum.pafoa.org/ammunition-re...223-loads.html

[daschnoz]

First off, do you have a chronograph? You will need one for 2 reasons:
1. Are your loads REALLY sub-sonic?
2. If you start seeing erratic speeds over the chrono, you're not getting consistent powder burn. THIS IS BAD!!!!

A program like QuickLoads would not be a bad investment either. Yes, it's coin, but it is less expensive than a trip to the emergency room.

Do as much research as you can on the topic before you start down-loading your rounds. Yes, you're dealing with lower powder charges, but it is very easy to blow up a gun if you don't understand the results that you are getting over the chrono. It only takes one round that spikes the pressure over limit to ruin your day.

Here are a couple of good pages to look at:
http://members.shaw.ca/cronhelm/762ProjectRifle.html
http://members.shaw.ca/cronhelm/762Page.html


I load these

in 308 over 7gr of Unique.
(get the mold here --> http://noebulletmolds.com/NV/product...roducts_id=205 <---)

If you run a jacketed 240gr Sierra bullet, 7gr of Unique should get you close to sub-sonic, and still be safe. 10gr of Unique should put you at about 1200fps and is still safe on the pressure.

Do know that you will get looks at the range; they come from 2 different camps. The first camp gives you the 'what the hell do you need something like that for' look. The look from the other camp is usually followed by something along the lines of 'what are you shooting, and how can I get some'.

Feel free to drop me a PM if you have questions.

[Nate7667]

My personal cheap 308 bolt gun load in a 18" 1:8 twist is 180grSP over 10.1 grains of Trail Boss gets me 1020fps avg. and 1/2" groups

OP:
With your twist rate, use caution with anything over ~200 projectiles. You do not have a fast enough twist rate to keep the longer bullets stable. This is more important with a suppressor on the end of your barrel. You can have a good chance of getting a baffle strike.
As always, test for key holing before you mount your can.

You want to lube the bullets as well. A very very skim coating of Crisco on the projectile before seating will work fine.
Also, drill out your flash holes. See the link below for more info.
Mark you cases if you do drill them out. I like to run a blue marker around the inside of the rim.
Loading full power rounds with a drilled out flash hole will make for a bad day.
http://members.shaw.ca/cronhelm/DevelopSubsonic.html

[tau_1point618]

Thanks everyone for the feedback thus far. I had a feeling that subsonic ammo would be more complex than simply working down a load. I do have a shooting chrony.. Will I need a scale that is more accurate than 1/10 grain?

[Nate7667]

Its not that much more complex. To me its just as time/detail oriented as reloading any other cartridge, just an extra step or two. Just take your time and pay attention to what you are doing like you normally would.
The outcome is well worth the added work.

Like posted above, work your way down with your loads using the chronograph.

No, if your scale can do 1/10 you are good to go with the one you have.