TC338
Well-Known Member
Looking for subsonic 308 win loads for suppressed deer hunting.
Subsonic 308 loads
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MudRunner2005
Well-Known Member
Use Trailboss and large rifle primers. You will have to work up a load for yourself to find out what stays subsonic in your rifle. I just made some for my buddy to shoot suppressed in his rifle.
Some people say to drill-out the primer pockets to 9/64", but I didn't on the ones I loaded up for my buddy. I've read of folks doing it both standard primer pockets and drilled primer pockets.
Some people say to drill-out the primer pockets to 9/64", but I didn't on the ones I loaded up for my buddy. I've read of folks doing it both standard primer pockets and drilled primer pockets.
TC338
Well-Known Member
Thanks for the info. Could you give me a good starting point? What bullet? Coal? Thanks
MudRunner2005
Well-Known Member
For friend's guns, I use a standard COAL of 2.810" for .308 Win. Simply because it keeps things simple, and they should have no problems feeding from the mag and using it as a repeater.
I loaded up some Nosler Custom Comp 168's for my buddy (he just wanted some for target loads, not hunting), and the Nosler CC is the cheapest option next to a Hornady Match 168 BTHP. Both are good options for cheap target shooting.
Nosler Custom Competition Bullets 30 Cal (308 Diameter) 168 Grain
Hornady Match Bullets 30 Cal (308 Diameter) 168 Grain Hollow Point
As for a starting load, I would start low around 9.5 grains of Trail Boss, working up in .2 grain increments (while shooting over a chrono) to find at which powder charge your particlar rifle goes supersonic. Then back-off .2 grains and you should have your subsonic load. From what I've read, most folks average around 10.5 grains of Trail Boss with a 168 grain bullet (that's not a guaranteed load, just one that I've read a lot of people shooting). Most folks try to keep it as close to 1050-1060 FPS to account for temp swing variations, to keep from cracking into the supersonic barrier when ambient temp, pressure, and humidity goes up (like it does in the summertime).
TC338
Well-Known Member
AWESOME!!!! Thanks
TC338,
What is your barrel twist? My .308 is 1-12" and at almost sea level I can only go up to around 200 grain matchkings before I start to get other than perfect round holes at 25 yards with sub loads. Not good for a can. My loads from 150-170 grain round nose are from 10.5-13 grain of trailboss. I have tried stuffing as much powder as I could behind a bullet (without getting too ridiculous as far as compressed) and couldn't get enough in to cause any pressure.
Unlike how most folks develop a standard (supersonic) load, DO NOT start low and work your way up! Start high and work your way down with TB sub loads as you don't want a bullet to stick in your barrel, been there and it sucks! I have also drilled out the flash holes with TB loads and from what I can tell it made my velocity increase a little and also dropped the spread a bit.
What is your barrel twist? My .308 is 1-12" and at almost sea level I can only go up to around 200 grain matchkings before I start to get other than perfect round holes at 25 yards with sub loads. Not good for a can. My loads from 150-170 grain round nose are from 10.5-13 grain of trailboss. I have tried stuffing as much powder as I could behind a bullet (without getting too ridiculous as far as compressed) and couldn't get enough in to cause any pressure.
Unlike how most folks develop a standard (supersonic) load, DO NOT start low and work your way up! Start high and work your way down with TB sub loads as you don't want a bullet to stick in your barrel, been there and it sucks! I have also drilled out the flash holes with TB loads and from what I can tell it made my velocity increase a little and also dropped the spread a bit.
TC338
Well-Known Member
Mine is a 1-10 twist.
MudRunner2005
Well-Known Member
Just remembered this video, and decided to post it up for you. Has a lot of good info in it, if you're just getting started with subsonics.
Also in the video, after proper calculations, he starts with 9.5 grains of Trail Boss as well... So, that's obviously not too low of a charge to start with (like I suggested in my first post). I knew it wasn't going to be, but yes, like was stated, you CAN start too low, but 9.5 grains would be a fine starting point for the .308 Win.
Another thing, a lot of people do work from higher to lower with subsonics, but that is because they don't want to go too low. Everyone has their preference. Part of the game is knowing where to start and where to end. If you know about where to start, then you shouldn't have any problems starting just slightly lower than your expected target charge, and working your way up for verification. Make sure you do your test work over a chrono.
[ame]http://www.youtube.com/watch?v=Ix2si1M2iM8[/ame]
Also in the video, after proper calculations, he starts with 9.5 grains of Trail Boss as well... So, that's obviously not too low of a charge to start with (like I suggested in my first post). I knew it wasn't going to be, but yes, like was stated, you CAN start too low, but 9.5 grains would be a fine starting point for the .308 Win.
Another thing, a lot of people do work from higher to lower with subsonics, but that is because they don't want to go too low. Everyone has their preference. Part of the game is knowing where to start and where to end. If you know about where to start, then you shouldn't have any problems starting just slightly lower than your expected target charge, and working your way up for verification. Make sure you do your test work over a chrono.
[ame]http://www.youtube.com/watch?v=Ix2si1M2iM8[/ame]
Wado
Well-Known Member
I dabbled a bit in subsonic .308's a while back but finally stuck to my 300 Blackout, it does the same thing and I bought it strictly for sub's so that's that. I started out with 220 grain Hornady round nose bullets that I hollow pointed and drilled about eight grains out of each one and fired them through a one in twelve twist Remington barrel screwed in a Mauser action. I drilled the flash holes and dry lubed the bullets before seating. My start charge was 13.8 grains of Trailboss and I never chronographed any but I know they went super just by the sound. I don't think you can cram enough Trailboss in there to get in trouble. I shot some into dry phone books at about twenty feet just to see what happened but never made it to the range with any. I know another shooter that loads 150 grain Ballistic Silvertips ( made for 30-30 Winchester ) with 10.2 grains of Trailboss and they do well in his one in ten twist Ruger, I ordered some projectiles but never have loaded any. Like everyone says start high and work down, keep your barrel clean and if you drill flash holes mark your brass. You might back a primer out with a high pressure load in a drilled brass. I have stuck a bullet in my 300 and it creates some anxiety just don't do a follow up shot. One of the gun shops I frequent had an AR with two Sierra Match Kings stuck in a barrel. If you do stick one clean the barrel before trying to push it out and plenty of lube helps also. I don't know anyone that has made an AR cycle a .308 sub, not saying it can't be done I just don't know that lucky devil. Pic's of my hollow pointer and 220 grain round nose into about four inches of dry phone books. It made it through but shucked the outer jacket. The last picture are some projectiles fired from a Blackout at subsonic speeds after being hollow pointed. I use 208 grain A Max as well as the hollow pointed round nose Hornady's but have never killed anything with the round nose variety. The A Max's don't expand at all and firing into dry paper they just bend or partially flatten. I have recovered some out of the burm I shoot against and they look unfired except for the rifling marks.
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redbullitt
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Your 308 will do fine with the 10 twist. Trail boss is going to be the easiest to work with. I usually wind up between 9 and 12 grains depending on bullet. Case fill is good enough. Never had much difference with drilled primer pockets, so I dont do it. Just not worth the effort in my experience. Your combination may be different of course. Primers do seem to matter; I have the best luck with the winchester LR. Small primer brass may be interesting to try, but I have not messed with it.
As to bullets, I suggest the flat nose 30 30 bullets in 150 or 170g. They have produced good results in multiple rifles. I have used the 160 FTX bullet a bit and it shows A LOT of potential. Will hopefully know more this summer when I get some time. The 180 RN is good as well. If you want to go heavier the 220 RN is excellent. I have not had any trouble stabilizing these from a 16.5 inch 10 twist 308. 1000 ft elevation, 30 to 90 degrees. Velocity between 950 to 1100 depending on rifle and load. I have had the best success with cast bullets in this application, though even if coated I try to stick to jacketed when suppressed.
Accuracy and precision can be tough here. You need to be on top of your form. That subsonic bullet spends more time in the bore than usual, so your mistakes will show up more than with a fast bullet. Your loading practices need to be top notch. 15 fps between shots WILL be a problem if you are shooting any distance at all.
Dont get discouraged. Keep working on it and you will eventually find a good loading. In my experience it is just tougher than usual. As far as groupings, I consider a CONSISTENT 2moa subsonic load to be good. 1.5moa CONSISTENT to be my target most of the time. If I can do better heck yes, but it gets tougher to get them tighter than 1moa consistently. It can be done though; its just not easy like most supersonics.
You should be able to get hunting accuracy without too much fuss. Deer and pigs inside 100 yards will be in trouble with trailboss and some 170 flat noses.
As to bullets, I suggest the flat nose 30 30 bullets in 150 or 170g. They have produced good results in multiple rifles. I have used the 160 FTX bullet a bit and it shows A LOT of potential. Will hopefully know more this summer when I get some time. The 180 RN is good as well. If you want to go heavier the 220 RN is excellent. I have not had any trouble stabilizing these from a 16.5 inch 10 twist 308. 1000 ft elevation, 30 to 90 degrees. Velocity between 950 to 1100 depending on rifle and load. I have had the best success with cast bullets in this application, though even if coated I try to stick to jacketed when suppressed.
Accuracy and precision can be tough here. You need to be on top of your form. That subsonic bullet spends more time in the bore than usual, so your mistakes will show up more than with a fast bullet. Your loading practices need to be top notch. 15 fps between shots WILL be a problem if you are shooting any distance at all.
Dont get discouraged. Keep working on it and you will eventually find a good loading. In my experience it is just tougher than usual. As far as groupings, I consider a CONSISTENT 2moa subsonic load to be good. 1.5moa CONSISTENT to be my target most of the time. If I can do better heck yes, but it gets tougher to get them tighter than 1moa consistently. It can be done though; its just not easy like most supersonics.
You should be able to get hunting accuracy without too much fuss. Deer and pigs inside 100 yards will be in trouble with trailboss and some 170 flat noses.
TC338
Well-Known Member
Thanks for the info but my suppressor idea fell through. Guess I'll just have to stick with the old fashioned ear plugs.
redbullitt
Active Member
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Bummer. Long barrel with subsonic loads, especially with a fast powder can be really quiet too! Definitely notably quiet.
If you want to get fancy, get a 26 or 28 inch barrel and counter bore it back as far as you care to. Makes a very big difference on sound. Extremely effective on smaller calibers like 22 lr and pistol.
Used to have a counter bored 357 mag that was a hoot with light cast loads.
If you want to get fancy, get a 26 or 28 inch barrel and counter bore it back as far as you care to. Makes a very big difference on sound. Extremely effective on smaller calibers like 22 lr and pistol.
Used to have a counter bored 357 mag that was a hoot with light cast loads.
TXAoudadKlr
Well-Known Member
Digging this one up.
Is it a waste of time running 308 subsonic?
The easy button appears to be 300 BLK
My thing is I'm interested in a 6.5cm first then have a second barrel a 1:8 for subsonic use.
Plan is to use the 230gr subsonic Raptors from CEB
Is it a waste of time running 308 subsonic?
The easy button appears to be 300 BLK
My thing is I'm interested in a 6.5cm first then have a second barrel a 1:8 for subsonic use.
Plan is to use the 230gr subsonic Raptors from CEB
QuietTexan
Well-Known Member
It's not a waste of time, just a square peg/ round hole situation. You can beat the 308 peg into the subsonic hole, but as you said there are easier ways to do it.
There are better calibers than .308 for subs also. 300 BLK and its predecessors worked around the dimensional restrictions of the standard AR-15, if you remove that there are a lot of good options.
The original 338 Whisper used the .470 bolt face, which would work with your goal of switching out with a 6.5CM. If you're restricting yourself to 1050fps, might as well put as much weight behind it as you can. The larger the bore, the heavier the bullet. The larger the bullet you stick into the case compared to the parent design, the less wasted case capacity you have to deal with.
Defensive Edge will chamber a 338 Whisper, dies are still available for it, and you can get high quality 7BR brass that will last forever with subs.
There's nothing wrong with getting a 308 WIN for subs, barrels are easy to find with the right twist, it's just not an ideal subsonic chambering looking at the balance between case capacity, bullet weight, and terminal ballistics.
There are better calibers than .308 for subs also. 300 BLK and its predecessors worked around the dimensional restrictions of the standard AR-15, if you remove that there are a lot of good options.
The original 338 Whisper used the .470 bolt face, which would work with your goal of switching out with a 6.5CM. If you're restricting yourself to 1050fps, might as well put as much weight behind it as you can. The larger the bore, the heavier the bullet. The larger the bullet you stick into the case compared to the parent design, the less wasted case capacity you have to deal with.
Defensive Edge will chamber a 338 Whisper, dies are still available for it, and you can get high quality 7BR brass that will last forever with subs.
There's nothing wrong with getting a 308 WIN for subs, barrels are easy to find with the right twist, it's just not an ideal subsonic chambering looking at the balance between case capacity, bullet weight, and terminal ballistics.
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