308 subsonic load question

[Jeepguy97]

I have a Remington 700 .308 22"bbl 1:12 twist. Just wondering if anyone has developed a subsonic load that's works with this twist. From what I've read everyone recommends the 1:10 twist to stabilize the heavier bullets, I'm hoping I don't have to rebarrel my rifle. I bought some trailboss and tite group don't have any bullets yet not to sure what will stabilize. If anyone has any advice I would appreciate it. thanks

Luke

 

[roggom]

I recently chopped a 1:12 from 24 to 16 and had a bugger of a time finding a sub load to stabilize. Scenars, amax, smk and on. No dice.

Finally got some Sierra 180 RN #2170 over 10.5 of trailboss , mixed brass, seated to the cannular (2.720) and it's a thing of beauty. No flyers or tumbling and addicting to shoot (@50Y)

Of course try em before you screw on your can.



Sent from my iPhone using Tapatalk Pro

 

[Jeepguy97]

Thanks for the load tip. Much appreciated

 

[culater]

I use the Horaday 30 cal 160 ftx bullet to sub with. Very stable out to 600 yards. I have a 1-12 twist on my 308 pushing 1050 fps.

 

[GhengisAhn175]

you got a lot of things working against you. Instead of a subsonic load why not go for a reduced load? any reason you want to go subsonic?

 

[Jeepguy97]

I have neighbors somewhat close by and just wanted a subsonic load so I didn't disturb the neighborhood untill I could get to the range

 

[Jeepguy97]

What powder are you using for the hornady 160 ftx bullets? And are you using magnum primers or standard

 

[Gunfighter14e2]

I have a Remington 700 .308 22"bbl 1:12 twist. Just wondering if anyone has developed a subsonic load that's works with this twist. From what I've read everyone recommends the 1:10 twist to stabilize the heavier bullets, I'm hoping I don't have to rebarrel my rifle. I bought some trailboss and tite group don't have any bullets yet not to sure what will stabilize. If anyone has any advice I would appreciate it. thanks

Luke

Yes, just buy some round nose or flat nose flatbase bullets and you will be fine. I've a 22" an 16.5" 12 twist I shoot to 500 w/o issue using a cast load I have come up with. That said I've shot the Sierra 180 gr prohunters over 10.4-.6 of trailboss to the same distance w/o issue. Those that say a 12 twist will not shoot a sub are flat out wrong. It's all about bullet shape first, twist second. Weight has a little to do with it but the first two more so. I went to my cast bullet load (Lyman 311332BV & Red Dot)as it is a semi pointed and takes less up to 500 vs a true round nose or flat nose. I do not have a dedicated sub gun as I have sub loads, for every stick I own from .223 to 300wm. Depending where you shoot the most your DA an SOS will dictate where your max muzzle vol needs to be. That said I have 2 loads one for a very low DA and one for a normal higher DA. My max at the muzzle is 1090 an lower max is 1010. If you use a flat nose the pressure wave is different than a round nose, an both are totally different than my semi pointed. You can get the crack at a lower muzzle speed with the round an flat vs the semi.

 

[culater]

What powder are you using for the hornady 160 ftx bullets? And are you using magnum primers or standard

Useing 9.7 gr of trail boss in a 24 in barrel and useing standard 210 federal primers

 

[Jeepguy97]

Thank you guys for all the advice. Now at least I have a starting point, and I can load up some cases and whenever the weather decides to clear 60 and sunny least week 21 and snowing all this week, got to love Michigan weather. I can do some testing

 

[Gunfighter14e2]

Thank you guys for all the advice. Now at least I have a starting point, and I can load up some cases and whenever the weather decides to clear 60 and sunny least week 21 and snowing all this week, got to love Michigan weather. I can do some testing

Best time to do your sub work up is in the coldest weather in your A/O.

 

[Jeepguy97]

Why dose that make a difference? I apologize for my ignorance but I'm still new to reloading

 

[culater]

Why dose that make a difference? I apologize for my ignorance but I'm still new to reloading

With finding your load you to sub with start with 13 gr of trail boss and work down to find the speed just below 1050 fps. have a chronograph to help you find the speed.

 

[Gunfighter14e2]

Why dose that make a difference? I apologize for my ignorance but I'm still new to reloading

The SOS (speed of sound) is lower in cold weather than hot, but the main reason is to find the threshold for your bullet. A flat nose bullet will break sound quicker than a round nose vs semi pointed, or pointed. I prefer the semi pointed as you get the best of all worlds. I have two sub loads for my .308 an 300wm one for winter an one summer. When I change the basic winter an summer setting for high speed that is when I swap the sub loads as well.

 

[Jeepguy97]

Just blown my mind lol. Thanks for the info guys, you all have been very helpful

 

[big_matt_duq]

Yes, just buy some round nose or flat nose flatbase bullets and you will be fine. I've a 22" an 16.5" 12 twist I shoot to 500 w/o issue using a cast load I have come up with. That said I've shot the Sierra 180 gr prohunters over 10.4-.6 of trailboss to the same distance w/o issue. Those that say a 12 twist will not shoot a sub are flat out wrong. It's all about bullet shape first, twist second. Weight has a little to do with it but the first two more so. I went to my cast bullet load (Lyman 311332BV & Red Dot)as it is a semi pointed and takes less up to 500 vs a true round nose or flat nose. I do not have a dedicated sub gun as I have sub loads, for every stick I own from .223 to 300wm. Depending where you shoot the most your DA an SOS will dictate where your max muzzle vol needs to be. That said I have 2 loads one for a very low DA and one for a normal higher DA. My max at the muzzle is 1090 an lower max is 1010. If you use a flat nose the pressure wave is different than a round nose, an both are totally different than my semi pointed. You can get the crack at a lower muzzle speed with the round an flat vs the semi.

Are you using gas checks? How are you coating them?

 

[Gunfighter14e2]

Are you using gas checks? How are you coating them?

Gas checks yes, but only use Hornady as Lyman are designed to exit the bullet at the crown an can be bad news for a can the next firing. Lube is Lee. Done right you can shoot a ton of subs or high speed an switch to the other an they all will be right were their supposed to be. I do not use any Tin or Antimony/Linotype when casting for subs either straight wheel weights from the mold into a bucket of cold water. The Mold is rated 187 gr using lyman # 2 melt but with pure w/w's the gas check and lude they come out about 193grs. Used many different weights bet that mold throws the best bullet for my type of shooting. This same bullet gets to 800yds in H/S trim just fine as well, but I add Tin, Antimony an Nickle to the melt an step the M/V up to 2525.

 

[cav has been]

Best time to do your sub work up is in the coldest weather in your A/O.

Dang it Gunfighter! Now you've gone and spoiled my day, Load development at -30???? Thanks for your posts though, i'll be looking for another mold to cast for .30 cal subsonics.
Have you tried powder coating rather than lube and gas checks?

 

[Gunfighter14e2]

Dang it Gunfighter! Now you've gone and spoiled my day, Load development at -30???? Thanks for your posts though, i'll be looking for another mold to cast for .30 cal subsonics.
Have you tried powder coating rather than lube and gas checks?

Not yet as I have 20 bottles of the Lee lube still left. Wait till you shoot subs at -30*f vs +55*f the difference is very interesting.

 

[Gunfighter14e2]

My favorite powder for that bullet is Red Dot first, Clays second, Bullseye third, an 700X fourth, but there is not a 1/4moa difference between them all. Price and Availability is the main consideration for me with subs, because I shoot so many compared to H/S stuff. In the sub matches we do our motto is, "It will be over, before the other side even knows it began".

 

[big_matt_duq]

I wonder if I could just coat them in hi-tek and not gas check them or have someone machine out the gas check groove and coat and shoot. I guess the third option is to gas check them then coat in hi-tek. I wonder which way is the best. The sealed suppressor thing is what scares me.

 

[Gunfighter14e2]

They shoot just fine w/o the gas check but depending Brinnell hardness, if you are anywhere near 1050 or more I'd make sure they were at least a 11.5 or better. When I alloy for high speed I want a minimum of 35 but even then I still use a gas check. Never messed with coating them so don't know anything about that. Did plate a few with copper but not worth the effort/time for the end result, to me.

 

[dopedealer]

Great info

 

[big_matt_duq]

I'm gonna have to order a pot and some molds. I have a couple hundred pounds of lead sitting in the garage and have been wanting to get into casting. 10mm, 44, and 454 were my plan but this 308 mold seems like the ticket

 

[redbullitt]

If you are still after results with jacketed do not forget about the flat nosed 30 30 style bullets. I have had the 150s work very well in a number of subsonic loadings from several rifle. I have an 11 twist that REALLY shoots well with them.

 

[big_matt_duq]

What b.c. are you using for that cast bullet gunfighter?

 

[Gunfighter14e2]

What b.c. are you using for that cast bullet gunfighter?

I don't worry about BC for anything, all my data is from shooting an keeping results. All my data is based on my high speed zero for that weapon. I do not have a dedicated sub gun.
At 100yds up is 15moa (over the weapons base high speed zero)
200 = 30moa
300 = 47.5moa
400 = 64.5 moa and so on. That data is base on my summer load 1080 MV , ASL 800 temp of 75*f the numbers change quickly when the D/A in the winter drops. Keep your data points for each 25yds base on D/A and you will do well. Hitting a 1.5 moa 1st round target is not hard to 400 with 1/2 ass'ed wind reading ability. 500-600 gets tricky but a 2moa target is a 80% or better probability on the first shot. Subs can be very addictive and they will teach you much about reading mother nature. The greatest issue with subs is getting them loaded consistently as they are much harder to load to sub moa than high speed stuff.

 

[big_matt_duq]

That makes sense. I'm going to have to try casting in the near future. I snagged 2 cans of trailboss the other day.

 

[cav has been]

I'm definitely keeping up with this post as I have fairly recently started down the sub sonic rabbit hole. I was glad to read GF's last line about consistency as my limited experience had lead me to think about being a lot more serious with case prep. I started out using kinda the bottom layer of 308 brass in my possession, imi of indeterminate history. I was thinking neck tension was the most likely cause of velocity swings. I was glad to see the recommendation for red dot as well. It seems more prevalent in the magazine than trail boss.

 

[Gunfighter14e2]

Guys, just remember always check your charged cases for a double charge before setting the bullet, when using either a fast pistol or shotgun powder. Also use cases that have the least internal capacity as possible.

 

[cav has been]

Well I bummed a mould from my shooting buddy, a Lee advertised to cast .309 diameter,180 gr. bullets, With my material ( wheel weights ) I ended up with .3085, 164 gr.
Started out with my 180 Sierra load WLRM, 10.3 of trail boss, in some WCC Nato brass. worked down to 7.5 gr. Trail boss @ 1059fps. Accuracy not determined as speed was the question of the day. Not bad offhand, certainly minute of Montana. Remmy 700, 20", 1:12 Next up stability check then fire for effect.

 

[cav has been]

Small update. The above mentioned load performed fairly well. It was indeed stable at 96 yds. Only fired two groups of 5, best was just under an inch. First ccb. was out by an inch, the next 4 went where they were supposed to.
Next step anneal another batch,clean,trim and load. Likely pay a bit more attention while seating as I shaved a bit on a couple when seating.

 

[NHPiper]

Sorry to be late to the post, I had trouble with find subsonic loads too. I even had the 1:10 twist barrel. Couldn't get any boat tail bullet to stabilize. Ended up using Sierra 180gr Round Nose bullets over 10.1gr of Trailboss from Lake City prepped brass, standard Federal primers. From my 18" barrel, subsonic and sub-MOA!

Good luck!

 

[big_matt_duq]

Just got my molds and casting stuff. Ordered some hi-tek powder to coat today. I can't wait to try this out.

 

[Jeepguy97]

Dumb question but why do have to powder coat them? The reason why I ask is because I know zero about casting bullets, but I always see them being powder coated

 

[big_matt_duq]

I'm doing it to eliminate lube and leading since they are going through my sealed suppressor.

 

[Jeepguy97]

Subsonic load update. I finally had some decent weather to go out and try some bullets, I originally only had three different kinds to test from but I scored a good deal from another member on here for some others. All bullet loads started with 9.0grs of trailboss just for a starting point. I only loaded one shot each. So here are the results that I came up with.

Rifle, Remington 700 varmint 22" barrel 1-12 twist. Target 25yrds away
1. Hornady 150gr btsp @ 1096fps- worked very well
2. Hornady 155gr a-max @966.5fps- worked very well
3. Hornady 165gr interbond @917fps- worked good
4. Sierra 165gr btsp @1023- bad started tumbling immediately
5. Hornady 168gr a-max @841.2fps- worked very well
6. Hornady 178gr a-max @815.8fps- worked good
7. Hornady 200gr eld-x @787.3fps- bad started tumbling immediately
8. Hornady 208gr bthp @955.7fps- bad started tumbling immediately

i would have liked to go further but another load work up I was doing on my 300 blackout I had everything set up got a phone call got distracted for a minute sat back down at the rifle pulled the trigger and shot and realized I put a bullet right through my chronograph. But at least I got a starting point for the 308 if anyone out there is still following this and wondering. FYI looking for a new chronograph lol

 

[Rog2069]

Trail boss and some 150s or 168s and you'll be fine

 

[Jeepguy97]

I was really surprised to see that the 178 worked

 

[Jeepguy97]

Oh I forgot to mention that I was using Winchester brass and CCI large rifle primers

 

[cav has been]

Interesting, both the 168 & 178 a-max's were unstable in my 1:12 twist at 100 yards. I wouldn't trust stability tests at any shorter ranges.
My own ongoing quests involving cast bullet sub sonics are now to the point of; " how the heck am I going to size these cast critters without lubing them?" I am pleased with the powder coating operation but I get just enough diameter variation to concern me as far as shooting distance. Also I occasionally sacrifice a case to the brass fairies during seating, crimping operation.

 

[big_matt_duq]

Coat with hi-tek and then size them. No lube needed

 

[cav has been]

Guess I'll do some studying on it. Not really enthused about absorbing mek or acetone. Got way more than my fair share of metals and chemicals in this old body.

 

[big_matt_duq]

You really shouldn't have to touch it and gloves wouldn't be a bad idea. To me it seems less dangerous than casting lead. I have some of the powdered version on its way so hopefully I'll have some firsthand experience soon with it.

 

[big_matt_duq]

They shoot just fine w/o the gas check but depending Brinnell hardness, if you are anywhere near 1050 or more I'd make sure they were at least a 11.5 or better. When I alloy for high speed I want a minimum of 35 but even then I still use a gas check. Never messed with coating them so don't know anything about that. Did plate a few with copper but not worth the effort/time for the end result, to me.

What are your sizing them to?

 

[cav has been]

Well this thread needs resurrected. I've been kind of hit and miss on this project but it is interesting. Still using 7.5 gr. of trail boss,castbullets using wheel weights out of a Lee 180 mould. WLRM primers, WCC brass. I have started sizing .309 after powder coating and recycling any that don't resize ( too small ) or any that take two much effort to size. ( too large ) The results have been pretty gratifying, I have 4" X 8" steel at 150 and 250 that I can shoot from my front yard. I seem to have a wild shot periodically with no obvious culprit but other than that most shots are sub moa. as I said gratifying.
Next up, try some heavier cast projectiles, improve my casting technique, put up some more targets, and let my Bride shoot more.

 

[mdmp5]

I've been using 175 SMKs over 9gr of trail boss in my M1a with a can. They shoot straight, pretty accurate, and quiet as shit

 

[Beneviolence]

I've done a handful of 175gr SMK's with 8gr of trailboss. I think 10+ put them supersonic?

I've heard rumors of seating the bullets backwards to help with stabilization, but haven't tried it.

FYI, if you look under Rainier bullets of the .308 diameter on Midway, they have some nicely priced leadsafe bullets

 

[cav has been]

Cast bullets have proven themselves to me. Started with the Lee 180gr. mould which delivered 164 gr. We drove those out to 557Yds. this past weekend. Thankfully winds were extremely light. This week i have been working with the Lee 200gr. mould. It delivers projectiles in the 193-194 range. These are stable in my 1:12. The home-brew powder coat then size program is working well. Leading is a non issue as are mis-guided or stray gas checks. Accuracy is improving ( or I've pulled my head out and started shooting ).
Following Gunfighters sage advice I have started using Red Dot in place of Trail boss. Gotta love 1K shots per pound! He is also to blame for this cast bullet affair.

 

[Gunfighter14e2]

This week i have been working with the Lee 200gr. mould. It delivers projectiles in the 193-194 range. These are stable in my 1:12.

I've shot 30 cal 220s to 600yds in a 12 twist an they arrived nose on, in way less than minute of chest an most less than minute of head. It's mostly bullet nose shape vs twist, not weight with subs. Hard to beat a 7-8 cent trigger pull for a ctr fire that will kill to 600 w/o issue. I shoot way more subs now than high speed, much cheaper to load, plus makes you understand mother way more than high speed. More places to shoot as most never even know your there. We have even shot some 600yds stuff in town from a van an no one has caught on to-date. Wait till you figure out how to load subsonic specials, that opens up a whole new world of enjoyment, as well as many specialized uses if it all goes to shit.