First timer messing with subsonic hand loads. Wanting to load a hunting round with maker’s 180 gr Rex bullets. Don’t need to hear .308 vs 300blk argument I have both. Just wanting to mess around with dedicating my Savage bolt action model 10 16” 1/10twist to subs. Only expecting to make shots <100. Would like opinions on amount to start with and type of powder, Primers, seating, any tips and tricks that sub newbie like me might need to know. Any advice appreciated.
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Needing some .308 subsonic hand load advice
- Thread starter Tmorri93
- Start date
Have loaded 308 subs. Just not those bullets. Trail boss is your friend if you can get it. Remember to start higher charge weight and work down, this is where a chronograph is needed. Shoot it unsurpassed first to make sure bullets are stabilizing. Hodgdon had sub load data, not sure if still do.
Another vote for trail boss. I’ve used it a bit for that very thing.
As others have said:
Step 1: get a Time Machine and buy a bunch of Trail Boss in 2019
Step 2: load it behind a 190 subX
Step 3: fine tune load DOWN from 10.0gn until you get your desired velocity. Prob around 8.3gn. Watch for squib.
Step 4: go back to 2020 in the Time Machine and buy more trail boss.
YWFMS
Step 1: get a Time Machine and buy a bunch of Trail Boss in 2019
Step 2: load it behind a 190 subX
Step 3: fine tune load DOWN from 10.0gn until you get your desired velocity. Prob around 8.3gn. Watch for squib.
Step 4: go back to 2020 in the Time Machine and buy more trail boss.
YWFMS
Titegroup may work well with the rex bullet in a 1/10 twist barrel . Hodgdon calls for 8.5 grains of Titegroup for a 175 Sub-x bullet and 8.7 grains for the 190 Sub-x bullet .
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This list from hodgdon has a couple besides trailboss.
About 308 subsonic-what’s the lightest bullet that a guy can realistically expect subsonic? I’ve heard some say 200 grains, but I don’t buy it.
The first link I posted, in that article they had 150 and 160 at subsonic.
I personally have loaded 165 sierras subsonic with trailboss. Was ok out to 100 yards.
There might be an advantage to heavier bullets for subsonic, but smarter brains then I can discuss that.
Not sure I understand what you're trying to ask. I've loaded 90gr bullets subsonic in both 308 and 30/06.
Come to think of it, I've loaded powder coated round balls too, well below typical subsonic speeds.
Use a fast powder. Cast coated lead bullets are more forgiving for very mild subsonic loads, but the 90gr bullets above were jacketed 90gr XTPs.
I still have some Trail Boss, so thats what I used with shotgun primers in a 308 case.
Around 11 grains will probably get ya close.
I found it varmint accurate at 50 yds with a variety of bullets except the 200 grs went sideways in the target, in a 12 twist.
But 155 through 175 gr bullets were accurate and fairly consistent velocities, some were a little high in velocity when I started but easy to adjust down.
Fun to shoot...
Around 11 grains will probably get ya close.
I found it varmint accurate at 50 yds with a variety of bullets except the 200 grs went sideways in the target, in a 12 twist.
But 155 through 175 gr bullets were accurate and fairly consistent velocities, some were a little high in velocity when I started but easy to adjust down.
Fun to shoot...
Attachments
I've been using Trail boss, as I have quite a bit still. I've started to see what others powders would work. I have h4895 on hand. My chronograph is in a friends hands right now, so no chrono data at the moment, but i'll have it soon. The h4895 was significantly louder (suppressed) than the trailboss. Trailboss is hollywood quiet, h4895 is not...at all. I'm going to try again when I have a chrono, perhaps I was at that nearly supersonic point, hence the additional noise, but we'll see. I'm working to get titegroup, and longshot in my hands just to see how it is by comparison.
I was looking for supersonic with some lehigh 198's and got to 15gr of trailboss, and lightly compressed, and still wasn't supersonic. But with a 208 amax, 13gr is right on the cusp of supersonic. I'm convinced at this point that I can't fit enough powder into the 308 case to push that lehigh bullet supersonic.
I'll have more when I have my garmin xero chrono back....hopefully this evening.
Branden
Do Not compress Trail Boss ...it changes the burning characteristics by breaking the little donuts...stated so in the IMR loading data, where it tells you how to load any case with Trail Boss ...follow directions.
It ain't about velocity attained... it's about safety...one can not get supers in many cases as the "powder fill" of the case is too small, for safe levels, according to manufacturer instructions and ya only have 900 fps...do not compress the charge, even a little bit, to get to 1100 fps or faster.
Trail Boss wasn't designed for that.
Other powders will work also. Trail Boss was the easy key in loading low velocity cartridges, in any cartridge. Even 50BMG.
Fluffy high fill shotgun powders work.
I use Red Dot in the 50BMG.
Titegroup and Clay's are listed for the 308.Win.
168 gr SMK
Titegroup 8.0 gr = 1080 fps
Clays 8.0 gr =1060 fps.
Titegroup has been easy to find around here, Clays has dried up, as to date.
Titegroup supposed to give consist velocity, regardless of powder position in case so says Hodgdon....but I have not tested that claim.
No surprise that H4895 is a lot louder suppressed - the slower burn rate equates to higher muzzle pressure (i.e. the uncorking that is the primary cause of the gunshot sound) so there's a lot more for the suppressor to handle.
Besides Trail Boss, other good powders for quite subsonics are at the fastest end of the burn rates for pistol & shotgun powders. Clays, Clay Dot, Red Dot, Green Dot, American Select, etc are just a few examples. You'll find some are quieter than others for a given bullet/cartridge/speed combo - that usually relates directly to burn rate and mass of the powder charge, but there are some exceptions.
The one problem with Titegroup is that it's a relatively dense powder, so it doesn't take up much case volume. Clays has been impossible to find, but if you have some it often works out as a direct match for Titegroup, grain for grain, but it's bulky so it takes up more of the case volume. In a small case like 9mm that can be safer because most loads with Clays can't be double charged, where Titegroup for the same charge weight can be double or sometimes triple charged. Not as big of a deal for something like 308 though where neither one will come close to filling the case, but you may find the bulkier powders are less position sensitive - just have to experiment with that.
I use titegroup with the 200gr REX in 308 but also played around with H110 and Lil Gun (magnum pistol powders). They worked decently well but were not as accurste as TG
I've been playing with trying to find an accurate, repeatable, subsonic load for my little Remington 738. It's supposed to be a host for a new 8.6 BLK, 6 twist barrel but it's so freakin quiet with the .308 sub loads I may have to buy another one to cannibalize it. Or get a much better made Ruger in .308.
"Accurate" isn't something I've seen discussed when it comes to subs and for good reason. I'm working in the 50-100 yard range with an eye on 200 yards as there is still plenty of energy left at 200. I need to do more testing but the initial results were promising. It's stupid quiet with the Nomad 20 I'm running.
I started with the well known Trail Boss / ream the flash hole to 9/64" load. I got to wondering if I could improve the dismal accuracy I was seeing by adjusting "something". In supersonic loads something would be powder charge and seating depth. With the Trail Boss load there was flash hole to adjust too.
Changing more than one thing will often lead down a deep rabbit hole. For that matter, changing one thing seems to lead down a deep rabbit hole
Enough blathering. For my little rifle, can on, heres the first round of results for powder testing. Imay retest this. The flash hole in this test has not been changed from factory. Ie I didn't drill it out.
Here's the flash hole diameter test. 9/64" was not the best choice from an ES perspective. I forgot to add the date on this test. 08/30/24. 0.1094" has the best ES but velocity was a little lower than 10.7gr was with the factory flash hole diameter.
I guess someone is going to want to know how I opened the flash hole up to "4 digit precision". That's fair. It's wobbly precision and I seriously doubt that that the 3rd decimal place, much less the 4th, matters. I don't have my mini-lathe anymore but I do have some very small chucking reamers. I held the brass in a K&M Precision collet and holder, put the reamer in my handy and long lived Sinclair turning widget, and hand fed the case into the reamer. It was kind of a pita. All of them had to be reamed to .0938". Then 2,3, and 4 were reamed to 0.1094". Then 3 and 4 were reamed to 0.1250". And then 4 was reamed to 0.1406" (9/64"). I'm kind of curious what the ES looks like on either side of 0.1094" but I think I'll make sure it repeats for a larger sample before do that test.
The numerologists out there will carp on the fact the 5 shots are statistically bs and to that I would say - True. Why don't you do the test and burn up your powder and bullets. I'll keep trying to figure out a good cold bore load that hits where I want it to with reliability.
"Accurate" isn't something I've seen discussed when it comes to subs and for good reason. I'm working in the 50-100 yard range with an eye on 200 yards as there is still plenty of energy left at 200. I need to do more testing but the initial results were promising. It's stupid quiet with the Nomad 20 I'm running.
I started with the well known Trail Boss / ream the flash hole to 9/64" load. I got to wondering if I could improve the dismal accuracy I was seeing by adjusting "something". In supersonic loads something would be powder charge and seating depth. With the Trail Boss load there was flash hole to adjust too.
Changing more than one thing will often lead down a deep rabbit hole. For that matter, changing one thing seems to lead down a deep rabbit hole
Enough blathering. For my little rifle, can on, heres the first round of results for powder testing. I
Here's the flash hole diameter test. 9/64" was not the best choice from an ES perspective. I forgot to add the date on this test. 08/30/24. 0.1094" has the best ES but velocity was a little lower than 10.7gr was with the factory flash hole diameter.
I guess someone is going to want to know how I opened the flash hole up to "4 digit precision". That's fair. It's wobbly precision and I seriously doubt that that the 3rd decimal place, much less the 4th, matters. I don't have my mini-lathe anymore but I do have some very small chucking reamers. I held the brass in a K&M Precision collet and holder, put the reamer in my handy and long lived Sinclair turning widget, and hand fed the case into the reamer. It was kind of a pita. All of them had to be reamed to .0938". Then 2,3, and 4 were reamed to 0.1094". Then 3 and 4 were reamed to 0.1250". And then 4 was reamed to 0.1406" (9/64"). I'm kind of curious what the ES looks like on either side of 0.1094" but I think I'll make sure it repeats for a larger sample before do that test.
The numerologists out there will carp on the fact the 5 shots are statistically bs and to that I would say - True. Why don't you do the test and burn up your powder and bullets. I'll keep trying to figure out a good cold bore load that hits where I want it to with reliability.
I load 178 ELDX or 168 SMK over 8gr of Titegroup with good results.
Has to be said... your blackout will do it better and with LOTS more loading options and way fewer headaches.
Otherwise....
Have had good luck with the 3030 style bullets like the flat nose 150s and the rubber tipped ftx ones too. 180 and 220 round noses do well too and eat up some case volume. Match bullets loaded backwards fly ok and eat up case space.
Trail boss and tin star of course if you're fortunate are the easy ones. Titegroup has data from hodgdon!! and red dot can do well too in my experience. Unique can be workable as well sometimes, though I'd prefer it fill the case better.
You need a fluffy fast powder that is easy to light and insensitive to position in case. Some guys drill out primer holes to make SUBSONIC ONLY brass and or use magnum primers. Sometimes this helps and is worth a shot if you dont get what you need with standards.
I've seen a few reduced volume cases in 30-06 and .308 guys have had made. Nice ones made on a lathe and poor folk ones with epoxy and a drill. THAT first one is a great solution if you can do it or get them. Last I saw they were like 10 bucks each at a gunshow here... not that helpful now unfortunately. Wish I'd have bought some.
If you venture into the world of fillers, a little dacron stuffing lightly put into the case against the powder opens up lots of options. AT YOUR OWN RISK of course. I've used it with success, but generally not needed with a good powder selection. Plenty of information for and against it out there along with details on the light fluffy powders to use with it. Weight of filler counts towards bullet weight and DO NOT pack fluff in there hard; it must stay fluffy between bullet and powder. Again, at your own risk. This is not considered normal loading practice anymore
Also consider a cast bullet. Much less likely to get stuck in bore and easier to remove if you do stick one. Also have had a few instances where cast was MUCH more consistent than jacketed.
Discussion on poverty style custom reduced cases here : ) https://www.snipershide.com/shooting/threads/subsonic-308-loads-with-unique.9642/
If you venture into cast bullets your options will expand quite a bit. These guys are a great resource If you go that direction.
This may be useful as well. These guys have a lot of reduced and oddball powder data for many cartridges.
All at your risk of course!
Otherwise....
Have had good luck with the 3030 style bullets like the flat nose 150s and the rubber tipped ftx ones too. 180 and 220 round noses do well too and eat up some case volume. Match bullets loaded backwards fly ok and eat up case space.
Trail boss and tin star of course if you're fortunate are the easy ones. Titegroup has data from hodgdon!! and red dot can do well too in my experience. Unique can be workable as well sometimes, though I'd prefer it fill the case better.
You need a fluffy fast powder that is easy to light and insensitive to position in case. Some guys drill out primer holes to make SUBSONIC ONLY brass and or use magnum primers. Sometimes this helps and is worth a shot if you dont get what you need with standards.
I've seen a few reduced volume cases in 30-06 and .308 guys have had made. Nice ones made on a lathe and poor folk ones with epoxy and a drill. THAT first one is a great solution if you can do it or get them. Last I saw they were like 10 bucks each at a gunshow here... not that helpful now unfortunately. Wish I'd have bought some.
If you venture into the world of fillers, a little dacron stuffing lightly put into the case against the powder opens up lots of options. AT YOUR OWN RISK of course. I've used it with success, but generally not needed with a good powder selection. Plenty of information for and against it out there along with details on the light fluffy powders to use with it. Weight of filler counts towards bullet weight and DO NOT pack fluff in there hard; it must stay fluffy between bullet and powder. Again, at your own risk. This is not considered normal loading practice anymore
Also consider a cast bullet. Much less likely to get stuck in bore and easier to remove if you do stick one. Also have had a few instances where cast was MUCH more consistent than jacketed.
Discussion on poverty style custom reduced cases here : ) https://www.snipershide.com/shooting/threads/subsonic-308-loads-with-unique.9642/
If you venture into cast bullets your options will expand quite a bit. These guys are a great resource If you go that direction.
This may be useful as well. These guys have a lot of reduced and oddball powder data for many cartridges.
Lever Gun Performance Studies
Reloading Data for cast bullets, result of lever gun accuracy studies on cartridges: 357 Magnum, 41 Rem Mag, 44 S&W, 44 Russian, 44 Magnum, 444 Marlin, 45-70 Goverment, Pistol Powders, Large Capacity Rifle Cases
gmdr.com
All at your risk of course!
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