My zero offset is also about 3mils vertical and 0.5 horizontal when compared with 175 SMK out of a 16in barrel.
- Thread starter Two Shoes
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That's pretty interesting. The elevation I get, but the horizontal makes me scratch my head a little. Something something twist rate, surface area, rate of spin...
It’s a bit random. On my 12in 1:8 twist 300blk I have about 0.3 mils shift between 110 TAC-TX super and 190 SubX. On my 16in 1:8 twist 308win DTA I have 0.5 between 175 fgmm and 200 Lapua sub and when I used to have a 10in noveske, I had a full mil between 110 Barnes and 208 amax subs and no matter what I tried, couldn’t find a way to reduce it.
Over the last 15 years, I’ve tried different bullet weights, length, powders, tuners, muzzle devices, no muzzle devices and haven’t really came to any conclusion of why the difference, I don’t believe it’s truly related to twist rate because all my barrels were 1:8. Could be a combination of barrel length, twist and harmonics. Maybe someone smarter than me can explain it but I gave up a long time ago and just wrote my offsets in StrelokPro or on the Kestrel and moved on.
I will echo the warning of checking for stability before using your can.
Old school was 1 / 7 twist but see now that it can be worked around with caution in a 308.
Oh well purchased some 300blks to cover the need but this thread has me rethinking projectiles.
You should be able to stabilize the short heavies like Lapua 200 fmjBT at a 1:10 twist.
11.25 twist I'd be careful with anything heaviver than 185 but then again it depends more on the length than the weight of the projectiles.
Always work from fast to slow and always check for signs of keyholing.
11.25 twist I'd be careful with anything heaviver than 185 but then again it depends more on the length than the weight of the projectiles.
Always work from fast to slow and always check for signs of keyholing.
Well… The 210 Berger subs in an 11.25” twist barrel was a shit-show for even trying to zero it. It was all over the damn place. They left the barrel straight, and went through the suppressor straight, but after that was anybody’s guess for impact. My 210 VLD supersonic load shoots amazing, but subs…Not so much. I figure it’s just too slow to stabilize the long bullet.
I guess I need to backup and punt and work up some 175 Custom Comp subs. Or some Berger 185 VLD subs…I have some of those sitting around, as well, for my old custom .30-06 AI that I hardly ever shoot anymore.
I guess I need to backup and punt and work up some 175 Custom Comp subs. Or some Berger 185 VLD subs…I have some of those sitting around, as well, for my old custom .30-06 AI that I hardly ever shoot anymore.
I’m trying to work with what I’ve got sitting around collecting dust for now, but I’ll keep a lookout for a box or 2. Thanks for the suggestion.
Alright... Going to the range today to try out some 168 Nosler Custom Comp subs in my .308 Win.
I used some old once-fired range pickup FC .308 brass that have been neck-sized and loaded with CCI 250's, and Trail Boss. I already FL-resized them before loading the Berger 210 sub test, so they're fire-formed to my chamber.
Hopefully these won't be an unpredictable shit-show, and they should actually stabilize and group at 100 yards, so I can then take it on out to 200, and get some dope data for my rifle. I don't use a thrower, I literally hand-weigh each charge with a plastic spoon to within 0.05 grains, and check concentricity of each loaded round to ensure the COAL is within 0.0025". I normally don't like my handloads having more than 0.0015", but with subs, it's not going to be THAT precise anyway, so...
I used some old once-fired range pickup FC .308 brass that have been neck-sized and loaded with CCI 250's, and Trail Boss. I already FL-resized them before loading the Berger 210 sub test, so they're fire-formed to my chamber.
Hopefully these won't be an unpredictable shit-show, and they should actually stabilize and group at 100 yards, so I can then take it on out to 200, and get some dope data for my rifle. I don't use a thrower, I literally hand-weigh each charge with a plastic spoon to within 0.05 grains, and check concentricity of each loaded round to ensure the COAL is within 0.0025". I normally don't like my handloads having more than 0.0015", but with subs, it's not going to be THAT precise anyway, so...
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Well, the 168’s are shooting really well, like 1/2 MOA good… But they’re keyholing like crazy even at 100! The 210’s weren’t accurate, but they didn’t even do that!
Flipping the bullet would change case capacity and jump, changing the load. Would also probably no longer feed. Even if it stabalized, BC would be much worse. Why try?
What twist on the barrel?
No, sorry, this is a precision rifle, and I refuse to follow fuddlore.
The subs were more for entertainment and experimentation than anything, but if I could get them to fly straight, I would consider finding some inexpensive low-velocity HP bullets as a means of quiet hunting/pest control. I'll probably just end up getting a Ruger American Ranch in .300 BLK to go with my custom 16" .300 BLK AR. At least the 1:8 twist will stabilize 220 subs.
22" Standard Obermeyer 5R 11.25"
It's just weird and ass-backwards. The 210's were flying straight, just wouldn't group for shit, but the 168's that SHOULD stabilize, are grouping 1/2 MOA, but keyholing... Been doing this a long time, but I'm truly at a loss for logic and reason on this one.
I know that stability has some to do with how many RPM the bullet spins. That is a function of twist and velocity. It may just be too slow for that twist? There is a reason 300 blackout barrels are usually 1:7 or 1:8.
Oh I know. I love my .300 BLK. It's one of my favorite cartridges. Like I said, the .308 Win subs were more for novelty and fun at the range for inside of 200 yards. But if they ended up shooting good, I was going to keep some on hand for nuisance/pest control and other things around the house. They're very accurate at 100, and even pretty damn accurate and consistent at 200 yards. I was having no trouble hitting the little 5" challenge tree gongs at 200 with it.
I wonder if the shorter bearing surface of say the Berger 185 VLD's will be better? That's probably what I'll experiment with next. Because the 210's have a fairly short bearing surface (comparatively) and they were flying straight, and punching straight holes at 100. Just not predictably at a set location. Which leads me to believe maybe the very short bearing surface and weight of the 185 VLD's might be the perfect combo for accurate/striaght shooting .308 Win subs in my rifle.
If it is just for fun and pest control, what about 110-150g bullets? Those for 30 carbine may even expand some.
I was about to mention how bad the SMK 168 were in the transonic/subsonic range but then I realized you were using Nosler and not SMK 168.
Even so I’d be curious how it compares to the 175s. 1:11.25 should stabilize 175s like the Bergers OTM even at subsonic speeds but then it also depends of your environmentals.
Nosler/Sierra 168 are basically the same thing. I’m thinking the shorter bullets are having trouble staying gyroscopically stabilized at the transonic range, even though they’re grouping really well. The longer heavier bullets might fly straighter, but the RPM’s spinning them needs to increase to improve accuracy. So, unless I re-barreled my .308 with a 1:8 twist, it’s per much going to either group like a shotgun with heavies, or keyhole into 1/2 MOA groups. UNLESS, I can find a compromise… I’m hoping the 185 VLD will be that compromise. We’ll see. I plan on doing some driveway powder charge range soon (probably this week or weekend), then take it to the range after experimenting with charge weights and finding my velocity ceiling.
New video is up with the R700 5R .308 Win showing supersonic and subsonics suppressed...
I haven't been crimping, and haven't had any issues. I also shoot them from a bolt gun, but I can't imagine a gas gun would be much different.
As for chamber, I'd say a SAAMI chamber is a good bet, though again, I've got a sample size of one. What's gonna matter more is free bore and twist rate. Free bore for bullet shape, twist fot bullet length. Someone more experienced than I could likely speak to specifics.
M1A SOCOM 16 with DeadAir Nomad Ti
H322 - 13.0gr
Lapua 200gr FMJ Subsonic
Alpha Brass
10 rnds fired avg 875fps. This was single action, adjustable gas block on the way
next I will be loading to 14.0gr and working with the gas block
looking to get closer to 1100fps ceiling.
Thanks
texashaag
H322 - 13.0gr
Lapua 200gr FMJ Subsonic
Alpha Brass
10 rnds fired avg 875fps. This was single action, adjustable gas block on the way
next I will be loading to 14.0gr and working with the gas block
looking to get closer to 1100fps ceiling.
Thanks
texashaag
The only thing I crimp is revolver ammo... I don't crimp any rifle ammo at all, super or sub, semi or bolt.
I crimp when loading lead and plated bullets just enough to remove the slight flare I used to make sure they do not get shaved during loading.
A few powder - load combinations burn dirty and a crimp will make them burn cleaner.
But for most of my rifle loads, semi or bolt, I do not crimp.
Anyone try the Hornady 190gr. Sub-x with Benchmark? Hodgdon has a load listed on their site at 13.4 grains. I have a metric ton of the 190 Sub-x bullets I could never get to work in my 300 blackout gas gun and thought they may be fun with the 308 bolt gun. I've got some test rounds loaded up but haven't gone to the range yet.
My thoughts lean toward, that the 308 rate of the twist is not very well suited for subsonic. With the rise in popularity, IMO when a suppressor is added to a high powered round like the 308, it is for your (the firer) and team mates to some extent protection from the concussion and blast. The crack you'll hear will always be there. Thus the rounds that were designed for subsonic.
Assuming there are no ballistic advantages to a subsonic 308 round vs. a subsonic 300 blackout round, same projectile. My bolt gun has a 20" barrel so it may be difficult to keep the bullets subsonic in that barrel length. My 300 blackout has a 10.5" barrel.
If you have a .308 caliber 220 grain bullet traveling 1,080 FPS, it doesn't matter what size cartridge it was shot from. The ballistics will be the same. But, I 100% agree with what you're saying. The reason I make .308 Win subsonics, is because I don't have a bolt-action .300 BLK...YET. But I will soon. And my .300 BLK AR is still a bit louder due to port pop. The bolt-action is so stupid-quiet with a good can on it. It's more for fun and novelty, than it is for practicality. The advantage to buying a bolt-action .300 BLK is the barrel twist rate that is setup to run the heavy 1:5-1:8 twist for the 200-220gr. bullets for subsonics, compared to the .308 Win twist rates made for supersonics in the 10-12" range.
Plus, like you said, the .300 BLK is more efficient for subsonic use, than .308 Win, because it was designed to be that way.
The .308 Win subs are fun, and really make people stop and be like "WTF was that!" because it sounds just like a CO2 powered pellet rifle.
I’m also wondering how the sub x series works in a 308. Just stumbled onto a box of 175s at a local shop and wanna run them over some trailboss that I traded some very dear powder for. Thinking about starting around 11 grains and going down… any thoughts? I’m new to the subsonic game.
Tikka ctr 20” 11.25twist Tbac Dominus.
New video comparing my Dead Air Sandman-S & Nomad-LT with my Otter Creek Labs Hydrogen-S on my new 10" .300 BLK build. I'm using a non-magnified EOTech 512 with the A65 "donut of death" reticle to holdover and hit a 10" steel gong at 200 yards.
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Greetings,
Got a noobie questions please... Getting a gas gun cycle fully with subsonic ammo? .308's will not cycle when subsonic, the round was never meant to go subsonic and have enough power to cycle fully.
Now lets talk about a round that was designed to go subsonic the .300 blackout. Who has a semi-auto in .300 ACC blackout, that cycles fully at subsonic velocities with a suppressor? and what are you shooting gun? and loads?
thanks....
texashaag
Got a noobie questions please... Getting a gas gun cycle fully with subsonic ammo? .308's will not cycle when subsonic, the round was never meant to go subsonic and have enough power to cycle fully.
Now lets talk about a round that was designed to go subsonic the .300 blackout. Who has a semi-auto in .300 ACC blackout, that cycles fully at subsonic velocities with a suppressor? and what are you shooting gun? and loads?
thanks....
texashaag
I've tried the short heavies like you mentioned in a SOCOM M1A... I was never able get the round to stabilize at subsonic. The same with my M1A NM.
All our 300 black out bolt and semi run 1/7 twist.
You have to figure there is a reason.
If your semi is working well you can run subs with or without a can.
12.1g cfeblk with a 220g rnfb cycles and runs 1 - 1 1/8 moa from the bolt guns and 1.25 - 1.5 moa from the sbr's .
About 1015 fps in cold weather and doesn't crack on a 100 degree day.
You have to figure there is a reason.
If your semi is working well you can run subs with or without a can.
12.1g cfeblk with a 220g rnfb cycles and runs 1 - 1 1/8 moa from the bolt guns and 1.25 - 1.5 moa from the sbr's .
About 1015 fps in cold weather and doesn't crack on a 100 degree day.
hit the plate, but key holed on paper, unstable!
Been shooting and developing 7.62x39 subs for years. The best set-up would be to develop a 9.3x39 barrel. This would allow for heavier bullets using a .366 diameter platform. Would like to tool up some 100 gr. .2245 diameter bullets for the AR platform too. Tried to work some up using Oilite bronze rod turned to .225". Used many different powders and maintained velocities within 900 to 1150 fps. However could not stabilize even with 1:7 twist. Any thoughts?
Presenting the world’s most expensively-scoped Ruger American Ranch in .300 BLK… 
My local store had 2 in stock Saturday evening when I stopped in there, so I decided to pick one up to play around with. I didn’t have any spare [appropriate] scopes on-hand to put on it, so I had to go with a spare I already had sitting on the shelf. It’s just a temporary setup, but it is a nice shooter. It is ridiculously lightweight with the Kahles Helia KX on top, but the travel bottoms-out right at 100, so it’s not gonna work on this rig. And it’s stupid-quiet with my Hydrogen-L and Nomad-LT with my 220 sub handloads. Sounds like a pellet gun.
Here it is with my Nomad-LT on it.
My local store had 2 in stock Saturday evening when I stopped in there, so I decided to pick one up to play around with. I didn’t have any spare [appropriate] scopes on-hand to put on it, so I had to go with a spare I already had sitting on the shelf. It’s just a temporary setup, but it is a nice shooter. It is ridiculously lightweight with the Kahles Helia KX on top, but the travel bottoms-out right at 100, so it’s not gonna work on this rig. And it’s stupid-quiet with my Hydrogen-L and Nomad-LT with my 220 sub handloads. Sounds like a pellet gun.
Here it is with my Nomad-LT on it.
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Finally got my new scope for it… Primary Arms SLx 1-10x28 34mm SFP LPVO wit the ACSS M10S MIL reticle. This thing is beefy!
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If you have any trail boss you better enjoy it. A buddy sent this
Man, f*** the war in Europe! Let them make their own damn ammo, and stop soaking up all our reloading components! This is the USA…Not Russia, not Ukraine… So stop pandering to them and feeding them our ammo, powder, primers, etc…, and ignoring your customer base here at home. The war won’t last forever, but your reputation of how you ignored your own countrymen’s needs, to profiteer from Elitist billionaire shell corporations to feed the proxy war machine in another country, sure will… 
Man, f*** the war in Europe! Let them make their own damn ammo, and stop soaking up all our reloading components! This is the USA…Not Russia, not Ukraine… So stop pandering to them and feeding them our ammo, powder, primers, etc…, and ignoring your customer base here at home. The war won’t last forever, but your reputation of how you ignored your own countrymen’s needs, to profiteer from Elitist billionaire shell corporations to feed the proxy war machine in another country, sure will…
I could be wrong but I thought it’s imported from Australia.
But rant away, I want more subsonic powder.
