Help needed for 308 subsonic load

[lmlalong]

Hi guys
I am new for reloading. right now trying to load a subsonic & supersonic 308 for my hunting rifle in 1:8 twist, 16"
currently for the subsonic i am thinking about:

Sierra #2180 220GR RN,
Trail Boss
and maybe mag primer?

and have no idea for the supersonic

could get some 151GR cast HP projectile cheap. dont know if it usable for my rifle.

is there anything need to be ajust?

much appreciated for any advice or help.

PS. sorry for the poor English.

[bladeracer]

Hi guys
I am new for reloading. right now trying to load a subsonic & supersonic 308 for my hunting rifle in 1:8 twist, 16"
currently for the subsonic i am thinking about:

Sierra #2180 220GR RN,
Trail Boss
and maybe mag primer?

and have no idea for the supersonic

could get some 151GR cast HP projectile cheap. dont know if it usable for my rifle.

is there anything need to be ajust?

much appreciated for any advice or help.

PS. sorry for the poor English.

You want a jacketed subsonic load but a cast supersonic one?
What is the purpose of the bullets you want to use, target shooting or hunting, and what sort of animals?

[SCJ429]

The trouble with slow moving jacketed bullets it that they don't work very well when they hit something unless they are right on the edge of instability and you can get them to tumble.

Then you want supersonic cast bullets which will need gas checks and they don't like going fast without leading your barrel. Nothing like a bit of experimentation to prove what works for you.

[in2anity]

You'll need to flare the case mouth as to prevent from lead shaving when seating. Then you'll (obviously) need to crimp that flare back in. Lee do both a "Universal Expanding Die" and "Factory Crimp Die .308 Win" which are fit for purpose.

If you're having trouble with flyers, if possible try increasing neck tension (either by a heavier crimp or preferably a different resizing die). The Lee Collet Die with an undersized mandrel works great for this purpose and also bypasses FL resize - this is actually a good match for TB loads as TB is a very clean powder.

FWIW in my experience fast powders like TB can be problematic relative to neck tension, although personally I've never really had flyers with my 308w lead loads - perhaps the factory crimp die mitigates this problem.

[bladeracer]

The trouble with slow moving jacketed bullets it that they don't work very well when they hit something unless they are right on the edge of instability and you can get them to tumble.

Then you want supersonic cast bullets which will need gas checks and they don't like going fast without leading your barrel. Nothing like a bit of experimentation to prove what works for you.

I can't agree with the instability bit. All you're doing is taking the first thousand meters away, and working with the last part of a high-velocity bullet's travel. I have some very accurate subsonic TB loads in a variety of calibers, with light and heavy bullets.
If you want to push lead harder than about 1600fps powdercoat the bullet.

[lmlalong]

Hi guys
I am new for reloading. right now trying to load a subsonic & supersonic 308 for my hunting rifle in 1:8 twist, 16"
currently for the subsonic i am thinking about:

Sierra #2180 220GR RN,
Trail Boss
and maybe mag primer?

and have no idea for the supersonic

could get some 151GR cast HP projectile cheap. dont know if it usable for my rifle.

is there anything need to be ajust?

much appreciated for any advice or help.

PS. sorry for the poor English.

You want a jacketed subsonic load but a cast supersonic one?
What is the purpose of the bullets you want to use, target shooting or hunting, and what sort of animals?

supersonic with cast not gonna work well. was choosing from 151 cast or 220 rn for subsonic. but if i'm gonna run at 1050 ish subsonic why don't i choose 220? same speed but much heavier projectile.
i am from New Zealand, trying to build the rifle for small to medium games? i have no idea if i could do big game with this rifle.

[lmlalong]

The trouble with slow moving jacketed bullets it that they don't work very well when they hit something unless they are right on the edge of instability and you can get them to tumble.

Then you want supersonic cast bullets which will need gas checks and they don't like going fast without leading your barrel. Nothing like a bit of experimentation to prove what works for you.

could i say its best to subsonic the 151 hp cast? which might expand at subsonic speed. and supersonic the jacket 220?
i have tried some factory 150-160gr ammo, unfortunately there were alot muzzle flash(unburnt powder) due to 16" short barrel length.

[lmlalong]

You'll need to flare the case mouth as to prevent from lead shaving when seating. Then you'll (obviously) need to crimp that flare back in. Lee do both a "Universal Expanding Die" and "Factory Crimp Die .308 Win" which are fit for purpose.

If you're having trouble with flyers, if possible try increasing neck tension (either by a heavier crimp or preferably a different resizing die). The Lee Collet Die with an undersized mandrel works great for this purpose and also bypasses FL resize - this is actually a good match for TB loads as TB is a very clean powder.

FWIW in my experience fast powders like TB can be problematic relative to neck tension, although personally I've never really had flyers with my 308w lead loads - perhaps the factory crimp die mitigates this problem.

thank you so much for the informations will definitely keep that in mind.

[bladeracer]

supersonic with cast not gonna work well. was choosing from 151 cast or 220 rn for subsonic. but if i'm gonna run at 1050 ish subsonic why don't i choose 220? same speed but much heavier projectile.
i am from New Zealand, trying to build the rifle for small to medium games? i have no idea if i could do big game with this rifle.

My preference for subsonic is a pure lead bullet as heavy as you can stabilise. An 8"-twist will stabilise just about any .308" bullet you can make.
For supersonic I would use a jacketed bullet designed to deal with the size of your target. A .308 would certainly deal with big game.

[bladeracer]

could i say its best to subsonic the 151 hp cast? which might expand at subsonic speed. and supersonic the jacket 220?
i have tried some factory 150-160gr ammo, unfortunately there were alot muzzle flash(unburnt powder) due to 16" short barrel length.

As long as the cast bullet is soft and not "hard cast" then it will function fine at subsonic velocities.
Try using faster powders in your short barrel to burn most of it before the bullet exits the muzzle, Trailboss for the subsonic loads.

[SCJ429]

The trouble with slow moving jacketed bullets it that they don't work very well when they hit something unless they are right on the edge of instability and you can get them to tumble.

Then you want supersonic cast bullets which will need gas checks and they don't like going fast without leading your barrel. Nothing like a bit of experimentation to prove what works for you.

I can't agree with the instability bit. All you're doing is taking the first thousand meters away, and working with the last part of a high-velocity bullet's travel. I have some very accurate subsonic TB loads in a variety of calibers, with light and heavy bullets.
If you want to push lead harder than about 1600fps powdercoat the bullet.

If you hit something with a bullet that is beginning to yaw it may tumble which makes it do a lot of damage for the size of the pill and the speed of the bullet. Without this tumbling the bullet might pencil through without enough speed to get the jacket to come apart. The classic case of this was the early ammunition supplied for the M16 assault rifle.

[bladeracer]

If you hit something with a bullet that is beginning to yaw it may tumble which makes it do a lot of damage for the size of the pill and the speed of the bullet. Without this tumbling the bullet might pencil through without enough speed to get the jacket to come apart. The classic case of this was the early ammunition supplied for the M16 assault rifle.

I think this would be entirely down to the design of the specific bullet you're using. A jacketed bullet designed to work at subsonic velocities will deform just fine without requiring it to be unstable.

[SCJ429]

The trouble with slow moving jacketed bullets it that they don't work very well when they hit something unless they are right on the edge of instability and you can get them to tumble.

Then you want supersonic cast bullets which will need gas checks and they don't like going fast without leading your barrel. Nothing like a bit of experimentation to prove what works for you.

could i say its best to subsonic the 151 hp cast? which might expand at subsonic speed. and supersonic the jacket 220?
i have tried some factory 150-160gr ammo, unfortunately there were alot muzzle flash(unburnt powder) due to 16" short barrel length.

If I was to use a bullet at relatively low supersonic speeds I would use a Speer TNT or Hornady Vmax which are very frangable. Unfortunately these are usually at the lighter end of bullet weights. Even so they probably need about 1400 fps terminal velocity to work well.

[SCJ429]

If you hit something with a bullet that is beginning to yaw it may tumble which makes it do a lot of damage for the size of the pill and the speed of the bullet. Without this tumbling the bullet might pencil through without enough speed to get the jacket to come apart. The classic case of this was the early ammunition supplied for the M16 assault rifle.

I think this would be entirely down to the design of the specific bullet you're using. A jacketed bullet designed to work at subsonic velocities will deform just fine without requiring it to be unstable.

Many bullet makers are making jackets very tough so that they can survive high rpm induced by fast twist rates. Many bullets will hardly deform at speeds lower than 1200 fps. If you have some suggestions of bullets that work at these speeds I am sure the OP would be glad to hear them. I have not heard of a 220 grain 308 pill that fits the bill.

[bladeracer]

If I was to use a bullet at relatively low supersonic speeds I would use a Speer TNT or Hornady Vmax which are very frangable. Unfortunately these are usually at the lighter end of bullet weights. Even so they probably need about 1400 fps terminal velocity to work well.

Not sure about the TNT, but the VMax doesn't deform at subsonic velocity in any caliber I've tried. They're specified at 1600fps minimum terminal velocity.

[bigpete]

There is specialist subsonic bullets available now you know...

[bladeracer]

Many bullet makers are making jackets very tough so that they can survive high rpm induced by fast twist rates. Many bullets will hardly deform at speeds lower than 1200 fps. If you have some suggestions of bullets that work at these speeds I am sure the OP would be glad to hear them. I have not heard of a 220 grain 308 pill that fits the bill.

Any of the bullets designed for 300BLK will function properly at subsonic velocities. Hornady's 208gn AMax for example. I'm sure most manufacturers do a line of 300BLK bullets by now, including some of the brass monolithics.

[bladeracer]

This gives a pretty good list of some jacketed subsonic 300BLK bullets - https://www.shootingtimes.com/editorial/ultimate-300-aac-blackout-ammo-test/99395 and this is an old article, there are a lot more bullets available now.

[SCJ429]

I can see that Hornady offer loaded ammunition for the 300 using 208 Amax but list it as target use. They also have a Sub X line for hunting using a 190 grain projectile. I don't know if the projectiles are available for reloaders. If it was it might be what the OP is after.

[bladeracer]

I can see that Hornady offer loaded ammunition for the 300 using 208 Amax but list it as target use. They also have a Sub X line for hunting using a 190 grain projectile. I don't know if the projectiles are available for reloaders. If it was it might be what the OP is after.

My suggestion is soft cast lead bullets for subsonic hunting loads.
This would be an excellent start I think.
http://www.castbulletengineering.com.au/bullet-moulds/rifle/30-calibre/309-225gc-double-cavity
225gn of pure lead at 1000fps is going to hit pretty hard.

[in2anity]

Hopefully blr243 is watching this - he has real world hunting experience with some of those expensive 220gr 300blk pills. I gather subsonic expansion isn’t quite what it’s cracked up to be...

[lmlalong]

supersonic with cast not gonna work well. was choosing from 151 cast or 220 rn for subsonic. but if i'm gonna run at 1050 ish subsonic why don't i choose 220? same speed but much heavier projectile.
i am from New Zealand, trying to build the rifle for small to medium games? i have no idea if i could do big game with this rifle.

My preference for subsonic is a pure lead bullet as heavy as you can stabilise. An 8"-twist will stabilise just about any .308" bullet you can make.
For supersonic I would use a jacketed bullet designed to deal with the size of your target. A .308 would certainly deal with big game.

if using a heavy pure lead cast, what do u reckon soft cast or hard cast? i assume soft cast will expand really well, but would it leave lead foiling on rifling?

will definitely use sierra 2180 as supersonic now(bought it already ). did some calculation: ideal twist for 220GR would be 1:10 ish. but 1:8 should be totally fine. more research to do now. hope i dont blow something up

[in2anity]

supersonic with cast not gonna work well. was choosing from 151 cast or 220 rn for subsonic. but if i'm gonna run at 1050 ish subsonic why don't i choose 220? same speed but much heavier projectile.
i am from New Zealand, trying to build the rifle for small to medium games? i have no idea if i could do big game with this rifle.

My preference for subsonic is a pure lead bullet as heavy as you can stabilise. An 8"-twist will stabilise just about any .308" bullet you can make.
For supersonic I would use a jacketed bullet designed to deal with the size of your target. A .308 would certainly deal with big game.

if using a heavy pure lead cast, what do u reckon soft cast or hard cast? i assume soft cast will expand really well, but would it leave lead foiling on rifling?

will definitely use sierra 2180 as supersonic now(bought it already ). did some calculation: ideal twist for 220GR would be 1:10 ish. but 1:8 should be totally fine. more research to do now. hope i dont blow something up

For hunting, give the hard cast a miss. Hard cast are alloys however (not 100% lead, as suggested by BR) The hard alloys poke holes and isn’t very humane (from personal experience).

[lmlalong]

could i say its best to subsonic the 151 hp cast? which might expand at subsonic speed. and supersonic the jacket 220?
i have tried some factory 150-160gr ammo, unfortunately there were alot muzzle flash(unburnt powder) due to 16" short barrel length.

As long as the cast bullet is soft and not "hard cast" then it will function fine at subsonic velocities.
Try using faster powders in your short barrel to burn most of it before the bullet exits the muzzle, Trailboss for the subsonic loads.

what powder would u suggest to use on supersonic?

[Blr243]

I just spent months of time and money doing very extensive research on how to get humane results with sub sonic 300 blk At $ 1.20 per projectile 220 grain noslers are supposed to expand at 1050 FPS.... all the copper stuff that is also soposed to work is impossible to get a hold of Australia or otherwise. One American company quoted me 7500 dollars to send me 200 copper expanding projectiles I wanted to go down this route because I was trying not to deafen my sniffer dog...I shoot close to him and he just about has a mental breakdown next to my 243. .. he was not phased at all on the last hunt when I used 300 blk subs ...but this ammo is a wounding combination on pigs and should be outlawed one this size game ...I have no doubt that with fast 125 grainers the 300 blk can perform nicely on pigs . I am selling this rifle. I have bought a 450 bushmaster and intend useing hollow point 300 grain xtp s that are designed to expand at pistol velocity......the new rifle / ammo choice also gives me 35 per cent more energy to do the job than what the 300 blk subs were giving me .......imagine a marble sized lead ball hitting a brick wall at 3000 FPS. Of course it’s going to expand or fragment. Now image a hard cast lead marble that is thrown by hand at the same wall.... you might get a tiny flat spot on one side of it .....and a much softer lead marble also thrown by hand will probably show a flat spot on one side ..... the point I’m trying to make is that at subsonic velocities bullet performance is extremely dependent on the softness of the lead and the design of the projectile ... so just grabbing a 220 grain Sierra round nose is bugger all improvement over a Fmj .....and it’s just not fair to the game we pursue

[mickb]

This gives a pretty good list of some jacketed subsonic 300BLK bullets - https://www.shootingtimes.com/editorial/ultimate-300-aac-blackout-ammo-test/99395 and this is an old article, there are a lot more bullets available now.

We have to be honest about the 300blk subsonic choices though. Some are match bullets, not expanding, not all are available in Australia, and looking at reviews for some of them ( nosler and the 208 grain amax) they are not getting great expansion reports in the field.

[lmlalong]

I just spent months of time and money doing very extensive research on how to get humane results with sub sonic 300 blk At $ 1.20 per projectile 220 grain noslers are supposed to expand at 1050 FPS.... all the copper stuff that is also soposed to work is impossible to get a hold of Australia or otherwise. One American company quoted me 7500 dollars to send me 200 copper expanding projectiles I wanted to go down this route because I was trying not to deafen my sniffer dog...I shoot close to him and he just about has a mental breakdown next to my 243. .. he was not phased at all on the last hunt when I used 300 blk subs ...but this ammo is a wounding combination on pigs and should be outlawed one this size game ...I have no doubt that with fast 125 grainers the 300 blk can perform nicely on pigs . I am selling this rifle. I have bought a 450 bushmaster and intend useing hollow point 300 grain xtp s that are designed to expand at pistol velocity......the new rifle / ammo choice also gives me 35 per cent more energy to do the job than what the 300 blk subs were giving me .......imagine a marble sized lead ball hitting a brick wall at 3000 FPS. Of course it’s going to expand or fragment. Now image a hard cast lead marble that is thrown by hand at the same wall.... you might get a tiny flat spot on one side of it .....and a much softer lead marble also thrown by hand will probably show a flat spot on one side ..... the point I’m trying to make is that at subsonic velocities bullet performance is extremely dependent on the softness of the lead and the design of the projectile ... so just grabbing a 220 grain Sierra round nose is bugger all improvement over a Fmj .....and it’s just not fair to the game we pursue

my first intention was the Nosler 220GR as their website stated it works from 1000fps to 2500fps. but someone stated that projectile just tumble all the way at subsonic speed and Sierra 2180 are way cheaper(at NZ Nosler 220GR are 1.32NZD per round, and Sierra 2180 are 0.79NZD per round).

[mickb]

There a more than a few negative reports on the noslers accuracy as well, several regards keyholing

[bladeracer]

For hunting, give the hard cast a miss. Hard cast are alloys however (not 100% lead, as suggested by BR) The hard alloys poke holes and isn’t very humane (from personal experience).

I think I was pretty clear on using pure lead rather than hard-cast, so I can't see how you managed to read my suggesting otherwise. I shoot pure lead 182gn in 8x57mm.

[bladeracer]

if using a heavy pure lead cast, what do u reckon soft cast or hard cast? i assume soft cast will expand really well, but would it leave lead foiling on rifling?

will definitely use sierra 2180 as supersonic now(bought it already ). did some calculation: ideal twist for 220GR would be 1:10 ish. but 1:8 should be totally fine. more research to do now. hope i dont blow something up

At subsonic velocities, pure lead won't cause leading.