.308 Powder choice

[nicke92]

If people can suggest a powder and load I will use that. Rather than just admonishing me to feel high and mighty if someone can make a positive suggestion of a UK legal powder I can purchase for subsonic .308 or even a load someone else has developed that would be amazing.

vihtavuori n32c ( tin star ) is like trailboss we use it in sweden thanks to trailboss has been to hard to find and now almost all usa powders are ilegal in europe

 

[Heym SR20]

a powder kernel burns from the outside in - think a log of wood. If you have a tight stack of logs, the outside ones have to burn before the inside ones can get going.

That is the same as a full case load of powder. Only some of it can burn, building pressure and pushing the bullet down the barrel giving more volume this allowing a few more logs to start burning. As the bullet moves down the barrel volume increases thus reducing pressure, but s progressive burn fills up the space and keeps pressure constant accelerating the bullet down the barrel.

Now instead of your tightly stacked logs, take say a 1/3 of the number and arrange them in open stack as would tinder sticks on a fire, with lots of space around each one. They will very quickly set alight and each burn at full rate.

Same happens in a half or a third full cartridge case. The initial primer will swirl up and ignite all the powder which will all burn at the same time, raising pressures hugely and raise the pressures at a speed beyond which the bullet can travel down the barrel lowering the pressure. This gives an over pressure situation which can stress the breach beyond its strength limits result the barrel and breech letting go.

For a subsonic load in a rifle cartridge you either a case with much less volume - and some are made this way, with very thick walls, or you need a powder which is pretty much sawdust - ie has a very low energy density. Trailboss is an example and was designed specifically for low velocity soft lead bullet training type rounds.

There have also been chamber inserts which allows you to fire pistol cartridges in a rifle, but these are mostly for big bore rifles.

 

[308tikka]

Well if 40 something grains does 2500fps then surely 20grains will do 1250fps etc.

Don't see how a low load is dangerous? Obviously going over would be but not going under.

unsure if this thread, or account, is a wind up.

if its genuine, Im astounded by a new low in disregard for firearms safety. Im not sure youre a fit and proper person to own firearms, by wilfuly advertising your casual attitude and apparently gleeful ignorance.

do the world a favour and dont try your ‘half loads’ on a range or in vicinity of normal people.

feel free to remove yourself from the gene pool, the average IQ in your village will increase.

Alternatively, put some time into researching subsonic 308. Entirely doable, but not with N135.

 

[fresh slots]

My .308 only has an 18.5" barrel, would Alliant AR-comp help me achieve higher velocities in this?

I use ramshot tac out of a 16” barrel, it’s fast burning and works really well. Dm if you would like more info.

 

[nicke92]

Well if 40 something grains does 2500fps then surely 20grains will do 1250fps etc.

unsure if this thread, or account, is a wind up.

if its genuine, Im astounded by a new low in disregard for firearms safety. Im not sure youre a fit and proper person to own firearms, by wilfuly advertising your casual attitude and apparently gleeful ignorance.

do the world a favour and dont try your ‘half loads’ on a range or in vicinity of normal people.

feel free to remove yourself from the gene pool, the average IQ in your village will increase.

Alternatively, put some time into researching subsonic 308. Entirely doable, but not with N135.

m32c is like trailboss

 

[12gsnapcaps]

Hi All,

Thankyou for your constructive comments, and not so constructive comments - some verging into the abusive (honestly .... what is the point?)

As an update, Ive searched far and wide for recommended powders, physically travelling as far as the lake district, and leeds but have been unable to source anything suggested.

Therefore I have followed the prevalent community train of thought/guidance on making light loads safe - drilling out the primer pockets to 3mm and using 'dacron' filler, and have a great subsonic load of 16.5 grains of n135. I've been rigorously checking for negative signs after firing and have found none.

I'll end this thread here. Hopefully it's of use to others like me who do the best we can with urban and semi urban permissions, thus needing subsonic centrefire loads.

Still in the gene pool,

Snapcaps

 

[12gsnapcaps]

a powder kernel burns from the outside in - think a log of wood. If you have a tight stack of logs, the outside ones have to burn before the inside ones can get going.

That is the same as a full case load of powder. Only some of it can burn, building pressure and pushing the bullet down the barrel giving more volume this allowing a few more logs to start burning. As the bullet moves down the barrel volume increases thus reducing pressure, but s progressive burn fills up the space and keeps pressure constant accelerating the bullet down the barrel.

Now instead of your tightly stacked logs, take say a 1/3 of the number and arrange them in open stack as would tinder sticks on a fire, with lots of space around each one. They will very quickly set alight and each burn at full rate.

Same happens in a half or a third full cartridge case. The initial primer will swirl up and ignite all the powder which will all burn at the same time, raising pressures hugely and raise the pressures at a speed beyond which the bullet can travel down the barrel lowering the pressure. This gives an over pressure situation which can stress the breach beyond its strength limits result the barrel and breech letting go.

For a subsonic load in a rifle cartridge you either a case with much less volume - and some are made this way, with very thick walls, or you need a powder which is pretty much sawdust - ie has a very low energy density. Trailboss is an example and was designed specifically for low velocity soft lead bullet training type rounds.

There have also been chamber inserts which allows you to fire pistol cartridges in a rifle, but these are mostly for big bore rifles.

Really interesting, thankyou for explaining the mechanics/science with such a great analogy. I'd be interesting to see those chamber inserts! .22lr out of a 700 nitro express anyone?

 

[Heym SR20]

Reloading is a rabbit hole. In terms of powder it’s a question of what is available locally, rather than what you read about. And once you have established a load, buy a couple of tubbs of powder, ideally from the same batch and several boxes of bullets and primers. If you have 60 to 100 cases, that should last you a good while.

 

[JTO]

Hi All,

Thankyou for your constructive comments, and not so constructive comments - some verging into the abusive (honestly .... what is the point?)

The point is, you probably won't forget it.
Walk round a clay ground with a closed gun! The bollicking you get will stick in your mind.
300 Blackout loads are the ones you should look for, I suspect, but I don't know if those cases are a lot smaller than 308 cases.

 

[Dr. Strangelove]

The point is, you probably won't forget it.
Walk round a clay ground with a closed gun! The bollicking you get will stick in your mind.
300 Blackout loads are the ones you should look for, I suspect, but I don't know if those cases are a lot smaller than 308 cases.

I wouldn’t advise .300 BO loads; the brass can be formed from 5.56 brass.

Henry Kranks have Viht N32C in stock.

 

[12gsnapcaps]

The point is, you probably won't forget it.
Walk round a clay ground with a closed gun! The bollicking you get will stick in your mind.
300 Blackout loads are the ones you should look for, I suspect, but I don't know if those cases are a lot smaller than 308 cases.

Considering I use a 9 shot semi auto for clays ... I couldn't close it! I jest, I use a chamber flag.