subsonic 308

[One on top of two]

😐

 

[BlueBoy69]

On 4/13/2020 at 4:03 PM, meles meles said:

NOE mould, 311-247 FN

I ordered one like this for my 300 AAC Blackout.

NOE sent it to the incorrect address, even though I gave them the correct one in my order. I couldn't find out where it had been sent to, or frankly what postal service was involved, and when I did the UK's postal service had sent it back the US of A.

I have never been refunded and they will not reply to my emails about not receiving the item, even though the mistake was theirs.

As such I would not recommend buying anything from them, even though they have some really good moulds.

Update as of 16th June: The mould did finally arrive, but only after a lot of pestering by me. It seems the mould had been returned to the US after it has been sent to the wrong person and address (even though both were given correctly when ordered) here in the UK. Unfortunately the person/company had not bothered to let me know this, if I wanted a refund, or if I wanted the item to be resent. Frankly I think they've/he's a bit snowed under with work and its all a bit too much for them/him. For note, the moulds are top quality.

[dodgyrog]

Strangely I have had a problem with NOE with my latest order.

I ordered a 6,5 mould for the Creedmore around December, paid as well. Nothing received and no answers to my emails either.

Very sad really after a lot of successful transactions (25 moulds) and I don't know what's happening there.

[terryh]

Gents,

If you are looking for a ‘nice’ mold from form folks who normally respond try BACo:

https://www.buffaloarms.com/bullet-moulds/buffalo-arms-bullet-moulds?cat=663

If they do not have what you are looking for (ignore the ‘out of stock BTW) then they can normally make what you want.

Turned moulds so round bullets - which helps.

Brgds T

[Dr. Strangelove]

I’ve finally got some N32C and have just loaded 20rds of varying weights. Will start at 12gr, then down to 11gr and 10gr. After that I’ve got incremental rounds to test velocity in the hope of finding somewhere close to what seems to be the magic 1050fps.

 

I’ve gone for 168gr HPBT bullets as by all accounts they’ll stand the best chance of stabilising in my 1:12, 25” barrel!

 

Anyone else gone for a similar load with N32C?

[sean c]

1 hour ago, Dr. Strangelove said:

I’ve finally got some N32C and have just loaded 20rds of varying weights. Will start at 12gr, then down to 11gr and 10gr. After that I’ve got incremental rounds to test velocity in the hope of finding somewhere close to what seems to be the magic 1050fps.

 

I’ve gone for 168gr HPBT bullets as by all accounts they’ll stand the best chance of stabilising in my 1:12, 25” barrel!

 

Anyone else gone for a similar load with N32C?

I'll be interested to hear how you get on. I should be picking some N32C up when I go to the range on Sunday.

[BlueBoy69]

On 6/16/2020 at 5:29 PM, Dr. Strangelove said:

I’ve finally got some N32C and have just loaded 20rds of varying weights. Will start at 12gr, then down to 11gr and 10gr. After that I’ve got incremental rounds to test velocity in the hope of finding somewhere close to what seems to be the magic 1050fps.

 

Don't try to get too close to the speed of sound (*) as you can still get shockwaves forming on the projectile even though its subsonic and they can make that characteristic supersonic crack you want to avoid.

This is due to the flow over the projectile being, at certain points, supersonic, even though the projectile's subsonic. This results in the formation of shockwaves normal (at approx 90°) to the projectile's surface.

Also, as the temperature drops, what was subsonic becomes supersonic (** & ***).

* = 340.27 m/s (1116.4 ft/s) at internation standard atmospheric (ISA) conditions (sea level standard reference point +15°C, 101.325 kPa, 0% humidity)

** = 331.30 m/s (1086.9 ft/s) at 0°C.

*** = 328.25 m/s (1077.0 ft/s) at –5°C.

Some image examples below of a bullet, then for a wing, transitioning from subsonic to supersonic. Oh, and a video showing a wing going supersonic, this visualised using soap films.

This change in the positions of the shockwaves formed as the object moves from subsonic to supersonic, results in a massive change in the centre of pressure. As far as I'm aware this is the primary reason for transonic instability problems.

 

[Scotch_egg]

NC32C also known as Tin Star. 
 

10.5gr worked under a 175gr matchking out of an 18” barrel. 
 

 

[Miseryguts]

Hi, I see this has cropped up again. I tried N32 in my 308 and 45- 70 when my friend gave me some to try. Unfortunately I could not get either rifle to group, and it was pretty dirty. So I am now back with my Green Dot loads for both rifles - both grouping nicely at 100 and 200 yards.

Good luck to those trying it out I hope it works better for you. It certainly did for my friend - he swears by it.

M in misty Monmouthshire 

[Dr. Strangelove]

On 6/16/2020 at 10:06 PM, BlueBoy69 said:

Don't try to get too close to the speed of sound (*) as you can still get shockwaves forming on the projectile even though its subsonic and they can make that characteristic supersonic crack you want to avoid.

This is due to the flow over the projectile being, at certain points, supersonic, even though the projectile's subsonic. This results in the formation of shockwaves normal (at approx 90°) to the projectile's surface.

Also, as the temperature drops, what was subsonic becomes supersonic (** & ***).

* = 340.27 m/s (1116.4 ft/s) at internation standard atmospheric (ISA) conditions (sea level standard reference point +15°C, 101.325 kPa, 0% humidity)

** = 331.30 m/s (1086.9 ft/s) at 0°C.

*** = 328.25 m/s (1077.0 ft/s) at –5°C.

Some image examples below of a bullet, then for a wing, transitioning from subsonic to supersonic. Oh, and a video showing a wing going supersonic, this visualised using soap films.

This change in the positions of the shockwaves formed as the object moves from subsonic to supersonic, results in a massive change in the centre of pressure. As far as I'm aware this is the primary reason for transonic instability problems.

 

Thanks for the reply, very informative!