Full power 240 grain cast in the 308

[rvpilot76]

Looking for a good full power load for an AR10 build I've got coming up. I am planning on using my NOE 311247, which drops 240's with my wheelweight alloy, but I can't find load data anywhere for something that heavy. I've used 41 grains of H4350 with 215 grain bullets in my 303 British, and things were OK, but I'd like to get some input on load data. Suggestions welcome.

Thanks guys,

Kevin

[Larry Gibson]

Just some thoughts and questions;

the AR's gas system is designed around the time/pressure curve of 145 - 155 gr ammuntion at 2750 fps.

They also do fine with upwards of 175 gr bullets at 2550 fps.

Assuming yours will also have the 10" twist(?). Considering a 240 gr cast bullet?

Will you get sufficient velocity for stabilization without exceeding pressures at the gas port?

Not sure but it seems a real potential for problems(?).

Perhaps someone has experience?

Larry Gibson

[winelover]

I once read something to the effect that a 308 will do everything a 30-06 will do up to and including 180 grain bullets. I don't ever recall seeing anything over 220 grains for a 30 caliber in the loading manuals I have. I just can't phantom 240 grainers. The trajectory alone would put a rainbow to shame. IMO.

Winelover

[stubshaft]

I once read something to the effect that a 308 will do everything a 30-06 will do up to and including 180 grain bullets. I don't ever recall seeing anything over 220 grains for a 30 caliber in the loading manuals I have. I just can't phantom 240 grainers. The trajectory alone would put a rainbow to shame. IMO.

Winelover

I used to shoot 220's in my Whisper and those would put a rainbow to shame,

[nanuk]

winelover: you do realize there is a very large following of the Whisper, and BLK's?

there must be a reason

[rvpilot76]

@ Larry: this is the barrel that will be going in my Mega Arms MA-TEN M110 clone build:

http://www.fulton-armory.com/barrelf...kthreaded.aspx

I figure that if I'm limited by velocity, I'll put as much weight in there as possible
I also just checked the nose length, and it will allow me to seat the boolit with the case neck about halfway on the front driving band. I'll make some dummy rounds tomorrow, as well as take measurements with my Stoney Point OAL gauge in my Savage 12 (1-10"). I think I should be able to reach at least 2000 fps with my 308 and 12'' twist without hitting the RPM threshold. I will be water-quenching straight wheelweight alloy when making these.

Kevin

[Larry Gibson]

That is a fine barrel but with the 12" twist non stabilization of the 240 gr bullet, even at 2000 fps, is a real possibility. That barrel should be a dandy with the 311299 upwards of 2200+ fps though.

Also my concern, once again, is the time/pressure curve with the slower powders you need to use to attain 2000 fps with a 240 gr bullet and it's attendent gas port pressure.

Only one way to find out though. Just be careful of bolt velocity so you don't beat the AR to death.

Larry Gibson

[rvpilot76]

Thanks Larry. I've also got a RCBS 200 SIL mold that throws a 215 grain slug with my wheelweight alloy that I'm gonna try as well. That will probably be the better boolit in this application I'm thinking. If I can get around 2200 FPS with that, I'll be a happy camper!

Kevin

[Larry Gibson]

Thanks Larry. I've also got a RCBS 200 SIL mold that throws a 215 grain slug with my wheelweight alloy that I'm gonna try as well. That will probably be the better boolit in this application I'm thinking. If I can get around 2200 FPS with that, I'll be a happy camper!

Kevin

Now, that's what I'm talkin'

Larry Gibson

[Idaho Sharpshooter]

I bought a DPMS heavy 24" fluted barrel model, it has 1:10" stamped on the bottom of the barrel. I am going to try the 240's, just for my own curiosity; once I get done with 311365 and 311284 wrung out. I have the SAECO 315 on order as well. I kind of go along with the option of a heavier boolet since velocity is not my main focus.

Rich

[405]

After all the conjecture and build-up sure would be nice to get a report back about the success on target and success of the function of the gun.

My 308 bolt gun does so well with 150-160 grainers I've no need or desire to play with 240s.

[BrassMagnet]

You baited and switched me. I want some .308 data for a Rem 40XB.

[BrassMagnet]

Help! I need data. The boolits are cast in GC and PB. I really need data.

[geargnasher]

Help! I need data. The boolits are cast in GC and PB. I really need data.

The Lyman reloading manuals, cast bullet handbooks, and several other big-name cast bullet manuals are chock-full of reliable data. Sounds to me what you need is one of THOSE.

Gear

[Moonie]

I load that 245/247gr boolit in my 30-06 with 35gr of H4895 which gives me 1950fps. Stabilizes perfectly in my Savage with 1-10" twist.

[PS Paul]

[QUOTE=winelover;1556729]I once read something to the effect that a 308 will do everything a 30-06 will do up to and including 180 grain bullets. I don't ever recall seeing anything over 220 grains for a 30 caliber in the loading manuals I have.

With the proliferation of much-better, higher quality projectiles nowadays, the heavy-for-caliber 200 and 220 gr. in .30'06 is kinda becoming a thing of the past for many manuals and companies who make ammo.

Not sayin' there ain't a place for 'em (Africa comes to mind immediately), just sayin', that's all.

[Idaho Sharpshooter]

I am certainly not an expert on Africa, but I have made three trips there since December of 2008.

Elephant and Cape Buffalo, and several head of plains game the last two.

Based on that, a dozen trips to the annual SCI Members Convention, and talks with a lot pf PH's,
it seems that most prefer a 300 magnum of some sort if you are going over 165gr in a 30 caliber rifle.

I bought both 311247 NOE molds with the primary focus being my 300 BLK pistol.

Rich
Sua Sponte

[cast367]

In my Win. M70 with a 1-12 twist works a Lee 200grs CB fine.
I tryed hunderds of them with 9grs Vectan BA 9. A French powder.
Small groups .

Leo

[Moonie]

[QUOTE=PS Paul;1849458]

I once read something to the effect that a 308 will do everything a 30-06 will do up to and including 180 grain bullets. I don't ever recall seeing anything over 220 grains for a 30 caliber in the loading manuals I have.

With the proliferation of much-better, higher quality projectiles nowadays, the heavy-for-caliber 200 and 220 gr. in .30'06 is kinda becoming a thing of the past for many manuals and companies who make ammo.

Not sayin' there ain't a place for 'em (Africa comes to mind immediately), just sayin', that's all.

I believe this has to do with the whole magnumitus speed is everything disease that is plaguing hunters these days. Us casters tend to do things that have worked for a long time, heavy for caliber works very well.

[DCM]

Manumitus aside PHs in Africa seem to prefer large diameter heavy projectiles at over 2000FPS for dangerous game.

On the American continents I doubt that you will find any game that cant be handled with a well placed 45-70FN at slower speeds.
Nice freight train that makes nice holeS.