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Hornady lists a maximum charge of 43.2 grains of IMR4064 in their 308 service rifle section for a 150 grain bullet at 2700 fps velocity. And that is with commercial cases and regular primers.

Using the search function, I've found where it has been posted several times here in the past of NRA data giving a charge range of 42-44 grains of IMR4064 using GI Lake City cases.

The NRA data would seem to be high to me compared to Hornady since Hornady max is 43.2 with a commercial case. I've always read that you have to drop a grain of powder when using mil-spec cases, so that would drop the Hornady value down to 42.2 grains of IMR4064. Supposedly it would drop even a little more if using a primer such as CCI#34.

So anyway, I'm a little confused and would appreciate any insight others have to offer. I'm trying to work up the following load and don't want to overdo it:

150 grain bullet
CCI#34 primer
IMR4064 powder
LC cases
2700 fps velocity

So what would/should be the max charge? Is 43.0, 43.5, 44.0 grade of IMR 4064 too much?
4064 is a good powder with a burn rate right next to 4895, it is just tougher to meter.
I use a charge of 43 gr. under a Hornady 150 FMJ , I would start at 41 and see how your rifle shoots.
Don’t look for pressure signs, compared to bolt gun ammo these leadings are very mild and weigh your cases. You won’t believe the variation in weight and don’t believe military are the heaviest. Federal commercial gets that title and Winchester are the lightest. Most military falls in the middle to heavier side so I just load for that and save all the FC for high performance bolt guns.
I trim to standard, throw charges close and trickle to finish, seat the 150’s to the chanlure and slightly crimp with a Lee Factory Crimp Die. Any LR primer works but I like CCI.
These rounds shoot very sub 2” in both my 7.62x51 M1 and my M14’s. I give the same treatment to my ‘06 rounds for my Garands and I have one that shoots so well you can cover a full clip with a quarter at 100 yards.
 

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No, Hornady's Service Rifle Section isn't the worst data, it's the most accurate and reliable.
No, Hornady's reloading manual wasn't written by lawyers, it was written by engineers that provide you with the most accurate data using HORNDAY BULLETS. Hornady bullets tend to produce higher pressures than most other brand bullets of the same caliber and weight.
No, you don't have to seat the Hornady FMJ to the cannelure but since the Hornady manual shows that that they seated the bullets that they tested at 2.70" then it's best for you to do that too.

Some misconceptions and knee-jerk assumptions will never die, especially now that we have the Ignorant-net.
 

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Weighing cases is an inaccurate way of determining case capacity. If you want to know the real capacity you need to check by water grain volume. There's very little difference between .308/7.62 NATO case capacities. I've checked Federal cases that weighed anywhere from 163 to 181 grains and the water capacity was within a .1-.2 grains, the difference is in the brass alloy.

John
 

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How do you check the capacity with water? Does one resize and trim first and plug the primer pocket with something?
 

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You use fired cases from your rifle, primer still in, very small amount of dish detergent in the water will reduce surface tension and keep bubbles from forming. Put the case on a digital scale and zero, then drip in water until at the meniscus of the neck . Then you read the scale for grain capacity.

John
 

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No, Hornady's Service Rifle Section isn't the worst data, it's the most accurate and reliable.
That always drives me nuts when I see that. If you are to believe some of the comments, Hornady SRD barely pushes the bullet out of the barrel... right?
 

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Most people that think that Hornaday publishes light loads but those people don't understand how bullet profile effects pressure and velocity.

Another problem is that most people believe in the discredited idea that the case will let you know when the pressure is too high, which usually leads to shooters unknowingly using loads that are hot.

And finally, bolt gun competition shooters typically build hot loads and the casual observer assumes that they can use that same load to improve their groups.

The end result is that people are lead down the path to a false conclusion, namely that most reloading manuals list light loads (with Hornaday being the worst) so that they can avoid litigation. The truth is that there are a lot of shooters out there that are wearing their rifles out for no good reason. I recommend following the recipes of the reloading manual that was published by the manufacturer of the bullet that you are using.
 

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I've found that Hornady bullets have more bearing surface so the pressure is higher was less of a charge. If you look at service rifle shooters back in the 80's and early 90's almost all were using Sierra 168's with 41.5 grains of either IMR or Hodgdon's 4895. I loading manuals this is at the upper limits but was being done to emulate M852 that was being shot in DCM/CMP team matches and Leg matches. Add to this the fact that the 168 was not intended for 600 yard shooting, it was originally labeled "168 grain International" for 300 meter Olympic competition.

John
 

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Hornady lists a maximum charge of 43.2 grains of IMR4064 in their 308 service rifle section for a 150 grain bullet at 2700 fps velocity. And that is with commercial cases and regular primers.

Using the search function, I've found where it has been posted several times here in the past of NRA data giving a charge range of 42-44 grains of IMR4064 using GI Lake City cases.

The NRA data would seem to be high to me compared to Hornady since Hornady max is 43.2 with a commercial case. I've always read that you have to drop a grain of powder when using mil-spec cases, so that would drop the Hornady value down to 42.2 grains of IMR4064. Supposedly it would drop even a little more if using a primer such as CCI#34.

So anyway, I'm a little confused and would appreciate any insight others have to offer. I'm trying to work up the following load and don't want to overdo it:

150 grain bullet
CCI#34 primer
IMR4064 powder
LC cases
2700 fps velocity

So what would/should be the max charge? Is 43.0, 43.5, 44.0 grade of IMR 4064 too much?
My lyman book calls for 48 gn medium gives you 2695 fps with 36000 cup pressure, 53 gn max with 3012 fps with 49600 cup pressure
hope this helps
 

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My lyman book calls for 48 gn medium gives you 2695 fps with 36000 cup pressure, 53 gn max with 3012 fps with 49600 cup pressure
hope this helps
You can't get that much powder in to a .308 case, are you thinking about a M1 Garand/ 30-06?
 
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Hornady lists a maximum charge of 43.2 grains of IMR4064 in their 308 service rifle section for a 150 grain bullet at 2700 fps velocity. And that is with commercial cases and regular primers.

Using the search function, I've found where it has been posted several times here in the past of NRA data giving a charge range of 42-44 grains of IMR4064 using GI Lake City cases.

The NRA data would seem to be high to me compared to Hornady since Hornady max is 43.2 with a commercial case. I've always read that you have to drop a grain of powder when using mil-spec cases, so that would drop the Hornady value down to 42.2 grains of IMR4064. Supposedly it would drop even a little more if using a primer such as CCI#34.

So anyway, I'm a little confused and would appreciate any insight others have to offer. I'm trying to work up the following load and don't want to overdo it:

150 grain bullet
CCI#34 primer
IMR4064 powder
LC cases
2700 fps velocity

So what would/should be the max charge? Is 43.0, 43.5, 44.0 grade of IMR 4064 too much?
Loading for military gas guns can be very tricky to obtain proper loads if your working on the higher end of loadings but 308 is easier than 30/06. You really need to watch your cases and weigh them. In 308 LC and most military are right there with commercial cases as far as weight goes, Federal commercial and CAVIM (NATO) is heaviest and Winchester is lightest and there's enough of a difference that I do cull them out and use them for bolt guns otherwise most brass weighs within 10 grains or so. Personally, I tailor my loads to run around 2650 fps ( 42.0 of 4064 ) using mixed brass which gives me enough of a fudge factor I can run them in both my NAVY M1 (7.62x51) and my M1a without issues. Inside 300 yards loading precision, repeatability and consistency are what win matches. I prefer H4895 but your load of 4064 looks OK and I would use 43.2 as max. I drop and trickle all loads up to spec which shoots 1 moa all day in my Garand ( 1.5 in my M1a ) using Hornady 150 fmj or 125 gr Mk 319 OTM bullets lightly crimped in the cannelure with Remington or CCI primers. A $100 chronograph can be your best friend and answer all your questions and you'll find a slightly lower charge than max shoots smoother and more accurately, you will really feel it.
 
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