308 velocity dilemma

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CaneCorso85

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Hey guys,

I'm having a bit of trouble getting my 308 ammunition to register anywhere near the load data velocity using the prescribed loads. Here's what i'm using:

Lake City brass
168 SMK
IMR-4895
Win LR Primers
Fired from an M1A Socom
Data from the Sierra and Lee manuals

The data in the lee manual calls for a starting load of 41gr of H4895 (they don't list data for IMR) working up to 43.5gr, which should produce 2703 fps.

The Sierra manual calls for 42.1gr of IMR4895 to only get to 2600fps (does not list data beyond that speed)

Here's what I loaded, and the speeds it chrono'd at:

(yes, I started lower previously and the speeds were in the 2300's)

43gr
#1 - 2415fps
#2 - 2487fps

44gr
#1 - 2525fps
#2 - 2539fps
(note I'm now exceeding data from both books and still not even close to the listed velocities. No signs of overpressure on the casings)

45gr
#1 - 2534fps
#2 - 2530fps
#3 - 2544fps

46gr
#1 - 2614fps

My target velocity is 2660

Question is, despite being pretty high above the max loads for each manual, I'm still not at the prescribed velocities; should I go to 27gr to try to hit 2660? I can take some pictures of the brass for each load if that would help, however, I had a couple of experienced reloaders take a look at them and they didn't see any signs of overpressure. I don't imagine Sierra and Lee got that data using a gas operated rifle like the M1A. It's probably safe to assume a lot of that pressure is lost operating the action, which would tell me I'm probably safe to keep going. I'm just curious what the experts at THR have to say about it.
 
The more relevant question would be "at which load are you pulling the tightest groups?"

Raw power is not everything. As a rifleman, you are going to learn to make each shot count, right?

If a well-placed shot is made and the bullet is going 200 fps slower than a lousy-shot into the gut, the well-placed shot will be the one with the meat on the table EVERY TIME -- whereas the lousy gut-shot will be the one where the animal suffers, only to be found by some pack of coyotes. Besides, dead is dead, the animal shot is not going to know that the bullet happened to be traveling 200 fps slower than some other loads DESIGNED FOR OTHER GUNS!

I have one load that is borderline maximum (some slight signs of overpressure), and the ONLY REASON I stuck with that particular load was because -- out of about 21 loads I tested, that load pulled, by far the most accurate and tightest group! The gun is a bolt action with 22" barrel! Had the less-powerful load been more accurate, that is what I would have gone with. I don't want to prematurely wear out my chamber and barrel. As it is, with that particular rifle, I shoot only when I know I am going to hit something. I know where it shoots, I know it is accurate, there is no need at all to shoot up bottles, rocks, cans, and go plinking with it. Unlike your gun, mine is not a gas-operated gun!

When you begin pushing pressures in a gas-operated rifle, the timing ends up being 'off' which will rapidly wear parts and may eventually result in a 'kaboom-situation' which we, as reloaders, strive to never have happen!
 
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getting my 308 ammunition to register anywhere near the load data velocity using the prescribed loads.
Click to expand...
M1A Socom huh.
Thats the one with the 16" barrel right?

That right there is your problem!

You will never reach load book velocity safely with a chopped off barrel like that.
So, don't even try it.

rc
 
Yes, M!A SOCUM? Do you have any idea of what high pressure signs are in a semiauto?

You better quit chasing velocity before you wreck your gun.
 
It's probably safe to assume a lot of that pressure is lost operating the action,
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You can safely assume NO pressure is lost in the action.

The bullet is long gone before any gas goes to the gas piston and starts the action operation.

You need to Cease & Desist Immediately, if not sooner.
By your own admission, you are already 5.0 grains over max, likely using Bolt-Action data.
Referancing H-4895 instead of the IMR-4895 you are using!!
And you are considering going higher yet in a gas gun!!

Mercy, mercy, mercy!!

rc
 
Short barrel, get some faster powder...I seriously doubt you are going to blow up the rifle.
Click to expand...

WRONG...on both counts!

Faster powder won't help...I know because I've been down that road. And he will most certainly wreck that gun if he hasn't already.

CaneCorso85,
You need to be using "service rifle data" in that rifle...and with IMR 4895 the max load with 168 grain bullets is 41.4 grains...going higher MAY NOT explode the rifle, but it WILL damage it if it hasn't already. Get some Varget powder, it will likely get you all the velocity that you're gonna get..which will be around 2,300-2,400 fps.

Thats what short barrels do...they cost velocity.

Please...be safe!

2,660 fps...thats hard to achieve even with a 20 inch barrel on a bolt gun. (For the record...that Sierra manual you have used a 26" barreled Savage as the test rifle)

Also, you could use lighter bullets...150 grains.
 
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IMR 4895 and H 4895 are not the same powder...IMR is a faster burning powder, and its a temperature sensitive powder. That means it burns a lot hotter in warmer ambient temperatures.

H 4895 is very temp stable, as is Varget...ambient temperature does not affect it.

You are playing fire...make no mistake...STOP, research what the folks here have said and you will see.
 
Isn't this the second time in the last few week's we've had somebody trying to get full-length velocity from a carbine barrel? :uhoh:

To the OP, STOP! CEASE AND DESIST! You're well into no-man's land already. You have a 16" barreled semi-auto and you're trying to get the speeds the .308 generates from a 22" barrel. Ain't going to happen. Your SOCOM is going to run about 200-fps under any book load you find. Be happy with about 2400-fps with a 165/168. You could get a bit more speed with a 150, but I'd doubt you will see much more than 2550 or so even then.
 
If it were me I would switch to a slower buning powder, you'll get the velocity and acuracy is generally excellent with them. Check out loads with RL17 or better yet RL19 and velocity will certainly improve.
 
gamestalker said:
If it were me I would switch to a slower buning powder, you'll get the velocity and acuracy is generally excellent with them. Check out loads with RL17 or better yet RL19 and velocity will certainly improve.
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Just curious. Have you ever loaded for an M1 or an M1A? Do you know what slower powders can do to the OP rod?
 
I used to "chase velocity", using just about every powder and load for my .308that was ever recommended.

Then one day, by accident, I found that the most accurate load was one of the slower loads published. It isn't what the "book" or "chronograph" says, it's what shows up on your target at the desired range that matters.

If you haven't achieved desired results by the time you reach "MAX LOAD", it's time to stop and reevaluate.
 
Grumulkin, I haven't loaded for one of those bugger's in 25 or so years, so I don't really recall what they like to eat. I was just trying to help what sounded like a plea for velocity.
 
For those suggesting Varget and slower powders; Every piece of material I have read about reloading for the M1A/M14 platform states that Varget (or powders of equivalent speeds) are too slow for the gas system.

For everyone else; Message received. The good news is that the rounds in the data I posted are the only excessive loads ever put through the rifle. The only reasons I loaded those, was because I got the ominus dominus from an experienced reloader and m14 armorer. He has, however, never owned a 16" barrel for one and that may be the disconnect.

I'm focused on velocity because I'm trying to load for long ranges (600 w/168 and 1000 w/175). I'm starting to accept that the SOCOM is limited by quite a few factors, but it's what I have to start with so I'm trying to get as much out of it as I can. I have no doubt I can load something accurate at 200 yards, but that wasn't the goal. I guess I should have stated that in the original post.

Thanks for the advice guys.
 
CaneCorso85,

I would recommend reading Zediker's article on loading for M14s located here. While a bit conservative, he highlights the unique aspects of reloading for an M14 type rifle. You can't get as creative with this beast as you can with a bolt gun. Seems like the "standard" loads for highpower are around 40.0-41.5gr using a 4895 type powder...with 40.5gr being "the" load. Winchester commercial cases are also preferred for the long-range events since they generally have more case capacity. I would stay away from any mil cases as they have less capacity...which means higher pressures with the same load.

Good luck with your pursuit!
 
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There are some folks that say Varget (or Reloder 15) is too slow for an M1 type rifle...but there are also a lot of folks who say that its fine...its one of those things that some folks like to debate...

All I can offer is this...I have shot a few thousand rounds using Varget and Reloder 15 in an M1a, and my rifle is still going strong, no problems whatsoever...very accurate too.

By the way...if you can get a 168 grain bullet (or even a 150-155) up to 2,300-2,400 fps it will perform just fine at 600 yards. It will have a bit more drop but it will be just as accurate as ever. And forget about 175 grain bullets if that rifle has a 1 in 12" twist...you'll never get them fast enough to remain stabilized.
 
CaneCorso85, I believe that you have proven how strong the M1A action really is.
My Lee manual doesn't list what barrel length was used in their testing, I don't have Serra book handy, so that's a no help. However my old Speer book shows there tests in a 22 inch barrel. I think it would be a safe guess that most if not all manuals test with barreled actions that are on the long side of what is carried in the field.

To the point:
I would not hope to expect to equal the listed velocities with a shorter barrel.
Using H4895 data but using IMR4895 powder is not safe! They are two different powders.
If your only goal is to shoot a faster bullet, get a 220 Swift or something like that.
To equal or exceed book velocities, get a 28 inch barrel for a Thompson take down action and then slowly work up with the correct components.

Oh, could you provide some photos of the brass that you fired with these loads? I would like to see the primers and head expansion.

Remember, no one wants you to be hurt. So only error on the side of safety.

OSOK
 
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2400 fps is about tops in what to expect using a 168 gn bullet in 16 in barrel 308. 2600 fps with 150/147 grainer.
 
Question is, despite being pretty high above the max loads for each manual, I'm still not at the prescribed velocities; should I go to 27gr to try to hit 2660?
Click to expand...
"max" is short for "maximum".

Maximum means:

1.
a. The greatest possible quantity or degree.
b. The greatest quantity or degree reached or recorded; the upper limit of variation.
c. The time or period during which the highest point or degree is attained.
2. An upper limit permitted by law or other authority.
3. Astronomy
a. The moment when a variable star is most brilliant.
b. The magnitude of the star at such a moment.
4. Mathematics
a. The greatest value assumed by a function over a given interval.
b. The largest number in a set.
adj.
1. Having or being the greatest quantity or the highest degree that has been or can be attained: maximum temperature.
2. Of, relating to, or making up a maximum: a maximum number in a series.

http://www.thefreedictionary.com/maximum

Notice that every definition and meaning of maximum implies that nothing exceeds the maximum.
It's probably safe to assume a lot of that pressure is lost operating the action, which would tell me I'm probably safe to keep going.
Click to expand...
Both of those are incorrect assumptions and also unsafe.
I got the ominus dominus from an experienced reloader and m14 armorer.
Click to expand...
Buy another reloading manual or 2 or 3 and use them to verify any data provided by "experienced reloaders".
I'm just curious what the experts at THR have to say about it.
Click to expand...
Reloading not a productive or safe activity for people who don't follow rules.

You can be thankful that you didn't blow up your rifle and harm yourself or others.
 
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CanCorso85,

You trying to blow your rifle up? The loads you listed using more than 43 grains of IMR4895 with Lake City brass are dangerous high pressure loads. I guarantee the load data you are using does not use Lake City brass. You cannot take .308 load data using commercial brass, and transfer it to 7.62x51 brass without reducing the charge weight. Adding more powder to reach a certain velocity without taking the pressure generated into account is an accident waiting to happen.

Don
 
You are already getting exactly what your 16" barrel will produce.
Like a dead horse, it isn't going to do any more. PERIOD.

2,400-2,425fps is your limit w/ any reasonable 168SMK/powder/pressure combo,
and that's only with the likes of 39.5-40.0 grains of IMR3031.
 
Lately I have been playing around with Alliants new 2000 MR powder and a 16" LR308. From what I have gathered it has a similar burn rate to RL-15 which SHOULD make it safe to use in your rifle but please do your own research to confirm. They have two max charges for 165gr bullets so I chose the smaller of the two, and that being 50gr. I went down 10% and worked up to the max, I started seeing signs of pressure (at 50gr) but nothing that would make ME think it was any where near unsafe. I would even venture a guess that I could go 1 or 2 grains over max and still be safe.

At max charge I was in the low 2700's with decent ES numbers, I chose 49.5 grains as the load for my gun since it gave the best accuracy and that gives a hair under 2700 from my rifle.

Im using LC brass, CCI #34 primers, and Hornady 165gr BTSP bullets.
 
As stated in my first response, message received. For those of you who provided useful feedback; Thanks. For those who copied and pasted from websters dictionary, not so much.

Obviously, in coming here I'm seeking advice and bouncing ideas off people who have more experience than me, in order to maximize my results and help keep me in check safety wise. I've been in the Marine Corps for almost eight years by now, and in that time I've acquired some pretty thick skin, but I can guarantee there are people out there trying to learn about reloading and for fear of receiving some snarky condescending response, won't even ask the question that may save their guns, or more.

Like I said, I took some bad advice from someone whom I perceived to be a very experienced reloader. That person made it seem as if most reloading manuals are written by rooms full of lawyers, who make all of the manufacturers reduce there data by some large margin before the load actually starts approaching dangerous. Additionally, after every shot from the above data, I had people who'd been reloading for 20 plus years inspect the brass and check for signs of overpressure. There were none.
 
Thank you for your service CaneCorso85.

Realize that you were admonished for your approach of loading to velocity, instead of to listed book maximum. No one here would like your rifle wrecked due to a lack of understanding of accepted loading practices.
I'm sure that a lesson has been learned, and you don't need to be offended by comments made because we are all here because of our love of firearms and our freedoms.
If I'm not mistaken, the M1A produced by Springfield Armory has the capability and clearance to fire 308 Winchester factory ammunition at SAAMI spec, and that can register up to 62,000 PSI.
Just be careful and try to adhere to maximum loads listed in the manuals, and at www.hodgdon.com.

Have a good day!


NCsmitty
 
For those who copied and pasted from websters dictionary, not so much.
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You don't know how lucky you are. Realistically, if you had blown the rifle at the range, you probably wouldn't have been in as much danger as those next to you on the line. Besides the liability involved in injuring a bystander, living with that kind of thing would not be easy or fun.

You have taken up a hobby that creates controlled explosions inside metallic casings. If you think that sounds a lot like making grenades, it is--except for ONE tiny detail. That detail is that you stay under max loads and that SINGLE fact means you're creating ammunition instead of grenades.

I softened my original response before hitting the submit button. Initially I stated that you should not be involved in reloading because reloading is about following rules and you apparently think that you are above that as long as you can find someone to go along with you. After re-reading your second post on the thread I decided that might be too harsh so I changed my post. But now you're still defending what you did, trying to make excuses for it, trying to prove why it wasn't really that bad, and that's making me think that my first response was on target.

YOU are the one who is responsible for making and firing overpressure loads even though the loading data you had access to clearly indicated that the loads were dangerous. NOT the "experienced reloader" who told you that reloading manuals were overly cautious. NOT the "experienced reloaders" who inspected the brass and told you the loads were safe.

Had you blown up your rifle, YOU would have had to pay to replace it, not your buddies who gave you horrible advice.

Had you injured yourself, YOU would have borne the consequences, no one else.

Had you injured someone else in the process, YOU would have been responsible and YOU would have had to live with the knowledge that your decision to disregard the clear warnings in the loading data caused someone else to suffer.

This isn't a game, and I'm sorry if your feelings are hurt, but your feelings don't really matter into the big picture. It's not about feelings or ego, it's about following the rules so you don't make grenades instead of ammunition.
Obviously, in coming here I'm seeking advice and bouncing ideas off people who have more experience than me, in order to maximize my results and help keep me in check safety wise. I've been in the Marine Corps for almost eight years by now, and in that time I've acquired some pretty thick skin, but I can guarantee there are people out there trying to learn about reloading and for fear of receiving some snarky condescending response, won't even ask the question that may save their guns, or more.
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You're still not getting it. You already had all the information you needed to load safe ammunition and you decided to disregard it. Even if you had come here and gotten some folks to cheerlead your actions instead of point out the danger, that wouldn't change anything.

So you take your pick. If you want people to tell you what you want to hear, go back to your buddies who know more than the reloading manuals. If you want the truth, you'll have to accept the fact that you screwed up bigtime and that the only thing that prevented a catastrophe was pure luck. There's no nice way to say that.
 
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