Author Topic: .308 powder: Does this make sense?  (Read 4193 times)

YoungGun

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.308 powder: Does this make sense?
« on: August 12, 2013, 07:43:40 PM »
OK, first off I will admit that burn rate charts are not really exact do to the many variations in powder types, shapes, and chemical compositions. In fact, I just read an article that explains why they are fairly meaningless. But i looked at one anyways.

I've just started reloading for my .308. Looked at the load data and it recommends N550 as having the best potential accuracy. I assume this is based off of the case volume used by the powder. a full case means consistent burn, long as pressures aren't going crazy anyways. I went with 3031 because I have almost a pound in the cabinet.

Back on topic now. The test barrel in the manual is listed as 24", my barrel is only 18" so I'm thinking that a slightly faster powder could allow better efficiency and help squeeze eveything I can out of the shorter barrel without having to push the max load.

The way my simple mind works, it seems like a powder that should burn faster, such as 3031, should give better results in the shorter barrel than a slower burning powder like N550.

Anybody do any testing in this area or have a better understanding on the subject that could shed some light and explain why I'm wrong about this?

TexasRedneck

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Re: .308 powder: Does this make sense?
« Reply #1 on: August 12, 2013, 07:56:11 PM »
If mauserman doesn't spot this thread and answer, message him about it.....bet he'd be able to give you some good insight!
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Vaquero

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Re: .308 powder: Does this make sense?
« Reply #2 on: August 12, 2013, 08:07:39 PM »
What grain of bullet?
I remember your pic but hate to just guess.
165gr?
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YoungGun

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Re: .308 powder: Does this make sense?
« Reply #3 on: August 12, 2013, 08:12:07 PM »
What grain of bullet?
I remember your pic but hate to just guess.
165gr?

168.

Not trying to make it go the speed of light, just not sure how much I'm gonna lose.

Accuracy is the goal.


Vaquero

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Re: .308 powder: Does this make sense?
« Reply #4 on: August 12, 2013, 08:24:47 PM »
What grain of bullet?
I remember your pic but hate to just guess.
165gr?

168.

Not trying to make it go the speed of light, just not sure how much I'm gonna lose.

Accuracy is the goal.

My older manuals list test rifle as Winchester model 70, 22" barrel and 1-12" twist for Hornady and Speer.
Sierra is 24" 1-10" rate, new Hogdon print is 24" 1-12.
That's as close as I got.

Hornady is the only manual I have that lists your powder and bullet weight.
36.1 to 40.2 gr.
No indication of better or worse accuracy at either end of the spectrum.

The "most accurate powders tested" comments don't include IMR 3031. FYI
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TrapperL

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Re: .308 powder: Does this make sense?
« Reply #5 on: August 12, 2013, 08:29:36 PM »
I've been loading for 45 years now and like most everybody, I still learn new things. When it comes to the 308, I load for that round a lot as I load for myself and a friend who is a trapper by trade. We came across several cans of N135 powder as well as a few of N550. We decided to load these powders in the 308 cases and run them thru my Remiongton 700 ADL Deluxe which had less than 50 rounds down the barrel. His SOCOM, Savage 110V, and a custom shop Winchester Model 70 which he shoots competition varmint weight with it. While I was loading up rounds, one of the big S Texas ranchers came by and asked us to sight in his new Remington 700. His new rifle has a pencil weight barrel, 18" in length as are most bolt 308's. Shooting the 150gr Remington Core-Lok bullet, which we've found to be as accurate as many "match" bullets, we started printing rifles on paper at 100 yds from a steel bench. When we hit the max published load for that powder and that weight bullet, most all of the rifles started shooting near one hole groups- all of them. The ranchers pencil thin barrel shot a 5 shot one hole group. The worst was the SOCOM at a little less than a half inch. The N550 powder wasn't any better than anything else we had ever tried like IMR4350, IMR4831, IMR4064, AA2520, H335, Varget, and others. The N135 powder is remarkably outstanding in a 308 and we have since tried it in other rifles of 308. All have shot their absolute best with this load. That would be well over 25 different 308s. While I won't guarantee it in every 308, it certainly is a powder you should try if accuracy is the name of the game. If you don't have the data, click here:
http://www.lapua.com/upload/downloads/brochures/2012/vihtavuorireloadingguideed10_2012eng.pdf

If you're shooting a heavier or lighter bullet, I can't help you with that as the 150 Core-Lok that we load thinks its a match grade bullet. Terminal performance is as good as anything you can buy on any Texas game.

Vaquero

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Re: .308 powder: Does this make sense?
« Reply #6 on: August 12, 2013, 08:45:36 PM »
I'll add that I am not a .308 loader.
My .243 is based on that cartridge,  well, all of them are, and IMR 4350 works best for me.
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YoungGun

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Re: .308 powder: Does this make sense?
« Reply #7 on: August 12, 2013, 09:22:51 PM »
What grain of bullet?
I remember your pic but hate to just guess.
165gr?

168.

Not trying to make it go the speed of light, just not sure how much I'm gonna lose.

Accuracy is the goal.

My older manuals list test rifle as Winchester model 70, 22" barrel and 1-12" twist for Hornady and Speer.
Sierra is 24" 1-10" rate, new Hogdon print is 24" 1-12.
That's as close as I got.

Hornady is the only manual I have that lists your powder and bullet weight.
36.1 to 40.2 gr.
No indication of better or worse accuracy at either end of the spectrum.

The "most accurate powders tested" comments don't include IMR 3031. FYI


I have a Lyman 49th addition(2011) and Speer 12th addition(1995), both show 3031 in the load data.

The speer manual tests with a rem 700,22" barrel, 1/10 twist.
The Lyman test is a universal receiver, 26" barrel, 1/10 twist

At 45gr IMR-4350 shows a 200FPS loss on the shorter barrel.
BL-C(2)    22"         26"
  41gr     2336      2444
  45gr     2625      2695


I can't compare 3031 because the powder weights aren't equal between manuals but it does appear some powders seem less effected by barrel length.     

YoungGun

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Re: .308 powder: Does this make sense?
« Reply #8 on: August 12, 2013, 09:33:20 PM »

If you're shooting a heavier or lighter bullet, I can't help you with that as the 150 Core-Lok that we load thinks its a match grade bullet. Terminal performance is as good as anything you can buy on any Texas game.

The cor loks are great, my .243 loves the 80gr and they do a great job on White Tails. Will probably use them when I start loading some hunting rounds for the .308 but for now I'm looking for the higher BC I can get with the HPBTs. Will eventually try some 175gr but not sure if they will stabilize so playing it safe for now.

YoungGun

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Re: .308 powder: Does this make sense?
« Reply #9 on: August 12, 2013, 09:41:49 PM »
I'll add that I am not a .308 loader.
My .243 is based on that cartridge,  well, all of them are, and IMR 4350 works best for me.

Right now I'm loading Hornady 100gr spire points over 38gr IMR 4831. Managed to get 1/2" 3 shot groups at 100yrds with them. Fought them forever until I figured out I was seating too far off the lands. At the recommended AOL I couldn't get better than 2.5".

Really looking forward to seeing what the sierra MKs can do.

Vaquero

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Re: .308 powder: Does this make sense?
« Reply #10 on: August 12, 2013, 09:44:55 PM »
I'll add that I am not a .308 loader.
My .243 is based on that cartridge,  well, all of them are, and IMR 4350 works best for me.

Right now I'm loading Hornady 100gr spire points over 38gr IMR 4831. Managed to get 1/2" 3 shot groups at 100yrds with them. Fought them forever until I figured out I was seating too far off the lands. At the recommended AOL I couldn't get better than 2.5".

Really looking forward to seeing what the sierra MKs can do.

Nice. The "test loads" sure get the trigger pull and breathing under control more than anything.
A flyer only makes it more interesting.
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YoungGun

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Re: .308 powder: Does this make sense?
« Reply #11 on: August 12, 2013, 11:35:54 PM »
Yup, I've learned more about the things I do wrong when trying to get a load worked up than any other time spent on a rifle.

Doesn't take long before you can pretty much call your errors without seeing the target. Soon as you pull the trigger you realize you just ruined a beautiful group,

Retarmysgt

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Re: .308 powder: Does this make sense?
« Reply #12 on: April 21, 2014, 04:31:12 AM »
For my .308 since it was built to US Army M24 spec I load the round that the Army uses for it.
175gr Sierra Matchking BTHP
41.75gr IMR 4064

If you want to look up the round its the M118LR.

Wolfwood

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Re: .308 powder: Does this make sense?
« Reply #13 on: April 22, 2014, 03:00:47 PM »
^that is vash's load too i think.
at least i know that's his bullet

brush_buster

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Re: .308 powder: Does this make sense?
« Reply #14 on: May 27, 2015, 07:30:18 PM »
My go to powder for .308 is BL-C2. FN PBR .308 will shoot 1/4 MOA at 200 yds using 168gr SMK.