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Old February 11, 2013, 01:01 PM   #1
cbforestry
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DPMS LR308 load tips needed

I'm working up a 168gr matchking load for an LR-308 classic. 20" barrel, free floated. Caliber stamp on barrel is actually 7.62 x 51 nato. Original load was the 155 palma matchking, 42.7gr AA-2230. Got horrible groups and was told to go with a heavier bullet (168-180). I switched to the 168gr w/44.4gr W-748. Accuracy improved but started getting over pressure signs (sticky extraction, cratered primers, one primer even had a hole in it). The same rounds showed no pressure signs when fired through a Sako bolt action. Looking at other peoples 308 posts I notice that w-748 is pretty much absent. I have a couple pounds of IMR 4895. Does anyone have any load suggestions?
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Old February 11, 2013, 01:15 PM   #2
HiBC
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With the 155 Palma in a very accurate Kreiger barreled Armalite,we did not get good accuracy,same in my DPMSLR 308L.Obviously,it is a wold class accurate bullet in a 308,but not necessarily in an AR.The Sierra bullet designated a 155 MK,not the Palma,shoots better in those two rifles.

I think you will find Varget works very well with the 168 in your AR.Loads are in the books.If you want to hunt,try the 165 or 168 gr Ballistic tip or Accubond,same powder.Work up for each bullet 's max,but these 3 bullets have you covered.
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Old February 12, 2013, 01:22 AM   #3
toolguy2006
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I have a Sig 716 Patrol, with a 16" barrel, 1 in 10 twist. So, kinda sorta similar to your DPMS. So far, I've had good luck with 40.5gr IMR 4895 under a 168gr A-Max, which is a "go to" load for an M1A. Hope this helps..... Also, for what its worth, I've always had better luck with the A-Max bullets than the Match Kings.
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Old February 12, 2013, 06:08 PM   #4
89blazin
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Reloading with a 4895, W748 and any powder will require load testing to get tight groups from any rifle. Start a couple grains below what you have tried. Load 3 rounds w/ 42gr W748, 3 rounds w/ 42.3, 3 w/ 42.6, 42.9, 43.2...etc. You'll notice the three round groups get tighter and looser...you'll finally discover the right powder charge/primer combo that gives you a tight group w/ the 168gr bullet. Use the same process for different powders and different bullets or primers. Once you think you've got a very good load, start experimenting with bullet seating depth. The perfect load for that particular rifle is out there...takes a little work finding it.

I prefer 168gr SMK w/ 41.5gr of H4895 in my M1A. That load in that rifle will put holes in holes all day long if I do my part. I also use W748 as well. Each rifle is unique....

IMR4895 usually take a couple more grains than H4895...look it up:
http://data.hodgdon.com/cartridge_load.asp
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Old February 14, 2013, 05:56 PM   #5
cbforestry
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DPMS 308 load improving

I tested 4 loads @100yds yesterday. I'm using Hornady's data for service rifle.
I'm estimating a drop of 100fps from the 22'' to a 20" barrel. Allowing cooling time and barrel cleaning between each group as a control.

Best load was 39.9gr of Varget-0.4" group avg.
2nd best was 40.0gr of IMR 4895- 0.7" average.
Next load, 40.5gr of IMR 4895- 1.1" avg.
Next- 43.3gr of w748- 1.6" avg. Once again with cratered primers. I'm scrapping 748 as a viable powder for my rifle.
Final load was 41.3gr of Varget- 1.9" avg. This group was a complete mystery to me. It really just opened up with no logical explanation.

The only problem I have with the best load is the velocity (est. 2300fps). This is going to awfully slow @ 600yds.
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Old February 14, 2013, 06:15 PM   #6
89blazin
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This group was a complete mystery to me. It really just opened up with no logical explanation.
The group opened up because the bullet speed / exit from barrel / barrel harmonics are out of sync more so than your other loads tested.

The only problem I have with the best load is the velocity (est. 2300fps). This is going to awfully slow @ 600yds.
Will you be shooting competition at 600 yds.? You have realized the quandry all long range shooters face...most accurate loads (tightest grouping) vs. maximum velocity (for flatest trajectory). You need tight groups @ 100 yds. so they can still be on paper @ 600 yds. You need maximum velocity to help offset bullet drop and yaw from cross wind.
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Old February 15, 2013, 01:27 PM   #7
HiBC
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Unless you are seeing pressure signs,or approaching max,I wouldn't necessarily take that loosening of group to be a "stop,back up"

I'd pour more powder in,so long as you are inside max,and not seeing trouble.

See what happens about 45 gr,or wherever your upper limit is.Note,Sierra shows a Max of 43.5 gr in the 5th ed.My 2011 Hogdon annual shows 46 gr compressed with the 168 gr MK.Brother is generally using Nos Custom Comps.

http://thefiringline.com/forums/atta...9&d=1316500028

That link is firing line,it will show you a 300 d target,three shots to check zero before antelope hunt.165 gr Ballistic Tips and someplace between 45 and 46 gr Varget in WW cases.Its not a fluke.

This is at 600,168 gr Nosler Custom Comp,Varget,2700 fps,20 in bbl

http://thefiringline.com/forums/atta...4&d=1307209204

Last edited by HiBC; February 15, 2013 at 03:35 PM.
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Old February 15, 2013, 02:40 PM   #8
cbforestry
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Thats nice shooting HiBc. How are you getting 2700fps out of a .308win 20" barrel? I don't think my DPMS will allow that kind of pressure. Something with head space and chamber tolerances I think.

To answer the question of why I'm concerned with external ballistics @ 600 yds, its not a matter of competition. It is a battle rifle. And I think most of us are looking at our battle rifles in a different context these days.
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Old February 15, 2013, 03:32 PM   #9
HiBC
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I did not shoot that,my younger brother did.

I did a quick look at my Sierra book.They advised a little less powder than I told you.,43.5 gr max with a 168 MK for 2700 fps 26 in bb;(5th edition)
My Hogdon 2011 annual says46 gr compressed for 2730 out of a 24 in bbl.

I have a CED chronograph that reads pretty good,2700 is what I recall.He has his own notebook.

It also could be thete is a difference in bore friction with the Noslers.I do not know.

Another powder that Sierra recommended as accuracy load was RE 15 at 2600 fps.

Please use published data and work up to your load

On your other comment on "battle rifle",IMO,lets keep the battle in the voting booth,etc.Nuff said,this is Reloading!
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Old February 15, 2013, 04:34 PM   #10
TATER
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I have found that W-748 has great accuracy for 130 - 150 grain bullets, Once I go past 150 grain with W-748, I get wacky pressure signs and accuracy goes to crap..
I use Varget with 168 – 175 . This holds true with all my gas guns, 16, 18, and 20in. HTH
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Old February 15, 2013, 05:11 PM   #11
hodaka
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I had an early DPMS with a 24" fluted barrel. I added a Jewel trigger and it was incredibly accurate with 155 Sierra's using 4064, both IMR and AA. I never got it to shoot as good when using 4895 or Varget.
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Old February 15, 2013, 09:32 PM   #12
led0321
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Re: DPMS LR308 load tips needed

Good thread
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Old February 15, 2013, 10:12 PM   #13
Bart B.
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I suggest you use extruded powders for your .308; IMR's 4895 or 4064 and Varget's also good. Nobody's ever got really good accuracy consistantly with a .308 loaded with ball powder. Even metered charges of these powder typically shoots more accurate than weighed charges of ball powders.
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Old February 16, 2013, 07:14 PM   #14
zeke
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makes a difference what primer and what case you are using, especially with 308 brass differences. If using a heavy case would suggest droping down to 43.0 grains 748, and use a chronograph. If you are getting higher than expected velocitys, you may be getting higher presuure than desired from that chamber.

I have trouble getting accuracy with 1:10 in twist and less than 165 grain bullets in gas rifle currently used. All the other semi's with slower twist handle 125 ,150 grainers just fine.

Am gettingvery good accuracy with 748
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Old February 17, 2013, 12:52 AM   #15
EVR
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DPMS LR308/H4895 Recipe

I have loaded and Chronographed 2 loads using:

-DPMS LR308 (24"bull barrell)
-CCI Benchrest Primers
-168g Sierra MatchKing HPBT
-H4895

Here is what I got:

42g-2650fps
43-2725fps

I am going for about 2700fps so my next load will be 42.7g H4895 and that should get me where I want to be...
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