308 Winchester AR Only

[padom]

What is the base temperature you're comparing the fps change from?

What base temperature? 88F to 40F.. 40F to 90F.... All shot over my Garmin with same loaded ammo in both conditions. I saw a 2fps per degree velocity change. Thats just for the CFE 6 ARC mentioned specifically above. Ive tested lots of different powders.

For example, exact same setup, bullets, brass, primers, etc for this 6 ARC rifle and testing. Same days, I tested AR Comp as well. I saw a 6fps change from 90F to 40F... AR Comp is some of the most temp stable powder out there..

 

[r.tenorio671]

FWIW, my test results out of 16" AR10 "self-build"....

Load Date = 23 Aug 2015			Powder = AR Comp
Bullet = Hornady 155 OTM BTHP		Primer =	WLR
Ballistic COE = .405				COAL =	2.280"
	Grains						Avg FPS	Std Dev	ES
Start	42	2659​	2596​	2619​	2659​		2633	27	63
	42.2	2514​		2554​	2648​	2657​	2593	61	143
	42.4	2643​	2647​	2630​	2625​	2620​	2633	10	27
	42.6	2606​	2603​	2588​	2593​	2592​	2596	7	18
	42.8	2618​	2595​	2600​	2609​	2628​	2610	12	33
	43	2599​	2599​	2585​	2669​		2613	33	84
	43.2	2622​	2630​	2630​	2608​	2612​	2620	9	22
	43.4	2658​	2630​	2646​	2659​	2662​	2651	12	32
	43.6	2656​	2652​	2688​	2663​	2640​	2660	16	48
MAX	43.8	2640​	2661​	2683​	2669​		2663	16	43

 

[r.tenorio671]

FWIW, 16" AR "self-build"....

Load Date = 23 Aug 2015			Powder = AR Comp
Bullet = Hornady 168 OTM BTHP		Primer =	WLR
Ballistic COE = .450				COAL =	2.280"
	Grains						Avg FPS	Std Dev	ES
Start	39.5	2416​	2435​	2377​			2409	24	58
	40		2452​	2441​			2447	6	11
	40.5	2411​	2449​	2434​			2431	16	38
	41	2443​	2451​	2464​			2453	9	21
	41.5	2486​	2484​	2474​			2481	5	12

 

[r.tenorio671]

FWIW, 16" AR "self-build"...

Load Date = 23 Aug 2015			Powder = AR Comp
Bullet = Hornady 178 OTM BTHP		Primer =	WLR
Ballistic COE = .530				COAL =	2.280"
	Grains						Avg FPS	Std Dev
Start	38.5	2327​	2313​	2324​			2321	6
	39	2343​	2328​	2347​			2339	8
	39.5	2373​	2388​	2368​			2376	8
	40	2404​	2411​	2404​			2406	3
	40.5	2435​	2418​	2394​			2416	17

 

[r.tenorio671]

...just a note on the 3 test results I posted above, all were conducted using assorted datestamp LC brass. Tested in tropical isle environment of high heat (85-95F), high humidity (80-85%H), "sea-level" altitude (approx < 600ft).

YMMV

 

[welditforyou]

Greetings guy,
Yesterday I shot a .22LR comp with those little steel critters. You know the ones I mean.
The guy who sets these comps up is a "mature" fella whose told the story of his dad and
the guy who originally built the range that we were shooting at. The story goes that these
2 guys shot many comps and won many of them.
These 2 fellas had the opinion that . . . . a full cartridge is a happy cartridge!
They used the OLD Lee reload data. Do you guys know anything about this?
Ahhh, the good o'l days, huh!

 

[Badmonkey]

Greetings guy,
Yesterday I shot a .22LR comp with those little steel critters. You know the ones I mean.
The guy who sets these comps up is a "mature" fella whose told the story of his dad and
the guy who originally built the range that we were shooting at. The story goes that these
2 guys shot many comps and won many of them.
These 2 fellas had the opinion that . . . . a full cartridge is a happy cartridge!
They used the OLD Lee reload data. Do you guys know anything about this?
Ahhh, the good o'l days, huh!

In my limited experience I have found that to be mostly true for bolt guns. My gas guns seem to be happier with milder charges. That could be nothing more than coincidence, as my sample size is small.

 

[smoothy8500]

In my limited experience I have found that to be mostly true for bolt guns. My gas guns seem to be happier with milder charges. That could be nothing more than coincidence, as my sample size is small.

Plenty reloaders find the mid to 2/3 up loads do very well in 308 semi-autos like the AR10 or M14 and 7.62 M1 Garand.

 

[Wizard1183]

Plenty reloaders find the mid to 2/3 up loads do very well in 308 semi-autos like the AR10 or M14 and 7.62 M1 Garand.

Well 16” ar10, starting load for service rifle is 41.5-43.9 (which I’m going to assume means lake city brass), IMR 4064 with 168gr SMK.

Accuracy at 100yrds is excellent at 41.5-41.8. Not saying others aren’t but up to 43.4gr it just wasn’t that good. Now 42.2-42.8 has produced good results as well.

 

[smoothy8500]

service rifle is 41.5 IMR 4064 with 168gr SMK.

Yes, one of the classic , "middle of the range" semi-auto load I was speaking of.

 

[Wizard1183]

Yes, one of the classic , "middle of the range" semi-auto load I was speaking of.

Right

 

[Thumper580]

Finally got my AR10 308 shooting the way it's supposed to. Craddock Precision 18" (Bartlein) barrel. 5 rounds each @ 100 yards.
Powder. Varget, 42.0gr.
Case. Lapua
Bullet. Sierra 175 SMK
Primer. CCI LR
Ogive 2.195

 

[max1840]

Very nice shooting.

 

[Huckleberry75]

Finally got my AR10 308 shooting the way it's supposed to. Craddock Precision 18" (Bartlein) barrel. 5 rounds each @ 100 yards.
Powder. Varget, 42.0gr.
Case. Lapua
Bullet. Sierra 175 SMK
Primer. CCI LR
Ogive 2.195
View attachment 8531592

What sort of velocity are you getting? Those are some fine groups.

 

[Ed Compton]

I have an Aero Precision M5 E1 with a Criterion barrel with the M118 chamber. Anyone got some good ideas or experience with what bullets/loads it may like? Hoping to be consistently sub MOA

 

[GhostFace]

Any of these loads in this thread should be good to go barring your barrel just doesn’t like a particular bullet. With the M118 chamber I’d look at these loads that use a 175 SMK or Nosler CC….

ETA there isn’t a free lunch when it comes to reloading, you still have to put in your own work because each barrel is an entity unto itself so to speak. While there are many proven loads that seem to work well across many rifles, sometimes you have a barrel that just doesn’t like them. I’d buy a box f whatever bullet you decide upon and a pound of whatever powder you’re thinking about and go from there. If your barrel likes it then buy kegs of that powder and larger quantities of bullets.

 

[Thumper580]

What sort of velocity are you getting? Those are some fine groups.

Sadly, right now I don't have chrono... Like to get the Garmin Xero. Can't say what the speeds are...

 

[Badmonkey]

I have criterion with that chamber. It likes 168 SMK/nosler CC the best as far as small groups. Can get in the .5 moa range. Got a just under MOA with 155 smk, 175 smk, and 178 eldm. Settled on 168 eldms. Closer to .75 MOA than half, but I get more consistent hits out past 750yds.

I have loads with similar results from the following-

A2495 42.1 grain
Shooters world precision 43.6
TAC 43.1

All right around 2600fps out of a 20” in LC brass

 

[jLorenzo]

Finally got my AR10 308 shooting the way it's supposed to. Craddock Precision 18" (Bartlein) barrel. 5 rounds each @ 100 yards.
Powder. Varget, 42.0gr.
Case. Lapua
Bullet. Sierra 175 SMK
Primer. CCI LR
Ogive 2.195
View attachment 8531592

Where did you get the barrel, rifle length gas?

 

[jLorenzo]

...just a note on the 3 test results I posted above, all were conducted using assorted datestamp LC brass. Tested in tropical isle environment of high heat (85-95F), high humidity (80-85%H), "sea-level" altitude (approx < 600ft).

YMMV

Which shot the best?

 

[r.tenorio671]

Which shot the best?

..for my purposes, each of the bullet weights had one good group. Understanding that my perceptions are just that, mine. I've added the test target results to this post, you can look at them and come to your own conclusions.

YMMV

 

[patscrazy]

Hey guys. Looking for some help here. Put together an AR10 using an aero precision upper and lower. LaRue .308 20 inch stealth barrel and SA gas block and aero precision nitrated BCG. Purchased some clymer headspace gages and put it all together no problem. I’ve done several semi autos with no issues. But I understand what I got into here with a mix master large frame gas gun.

So I’ve shot some factory Hornady 168 ELD match ammo. I also loaded up some reloads using some 1x fired Hornady brass out of a bolt gun, with Berger 185 juggernaut over 41.5 and 42 grains of Varget. Velocity avg 2400 and 2450 respectively. No pressure signs that were evident with primers at all. Brass dinged up a little, but it’s a 308 gas gun so I expected some.

But the problem came up when I go to resize all these brass cases, and I can’t get them to fit in my RCBS match master sizing die. Press handle feels like it would be impossible to press down any further.

So I measured the 1x fired Hornady brass out of the bolt that I was able to resize and create my loads with. They averaged. 469-.470” @ .20” above case head. Everything being shot out my gun at the same spot measures .474-.475”. So this has to be the problem. Is my barrel chamber out of whack to allow that much growth in the case web area?

Again headspace checked out fine with go/no-go and field gauges. I added pics showing measurements the brass. Last pic show brass after I try to resize.

 

[BCP]

Hey guys. Looking for some help here. Put together an AR10 using an aero precision upper and lower. LaRue .308 20 inch stealth barrel and SA gas block and aero precision nitrated BCG. Purchased some clymer headspace gages and put it all together no problem. I’ve done several semi autos with no issues. But I understand what I got into here with a mix master large frame gas gun.

So I’ve shot some factory Hornady 168 ELD match ammo. I also loaded up some reloads using some 1x fired Hornady brass out of a bolt gun, with Berger 185 juggernaut over 41.5 and 42 grains of Varget. Velocity 2400 and 2450 respectively. No pressure signs that were evident with primers at all. Brass dinged up a little, but it’s a 308 gas gun so I expected some.

But the problem came up when I go to resize all these brass cases, and I can’t get them to fit in my RCBS match master sizing die. Press handle feels like it would be impossible to press down any further.

So I measured the 1x fired Hornady brass out of the bolt that I was able to resize and create my loads with. They averaged. 469-.470” @ .20” above case head. Everything being shot out my gun at the same spot measures .474-.475”. So this has to be the problem. Is my barrel chamber out of whack to allow that much growth in the case web area?

Again headspace checked out fine with go/no-go and field gauges. I added pics showing measurements the brass. Last pic show brass after I try to resize.

It could just be the chamber fluting that larue does.

Try a regular sizing die and not the match master?

Is it blown out lengthwise as well? How are the shoulders are they oversize too?

I had a 223 barrel from a certain maker with an out of spec chamber and when I rolled the cases across a flat surface they looked like little footballs.

 

[JR1200W3]

Hey guys. Looking for some help here. Put together an AR10 using an aero precision upper and lower. LaRue .308 20 inch stealth barrel and SA gas block and aero precision nitrated BCG. Purchased some clymer headspace gages and put it all together no problem. I’ve done several semi autos with no issues. But I understand what I got into here with a mix master large frame gas gun.

So I’ve shot some factory Hornady 168 ELD match ammo. I also loaded up some reloads using some 1x fired Hornady brass out of a bolt gun, with Berger 185 juggernaut over 41.5 and 42 grains of Varget. Velocity avg 2400 and 2450 respectively. No pressure signs that were evident with primers at all. Brass dinged up a little, but it’s a 308 gas gun so I expected some.

But the problem came up when I go to resize all these brass cases, and I can’t get them to fit in my RCBS match master sizing die. Press handle feels like it would be impossible to press down any further.

So I measured the 1x fired Hornady brass out of the bolt that I was able to resize and create my loads with. They averaged. 469-.470” @ .20” above case head. Everything being shot out my gun at the same spot measures .474-.475”. So this has to be the problem. Is my barrel chamber out of whack to allow that much growth in the case web area?

Again headspace checked out fine with go/no-go and field gauges. I added pics showing measurements the brass. Last pic show brass after I try to resize.

The chamber in your barrel is fucked. It should not allow the webs to expand to that size. Though this can happen through spring back in a properly chambered barrel, you wouldn't be able to easily extract the brass. So the gun wouldn't cycle, and you would see massive pressure signs. If you're brass doesn't show pressure signs and the over expanded webs happen with multiple types of factory ammo then the chamber is oversized. The cause of the chamber being wallored out is often a loose tailstock allowing the reamer to wobble and over cut the base of the chamber.

 

[patscrazy]

The headspace on this barrel is very tight to begin with. I know these my comparator numbers and don’t mean much to anyone but my fired brass in this gun measures 1.6225”~ so I bumped the shoulder down .003-004 to 1.6195-1.6185”~.

1x Fired brass out of the AIAW bolt gun measures 1.6260”~.

So basically I need to pull this barrel and send it to larue and see what can be done.

 

[Snuby642]

My brass is sized to 1.626 to give me 0.002 bump

 

[patscrazy]

My brass is sized to 1.626 to give me 0.002 bump

Yeah that is more in line with what I’m used to as well. The 1x brass I get from the AIAW and a GAP10 as well, both are around those numbers after firing.

Fired brass in this Larue barrel coming out at 1.623-1.622 seemed tight

 

[Snuby642]

Checked spec.

1.627 is min chamber listed.

 

[BCP]

If your chamber is that wonky you should be able to put a sized piece of brass in there and wiggle it around by hand. I know how you're feeling because I went through the same thing with another barrel from a maker who tooted their horn a lot and they told me to get fucked. Hopefully if you send your bolt, fired brass and barrel to Larue someone with a brain will open the box and take care of it.

 

[patscrazy]

I sent an email to Larue explaining the issue and they told me to send it in. I’ve never dealt with their customer service but given their reputation overall in the firearms world I’m a bit pleasantly surprised. But we’ll see what they ultimately tell me and how they handle it.

 

[BCP]

I would send in the barrel and fired brass, possibly bolt as well, ask them to headspace check it with a new replacement barrel

My Larue 308 with fluted chamber didn’t do that the brass sized just fine

 

[Badmonkey]

Hey guys. Looking for some help here. Put together an AR10 using an aero precision upper and lower. LaRue .308 20 inch stealth barrel and SA gas block and aero precision nitrated BCG. Purchased some clymer headspace gages and put it all together no problem. I’ve done several semi autos with no issues. But I understand what I got into here with a mix master large frame gas gun.

So I’ve shot some factory Hornady 168 ELD match ammo. I also loaded up some reloads using some 1x fired Hornady brass out of a bolt gun, with Berger 185 juggernaut over 41.5 and 42 grains of Varget. Velocity avg 2400 and 2450 respectively. No pressure signs that were evident with primers at all. Brass dinged up a little, but it’s a 308 gas gun so I expected some.

But the problem came up when I go to resize all these brass cases, and I can’t get them to fit in my RCBS match master sizing die. Press handle feels like it would be impossible to press down any further.

So I measured the 1x fired Hornady brass out of the bolt that I was able to resize and create my loads with. They averaged. 469-.470” @ .20” above case head. Everything being shot out my gun at the same spot measures .474-.475”. So this has to be the problem. Is my barrel chamber out of whack to allow that much growth in the case web area?

Again headspace checked out fine with go/no-go and field gauges. I added pics showing measurements the brass. Last pic show brass after I try to resize.

I’m getting the same measurements from my fired brass out of my Criterion barrel. I’ve got no issues resizing with Lee dies.

 

[patscrazy]

I’m getting the same measurements from my fired brass out of my Criterion barrel. I’ve got no issues resizing with Lee dies.

So you’re getting .474–.475” just above the case head on your fired brass, out of that barrel? I can’t even come close to getting them to fit in my RCBS gold medal match dies. I thought this for sure was my issue being that my other 308 rifles, including a gap 10, are coming out at .471~.


Maybe I have to try a different die set. But needless to say, I already pulled the barrel and sent it to Larue for them to inspect. We’ll see.

 

[JR1200W3]

Web diameters on these caseheads are standard at .470. Give or take a few ten thousandths depending on custom reamers. If someone is getting over .471 they are either over pressuring the brass, have an out-of-spec chamber, or are measuring incorrectly. The correct tool to measure the webs will be a mic, not a vernier caliper

 

[Badmonkey]

Web diameters on these caseheads are standard at .470. Give or take a few ten thousandths depending on custom reamers. If someone is getting over .471 they are either over pressuring the brass, have an out-of-spec chamber, or are measuring incorrectly. The correct tool to measure the webs will be a mic, not a vernier caliper

I measure 3 fired cases and got .4695, .4705, and .4705. I apologize, I didn't scroll down and see the last two measurements of .474 and .4745. I did not have any cases that measured that big.

 

[Phil McGrath]

Sometimes an old 30.06 sizer works wonders on phat bloated cases….

 

[45-90]

I have 308 AR 10s in 16", 2- 18", and 24".
Usually shoot the 16" & 18".
The 16" shooting 155 gr over 2800 fps, work up to 2875 fps hit 2920 fps and pressure. Run it at 2875 fps
Best load is 168 ELDM at 2756 fps and 1/2" 5 shot groups with this light 6 lb AR 10...not counting the heavy scope.
It's magnesium, titanium, & carbon fiber, with light fluted barrel.
A favorite to carry., short, light, accurate, and over 2800 ft/ lbs of energy.

 

[Badmonkey]

I have 308 AR 10s in 16", 2- 18", and 24".
Usually shoot the 16" & 18".
The 16" shooting 155 gr over 2800 fps, work up to 2875 fps hit 2920 fps and pressure. Run it at 2875 fps
Best load is 168 ELDM at 2756 fps and 1/2" 5 shot groups with this light 6 lb AR 10...not counting the heavy scope.
It's magnesium, titanium, & carbon fiber, with light fluted barrel.
A favorite to carry., short, light, accurate, and over 2800 ft/ lbs of energy.

Holy crap. I had 168 eldms up to 2770 in a 20" with TAC and it was getting sketchy. The brass was one and done with the gas turned down so far lock back was inconsistent.

What powder are you using to get that velo?

 

[Bevo]

Holy crap. I had 168 eldms up to 2770 in a 20" with TAC and it was getting sketchy. The brass was one and done with the gas turned down so far lock back was inconsistent.

What powder are you using to get that velo?

I'd like to know as well. I shoot 155 Berger VLDs at 2700 from my 16" bolt gun using TAC.

 

[45-90]

Holy crap. I had 168 eldms up to 2770 in a 20" with TAC and it was getting sketchy. The brass was one and done with the gas turned down so far lock back was inconsistent.

What powder are you using to get that velo?

TAC is not even listed on the page of the loading manual in question, page 416 of the Speer loading manual.
As I have stated and the exact load data is posted on 168 gr eldm target shown.
One more time ...Alliant PP 2000MR.
Noone looks...just keep asking over and over...the manual top load is 2889 fps from a 24" barrel my 16" AR shoots the 168 gr at 2756 fps. With .2 less powder, its very accurate there in my 16" AR's barrel.

 

[45-90]

I'd like to know as well. I shoot 155 Berger VLDs at 2700 from my 16" bolt gun using TAC.

Again... the same powder Aliant PP 2000MR.
With a 22" bolt gun the same powder in a hybrid case will get 3100 fps, but that would be over pressure for an AR 10.

 

[45-90]

For long range AR single load, use the bobsled mag to just drop in, bolt release shoot.
The 200 gr SMK G1 .716 BC is an interesting bullet I use it in my Proof 18" barrels at 2670 fps max run at 2620 ish fps in AR 10, but it needs a 9 twist for LR.

Go to 9 twist and even 8 twist for heavy bullets 200 to 230 gr.
My 22 " bolt gun 9 twist loves 230 gr SMK at 2500 to 2550 fps, & 225 gr eldm (not 255 on the paper)around 2570 fps. Without using hybrid cases.