OCW Test 308 opinions needed

[jpspeeddemon]

I finally conducted my first reloading session this weekend. I only had access to 100yds, so I decided to do an OCW. Certain days of the week i can get to 300yds.

Rifle: AI AE MKIII 20" 308win
Load: Winchester once fired brass, Varget, F210M, 175smk loaded at mag length, 2.810ish, 3.223" to ogive using Hornady bullet comparator.

Charge Range: 41.5 to 45.0, 0.5 grain increments

Course of Fire: Round robin, 3 shots per charge. Dots are 1" pasters.

Results: 100yds, no wind, 65 degrees, 1200'

I set up my NPA on 41.5 dot and by the time I got to the right side, shooting wasn't as good, vertical dispersion is all me.

What are your opinions?

 

[ksthomas]

Re: OCW Test 308 opinions needed

Based on three-round groups? Sample population needs to be large enough to have some statisical validity, otherwise you'd do just about as well picking a load at random. Sorry, but there's a bunch more rounds needed here to have anything close to a accurate opinion.

 

[jpspeeddemon]

Re: OCW Test 308 opinions needed

The OCW website said 3 shots per charge. Do you think 5 would be better? I can understand why 5 would be better, just thought 3 would also work.

Maybe I'll load some more.

 

[MALLARD]

Re: OCW Test 308 opinions needed

41.5 and 42 look pretty good. Im lazy, and not obsessive. I would settle around there. Do a seating depth test next.

 

[jpspeeddemon]

Re: OCW Test 308 opinions needed

yeah 41.5 to 42.0 is definetly a node. For short range that would be an easy choice. But, I was hoping to find a node at 44-45 grains for increased velocity.

42.0 is probably like 2500fps

I think there is a node at 44.5 which should be up above 2600fps.

 

[NoFail]

Re: OCW Test 308 opinions needed

3 shots per charge is what I do. Your 42 grainer is awesome so I would now run some 5 shot groups, five 5 shot groups, with that charge and check validity.
If you desire more velocity you can see if you can play with seating depth of one of those later groups load and after that you can experiment with different primers, like CCI BR-2 or 200's, whatever.

 

[Brandon05_88]

Re: OCW Test 308 opinions needed

Did you hit any signs of pressure?

Reason I ask is my buddy shoots an AIAE MKII with AINA Bartlein 308. He developed a load in his Rem 700. Shoots great in his AI. Pretty sure he is using:
175 SMK
45.8 gr Varget
BR-2 primer
Win brass
2.800" OAL

Checked with my buddy, the load is correct.

What I'm getting at is, you might find something around 45.5 if you aren't seeing pressure.

 

[jpspeeddemon]

Re: OCW Test 308 opinions needed

No pressure signs at 45.0

I may try a ladder test at 300yd going from 41.5 to 46.0

AI rifles can usually accept hotter loads for sure.

 

[Gene Poole]

Re: OCW Test 308 opinions needed

From an OCW standpoint, there is no real trend to spot a node. They all pretty much look the same (except one outlier):

 

[jpspeeddemon]

Re: OCW Test 308 opinions needed

Gene Poole, that is interesting. I did notice that basically all the group centers were a 2 o clock near the edge of the paster.

That's the main reason for posting this, to get opinions and possible options.

I'm not going to get caught up in load development.
Clearly a good load is 41.5 to 42.0.

But for more velocity, perhaps a ladder test at farther distance is in order.

 

[shoot4fun]

Re: OCW Test 308 opinions needed

Gene Poole and his fancy program confirm what I was thinking. That is a great shooting rifle and appears to not really ever go out of a node. For what it is worth, I have been shooting 45 gr Varget with the 175 SMK for years and it has given me excellent accuracy in many different rifles. It appears your rifle likes it too. The reason I would choose it over the 42 gr load is that it will have better performance at longer distances should you ever find a longer range.

 

[peligro113]

Re: OCW Test 308 opinions needed

Gene Poole what program is that?

 

[Bluesop7]

Re: OCW Test 308 opinions needed

I would do another OWC loading up from about 44.4 on up as high as you feel comftorable in 0.2 increments. My old standby load was 45.2 gr Varget with 175 SMK loaded to mag length. Gave me right at 2710 fps with a 22" barrel.

 

[Gene Poole]

Re: OCW Test 308 opinions needed

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: peligro113</div><div class="ubbcode-body">Gene Poole what program is that? </div></div>

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