OCW results

[poke5353]

I performed a small OCW test today and below are my results. The top pic was from a 24" Stag arms barrel and the bottom pic is for a 20" WOA . I was shooting 75gr Hornady BTHP with AR-Comp loaded at 22.1,22.4,22.7, and 23 seated at an OAl of 2.26". No pressure signs other than some flat primers. Where would you go from here? Any information is appreciated.

Stag Arms

White Oak Armament

 

[MitchAlsup]

Re: OCW results

In the bottom image, 22.1 and 23 both look acceptable.
In the top image, none of the groups are "all that great" or even usefully different from each other.

A) Suppest more time at the range
B) repeat experiment with more rounds/target
C) repeat experiment with finer step size.

As to c): my AR15 only shoots one load realy well, and it took me a long time to find it. It requires 0.1 gr step size and some seating depth experiments. It is a std AR15 with military grade barrel. Still, with carefully loaded rounds it will shoot 0.8" 10-shot groups, but with FGMM it shoots 1.6" 10-shot groups, and with random surplus, 2.2" groups.

 

[X-fan]

Re: OCW results

What Mitch said X 2.

 

[shoot4fun]

Re: OCW results

I think Alliant would set their max for your bullet and powder at around 23.3 or 23.4 grains.
Do your test again.
Start @ 21.1 and increase by 2% until you get 2% over the 23.4 charge.
I am with Mitch in that, especially with the Stag, there is some wind or shooter error that is skewing the results.
Also, some semis will shoot differently when single fed vs mag fed.
How did you stoke the chamber?
You may want to load a fouler, then one each of the test loads in a single mag. Fire the fouler into a different spot every time. Then follow thru.
BTW, do your testing at 100 yards.

 

[trailrider121]

Re: OCW results

22.1 and 22.4 seem to share same POI in both targets. The others seem to be shifting up on the Stag Arms. I would retest again and start a little lower around 21.5 or so. Dont change anything in your loads, once you find three loads sharing same POI and within 1-1 1/2% would should be good. Pick the middle charge and then fine tune. Good luck.

 

[poke5353]

Re: OCW results

Alliant show max is at 22.1 with ar comp when using a 77gr smk. That is the data I used to perform this test. I now have loaded 10rds each of 22.4,22.5,22.6, and 22.7. I'll be back at the range tomorrow.

 

[Will Lee]

Re: OCW results

I like what I see out of the Stag better than I see out of the WOA.

The rounds are all in the same quadrant (1 to 3 o'clock and not a lot of variance from POA). I also like that all the groups are in some form of a triangle. I think this speaks very well of that barrel (no real wild changes in POI). I would test those exact same loads but shorten the OAL by .030 and compare the results(you may have to really play with the OAL). I have some rounds with 55g bullets that shot < 1/2 groups at an OAL of 2.170.

As MitchAlsup said it takes a lot of time to develop a load. And I'll add a lot of experimenting.

Remember this - only change one thing at a time.

Another though.
You need to take the shooter out of the equations for load development. A good rest is almost a must, here is the one I use.

http://www.midwayusa.com/product/394466/caldwell-lead-sled-solo-rifle-shooting-rest

Good luck and let us know how your future testing turns out.

After rereading your post I wanted to add this:
AR-Comp may not be the powder that will produce the results you are looking for. I tired it an gave up on it.

It has been written on this forum several time that "light bullets like faster burning powder & heavier bullets like slow burning powder". I have found this to be very true.

 

[Will Lee]

Re: OCW results

I hope your barrels are at least 1 in 8 twist with that 75g bullet.

 

[Leaddog]

Re: OCW results

Accurate load development requires that you hold the exact point of aim with each shot. You aren't looking for groups. You are only looking for vertical dispersion and good ES/SD's. You are using a chrono, right?