Grade my latest handloads...

[ny32182]

I'm still a relatively new reloader. I fired my second batch of 100 handloads this past Saturday through my 20" M16 spec AR/4x scope. I was using Varget again, and once fired RORG (which I'm starting to suspect is not very good brass, but anyway..) 68gr Hornady BTHP, and varied the charge in .1gr increments from 23.4 to 24.3gr. 10 rounds per group, measured 100 yard range.

I had three 10rd groups that were right at 3". My best group was 1.3" at the 23.7gr load. All the others were somewhere between those extremes. 1.3" sounds pretty good to me for this rifle, if that turns out to be repeatable.

I do not presume that my rest is perfect either. I have to re-seat the rear bag that I am using for each shot, etc.

I did have one odd malfunction in the last string of 10 rounds; the fired case ejected fine, but the next round jammed with the bullet tip above the chamber, and the case head still pressed against the lower lugs of the bolt, outside the indentation where the bolt face is. I have seen a little bit of odd behavior out of this magazine before and suspect that might be responsible, but have no way to know for sure. I don't see how this could have been caused by the rifle or the ammo though.

 

[30Cal]

68gr Hornady BTHP, and varied the charge in .1gr increments from 23.4 to 24.3gr. 10 rounds per group, measured 100 yard range.

I do 0.3gr increments for fine tuning. 0.5-1.0grs (depending on caliber) for the initial pass. I am looking for loads that shoot well without a lot of fuss. 0.1grs increments is what I would use if I was looking for a fussy load.

As long as the brass is halfway decent, it's not going to play any real role in accuracy.

 

[USSR]

I agree with 30Cal, increments of 0.3gr for load development.

Don

 

[JackOfAllTradesMasterAtNone]

For any rifle I'm loading for. I take the load that gave the best results and take the fired brass from that session, neck size only, then load -1%, reference, and +1% powder.

Refire to make sure the reference is still the best.

With an auto-loader you might want to full length size. But you might not need to. (Sorry, I don't own an AR/.223, so I am admitting a bit of lack of experience with them).

Then, I play with seating depth for the most accuracy. (again, an auto loader you might not have this luxury.) But, even a couple thousanths of an inch can make a difference.

With a better rest, maybe a fine tuned trigger, it appears that you might be on your way to sub moa groups. -That's something to be proud of.

Mark that magazine, then use a different one to reproduce (or not), the feed issue.

-Steve

 

[ny32182]

The only thing is, there is only a 2.2gr range for this bullet and powder, and there doesn't seem to really be any linear correlation between accuracy and powder weight, at least around the most accurate loads that I found...

Here is what I got:

23.4: 2.977"
23.5: 1.726"
23.6: 2.557"
23.7: 1.3"
23.8: 2.79"
23.9: 1.91"
24: 2.09"
24.1: 2.95"
24.2: 3.025"
24.3: 3". 2.12" minus one flyer

So as you can see, there is a little trend toward less accuracy as I was getting up toward the top, but not much right around my best group...

I suppose there are plenty of factors other than the powder weight that are responsible for this.

 

[JackOfAllTradesMasterAtNone]

All other factors being equal, you have what you suspect is an accurate load. You still need to be able to duplicate it. -Load it again. Shoot. Load a bit more/less to verify that your shooting/documentation wasn't in error. I'm not ignoring that you have a very small charge variation.

Don't focus on max/min load or pressures. Some barrels just like something. A little faster, a little slower, and everything goes out the window. Learn to go with it.

If you can't duplicate the earlier 'best results' then you're back to square one. If you can, well...


I have a hunting rifle that does not like Nosler Balistic Tips or Partitions. Period. No matter what powder/charge/length I load them to. But it shoots Speers and Sierra's at MOA. Go figure!:banghead:

-Steve

 

[GaryL]

I have a hunting rifle that does not like Nosler Balistic Tips or Partitions. Period. No matter what powder/charge/length I load them to. But it shoots Speers and Sierra's at MOA. Go figure!

-Steve

That wouldn't happen to be a BAR would it?
I might have to pick up some Sierra's or Speers to try....

 

[JackOfAllTradesMasterAtNone]

That wouldn't happen to be a BAR would it?

Actually it's a Ruger77 in 30-338. I can push the Speer 180 spitzer or boat tail, or Hornady 190 BT to 3100fps and still retain accuracy. But the Sierra's lose accuracy past 2775fps. It just doesn't like the Noslers at all.

-Steve

 

[ny32182]

Jack, thanks, I think what you are saying makes sense.

There is another factor I'm wondering about: how much does fouling affect accuracy in these circumstances?

I took 10 "fouling shots" with some cheap Silver Bear before starting in on the handloads, and then as you can see I saw a trend toward less accuracy in the second half as my total round count since last cleaning was approaching 110.

Should I be cleaning between each string just to try to eliminate another variable, or would that just not be a big enough factor to matter on a milspec type AR15?

 

[JackOfAllTradesMasterAtNone]

I believe in one cold bore fowling shot for other than heavy barrel rifles. Yes, to truly fine tune, the bore should be cleaned/cooled between test strings. But I don't know that you're quite to that point yet. First you need to duplicate the best string you had. And at this point, it appears you were 50+ shots in when the best group appeared. Not knowing how rapid you were shooting, this could have been a barrel temperature thing more than how clean the lands were. Hopefully it was the sweetspot for that load/bullet/rifle. In theory, no barrel should shoot better as it gets dirtier. (in practice, I'm sure there are some that will argue that point)

When I'm fine tuning, I clean after every ten rounds.

We have a match at our range. 200m. No sighters. One cold bore single shot target, followed by more targets in strings of five with time limits. The RO that runs that match says I'd be surprised at how many people don't know where their POI wanders as the barrel temperature rises.

-Steve

 

[ny32182]

So, I'm going to load up about 30 of the accurate loads, and then about 30 each of the +/-.1gr loads, and see if my results repeat, or come close to repeating. How does that sound?

 

[JackOfAllTradesMasterAtNone]

I dunno.. You probably shouldn't need 30 rounds of each. 10 of each should be quite sufficient.

-Steve