Get up and down between each shot, groups or dots... Believe dots are a better test.
I was using load data from IMR's website.
Just found a copy of a page from Hornady's 10th reloading manual that shows a lower max charge than what IMR gives for the same bullet weight. Although I know bearing surface and other factors come into play as well.
I'm going to do a little more research but it looks like I may need to back off some on this bullet with this powder.
Flame Suit on....
I tend to believe that the Min and Max charge weights are suggestions. Especially the Max charge. They are naturally drawn up by the ever present Lawyers at the publishing corporations.
A careful and observant reloader will pay close attention to the markers of over pressured brass; hard bolt lift, popped primers, flattened primers, ejector marks, ect.
Maybe I'm stupid or lucky or whatever, I have a few loads that exceed "max published". But they work and have not caused failures in thousands of rounds.
Duty is the sublimest word in the English Language - Gen Robert E Lee.
I don't disagree in many circumstances.
They are forced to publish data that would be safe in the tightest bolt action rifle chambers.
I'm not looking to hot rod a cartridge and try to turn a 223 into something that it isn't. But I know I am operating at lower pressures than typical lake city M193. That stuff is loaded HOT in my experience.
I'm after accuracy not velocity, but velocity helps. Looking at primers again with the advantage of daylight, and having an unfired cartridge to compare them to, I feel pretty comfortable. No brass extrusion into the ejector. Primers still have a decent radius on the outside edge.
Yep -- my 20" Krieger with Hornady factory 73 ELD-M ammo.
Initial MV at 70 degrees F without a can produced MV of 2,727. A few months later with a TBAC can at 85 degrees F produced MV of 2,769. My zero was good and data input was good -- height over bore and Density Altitude. The NF 4-16x ATACR tracks well. This ammo is accurate -- my records show 5 different 5-round groups at 100 yards, with spreads of .55" to .85". The two largest (.75" and .85") groups occurred while the Magnetospeed was on the barrel. The other three were .55" through .60"
I had to confirm elevation dope at 700 or 750 yards, then work back via JBM for a workable MV for data cards. Turns out that 2,800 fps in JBM works almost exactly out to 850-ish, which is the furthest I've really tested elevation dope on this rifle.
So yeah, for some reason my 73 ELD-M bullets fly better than JBM predicts in this Krieger barrel. I don't have a good data on other barrels, as they seem to prefer Hornady 75 HPBT or SMK 69 bullets better.
FWIW, this 20" Krieger with Hornady Superformance 73 ELD-M produces 2,861 fps with a can at 85 degrees F. Accuracy is not as good with the Superformance -- groups of .97" to 1.27", with the larger groups done while using the Magnetospeed. I saw no pressure signs with the Superformance ammo.
This was a fun experiment. Handful of Oklahoma PRS shooter have shorty Dashers, 20", 22".... suppressed. They swear by them, run at similar speeds to 26"ish barrels, not as good as barrel life. Claim the pressure is completely different in a stubby barrel.
A friend sent his 26" barrel to jelrod1 (jelrod1 originally chambered it) with a couple boxes of his load, 31.7/Varget/115 Dtacs/2820. At 32 grains, he had pressure. Barrel had 1800rds on it, still shooting. jelrod1 cut it off 1" at a time, shot it, chrono'd it with the supplied load. Stopped at 18". Lost about 14fps per inch, yikes! My buddy gets the barrel back gives it to me. Barrel was chambered for a Bighorn TL3 action headspaced perfectly on my TL3. OK, going to put the petal to this barrel see what I find. Loaded .5 grain increments 32-34.5. Slight pressure at 34, shot one round of the 34.5 and stopped. Barrel shot very well at 33.5/2850fps. I was surprised could go that high w/o pressure, velocity I got. No doubt that would be waaaaay over any book max.
Handy rifle for sure. While at the range during my test a retired Denver SWAT guy was there. Hey what's that, what are you doing....? Let him shoot it. Oh man, that would have been a sweet urban duty rifle he says. Like that would ever happen.
IndianaBoy -- just a shooting position thing that I've learned over the past couple of years.
I've struggled with holding consistent vertical for a few years. Just seemed that I couldn't do it very well with rear squeeze bags. I attended a 3 or 4 day course with Frank Galli (Snipers Hide site owner, ex instructor for Rifles Only) -- Frank noticed on the second day that my rear bag technique could be improved.
Maybe two seasons ago I carpooled with a local shooter ("Shawn") to a regional match. We shot the breeze on many subjects -- holding elevation was one of them. During morning dry-fire practice in the hotel room before the match, Shawn noticed that my cheek pressure on the buttstock was probably too high.
Eureka! -- the primary cause of vertical variation was found. I was letting the full weight of my head plop down in the buttstock. Coupled with sometimes a weak grip on the rear bag, and I tend to send rounds high when I miss. We all mess up in our own ways, but just something to think about.
Another item that offgrid pointed out. In uneven terrain, position behind the rifle/scope can be an issue. For awhile we had a Wyoming steel match that had prone shooting positions that sloped down, but our shots were high on the opposing ridge. Almost always the shooters missed by sailing over the targets. I consider this a combination of eyebox/parallax error and "climbing over the stock" with our head position. The combined effect is similar to my pressing downward on the buttstock with my head.
A similar issue occurs at a winter match in the town of Rifle, CO. We have flat prone shooting positions, but he must aim high on to the side of a mountain for the longest targets. My performance on the longest targets was helped by getting short bipod leg extensions, but I still must be careful that I don't try to squish the rear bag down with head pressure, and that I keep my eye in the sweet spot of the scope's eyebox.
I don't know if any of this occurs with you, but just a thought.
But back to the 73 ELD ammo, it does fly better for me than MV predicts.
Great post, thanks.
I have played around a bit with trying to muscle the rifle a bit less. Not exactly free recoil but, less pressure.
This gives me another thing to consider, thank you.
I've tried a bunch of things, too. I came to realizing that I shoot best with:
- limited cheek pressure on the buttstock
- noticeable weighting of the bipod -- or forward pressure on a barrier, it that's what I'm shooting from
- firm rearward pressure of the buttstock into my clavicle -- done with pressure from the pinky, ring, and middle fingers of my shooting hand
When I'm straight behind the gun, doing the above, and limiting the amount of cranial/rectal inversion -- the scope's retical just doesn't move during the recoil cycle and the bullets pretty much impact where intended.
Good stuff. I'm taking notes. Thank you.
Me, too. Thanks.
“The [Roman] legions had crumbled not because organizational weaknesses, technological backwardness, or even problems of command and discipline, but because of the dearth of free citizens who were willing to fight for their own freedom and the values of their civilization.”
— Victor Davis Hanson, Why the West Has Won
Definitely think you'd benefit from formal instruction. You're close enough for a good class from K&M Precision Rifle with Shannon Kay and crew. He's one of the best in the business and currently has the top 3 PRS shooters on staff as instructors.
It sounds like a step backwards - but consider his Basic Long Range Precision Rifle class as an excellent foundation builder.
Duty is the sublimest word in the English Language - Gen Robert E Lee.
I will certainly consider that. I'm hoping to snag an opportunity to learn from Todd VanLangen the next time he is in Kentucky.
Pleasant conditions for once at the range. Winds of 2-8 mph, switching back and forth between 9 o'clock and 1 o'clock. Not optimal by any means, but I think the first time winds were less than 10 mph in many months.
I fired the last of my .308 Black Hills 168 TMK ammo, and it actually shot pretty well this time. It held 4-3/4" vertical at 630 yards (.75 MOA) and 4-1/8" vertical at 750 yards (.55 MOA). I still doubt I will ever buy any more TMK, but at least the 168's do have some merit.
I'm also thinning the 223 ammo inventory, with Black Hills 52 HPBT now down to one box. The 52 grain bullet is quite accurate in my ARs, but it seems to get tossed both vertically and horizontally if the wind is up. I shot one group of 5 with hardly any wind, and got a 1-7/8" vertical group at 374 yards -- .50 MOA.
With 4900 rounds on the barrel, the .308 still likes Southwest 155 Scenar. Five rounds at 566 yards, 2-3/8" vertical (.42 MOA):
Then six rounds at 630 yards, 3-1/8" vertical (.49 MOA).
And finally six rounds at 750 yards, 4-7/8" vertical (.65 MOA):
One thing nice about shooting in winter is that the suppressors cool down quickly between strings.
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