New Creedmoor load test

[kilotanker22]

So I have been thinking about ways to tighten up my Creedmoor loads a little bit. Decided to try a new bullet and start load development again. Might have found my new load for this Savage Tactical rifle.

New Hornady brass
CCI 200
140 grain Sierra Matchking, loaded to 2.810" (At the lands) not jammed into just at the lands.
41 grains of H-4350
Brass trimmed to 1.908"

Average Velocity 2769FP
Extreme Spread 15 FPS
Standard Deviation 6 FPS

.397 MOA 10 shot group. Measured outside distance and subtracted bullet diameter then divided by 1.047 to obtain the MOA value.

No primer ctareing or flattening at all, although there is the slightest ejector mark on the case head. Almost can't even see it unless you angle it just right. Over all very happy with this load.

[Rimfire5]

That is nice shooting, kilotanker.

I have never been able to get the 140 SMKs to shoot as good as just about any other 140 grain bullet.

My long term 5-round group average with the 140 SMKs is just over 0.5 inches.
My best 5 140 grain bullets 5-round averages are all in the low 0.3s.

I generally load with a 0.020 +/- 0.005 jump so maybe it would be worth a try seating the 140 SMKs deeper.

[Bart B.]

Any visible ejector mark is a sign of excessive pressure. Nice shooting anyway.

7.62 NATO proof loads have tested very accurate in M14 and M1 match rifles

[Unclenick]

Kilotanker22,

Nice shooting.


BartB,

In testing samples I provided of several brands of brass, board member BobCat45 found Hornady proved to have the softest heads (see table below). So I am not as concerned about a slight ejector mark on them as I would be with LC.



The Hornady head measurement, HV-500 test:



For size reference, 50 um is almost 50.8 um, and 50.8 um is exactly 0.002 inches.

[kilotanker22]

Unclenick, Today I took a trip to Eurooptic and bought a bunch of Peterson SRP brass for this Creedmoor.

Gonna test this same load with those and see where I am at. I am hoping that I will be able to get more Velocity. With the Winchester Brass I was using, I was able to load much higher powder charge than with the Hornady. Hoping the SRP will help with that.

I was originally hoping to shoot a mile with the Creedmoor, but I am having trouble keeping a bullet super sonic that far. The only one that has come close was the 147 grain ELD. Got those to about 1700 supersonic, but did not shoot nearly as well as this Matchking does.

I am thinking that I will need a bigger cartridge to get there and stay Mach 1.2 or higher.

I am thinking 6.5 PRC, 300 PRC or 338 Lapua.

[mel80]

nosler 130rdf moving at 3000fps will stay supersonic till 1800y ,140 rdf going 2850 fps will stay supersonic to 1730y
atleast at my altitude

i wouldnt worry about the bullet staying super sonic ive shot 1 mile with my grendel
130g rdf stayed super sonic till 1450y velocty at impact was 877 fps
140g eld-m stayed supper sonic till 1300y velocity at impact was 761 fps and i could still hit my 18inch gong

[kilotanker22]

At 80 degrees F and 1200 ft elevation. The speed of sound is around 1150 fps. The temperature of the air makes more of a difference on the sonic speed than the altitude at most elevations people will be shooting

[std7mag]

Mayhaps density altitude would be a more telling measurement.

[kilotanker22]

Maybe,

Getting a bullet to a mile while supersonic in a Creedmoor can be done if I can get the velocity I need. Although as stated earlier, I might be better off with something bigger for this particular task. The current load shoots super well and is only super sonic to around 1400 yards. I have a place where I can shoot out to 1200 yards now and plan to shoot this weekend.

STD7mag, I wonder if a 7mm wsm would get me there super sonic? I have a friend who has a couple rifles for sale right now. One is a 338 Lapua and the other is a 7mm wsm

[kilotanker22]

With that newish, Barnes 145 grain .264 Match burner I can keep the bullet supersonic to 1800 with it's BC of .703. Just not sure I want to buy them, because I will be at least .100" from the lands to fit them into the magazine.

Of course I can always get a velocity boost from any of these bullets if I use Reloder 26, but it does not shoot as well as H-4350

[mel80]

how about reloader 17 or reloader 16

[hounddawg]

outstanding on both the load development and the shooting bench Kilo, you be the king of Creedmoor. Never did a mile myself but I have a few friends that took a trip up to Virginia and made the mile club and they don't sweat going subsonic. Here is a guy using 4350 and 140's in his stock Ruger at a mile

https://www.youtube.com/watch?v=erHNVSNwp8Q

[Unclenick]

Kilotanker22,

Have you tried the slightly higher BC 142-grain SMK? Does it shoot as well for you?

It looks to me from Hodgdon's site like the new StaBALL 6.5 powder produces the most velocity with both bullets. If I ratio your slightly-beyond Hodgdon maximum load of H4350 to that powder and not knowing your barrel length, it should get you past 2900 fps.

Switching to 6.5-284 and using StaBall 6.5, there is no data published yet for the bigger cartridge, but comparing Hybrid 100V velocities for percentage difference from StaBall 6.5, I'd guess you could get 2975 fps out of it with a 24" tube and get past 3,000 fps with a 26" tube or longer.

[hounddawg]

To stay supersonic past 1500 yards you will need a .338 or larger.

[Unclenick]

Yeah, based on Litz's measurements for a pointed 142-grain SMK, I worked it backward. To get it out to a mile supersonic would require about 3300-3400 fps MV. I'm not spotting any way to get there without wildcatting down a much bigger case.

[kilotanker22]

I bought some 147 grain ELD Match bullets today. Box says .697 for a G1 BC.

Using the Hornady calculator and inputting my current atmospheric conditions. If I can get that bullet to 2850 fps at the muzzle, the projected velocity at 1760 yards is 1159 fps. Ironically in those same conditions the speed of sound is 1138.76 FPS. So I am not super sonic. Although the bullet will still be traveling faster than sound in the atmosphere. I believe that is called Transonic??

I need another 200 fps to stay super sonic to a mile. Which I believe can be done with a 6.5 PRC. (I have loaded a 140 well past the needed velocity in my 6.5 PRC.) Although, that load didn't shoot worth a damn.

Unclenick, I almost bought some of that StaBall 6.5 today too, but I have 10 pounds of H-4350.. I can get to 2850 in a Winchester case and H-4350 with a 140 eld, but not with my Hornady cases without trashing the primer pocket after a single firing.

I purchased the Peterson small rifle brass and some small rifle Magnum primers in the hope that this brass will handle the pressure better than that really soft Hornady stuff.

I have loaded up to Hodgdon's max load for the 147 ELD and H-4350. Their max listed load is 41.8 grains. With this bullet at Magazine length I am Jumping .065" to the lands. With the 143 ELDX at the same powder charge, I was able to attain 2870fps with the same amount of jump out of this barrel. I am hoping to get to 2800. I do realize that the Peterson has a lower case capacity, but I am confident that the max load will be ok to shoot in this rifle.

[kilotanker22]

I am going to the range with my kids today. I am gonna test all the loads while there and report back here. I loaded 25 rounds of the 41.8 grain charge weight. If they are not blatantly over pressure I intend to shoot a ten round group and record velocity data from ten rounds and a 5 round group at 300 yards

[kilotanker22]

2751 avg
12 ES
4 SD

That is shooting the listed max load of H-4350. Primers look good, but alight ejector mark

10 round group size was about .75 MOA

[kilotanker22]

A friend of mine has a Savage 110 HS Precision in 338 Lapua Magnum. It sports a 5-22x Nightforce NXS. He is asking $2500. He says it has 100 rounds through it. I might buy it for my one mile project

[kilotanker22]

Final measurements on the ten round group corresponding to the velocity data above came to .80" exactly. So a .76 MOA ten shot group.

I think that I could tighten this up with a seating depth test, but I can't go closer to the lands. These were loaded .065" away, so I will try .085" and .105" jump on the next range trip. I will post a photo of the target shortly

[kilotanker22]

Here is the group. Even with that shot I pulled to the left it measures .80"(.76 MOA)

[std7mag]

Looks like you have 3 groups there.

Even with the 7mm Rem Mag, most of my bullets go subsonic at 1,500 yards.
Exception would be if you could get a 195gr Berger to go 2,800 fps. At my conditions it goes subsonic at 1,700 yards.

Personally, i'd shoot your distance and see what happens. See how the bullet actually reacts to going subsonic.

[kilotanker22]

Yeah, I am going to re shoot that group today. I also bought some StaBall 6.5 to try out.

[Unclenick]

Bryan Litz's book, Ballistic Performance of Rifle Bullets lists measured BC's to use. Manufacturer G1 box numbers are often given at the high end of the velocity range they expect the bullet to be used at for competitive selling point reasons. These numbers work OK to 300 yards or so, but will mess up with long-range calculations. For the 147-grain ELD from Below 3000 to below 1500 fps, the measured G1 BC drops by 16%. The G7 BC only drops about 6% in that range and would be better to use.

However, you don't have to rely on a BC model to approximate Hornady bullet performance anymore as the Hornady 4 DOF calculator is linked to a list of actual Doppler RADAR-measured individual drag functions for its bullets. In very long-range shooting, where BC errors accumulate by the time the bullet gets to the target, this will always be the more accurate way to go, try the advanced calculator.

I ran it for your altitude (average barometric pressure 28.70 in-Hg at 1200 feet) in 80°F and with 50% RH, where Mach 1 works out to 1,142.5 fps according to this calculator. (Humidity thins air density, but is not a huge influence; going to 78% RH raises Mach 1 to 144.3 fps). What the Hornady calculator shows is the bullet needs to start out with a muzzle velocity of 3155 fps to fall just to that speed of sound at 1760 yards.

I looked further to see what would happen with range calculations from BC's to see how far off they could get, and the answer is, a lot. For each BC type (single G1, single G7, multiple breakpoint G1 and G7 tables) and for the single BC numbers I got disagreements of over 200 ft/s between various ballistics calculators. The reasons are cumulative iteration and rounding errors and conversion precision errors between native metric and native inch calculators. When I went from the BC on the box through the measured G1 and G7 average BC's as well as the multiple BC's broken up by velocity ranges, the result showed required muzzle velocities from 2756 fps to 3064 fps to stay above the speed of sound to 1760 yards. All were slower than the actual drag function says is required because what is actually required is greater for an important reason:

As you probably know, drag coefficients rise sharply at the speed of sound and change a lot with relatively small changes in shape. This matters because it means BC-based calculations can be easily befuddled in what is called the transonic velocity range. Why? Well, bullets have curves and angles on their surfaces and the air flows over them all at once. When the bullet is going at exactly Mach 1, the shockwave formation drops off, but air flowing over the ogive has a greater distance to travel than air along the sides does with the same amount of distance covered, so there is some supersonic airflow over the ogive at Mach 1. The tail also should have that, but laminar separation can occur, and at what velocity and bullet diameter that occurs depends on the angle of the boattail. The net result is there is changing drag messing with the bullet starting between about Mach 1.2 and 1.25, depending on the bullet profile. It doesn't stop completely until below about Mach 0.75 and 0.85, again, depending on the bullet profile. So the transonic range can be considered anything from Mach 0.85-1.2 to Mach 0.75-1.25, and some bullets can get jiggy in that range. So, if you want the best ballistic performance, you really would prefer to keep the bullet from falling into that transonic range, though some will get through it a lot better than others.

Quite a mess, isn't it? Bottom line, I think you'll probably like the .338.

[kilotanker22]

CAUTION: The following post includes loading data not covered by currently published sources of tested data for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

Thank you for breaking it out in that Fashion Unclenick. Basically things that I I understand in a limited way. I ha e been really thinking hard on that .338 Lapua my friend has. Or buying a Savage 110 Elite Precision in 338 Lapua. I plan to top it with a Leupold Mark 5 HD. I am thinking buying the Elite Precision, because of the 30 inch barrel, over my friends HS Precision with a 26 inch barrel. The sole purpose of that rifle would be getti g to a mile super sonic.

On another note, I bought some StaBall 6.5 to try and I jumped right to Hodgdon's max load since I figured I would be there anyway. And the trend of this rifle's max load being slightly higher than Hodgdon's data across the board.

At their maximum listed charge of 43.3 grains, My average velocity was only 2661 with an ES of 36 fps There were no pressure signs at all.
Tonight I am going to load 43.5, 44 and 44.5 grains and see where that gets me.

I would like to at least be able to push these bullets as fast as I can with H-4350. Hopefully with a velocity spread similar to H-4350. I am looking for ES less than 20 fps across a ten shot string. It's easy to do with H-4350, I just think that the pressure needs to rise a little for this StaBall to burn More efficiently.