My New 284 Build and Chrono results

[Steve Blair]

I am wishing to get good chrono readings around the 2,900 fps area, maybe 2,925.

[br]
Dennis, it could work if you have a very fast barrel, but that is generally Shehane territory for 28". I get about six reloads running 2940-2950 in a 32" Shehane barrel. My brass never shows pressure indications, the primer pockets become loose.

 

[Immike]

Something seems way off with this information. If the chronograph checks out then check your powder scale too. My 32” barrel with 55.9 only gives me 2850. I'm concerned that something is being overlooked.
Mike
PS : weigh one of those bullets that your shooting.

 

[DennisH]

I have 4 powder scales and usually double check my loads for matches, all concur.

I have weighed my bullets, all in the 180 range, 7mm.

I have not stocked up on 7mm bullets, just waiting to see which one the rifle likes.

I know it does not add up, this is why I posted this information.

Dennis

 

[KT]

Dennis,

Here's some info to look at.
I'm running a 30 inch bartlien barrel,
Using 56g 4831sc, @2840fps in 45 degree weather
Using 55.5g 4831, @2840fps in 90 degree weather, this load in 45 degree weather ran 2785 fps.
I'm using the magneto speed!

I have 5 firings on my Winchester brass, one more firing and they will be done. This is due to the primer pockets being lose.

I know that you are running the .188 freebore. So your loads will have more pressure than mine due to the bullet being farther in the case. My free bore is .230

With that being said, the guy that shoots F/O with me is running a 30 inch bartlien with a .188 freebore.
These test were done at 45 degrees, with 4831sc, norma brass, and magneto speed chrono

54.5 gave him 2781
54.8 gave him 2807
55g gave him 2832 (this load shot the best)
55.3 gave him 2854
55.5 gave him 2878 (bolt started getting sticky)

KT

 

[TrapperT]

In my opinion, your chrono is off. This can be caused by a number of factors but is probably the available light that is over the chrony. I use an Oehler 35 and see large changes in velocity numbers with the same load depending on the sun or lack thereof. For example, I was checking loads in my 7/300WSM using some new Norma brass. When I first chronographed the loads I saw 2994fps for one of the loads. Later that day I loaded some more and the loads now shot at 3035fps. Same gun, same lot of new brass, same powder, primers, etc. But what was different is the angle of the sun and corresponding cloud cover. I have also found that in bright light your ES/SD will vary substantially but the loads will hold great vertical at 1000. So I have come to trust my chrono only so much and rely on results at the target to tell me what to load.

I have found that my Oehler works best with overcast skies as the light is obviously diffused and reflections are minimized.

I agree with what others have said. Look at your results on paper. It is the best indicator of the loads performance.

My .02

Tony

 

[DennisH]

UPDATE: I loaded up more rounds this weekend and headed to the range with my chrono. Sunday the results were completly different! See the below picture. 55.3grns showed promising results. One thing I can say is the ES and SD are very low and consistant in this rifle. It looks like the first of the year I will get a new chrono and go from there. I am trying to get 2,925fps, but it looks like I will have a charge of 56.2+ to acheive this. 55.9grns were showing pressure signs, so I don't know if this is going to be possible. The first test were done with Federal brass. The below results I was using 6.5x284 Lapua necked up.

The below printout is more inline with KT's posting.

I don't know if RL17 is the answer, but let me know if it's worth a try. I would think it would show pressure signs as well. Let me know your thoughts, Dennis

 

[Steve Blair]

Reloder 17 gave good velocity but I could not keep it in the node when temperature varied. My best results are with H4831 SC. Some folks do really well with H4350.

 

[dooley]

I have tested ammo at 75F 2921 FPS, tested this same load at 43F and Velocity came down nearly 100 FPS, both times using 2 Chronographs, now I just allow for the extra drop, Temp will make a huge difference in velocity
dooley (UK)

 

[FroggyOne2]

Dennis,

When I was shooting the 284, my RL17 load was 49 grains. for a accuracy node at 2830..I think that you will find that the 284 likes to shoot around that node.

Randy

 

[FroggyOne2]

Oh, and another thing, I don't think that you will see that much difference in a 100 fps to matter that much in the wind.. maybe what.. a click, maybe two at most..

 

[DennisH]

???

Question?

What makes the 284 an accurate 1k yard rifle?

Many are using it along with the 6.5x284.

Just wondering, I am looking at some of my 308 test and most are around 2,725fps shooting 185's. The 284 outshoots the 308 at long ranges. Just wondering.

 

[Steve Blair]

Oh, and another thing, I don't think that you will see that much difference in a 100 fps to matter that much in the wind.. maybe what.. a click, maybe two at most..

[br]
About a 1/4 MOA in a 10 mph crosswind. The inch or two in most conditions may occasionally save a point but it is no game changer. What is more important is shooting the highest B.C. bullet your cartridge can handle and whose recoil you can tolerate. Loaded to equal pressure in the same cartridge, the higher B.C. bullet will always perform better in wind.

 

[Steve Blair]

???

Question?

What makes the 284 an accurate 1k yard rifle?

Many are using it along with the 6.5x284.

Just wondering, I am looking at some of my 308 test and most are around 2,725fps shooting 185's. The 284 outshoots the 308 at long ranges. Just wondering.

[br]
The .284 Win is an inherently accurate cartridge with forgiving load characteristics. It shoots high B.C. bullets at velocities in the 2800-2900 fps range and whose recoil is tolerable to most shooters. It just hits a sweet spot in overall balance.

 

[DennisH]

It just hits a sweet spot in overall balance.

I will have to admit, the chrono results are unbelievable. I read Charles Ballard's (gunweek88) several times before deciding to build one. I couldn't believe the results he was posting, but I am almost matching them! The ES & SD are unbelievable. It will be after next Feb before I try it long range, but I can't wait.

I might try RL17 just to see how it performs. I am going to try some loads with 4831sc above 55.5grns to see if 2,900 is achievable.

There is tons of info on loads for the 284.

If anyone has suggestions on a starting load using RL17, I would appreciate it. I know I should start about 1.5 grns lower vs 4831sc.

I am just trying to get the max out of the barrel, but maintain my ES & SD.

Thanks, Dennis

 

[KT]

Dennis,
I agree with Steve. 4831SC has performed the best in my .284s.

Any particular reason your running .050 off the lands?

2925fps may be attainable, however your brass isn't going to last more than a firing or two.

Either way I'm glad to see your getting good results.

KT