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Overpressure!!!

tinymike66

So loaded 15 rounds of 284 win.
Starting at 51.3gn of H4350 and moving up by .2 all the way to to 54.1gn.

Well at 53.7gn at a speed of 2968fps it looked as if primer might have been flattening out. I decided for one more round, sure enough at 53.9gn I got 2996fps but when I removed the empty case from receiver the primer had been blown out.
Pressure or enlarged primer pocket???

Time to shut'er down...lol.

Now I did find my best accuracy and Standard Deviation was with 51.3gn but only at 100m or 200yd range with average velocity of 2867fps

I know speed isn't everything. I've heard guys using up to 54gn of h4350 with no issues, but I realize every rifle is different and each chambered barrel will produce different results.

Is 2800 + good velocity for range of 500 to 1000yds?

Lapua brass
Lapua scenar L 180gn projectile
Fed Prem Match Large Rifle Primer
 
I also shoot .284 using H4350 and with a powder charge of 53.1 grains I am able to push the 180 hybrid around 2,825 fps. During load development I was able to reach close to 2,900 fps but was not consistent out at LR distance. After speaking with a few HM's in my club it was brought to my attention there are two identified accuracy nodes one at 2,820 and another at 2,900 fps. I settled in on 2,820 and have been very happy with the results on target.

The speeds you are seeing are closer to .284 Shehane or KMR out of a straight .284 Win are definitely on the high side IMO. From my experience the accuracy node is much more important than pushing it as fast as physically possible. You will have both your barrel and brass will last quite a bit longer as well.
 
ballisticdaddy said:
I also shoot .284 using H4350 and with a powder charge of 53.1 grains I am able to push the 180 hybrid around 2,825 fps. During load development I was able to reach close to 2,900 fps but was not consistent out at LR distance. After speaking with a few HM's in my club it was brought to my attention there are two identified accuracy nodes one at 2,820 and another at 2,900 fps. I settled in on 2,820 and have been very happy with the results on target.

The speeds you are seeing are closer to .284 Shehane or KMR out of a straight .284 Win are definitely on the high side IMO. From my experience the accuracy node is much more important than pushing it as fast as physically possible. You will have both your barrel and brass will last quite a bit longer as well.
Click to expand...


Yes I agree, I think I will stick at 51.3gn and start working on my skills. I am looking to join my provincial rifle association here in Canada and that will give me access to ranges from 300yards to 1000yards and also allow me to compete in some F-class and long range matches.

thanks for reply
 
An easy check to see if your MV is enough. Run your info through a good ballistics calculator. What is the speed at the intended ranges? How much wind drift for a 10 mph wind at your intended ranges? Run the analysis at the MV you think you want and compare. Is there enough difference to try and load at the higher node? If this is for hunting, is there enough energy at the intended ranges?

I was running a load in my 6.5x47 with 140's around 2600 fps. No issues out to 1100 yds. Without running the numbers, I would expect the 180's at 2800 fps would do well.
 
I bet the bearing surface on the Scenar is longer than the Hybird causing more pressure at the same powder charge,,I also thought most people shot the straight 284 with 180`s at about 2820 -2840 for best accuracy..
 
Yes..im seeing that at that velocity range as well.
Groups are tighter as well.
The bearing surface is longer..
I was shooting the berger hybrids and switched to lapua. Im getting better groups with lapua and saving $25 a box lol
 
tinymike66 said:
Yes..im seeing that at that velocity range as well.
Groups are tighter as well.
The bearing surface is longer..
I was shooting the berger hybrids and switched to lapua. Im getting better groups with lapua and saving $25 a box lol
Click to expand...
Wow, where do you buy Lapua at 15 a box? Matt
 
It depends on powder lot, barrel length, age, blah, blah.. but 53g of H4350 is definitely on the high end! Your primer pockets are only going to last a few cycles at the higher end even if they aren’t blown.
Also If you are going to shoot 20+ round strings in F Class you don’t want to be too close to the top end cause you may not finish. Ask me how I know o_O
 
murray brook said:
Better prices at these places in canada
https://x-reload.com/reloading-components/bullets/rifle-bullets.html?brand=44&diametre=271
https://www.londerosports.com/reloading/components/bullets/berger/hunting-bullets/7-mm
Click to expand...


Add in your shipping and taxes all those are over $100.

The bottom link...those are not the targets.

Problem with it is anyone who gets them at decent price is far and then the shipping kills ya. Lol.

Welcome to Socialist Canada

I'm a criminal here and just don't know it yet...lmao
 
Do you know what freebore your chamber has? I shoot a lot of 180 Scenar L in a 284. My accurate load of H4350 is only 50.4, I had tried up into the 51 range and it was too hot. I know several others that also load in the lower 50's, the highest load that I've heard from fellow shooters is 51.3. The long bearing surface of Scenar might be into the donut also. I fight them trying to shoot the Scenar.
 
Ringostar said:
Do you know what freebore your chamber has? I shoot a lot of 180 Scenar L in a 284. My accurate load of H4350 is only 50.4, I had tried up into the 51 range and it was too hot. I know several others that also load in the lower 50's, the highest load that I've heard from fellow shooters is 51.3. The long bearing surface of Scenar might be into the donut also. I fight them trying to shoot the Scenar.
Click to expand...

Min chamber length of 2.165
Neck diameter .317
Shoulder length .281
Freebore Diameter .285
Freebore .240
 
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