Strange load development results

Krazy

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Joined
Dec 10, 2004
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5
I am trying to work up a load for my 300WM using Barnes TSX 165's and RL22. I started at 76 grains and worked my way to 80 grains keeping the bullet .03 from the lands. Accuracy was great (for me anyway) as all the loads shot under 1 inch at 100 meters. Oh ya I was using Fed 215M primers, Winchester brass and my rifle has a 24 inch barrel. Here is the data:

76 = AVG 3006 MV
77 = AVG 3099 MV
78 = AVG 3096 MV
79 = AVG 3056 MV
80 = I stopped shooting as the thump was getting bigger but the velocity wasn't!

Other than the kick there were no signs of excessive pressure up to this point.

Can anyone tell me what's happening here? My loading manulas show that RL22 should take me to almost 3300 FPS with a 165 in a 24 inch barrel. Since this powder is not doing it, any suggestions on what type of powder to try next?

Thanks
 
What manual are you using?
I don't know how much it would affect things, but Barnes recommends .050" off the lands
last I read (Barnes #1).

DK
 
Deerkiller

I was actually usng an old Nosler and speer manual as well as online data from places like handloads.com

Yes there was a set of instructions from barnes that came with the bullets - they recomend .03 - .07 off the lands.

I'm not so concerned with the velocity as I am curious as to why the velocity would not continue to increase over a certain point even though the loads were kicking harder and no pressure signs were showing?
 
You've got a good one there.
I would consider a speed plateau maybe.
If this lot of powder has been used before & behaved normally,
I would continue to carefully work the load up.

DK
 
Krazy, You ran out of powder!! Really, you passed the efficiency point of that powder. If you monitored the SD, you would have usually seen the SD getting better to 77 or 78 grains and then open up. You'll need to go to a slower powder to go any faster. Also, I usually start Barnes bullets at .050 and the work up my loads. After I find the speed I want, I then shoot groups going in & out with the OAL to see if I can find the sweet spot. But be careful, pressure goes up as you seat closer to the lands and down as you seat the bullet deeper and further off the lands. Some rifle shoot best at .100+ off the lands! Find your sweet spot and then adjust powder charge for speed and accuracy. I would go to the 168 match bullet TSX myself. BC is lower, but accuracy is usually better. Good luck. /ubbthreads/images/graemlins/cool.gif
 
wapiti13

Thanks for the tip - I will back the bullet out to .05 off the lands.

You are correct about some extreem diffences in velocity. Unfortunatley my chronie errored out a few times but here is the data i have:

76 grains = 3015, 3020, 2986.
77 grains = 3099, error, error
78 grains = error, 3144, 3047
79 grains = 3018, 3094, did not shoot the 3rd shot

I don't understand what you mean when you say 'i ran out of powder'. Are you saying that i was not able to burn all the powder before the bullet left the barrel? If so wouldn't that mean that I should go to a faster burning powder? (bear with me i'm new to this - lol) Lso, which powder would you recommend?

Thanks for the help /ubbthreads/images/graemlins/smile.gif
 
Krazy, I meant that you maxed out that powder for its burn rate. Once you pass the peak pressure for that powder, adding more powder will actually lower the velocity and SD goes to pot. It usually means that you need to try a slightly slower powder to gain more velocity or go to a different brand of powder to match case capacity to powder volume and burn rate. I think that you were loading a 300 WM with the 165 Barnes TSX. Barnes #3 manual recommends H4831 for 3157 fps max. The TSX could actually beat that since manual was built with the older BT or FB bullets. Newer TSX actually lower pressures which should allow you to add a "little" more powder and gain a "little" velocity. Obviously, every rifle/chamber/barrel, etc. changes the variables. Primers can make a major difference in large amounts of powder. Try different primers to find the best SD and velocity. Good luck.
 
Krazy
As Wapiti13 said you maxed out at which point you peak and loose FPS. I don't know anything about the Barnes bullets but for a 165 pill in a 300 Win you will be hard pressed to find a powder that will push em faster than R-22.
In my Sendero 26" R-22 would push a 165 NBT between 3320 and 3420 depending on the lot. 77.5- 79.5 At 79.5 I was still gaining fps but started to show signs of pressure. I have since sold the rifle but, I can say It was a deadly combo. With the 165 NBT R22 was top fps with the 180 R25 shined. I dont know if it could be the bullet but I would be curious to see what happens if you used a 165 NBT.
 
Thanks guys,

I think I understand what you are saying but am having a hard time trying to reason why I would try a slower powder as opposed to a faster powder in this situation. I have some H1000 (which I read burns slower than RL22) so I guess I could load some up and see what happens. Wapiti you mention 4831, which is actually burns faster than RL22, so maybe I'll try that too. If I can't crack 3200 with a 165 I think I will just move up to a 180.

By the way, I loaded some more tsx's and some NBT's today and confirmed that it is not just the bullet. Both the NBT's and the TSX's increased velocity and grouped quite well right up to 78 grains of RL22 at which point they both started to plateau velocity and the groups opened up a bit. At just under 78 grains both bullets maxed out at about 3125 fps with excellent groups (the tsx's actually out performed the BT's with a .417 group to the BT's .537 @ 100M). So I guess that's the best I can expect from RL22 and my 300WM.

Thanks again for the help. If anything else that I could try comes to mind please let me know........

Hey just one more thing. I am using fed215MG primers for the first time ever - do you think this could be contributing to what is happening?
 
Is this a factory rifle or custom? Some barrel / chamber cobmos just run slower than others. Don't beat yourself up. Accuracy kills better than speed.
 
Krazy, You may be right in needing a faster powder, but I don't think so. Since it appears that you ran out of "burn rate" before case capacity, that indicates that the powder and other factors are too fast. You might just have a slow barrel/rifle combo. Not much you can do but experiment with other components and see what happens. Try to borrow another rifle from someone and chrono your load for comparison.
 
Well here is an update. I don't really understand why it works like this but it seems that seating the bullet deeper in the case makes the powder burn more efficiently. Here is what happened:

I tried faster powders (IMR 4350 & H4831) and just broke 3100 FPS at max charge with slight pressure signs. I also tried a slower powder (H1000) and maxed out without pressure at just under 3100 FPS. So back to RL22 as at least I got 3125 with it. I started playing with seating depths and found that the deeper I seated the bullet in the case the more effect each grain of powder had on velocity. For example:

.03 off the lands with a 165 TSX

77 grains of RL22 got me 3100 FPS
78 grains got me 3096 FPS
79 grains got me 3056 FPS

Seems the powder stopped 'working' at 77 grains. In each case there were no pressure signs.


I moved to .05 off the lands and found that:

77 grains of RL22 got me 3057 FPS
78 grains got me 3125 FPS
78.5 grains got me 3161 FPS
79 grains got me 3195 FPS
79.5 grains got me 3187

Seems that at this bulet seating the powder stopped 'working' at 79 grains. In each case there were no pressure signs.

I am going to try seating at .07 off the lands next to see if it will allow the powder to use the full 80 grains that my book says is max.

The consequence of gaining velocity using this method, however, seems to be accuracy. Not much so far though as the 78.5 shot .7 and the 79 shot 1.18. At .03 off the lands 77 shot at .7 while 78 and 79 shot .6 even though velocity dropped and ES increased.

So that's my story - is this typical or is my rifle a freak?

Thanks for all the help.........

The OAL for this bullet in this rifle is 3.567. I guess I should have started at 3.34 like my manual said and I would not have experiened these issues - i just thought I would get better performance closer to the lands so that is where I started.
 
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