New To Reloading And Have A Question

[highside74]

So I worked up some test loads for my 6.5PRC. I shot 4 loads half grain from 57.5 to 59gr. I had signs of pressure at 59 but it was a good group save my flyer. 58.5 was real good no pressure  and an SD of 9.3. 58 was good with a flyer but an SD of 12.6.

57.5 2893 SD 19.1
58.    2937 SD 12.6
58.5 2955 SD  9.3
59 pressure 2977

That's a .5 diamond
My question is
Do I just rock 58.5 or should I go up or down a 10th or 2 to see if it gets any better? The FPS isn't much different.

[jrebel]

What powder and bullet combo?  Is your powder temp sensitive?   If it is, I would back down at least 1 grain from pressure and then play with seating depth.

More info would help.  Any of those SD’s is respectable.  Most shoot for less than 30 fps SD with hunting loads. 

[Bareback]

I’d stay at 58 try seating depth.

[highside74]

Bullet is Berger 156 eol
Powder is N565
OAL is 2.956

My gun to ogive is 3.03 but the magazine won't hold over 2.98ish I believe

[jrebel]

So cup and core bullet with a temp star powder.  Shot in warmer weather without pressure at 58.5 grains.  I would be comfortable leaving the load at .5 under pressure given that info. 

What kind of pressure signs did you see at 59 gr?

[highside74]

So cup and core bullet with a temp star powder.  Shot in warmer weather without pressure at 58.5 grains.  I would be comfortable leaving the load at .5 under pressure given that info. 

What kind of pressure signs did you see at 59 gr?

Bolt stiffness on all and an ejection mark on 2 of 4

I also had my son put them in the fridge for a couple hours before I got home. They did warm up by the time I shot them but they were still cool to the touch.

[jrebel]

Ok, I take back what I said earlier.  Drop down to 58 and shoot them without being in the fridge to check for pressure.  Heavy bolt, in my experience, is a late sign of pressure.   Usually flattened primers or cratered primers is first (and not the best indicator of pressure), then ejector marks or swipes, and lastly heavy bolt lift and clickers.   If you had a heavy bolt, you’re playing with fire (IMO).  Best case scenario….your shortening the life of your brass.  Worst case scenario you start blowing primers, damage your bolt face, stretch your chamber, or heaven forbid….blow up your gun. 

[birdshooter1189]

Can you post pictures showing clearly the primers on your fired casings.

I agree with Jrebel, when I'm reloading if I get a bolt that is difficult to lift, this indicates to me that I am WAY too hot of a load.  If i'm trying to push a hot load I try to get to where I get just a little bit of cratering on the primer, but no extractor marks and no hard-to-lift bolt.

[highside74]

I have them all still separated by charge. I'll take some pics this afternoon. Thanks

[Karl Blanchard]

I have 3 prc's worth of experience with 156's and n565. 57.5-58 is as high as you want to operate 

[chukardogs]

Are you trickle charging each round on a scale to the tenth or using volume? Other than the person behind the rifle squeezing the trigger, powder charge consistency and OAL to your guns liking are the two things that you can control easily and will have the most impact on your grouping.
Over 35 years of reloading for a multitude of calibers, speaking soley to accuracy, which in my opinion is everything that matters, I've never had one firearm perform better, much above middle of the prescribed powder charge range. Having excess powder burning outside the end of the barrel can be tough on accuracy. If you're shooting a rifle with a longer than standard barrel, forget you ever read this.
 Also, having a rifle freeze up in "that moment," would absolutely suck!

[highside74]

I'm using an RCBS Chargemaster Supreme

[highside74]

Last night I played with seating depth. I have 3.03 to the lands. I made a dumby round at 2.984 that fits my magazine and cycles in my rifle. I going to work up 3 loads after work. My plan is 57.7, 58 and 58.3 and see how they shoot.

[Stein]

You might consider 10 round groups, especially when you get down to a couple loads and want to be precise.  They will show you so much more than 3 or even 5 shot groups.

[dreadi]

I have alway tested loads in 3/10 increments.


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