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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[highside74]

Pics

#2 and #3 were the ones that had marks. #1 possibly also

[jrebel]

3 of the 6 cases appear to have significant ejector swipes (if I’m seeing it correctly.  The primers don’t look horrible, though there does appear to be mild cratering (not in and of itself a reliable indicator of pressure.   

Is what u am seeing….ejector marks?   Also. Pop a couple primers out a measure them to see how much they have expanded inside the primer pocket.  Compare them to a new primer. This can tell you a lot as well.  In my experience, Norma brass is softer brass and will not tolerate max pressure like say lapua, alpha 1, or petersons. 

[savagehunter]

I would use some sort of seating depth test at 58 gr  the berger seating depth procedure has worked well for me. You are over pressure above that and appears that your group and SD is acceptable.  Start at the lans and work your way out. You should find acceptable accuracy this way. Mr Blanchard gave the example of 3 prcs being maxed at 58 gr. Work within your rifles capabilities and use the tools as they let you. Tight is tight too tight is broken.

[Caseknife]

Stick with one brand (and lot if possible) of brass.  Don't mix and match brass when trying to build accurate rounds for your rifle.  Don't need the last 100fps to kill animals.  Trying to max out the velocity can lead to trouble and issues, listen to Karl.

[Bareback]

At some point you may be chasing accuracy due to a fouled barrel. When developing loads I clean the barrel every 25-30 rounds. Copper removing and brushing until the bore scope shows zero fouling. It’s a parameter often over looked.

[jrebel]

Stick with one brand (and lot if possible) of brass.  Don't mix and match brass when trying to build accurate rounds for your rifle.  Don't need the last 100fps to kill animals.  Trying to max out the velocity can lead to trouble and issues, listen to Karl.

Funny….didn’t notice that as I was looking at pressure signs.  Yes, one brand of brass is a necessity.  If you’re gonna use multiple brands, you may have to work up different powder charges.  Same goes for virgin brass vs fired brass. 

My sons 300wsm shoots hornady and nosler brass with the same load / powder charge…..just have to experiment to see what works.

[highside74]

Stick with one brand (and lot if possible) of brass.  Don't mix and match brass when trying to build accurate rounds for your rifle.  Don't need the last 100fps to kill animals.  Trying to max out the velocity can lead to trouble and issues, listen to Karl.

Funny….didn’t notice that as I was looking at pressure signs.  Yes, one brand of brass is a necessity.  If you’re gonna use multiple brands, you may have to work up different powder charges.  Same goes for virgin brass vs fired brass. 

My sons 300wsm shoots hornady and nosler brass with the same load / powder charge…..just have to experiment to see what works.

I knew better than to mix brass. I'm not sure how I ended up with a couple Norma in that group. I don't even have that many. I made sure to look at everything that I loaded for yesterday.

[luvmystang67]

When I anneal brass, I've noticed significant differences in wall thickness and anneal time as well.  My winchester brass was WAY thicker than my Prvi brass.

[highside74]

I shot 2.984 oal at 57.7, 58 and 58.3. 57.7 didn't group as good as 58 but had SD under 10. 58 was the best group and just over half inch at 2974fps and an SD of 7. I'm going to shoot 58 today at 2.965 and 2.975 just to see what the fps and SD does.

[jrebel]

I shot 2.984 oal at 57.7, 58 and 58.3. 57.7 didn't group as good as 58 but had SD under 10. 58 was the best group and just over half inch at 2974fps and an SD of 7. I'm going to shoot 58 today at 2.965 and 2.975 just to see what the fps and SD does.

I would not worry, or get fixated on your ES and SD.  Based on all your data, you have found the right match for the combustion side of the load.   Now concentrate on pressure and accuracy.  I will also add….accuracy at 100 yards does not equal accuracy at range.  Most reloaders test accuracy at 200-300 yards. 

In my experience, most loads that group well at 100, will also group well at range…..though I have seen loads that won’t. 

[jrebel]

This is a great video that explains the most important aspects of reloading.  Again, it looks like you have the combustion figured out.

[highside74]

I think this will work 

10 total shots
#1 fouler and low velo 2906 subtracted. Everything else was 2928fps-2956fps

2-10 .73 group
2936fps avg
ES 27.5
SD 8.5

[jrebel]

That will hunt!!!  Confirm your accuracy at range if you plan on shooting further than a couple hundred yards.  I'm sure it will be fine, but some reloads group well at 100 and won't at 200, 300 and further. 

[addicted]

Depending on how temp stable the powder is you may want to stay a grain low.

As far as which one is optimal load, New line of thinking is that your sample size is too small. The "flyer" you want to throw out is a massive part of your data and probably shouldnt be ignored.

Did you perform this test round robin so each load got a fair shake?