243 not sure if over pressure or not

[Uncle Ed]

Bolt lift was normal, when I first saw it I though it was a sign of over pressure but I looked back at my brass and was still seeing the mark down at 43 grn which is less than half way to max according to hornady

You had brass flow into the ejector, meaning the brass stretched beyond its elastic limits.

It doesn't matter what the reloading manual tells you, your brass is telling you another story.

My WAG is you have soft brass or less case capacity with your cases vs the manual.

I would buy another brand of brass and make a new workup load and compare.

 

[Rsadams]

Keep in mind that a reloading manual is just a reference and that's all.... Your gun , brass and chamber are different... From the ejector mark , I would back it down some.... I have seen middle of the road data be as fast as factory... You MUST start low and work up for YOUR rifle.... I have one of those rifles that just a hair above middle in the load chart is plenty fast enough... If I would have gone any more it would have been very fast.... Keep in mind also that a screaming hot round isn't necessarily an accurate one..... Each rifle and chamber is different , even if you buy two rifles that are the same at the same time they will want something different... If your gut is telling you something is wrong...STOP..

 

[Rdlningcltchdmpr]

I'm building up a 243 round with h4831 and I'm getting a mark on the case head from the ejector pin. Also have makings on my bolt head just looking for some direction as to where I'm going wrong or if there's anything wrong at all. I have a few pics of the issues

Some guys have made a very good point. Max is not always max, as one source says 45 max, another say 42 max, another say something else is max. So to be safe you need to apply reason to the task. I have seen data on 308 load where one said 50 max and another said 55 was max. 110 grain bullet's.So you need to take this into account when reloading.

 

[wkdickinson]

I personally have been very confused about what "max" is for a long time. Every source of data you look at has a different "max", some VERY different. I shot a Savage Target, in 243 Win, with a 1:8 Criterion. The load I shoot is 105 Berger Hybrid, Peterson SRP brass, CCI 450, 41.0 gr of H4350. The Hogdon website shows a "max" of 37.5 gr of H4350, the Berger manual shows 39.5 gr of H4350. Yet after carefully working my load up, my rifle shows absolutely no pressure signs at 41.0 gr.

The other interesting thing about this dilemma is, the Hogdon site shows a load with 37.5 gr produces 49.5K CUP of pressure (95% of MAP, 93.8% pf MPLM and 89.5% of MPSM for a 100 gr. bullet):

SAAMI Spec:

• Maximum Average Pressure: 52K CUP
• Maximum Probable Lot Mean: 53.3K CUP
• Maximum Probable Sample Mean: 55.3K CUP

So what truly is the "max" - I guess it ultimately is whatever your rifle says it is.

 

[Bill K]

I am like most others, you are on the upper edge of having pressure signs. I would back off on that charge and work up a load, if you are staying with that powder, that is safe and under pressure in YOUR rifle.

 

[David Milisock]

Certainly an indication that you need to be careful. The Mark's at lower loads speaks to other issues. I'd try another brass manufacturer, if it remains similar there may be issues with the bolt. Is this a factory rifle? Maybe true up the bolt.

 

[Walt Schmidlin]

What is the OD of the neck of the fired case? What is the OD of the neck of a loaded round? Usually a .003” difference is adequate.

A difference of .001” or less will increase pressure, required neck turning of
the brass to get required clearance.

If you change to another brand of brass recheck the loaded round OD at the neck. The OD of the neck of the fired brass will not change unless you change barrels.

 

[Clark]

243 made by necking down 308 brass, 100 gr bullets and 4350.

 

[Rdlningcltchdmpr]

Look at R26 data 47-48 max , 3100-3200 fps temp stabil. Copper removing agent also. R26 is my new favorite powder. Tiny groups.

 

[Bkrips]

What is the OD of the neck of the fired case? What is the OD of the neck of a loaded round? Usually a .003” difference is adequate.

A difference of .001” or less will increase pressure, required neck turning of
the brass to get required clearance.

If you change to another brand of brass recheck the loaded round OD at the neck. The OD of the neck of the fired brass will not change unless you change barrels.

I'm 0.005" difference, too much?

 

[Bkrips]

Look at R26 data 47-48 max , 3100-3200 fps temp stabil. Copper removing agent also. R26 is my new favorite powder. Tiny groups.

I may have to look into r26

 

[Bkrips]

I'm thinking I'm going to try another brand of brass and work up from 10% bellow max based on what the powder manufacturer says. Maybe try cleaning my brass after resizing also. Just to rule out any lube being left over on the cases. Thanks for the input everyone.

 

[Whisky Tahoe Foxtrot]

I shoot 6SLR which is Die formed from 243 cases. Ejector wipe is common with loads near or at max. The best pressure sign for me is the expansion of the case above the web and resulting "clicky" bolt.
High pressure 243 loads might require use of a small base die before resizing and considering if you should stick with a lower pressure load.

 

[243winxb]

If primer pockets get loose in 5 firings or less your over pressure. Gas leakage between primer & pocket is another sign.

The primer pocket may expand a tiny amount at each firing. Not what i want.

I have 2 batches of 243 Win, Win brand brass, with over 20 loadings. Running IMR 4831 with a Berger 90 gr hpby.

Accuracy first.

 

[jonbearman]

I would back off and just for the record H4831 is one of my favorites for this cartridge. It is too hot and I don't think a groundhog can tell the difference between 3000fps to 2800 fps. Your barrel life will suffer and you could start blowing primers and that isn't good. I think sometimes we get hung up on speed and performance rather than just nice accuracy.