A little stumped load development virgin brass vs once fired

[30BR]

Since you are talking reloaded vs new, I suspect that some residual lube could have been left on the cases. Wipe the cases down with alcohol very well, and the pressure sign may go away. At or near max loadings, doesn't take much lube to cause the case to slip before grabbing the chamber wall. My 6.5-284 is very sensitive in that regard. I won't post the load data since it exceeds max, but is safe in my guns. (Been shooting basically the same load for 4 years.) I do have to sometimes wipe the cases twice, or I get serious ejector marks, with really flat primers.

 

[RUFFIAN R - NY]

did you change primers ? are they all the same lot ? the same for powder & bullets ?? also did you check your bullet's OG's -I sort all of my bullets, some brands / styles have differences even between the batch # and or same batch !!!!! just check !

 

[ripzip]

Well since Hodgdon lists 56gr at 2822fps as max, we are all lucky you are here posting about it!

Agreed, just strange that I really did not get pressure signs on the virgin brass until it was really crazy high. This was Lapua brass if that made a difference also.

 

[ripzip]

Since you are talking reloaded vs new, I suspect that some residual lube could have been left on the cases. Wipe the cases down with alcohol very well, and the pressure sign may go away. At or near max loadings, doesn't take much lube to cause the case to slip before grabbing the chamber wall. My 6.5-284 is very sensitive in that regard. I won't post the load data since it exceeds max, but is safe in my guns. (Been shooting basically the same load for 4 years.) I do have to sometimes wipe the cases twice, or I get serious ejector marks, with really flat primers.

I usually run them through the tumbler after I resize, then run my mandrel through the necks that have been dipped in imperial dry case lube. Just wipe off any left over dry lube.

 

[ripzip]

did you change primers ? are they all the same lot ? the same for powder & bullets ?? also did you check your bullet's OG's -I sort all of my bullets, some brands / styles have differences even between the batch # and or same batch !!!!! just check !

Nope same primers and bullet lots were the same too. I did find this issue with two different brand bullets same weight and same issue. When I had the Issue with the Hornady 153 A-tips I cautiously loaded up Berger 153's and found pressure signs at 57gr exactly the same as the Hornady bullets. Must have been the virgin brass expanding and masking pressure.

 

[ripzip]

Another thought might be what you used to read your speed. I fully trust the Magneto and Labradar but no longer believe most numbers I used to get with a Chrony.

Using Labradar.

 

[ripzip]

You are up over the reloading manual call out for max loads. I generally go over the books call out. (that's me, but I am very careful) If the case is in the 70gr area, I move up at the rate of .5 gr at a time. (note I start out with the manual low load first) I load only a single case and step up the next .5gr until I see flatten primers, no creators, or ejector makes. (So say that not correct, but that's what I do) New case need to be fireformed, and a new barrel need to be used. Now your rifle. It's about a 60gr case. If I go up above there max load, I only go up at the rate of .2gr at a time. Watching for pressure signs. You didn't state if you are in the lands or back off. When fire forming your cases, use a reduced load and set up with the bullet into the lands .003 to .005. That way your case base is push against your bolt face. That makes the shoulder move forward to form to your chamber with out case stretch at the base. This stops the case from moving back, and forces the case at the shoulder to move forward to fit the chamber.
All can I say is, I have learn a bunch by staying on top of what is written here over the years. Put a lot into my reloading steps. All to the better.

I was at .045 of lands. Started at .020. Long skinny bullets seem to like jump better but I see what you are saying and that does make sense.

 

[Valek]

I would assume you would want to, to find out where you're at accuracy wise.

Typically starting development on the second loading...except when switching to AI using standard brass: then start load development on the 3d loading. But, that's just I and a bunch of others.

 

[milboltnut]

Never seen pressure variations after shooting new brass. Even with faster powder, the only time is near max occasionally. Never noticed it. Extraction, no stiff bolt, or impressions on the case head. Maybe bolt was a bit stiff backing off on loads did the trick. I usually load heavy bullets with slow powders that might explain why... Even with my 300 Weatherby, no signs heavier bullets with slow powders.

 

[kfreeze]

Measure the difference between new brass and fired brass with a headspace comparator. Sometimes you have more brass expansion and things get wierd.

 

[ajkellerusmc]

That was what I thought to. Initially I was only loading to 56.5gr. Then I also had some Berger 153.5's. Called Berger and they told me 57.0 min to 63.3 max Retumbo, I thought the guy was on Crack called back another day and talked to a different guy he told me the same thing. Told him that the case will not hardly even hold 63.3 he said that it was a compressed load. I actually got to 62gr before pressure signs on the virgin brass. That is when I decided to tried pushing the A-Tips a little more and came up with the 60gr load for both the Bergers and Hornady bullets.

Berger did the same thing to me with their 140 vld target bullet for my 65PRC. New cases and all, now that they are fireformed I got all kinds of pressure signs you describe. The case will not hold the amount of powder that they give you over the phone.

 

[ripzip]

Berger did the same thing to me with their 140 vld target bullet for my 65PRC. New cases and all, now that they are fireformed I got all kinds of pressure signs you describe. The case will not hold the amount of powder that they give you over the phone.

Well at least we know they are not conservative on 6.5 PRC. I have used there book for my 264 win mag and 270 with no issues, but again that was from the book.

 

[Mikecr]

Well, it's good learning for you.
After another firing or two, your brass should be stable and ready for load workup.

 

[nksmfamjp]

This is the third time I've heard from customers telling me that Berger is handing out insane load advice in the last 6 months.

If it is dangerous, I agree. I have seen their bullets run faster than other brands. I have a 300 Sherman. Obviously no book data, but I safely Rand the 180g EH to 3050fps. I can barely get the Hornady 178gr ELD-X to 2950fps. I need to confirm charge weights.

My point is Berger's have a unique shape that allows a bit more!