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Recently I bought few bertram brasses (6.5 saum) and noticed they are very soft, to the point I have to decrease my load by 2-3 grains, comparing to the load I normally use with norma brass.
I noticed once the brass is over-pressured there is no use to anneal it, it is always hard to load a projectile. I ended using my expender die to "soften" the neck. But still, the accuracy is always bad, I mean from 1/2 to 2 inches. Has anyone know/read why it could cause the accuracy to drop? Elasticity?
When you say your brass has been "over-pressured", are the primer pockets still able to hold the primer? Sounds like the neck portion of your die or the button is way under required diameter?
thanks 6x47, yes the brass can still hold the primer, albeit bit loose. I don't use neck die, collet die what I use for neck resizing. Body die is used for body resizing. I have tried to increase annealing time but it was no use. My guess the brass has lost it elasticity. But I am interested to know why the accuracy can be so bad
Are you using a proper 6.5Saum die set??
I mean do you have a proper full length size die?
What does a loaded round measure across the neck with a bullet seated for both bertram and norma cases.
You are better off sticking with norma brass or genuine 6.5Saum ADG brass
Hi Mikee,
I use body die to resize the case & bump the shoulder but not neck, as I don't like the full length resizing's resizing button which tend to pull the neck out of concentricity. I use the collect die to resize the neck only.
Agreed I will never buy the bertram brass again, quite disappointed as I found the ADI brass is really good.
Have you had a careful look inside the case necks, sounds to me like you might have a "donut" inside the case neck . . .
If its new brass and the necks are too thick for your chamber then maybe its "pinching".
As you know with the 6.5Saum being a wildcat there are many "spec's" for chambers all similar but different.
I have to turn my necks on necked down 300 Norma Brass but not ADG
I also have to ream the inside necks after first couple firings as I do get donuts.
Best thing I ever did was throw away the neck sizing die.
Donuts can happen for a variety of causes (none of which I understand) but they got my attention real quick when I got them on a 6.5x47 on sizing after first firing - what do you mean Mr Lapua, this is a 30 plus shoulder on a short modern case! I changed dies and it didn't happen anymore.
thanks Mikee, Tentman. yes the 6.5 saum does get donut quite easy. I used to use inside reamer along with case trimmer to remove the donut. but now days I just use a 6mm drill bit and rotate case around the shoulder area against the drillbit and it removes donut just as good. for case that has pressure/accuracy problem I have also checked the base diameter, and it has about 1 thou expansion, which is about same as my norma brass. But unlike norma brass if I put the fired bertram brass(over-pressured) back to the rifle, I am struggling to close the bolt. I did check the case oal too.
Mikee, I have the original 6.5 SAUM 4s reamer, so neck sizing is a must. I just got sick of downsize 300 norma saum brass, with lots stages. will give the ADG brass a try if I can find any.
I never bothered to fix the donuts on my cases cause I read that trimming them off the inside doesn't really fix the problem, and the only way to really fix them is to "push" them to the outside of the neck with a expander, and trim them off on the outside. I've never had the right gear to do that.
I have never used it but Bertram brass has, in the past at least, had a reputation for poor quality.
In some of the big bore calibres I'm told it wasn't unusual to get split necks even after one firing of moderate loads. At least online I read of many shooters who won't touch Bertram brass.
For what its worth i use bertram brass in my 300wsm without issue. Most of it on its 5th firing now with pretty warm loads. Not saying brass isnt your problem just offering my experience with bertram.
You say you have to reduce your charge, where did your velocity end up? Ie was it just a case of the bertram brass having less volume & you had to reduce charge to get back to the same pressure/velocity?
After reading this, I would suggest full length sizing (humor me) if you don have a die then send me 3-4 cases and I will size it and you can tryQuote:
Originally Posted by hey
I also have 6.5GAP
What neck dimension is your 6.5 SAUM?
I have a 6.5 SAUM with 0.296 NK that I can’t run Bertram brass in, necks are too thick (major pressure signs even at what should be start loads).
Didn’t bother to neck turn to see if that fixed it as ADG brass had a thinner neck and has given great accuracy.
I used a 7 saum bushing dies for my gap4s and adg brass never had an issue
Thanks Mikee, it is all good. I have no issue with norma brass so will stick to it. I was just curious why the over-pressured brass could cause accuracy problem. have a great weekend!Quote:
Originally Posted by mikee
Hi overflow50, mine is 0.2962, so same as yours. GAP later released 0.298 neck reamer, which you can use normal cases without neck turning. I neck case down from 300 saum so neck turning is a must. will check the ADG brass, thanks.Quote:
Originally Posted by overflow50