Lately I have been researching how to shoulder bump my 6.5CM brass. I have all the necessary tools, but when I back off the shell holder .002, for some reason the cartridge will bind pretty hard upon closing the bolt. I am puzzled as to what I am doing wrong. Obviously I am missing something here, but can't seem to pinpoint it. Also, if I was so chamber the rounds being as tight as they are, can it be dangerous? I don't want to have to take everything apart and start over. Figured I would just correct it after they have been fired. Any help would be appreciated!
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Shoulder Bump Problem!
- Thread starter RaptorAddict
- Start date
Color your round with a sharpie marker and slowly chamber it. Slowly eject it and see exactly what is making contact.
I am guessing that you used a feeler gauge to space the die away from the Shell plate. If this is the case I would say that die setting is not causing enough sizing.
You need a headspace gauge like the following to measure how far back you actually setting the shoulder.
www.hornady.com
Lock-N-Load® Headspace Comparator & Anvil Base Kit - Hornady Manufacturing, Inc
Lock-N-Load® Headspace Comparator & Anvil Base Kit Lock-N-Load® Headspace Comparator The Lock-N-Load® Headspace Comparator extends brass life, improves accuracy, and enhances safety. The gauge measures...
Yes, it's almost as if when I apply it regularly with a bit of over cam, the cartridge fits smoother while chambering. So maybe my rifle doesn't require any bump. Been reloading my whole life, but precision rifle reloading is quite new to me.
I have all the necessary tools, including headspace gauge. I would think the more I bump, the more it would be looser in the chamber. I know we don't want it loose. Just saying. But it went backwards on me somehow.You need a headspace gauge like the following to measure how far back you actually setting the shoulder.
Lock-N-Load® Headspace Comparator & Anvil Base Kit - Hornady Manufacturing, Inc
Lock-N-Load® Headspace Comparator & Anvil Base Kit Lock-N-Load® Headspace Comparator The Lock-N-Load® Headspace Comparator extends brass life, improves accuracy, and enhances safety. The gauge measures...
Thats becuase your actually sizing the case ebough at that point to smoothly chamber.
My chamber was cut to be .002" longer than a new piece of Lapua 6.5CM brass, which i verified with fired brass.
Although its a bit crude a piece of 9mm handgun brass with the spent primer removed can be used to measure base to datum on shoulder until you can source the proper tools.
The case dimensions / length can grow if you dont have the die set far enough down to bump the shoulder.
Instead of compressing it is extruding and elongating the case dimension.
Are you adjusting the gap between the die and the shell holder trying to set bump? If so that is not necessarily going to work. Measure a piece of fired brass with the headspace comparator, then size it with the die contacting the shell holder with a bit of cam and remeasure the brass. You should see a bump along the order of 6-8 tho, then slowly back the die out and size a new piece and measure again. You should have to only back the die out maybe a 1/8 turn or so. It’s a finite adjustment.
How many pieces of brass have you attempted to size that won’t chamber?
What are the case head to shoulder and case web diameter dimensions before and after firing?
Are you sizing virgin brass, brass fired in the rifle you’re currently trying to load for or brass previously fired in another rifle?
What did the sharpie marker tell you when you tried it?
It’s getting stuck either due to ch-shoulder datum being too long or case web diameter being too thick.
After gathering information you all stated and with some playing around, it seems I don't need to have any space whatsoever between the shell holder and the die. Instead, it needs to be over-cammed a bit to get the setting I want. Now it loads smooth and perfect. Maybe Sako does something different with the TRG 22's. Mine is in 6.5cm. Don't know. I used my Hornady Comparator gauge to measure the differences. Now I need to extract the bullets and get them all right. Ugh! Fun.
Forget what the instructions that came with your die set says.
With a new caliber and die set for bottle neck rifle cases i run the die in until it just barely touches the shell holder with the ram at its full extension.
Size a piece of brass and compare that to your fired brass dimension with the spent primer removed and make small adjustments from there and you should be good after verifying it chambers smooth with no restistence closing bolt.
The desired shoulder bump will depend on bolt action or semi and intended purpose, such as if it is a field rifle that will be used in very dirty conditions and possibly high round count before cleaning you probably dont want the absolute minimum on sized dimensions.
Hope that makes sense.
The die that you need space between the shell holder and die is the seating die, if you don't want a crimp. If you set the seating die too low, you can buckle the case shoulder, which will cause chambering issues.
I've been using the RCBS Matchmaster seating die. Works like a champ for seating. As far as I am experiencing so far.
