I've got one of the early Mark V Backcounrty Ti in 6.5 RPM, it will shoot factory loads just fine with no problem with ejecting the spent cartridge, so with reloads I have been getting cartridges that stick and a bolt that is hard to eject the spent cartridge, full length resized with RCBS dies, trimmed to length, federal GM215M primer, 65 gr H-1000, 140 gr Berger Elite Hunter bullets gives me a muzzle vel of 3050 FPS. Should I be doing something different when reloading to stop the cases sticking?
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Sticky bolt and cartridge help!
- Thread starter mnhunter2
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ShtrRdy
Well-Known Member
You're going to have to take measurements of a new, unfired, case and a problem case, and compare them to the SAAMI specs.
How much are you bumping the shoulder? Also does the brass chamber fine? Or is the resized cases sticky too?
wvbearhunter
Well-Known Member
Most likely the shoulder needs bumped
MagnumManiac
Well-Known Member
First thing to do is buy a case headspace comparator tool, not headspace gauges for a chamber.
Start measuring your new brass, fired brass and sized brass. Next, get yourself a Mitutoyo 0-1" Micrometer that reads accurately to .0001", then measure the expansion line, below the expansion line and .200" up from the case head.
The answer will be within all of these measurements.
Most likely, it will be the expansion line not being sized enough and it causes sticky extraction.
Cheers.
Start measuring your new brass, fired brass and sized brass. Next, get yourself a Mitutoyo 0-1" Micrometer that reads accurately to .0001", then measure the expansion line, below the expansion line and .200" up from the case head.
The answer will be within all of these measurements.
Most likely, it will be the expansion line not being sized enough and it causes sticky extraction.
Cheers.
Marky_mark
Well-Known Member
this
A simple test is to cover one of the cases that were already fired with a sharpie. Put the case back in the chamber close the bolt, remove the case and see where it is rubbing.
More details would help. Is the loaded once fired case easy to chamber? Is the primer flattened? Is the bolt handle difficult to pull upwards? Did it have a hard click at end of stroke? When pulling the bolt rearward is it difficult? You said it is hard to eject. Which is not the same as extracting the case from the chamber.
More details would help. Is the loaded once fired case easy to chamber? Is the primer flattened? Is the bolt handle difficult to pull upwards? Did it have a hard click at end of stroke? When pulling the bolt rearward is it difficult? You said it is hard to eject. Which is not the same as extracting the case from the chamber.
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Jeffrey Van Zandt
Well-Known Member
yes bump the shoulder 2-3 tho
lancetkenyon
Well-Known Member
When doing your load development, where was the last charge you were not getting pressure with the combo?
You also might want to check for a carbon ring in the chamber if you have a borescope.
Many here keep saying increase the bump to the shoulder which will also deal with body taper.
He can try it and report back.
I think we need more details. He said the case was FL sized but to what extent who knows. I suppose he could cam the press against the die. Or even grind off some of the shell holder or in the extreme, grind off some of the FL die. There is the possibility any amount of sizing will do nothing.
IMO Investigating the cause is the answer. There are chambers and cartridge cases that have issues and sizing attempts do nothing. 6.5 PRC with its clickers is one example.
I had a bolt lift and extraction issue which I tried desperately to resolve back in 2008. This is when the first 338 RCMs hit the market. Used a SAMMI spec reamer, tried three sets of dies and still had issues. I even went so far as to grind some of the bottom of one FL die to try and solve it. I went even further and cut off the top and bottom of the same RCBS die to make a small base sizing die. None of the sizing attempts worked. Turns out this cartridge, which is the parent to the 6.5 PRC, had the same clicker issue that is now common knowledge. Solution? Increase the diameter of the chamber near the case head by sanding. Now that folks know it, reamer specs can be altered for additional clearance, thanks to the efforts by Alex Wheeler.
A chamber that has an anomaly somewhere along the side will cause the case to expand to conform to that low spot. The resultant difficult effort to extract it from the chamber will rub off the high spot on the brass. This is easy to spot as there will be a shiny area on the case body. Stuff like this does happen. I know it happened to me.
I await the OP's new attempts and resultant information.
He can try it and report back.
I think we need more details. He said the case was FL sized but to what extent who knows. I suppose he could cam the press against the die. Or even grind off some of the shell holder or in the extreme, grind off some of the FL die. There is the possibility any amount of sizing will do nothing.
IMO Investigating the cause is the answer. There are chambers and cartridge cases that have issues and sizing attempts do nothing. 6.5 PRC with its clickers is one example.
I had a bolt lift and extraction issue which I tried desperately to resolve back in 2008. This is when the first 338 RCMs hit the market. Used a SAMMI spec reamer, tried three sets of dies and still had issues. I even went so far as to grind some of the bottom of one FL die to try and solve it. I went even further and cut off the top and bottom of the same RCBS die to make a small base sizing die. None of the sizing attempts worked. Turns out this cartridge, which is the parent to the 6.5 PRC, had the same clicker issue that is now common knowledge. Solution? Increase the diameter of the chamber near the case head by sanding. Now that folks know it, reamer specs can be altered for additional clearance, thanks to the efforts by Alex Wheeler.
A chamber that has an anomaly somewhere along the side will cause the case to expand to conform to that low spot. The resultant difficult effort to extract it from the chamber will rub off the high spot on the brass. This is easy to spot as there will be a shiny area on the case body. Stuff like this does happen. I know it happened to me.
I await the OP's new attempts and resultant information.
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cowboy
Well-Known Member
Another thing you can try - another resizing die. I've had 2 sets of dies over the years that I've sent back to manufacturer with 3 fired pieces of brass and they sent back a new die each time.
My guess is you probably got the inherent 6.5 clicker situation if it's not your die.
My guess is you probably got the inherent 6.5 clicker situation if it's not your die.
