Bolt sticks, carbon on outside of brass

Only time I've had stiff bolt closures on a savage action when the load itself I knew was within normal peak pressures was when there was a mismatch of some sort between the bolt and receiver lugs. Did you see any signs of abnormal wear on either when you had the action apart?
 
I think what I am learning is that necking down military brass is false economy.
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Just necking it down and using it as is other wise and NOT working up loads specific to the GI brass is the problem.

Up to you to figure out if the lower cost of GI brass is worth the work it takes to use it safely.

Thinking you can just neck it down and use data developed with other cases is what's false.
 
I looked at that load in QL--even if your losing quite a bit of case H2O capacity I still don't see you reaching anything close to a dangerous over-pressure, unless maybe you're really jamming that bullet deep in the case somehow. My guess is that you have a mechanical configuration error in the build somehow. As a starting point--I would start at a lower load, perhaps backing your COL off to a point where you can fire something without a stiff bolt resulting. At a bare minimum I would recommend getting a case expansion measurement at unfired brass (preferably new unsized) and then compare it to a fired case. Please post a picture of your fired brass.
 
First, I set headspace on a Savage with a GO gage plus a piece of clear tape on the end. That gave it min plus a bit, but not over NO GO.

Then I remove the gage and torqued with the wheeler wrench set and barrel vice. It worked pretty good for under $100. Torque was moderate.

Then to properly assess pressure, I find I have to size to where the bolt handle drops freely with brass FL sized. Maybe even -0.001” beyond that….depends on the brass condition….is it all annealed, same lot or something making it FL Size the same? Otherwise, FL Sizing can be all over the map.

Then, annealing while not mandatory is a good idea for changing things like neck diameter.

Regardless, you have shot some…..can you push a bullet back into the case with finger pressure? If not, there is issue #1. Basically, when the bullet releases, it should leave the OD to where a bullet will slide in the ID with finger pressure. If not, then you probably need to turn or ream necks. This is common going dow a size or 2.

Last, try a pressure ladder. Start with a load which a book, QL or something tells you that you are 45000 to 50000 psi and increment up ~0.4gr increments until you get bolt lift. Then your last load before bolt lift is absolute max.
 
Update #2

Update #2 with some recap and conclusions:

Started with military (PPU) 7.62x51mm brass necked down to 6.5mm.
Powder is Winch StaBALL 6.5. Bullet is Hornady ELD-M 140gr.
hodgdonreloading.com does not have loads for this exact bullet and powder combo for .260, but they do have loads for the 147gr ELD-M, with 43.6gr the max.
They do have loads for this combo for 6.5 Creedmoor, which is not the same but is similar to .260, with 44.0gr max.
So y'all calling me a bomb-maker??

This is why I assumed 41.0gr was a safe starting point. With the recycled brass, with this load, the bolt stuck tight.
So I loaded up some with the new Norma brass. Five each, starting at 41gr, max 44gr.
41gr, no pressure issues.
42gr, no pressure issues.
43gr, no pressure issues.
44gr, STILL no pressure issues. So I think this is where I stay.

Conclusions: Yes, you can take Pawpaw's old deer gun and turn it into a target rifle. Barrel nut wrench, headspace gauges (NOGO and GO, from the same manufacturer) and a bench vise are absolute minimum. I will be adding an action wrench and a torque wrench.
You can NOT neck down military brass for this kind of project.
 
The bombmaker stuff is all in good fun, I’d guess…..maybe not.

Did you ever figure out why the once fired wouldn’t neck down? I.e. did you see if a bullet slides in/out of a fired case?
 
probably need to turn or ream necks. This is common going down a size or 2.
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My chronic cheapbastardism is always in conflict with my laziness. I think I will just abandon the notion of recycling brass.
 
Glad you found a solution that at least the bolt sticking issue appears to have gone away. I personally have a nagging curiosity that always wants to know with as reasonably as close to certainty as I can get why something malfunctioned--because I will surely experience the same thing again if I don't. That's just how my luck goes.;)
 
Did you trim brass after necking down? PPU is not necessarily military. Even it is, it usually doesn't turn a min to above max. I'm leaning towards something else.

I did my fair share of brass conversions. One time or two I got stuck brass. Never caused by over pressure though.

-TL

Sent from my SM-N960U using Tapatalk
 
As asked, will a new bullet slide into a fired case, one of your original sticky ones that made the bolt hard to open?
 
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Generally, that is a sign your necks are not opening enough. Unless you can measure neck wall thickness, generally you need to be able to reseat a bullet by hand to be safe.
 
Or the neck wall too thick that it pinches the bullet in place and hence caused high pressure. May need to be turned down a bit.

-TL

Sent from my SM-N960U using Tapatalk
 
yeah the "bomb maker" phrase was just a jab, no intention of offending. but the load data from hodgdonreloading.com.

Reloading Data Center
260 Remington
Your search returned 1 loads items
Twist: 1:9.000"|Barrel Length: 24.000"|Trim Length: 2.025"
Bullet: 140 GR. NOS PART|Diameter: 0.264"
Case: Remington|Primer: Remington 9 1/2, Large Rifle
Manufacturer, Powder, C.O.L., Starting Grains, Starting Velocity (ft/s), Starting Pressure, Maximum Grains, Maximum Velocity (ft/s), Maximum Pressure
Winchester, StaBALL 6.5, 2.780", 36.9, 2,441, 47,700 PSI, 41.1, 2,689, 59,700 PSI

that's a dirrect cut and paste. it's not formated correctly but they surely do have load data for winchester staybil 6.5 and the 140gr bullet, in 260rem.
admittedly it's not hornady eld-m it's nosler partition, which might be a harder allow with a thicker jacket and thus build more pressure.
but it would be a very good "starting" place.

at any rate; it looks like you have it all worked out now. cheers.
 
Is your barrel cut to match grade by any chance? That can result in changing the chamber delta by as much as .002", in which case your loads may need to be adjusted downward; I usually factor in at least a 10% reduction compared to typical SAAMI-based published data when generating new data for match barrels.
 
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