Ok now on my 22-243 the load I developed last summer has been showing pressure signs, when I chambered it the bolt went in fine but closing it was hard or stiff. I took the brass resized it and measured how far the shoulder got pushed back .002-.003 but it’s still closing hard? What’s causing this? I just cleaned the rifle too using Montana cooper cream and accelerator and patch out. The barrel is clean.
Bolt closing hard on sized brass?
- Thread starter zr600
- Start date
Pressure signs you say... What kind of signs, exactly? Exceed the elastic limit of the brass and it might be case diameter you are fighting not shoulder length. Often not correctable with a tight custom chamber and off the shelf sizing dies.
Sometimes a different brand of brass can make a difference. Have dealt with that a couple times.
- DAA
Sometimes a different brand of brass can make a difference. Have dealt with that a couple times.
- DAA
204 AR
Well-known member
There's only so many dimensions to a piece of brass, so if you're sure the shoulder is pushed back enough, and if the over all length of the brass is short enough, then I'd say either the case diameter is swelled a bit like Dave said or even the case neck is too thick. I've fought both those with AR's in wildcat chambers with brass necked down from another caliber.
Try some new brass. Don't even mess with bullets until you figure out the brass. Then seat a bullet to a depth known to be short of the lands in a case that chambered easily without a bullet. One question, easy to check. On your fired brass, before sizing, does a bullet slide easily into the neck? If not your necks are probably too thick.
Try some new brass. Don't even mess with bullets until you figure out the brass. Then seat a bullet to a depth known to be short of the lands in a case that chambered easily without a bullet. One question, easy to check. On your fired brass, before sizing, does a bullet slide easily into the neck? If not your necks are probably too thick.
A bullet does slid in fairly easy they don’t just fall in but they go in very easy. I’m going to trim to length resize bump maybe a little further bumping back .002 for now but going to go to .003 I think. Going to clean the bolt face really good and see what happens. I have shot this gun plenty with this same load wasnt getting pressure sign when I developed it or ever before. The pressure sign I was getting was heavy bolt lift the primer and brass still looked good no ejector marks.
I am decapping with a universal decapping die before hand. Ok I think it might just be case sweeling. I measured some and measured new ones at the head and they are .002-.003 bigger then new pieces which they seem to feed and eject just fine thanks for the help. This is Winchester brass if that matters and I’m using a Redding 243 fl bushing die. What would be the best thing to do fire a new piece of brass and have a die made to my chamber so it would squeeze it down far enough?
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Originally Posted By: zr600What would be the best thing to do fire a new piece of brass and have a die made to my chamber so it would squeeze it down far enough?
No the best thing would be to stop loading so hot you are swelling case heads as much as .003. That is a LOT. Only way that happens is exceeding the elastic limit of the brass which requires pressures way above normal.
Stop using that load.
Then get Lapua brass - why anyone would not use it on a rifle like that, is beyond my ability to comprehend. Seriously, custom barrel work is so expensive, then to not use the best brass available, makes no sense. For that matter, choosing brass at this point is doing it backwards anyway. Always start a custom project with the brass you are going to use already in hand (I always have enough to wear out the not yet chambered barrel). Then have your chamber reamed to dimensions that match YOUR brass. Too late for any of this now though.
But get Lapua, then don't use that load in it and don't ruin it. With .003 head swelling, those cases ARE ruined, too, you can just throw them away. No point in trying to size them. You won't be able to but they are damaged goods even if you could. Toss 'em.
- DAA
No the best thing would be to stop loading so hot you are swelling case heads as much as .003. That is a LOT. Only way that happens is exceeding the elastic limit of the brass which requires pressures way above normal.
Stop using that load.
Then get Lapua brass - why anyone would not use it on a rifle like that, is beyond my ability to comprehend. Seriously, custom barrel work is so expensive, then to not use the best brass available, makes no sense. For that matter, choosing brass at this point is doing it backwards anyway. Always start a custom project with the brass you are going to use already in hand (I always have enough to wear out the not yet chambered barrel). Then have your chamber reamed to dimensions that match YOUR brass. Too late for any of this now though.
But get Lapua, then don't use that load in it and don't ruin it. With .003 head swelling, those cases ARE ruined, too, you can just throw them away. No point in trying to size them. You won't be able to but they are damaged goods even if you could. Toss 'em.
- DAA
My chamber is to small for Lapua brass I actually started with Lapua and with very low charges I was getting hard bolt lift. Like I was only getting 3000 FPS and everybody running this caliper and bullet combo is getting 400-600 FPS more then I was with the loads I started with in the Lapua brass. I switched to Winchester brass and the pressure went away. Maybe I’ll rework a load up I did get a new lot of powder since i originally worked the load up. What would you recommend for working up with new lots of powder just back off a grain and work back up to what you were for FPS?
I don't think you are listening. At all.
If your solid case head has swelled .003, you are running sky high pressure. Sky high.
Same powder = same velocity = same pressure. Those are words to live by. Slightly faster lot, less of it to = same velocity, but still = same pressure. Slower lot, more of it to = same velocity, but still = same pressure. Not technically 100% precisely true, but as a general rule, it's a good one to live by.
Whatever FPS you are running with that load, you can't get there with the same powder without the same pressure. Can't get there from here.
Back off a helluva lot more than a grain. 10% would be more like it. Start working up while carefully measuring case head expansion. Personally, I don't like to see any case head expansion, period. But if I'm in a real hot rodding mood and I'm okay with short brass life, I'll tolerate .001 as long as it doesn't affect function. I wouldn't tolerate a load that causes .0015, for any reason. I'd run the fawk away from a load that causes .003. Hearing that it's a tight chamber, and still getting .003, I'd run fast and far from that load.
Just my take.
- DAA
If your solid case head has swelled .003, you are running sky high pressure. Sky high.
Same powder = same velocity = same pressure. Those are words to live by. Slightly faster lot, less of it to = same velocity, but still = same pressure. Slower lot, more of it to = same velocity, but still = same pressure. Not technically 100% precisely true, but as a general rule, it's a good one to live by.
Whatever FPS you are running with that load, you can't get there with the same powder without the same pressure. Can't get there from here.
Back off a helluva lot more than a grain. 10% would be more like it. Start working up while carefully measuring case head expansion. Personally, I don't like to see any case head expansion, period. But if I'm in a real hot rodding mood and I'm okay with short brass life, I'll tolerate .001 as long as it doesn't affect function. I wouldn't tolerate a load that causes .0015, for any reason. I'd run the fawk away from a load that causes .003. Hearing that it's a tight chamber, and still getting .003, I'd run fast and far from that load.
Just my take.
- DAA
Originally Posted By: zr600Ok I’ll back of and go back up and measure head expansion. If I’m shooting brand new brass will I see the head expansion I one firing if it’s hot? Or will it take a couple firings?
Head expansion should be measured on fresh cases. Fired brass has work hardened and will give a false indication as it will be less.
Greg
Head expansion should be measured on fresh cases. Fired brass has work hardened and will give a false indication as it will be less.
Greg