10Turkeys Report post Posted October 8 What kind of powder were you using and how many grains, and how close to the lands, and what bullet? Share this post Link to post Share on other sites
bowhunter-tw Report post Posted October 8 44 minutes ago, 10Turkeys said: What kind of powder were you using and how many grains, and how close to the lands, and what bullet? 260rem, IMR4350, 41.5gr, 143gr eldx, I might have been into the lands. I just re checked and I only had a .005” jump on the few that were still loaded. Theres a chance that one was seated long Share this post Link to post Share on other sites
L Cazador Report post Posted October 8 The best way to know if you have a max load situation is to monitor the head expansion. Head expansion over .0008" is an indication of an over maximum load. It is not good for your brass or your rifle. Measure just above the extractor slot on the case head and use a micrometer or a caliper with a .0001" resolution. You should make a note of the case head dimension at the start of your load development in case you have a situation like this where you need to know what case head expansion is. I'm sure that case with the primer leak has an over expanded head. You may want to try reducing that load a bit and backing off on the seating depth as well. By the way did you wet tumble those cases? Share this post Link to post Share on other sites
bowhunter-tw Report post Posted October 8 10 minutes ago, L Cazador said: The best way to know if you have a max load situation is to monitor the head expansion. Head expansion over .0008" is an indication of an over maximum load. It is not good for your brass or your rifle. Measure just above the extractor slot on the case head and use a micrometer or a caliper with a .0001" resolution. You should make a note of the case head dimension at the start of your load development in case you have a situation like this where you need to know what case head expansion is. I'm sure that case with the primer leak has an over expanded head. You may want to try reducing that load a bit and backing off on the seating depth as well. By the way did you wet tumble those cases? Do you mean 8 thou? (.008”) 8 tenths is so small my calipers probably wont measure that accurately. I did not wet tumble. Max load on this is 42.9 C my COL keeps this load from being compressed Share this post Link to post Share on other sites
L Cazador Report post Posted October 8 1 minute ago, bowhunter-tw said: Do you mean 8 thou? (.008”) 8 tenths is so small my calipers probably wont measure that accurately. I did not wet tumble. Max load on this is 42.9 C my COL keeps this load from being compressed Not 8 thou, 8 ten thousands. Thats less than one thousandths of an inch. When you have hit one thousandths (.001") of an inch you have over expanded the case head and your resizing die may not bring the case back into a proper dimension. And if you caliper doesn't have that resolution you may want to think about investing in a caliper that does. Mitutoyo, Starrett, or Fowler can be found with .0001" resolution. Share this post Link to post Share on other sites
bowhunter-tw Report post Posted October 8 5 minutes ago, L Cazador said: Not 8 thou, 8 ten thousands. Thats less than one thousandths of an inch. When you have hit one thousandths (.001") of an inch you have over expanded the case head and your resizing die may not bring the case back into a proper dimension. And if you caliper doesn't have that resolution you may want to think about investing in a caliper that does. Mitutoyo, Starrett, or Fowler can be found with .0001" resolution. Good to know, wouldnt have figured it was that sensitive. I probably should get some nicer calipers. Will check when im home from work. I appreciate the info Share this post Link to post Share on other sites
L Cazador Report post Posted October 8 4 hours ago, bowhunter-tw said: Do you mean 8 thou? (.008”) 8 tenths is so small my calipers probably wont measure that accurately. I did not wet tumble. Max load on this is 42.9 C my COL keeps this load from being compressed I saw this happen to a friend last year. When we checked the head diameter expansion it was over 1 1/2 thousands expanded. That load was 3 grains under max. Brass capacity, bore, and powder lot all play a big role. I recommend you do a powder ladder first and find your the maximum for that brass, bullet, primer, and rifle. Proceed in increments of .3 tenths powder weight until you hit .0005" head expansion. That will be the maximum load for that combo of components. Share this post Link to post Share on other sites
Mike S Report post Posted October 8 4 hours ago, L Cazador said: Not 8 thou, 8 ten thousands. Thats less than one thousandths of an inch. When you have hit one thousandths (.001") of an inch you have over expanded the case head and your resizing die may not bring the case back into a proper dimension. And if you caliper doesn't have that resolution you may want to think about investing in a caliper that does. Mitutoyo, Starrett, or Fowler can be found with .0001" resolution. I've seen digital calipers with 4 decimal place readouts, but they only are good for 5 tenths resolution. If you want to measure head expansion I think you should be looking at a micrometer. Share this post Link to post Share on other sites
L Cazador Report post Posted October 9 18 hours ago, Mike S said: I've seen digital calipers with 4 decimal place readouts, but they only are good for 5 tenths resolution. If you want to measure head expansion I think you should be looking at a micrometer. Mike I agree with you there are some instruments out there that are not going to do the job. While I certainly would recommend a blade micrometer for the job of measuring head expansion it may not be an option for someone on a budget. I'd rather recommend investing in a high quality caliper like the Mitutoyo IP67 which has a resolution of .0001" and accurately does the job. I use a blade micrometer that measures to .00001" but my Mitutoyo IP67 does the job equally well. Both of the units in the picture are in the $200 range. 1 Share this post Link to post Share on other sites
Mike S Report post Posted October 9 That does look like a quality caliper, but I still think the caliper by design design is unsuited for .0001" resolution and all of those I've seen show a digital readout of 0 or 5 for the 4th decimal. Are you saying yours shows .0001, .0002 etc.? Id hate for a member to buy something that didn't meet his expectations is all. Yours looks a lot like this one. Share this post Link to post Share on other sites
L Cazador Report post Posted October 9 24 minutes ago, Mike S said: That does look like a quality caliper, but I still think the caliper by design design is unsuited for .0001" resolution and all of those I've seen show a digital readout of 0 or 5 for the 4th decimal. Are you saying yours shows .0001, .0002 etc.? Id hate for a member to buy something that didn't meet his expectations is all. Yours looks a lot like this one. Don't know if that's the same. There are a lot of Chinese copies buy only Japanese made ones. That looks like it's accurate to .0005". So if you're measuring a head diameter it could be off enough to not detect a .0005" head expansion. When measuring something to this dimension it's important everything is clean including the measuring blades. Also another thing that's critical in using a caliper . since it doesn't have a ratchet you should close the caliper gently till it stops to avoid crushing the dimension. Check country of origin on the ad if it doesn't state that don't buy it. I check my Mitutoyo caliper regularly and it's always dead nuts on! And yes it reads to .0001" Share this post Link to post Share on other sites
Mike S Report post Posted October 9 Not seeing any of that resolution in current catalog, so potential buyers should do their homework. https://www.mitutoyo.com/webfoo/wp-content/uploads/US-1005_Mitutoyo_Catalog.pdf Share this post Link to post Share on other sites
