I am shooting a CZ 550 HS Precision 22-250. I have been working with 55 and 60 grn bullets and Varget, H380 and Superperformance powders.
I loaded the max load of 41 grns of H380 under a 55 grn V-Max bullet and chronoed it in my 20 yard basement range. I got pretty close to the published 3,713 fps velocity. However, I got no signs of pressure. Primer is not flattened. No cratering on the firing pin impact. No leakage around the primer and pocket. Head stamp looks as good as new. Primer pocket has not loosened. No evidence of case separation. The case has not stretched. Bolt opens easily and extraction is a breeze.
So, I took the liberty of increasing the charge weight one half of a grn. No signs of pressure. I did this up to 44 grns of H380 and used the same Hornady case. Definitely a compressed load. Pretty impressive velocities too. Given my short range setting I have no clue about accuracy but I am testing that this weekend. Despite being 3 full grns in excess of max, still no signs of excess pressure.
If I am not getting any signs of excess pressure, can I safely load this round or am I missing something? Are max loads published by the bullet/powder folks with a safety factor in mind to keep the lawyers away?
By the way, I did shoot the factory Hornady Superperformance 22-250 50 grn. rounds and they chronoed around 3,850 fps.
I loaded the max load of 41 grns of H380 under a 55 grn V-Max bullet and chronoed it in my 20 yard basement range. I got pretty close to the published 3,713 fps velocity. However, I got no signs of pressure. Primer is not flattened. No cratering on the firing pin impact. No leakage around the primer and pocket. Head stamp looks as good as new. Primer pocket has not loosened. No evidence of case separation. The case has not stretched. Bolt opens easily and extraction is a breeze.
So, I took the liberty of increasing the charge weight one half of a grn. No signs of pressure. I did this up to 44 grns of H380 and used the same Hornady case. Definitely a compressed load. Pretty impressive velocities too. Given my short range setting I have no clue about accuracy but I am testing that this weekend. Despite being 3 full grns in excess of max, still no signs of excess pressure.
If I am not getting any signs of excess pressure, can I safely load this round or am I missing something? Are max loads published by the bullet/powder folks with a safety factor in mind to keep the lawyers away?
By the way, I did shoot the factory Hornady Superperformance 22-250 50 grn. rounds and they chronoed around 3,850 fps.