.224 77 g HPBT Custom Competition with Cannelure

[Payroll1968]

I trim my brass to 1.750. I found that seating these bullets to mid cannelure brings the OAL to 2.250. The load data published for this bullet without cannelure specify an OAL of 2.260. What is the safe range for a load using W748 considering the OAL will be 2.250? Are the published loads acceptable? I'm not sure what effect the reduced case length would have on pressures if any.

 

[jimbires]

you will be fine . 0.010 difference in length is not going to change your pressure enough to notice . you can also seat this bullet to the 2.260 length . you do not have to seat a bullet to it's cannelure , unless you are crimping .

 

[1Shot]

It you are shooting an AR your COAL of 2.250 will fit into the magazine and work OK. That is the COAL I load EVERYTHING for the AR. I have not used 748 with 77 gr bullets but from the data from a number of manuals I would do a work up from 22.5 up to 23.3 grs. watching for pressure signs and best accuracy. There are a lot of variables to deal with just to say what specific load to use. Cases have different capacity and primers make a big difference and by the way mag primers are suggested to be used with 748.