FWIW, max charge for the 180 gr as he lists per hodgdon is 46.5, with a 2.8 COL.
In my speer book, it runs 41 to 45 grs, and specifies a magnum primer.
In my Hornady book, it does not list 748 for 180 gr bullets. Given that they are Hornady bullets, mebbe that tells you something. In reality, I doubt it- but ya never know. You can call them (Hornady) for load data- they will find it if they have it. I've called them before on what I thought was simple stuff- and they don't have it, so thats a mixed bag.
The cannelure length for loading on that bullet is 2.740... If you are using load data for 2.800, and seating the bullet to 2.740, you are increasing pressure there too, as I noted may be possible.
Now, for my advice- which is free, and worth exactly that :
Please, start over.
Get a load manual, follow recipes exactly - component, powder, primer, even brass if you can at first.
It sounds like you've mixed a few pieces of the recipe up on your first time out of the gate- part of it from here, part of it from there, unknown components.... I'm glad you are OK, but you are in some dangerous turf right there.
Stop.
Grab all your tools.
Sort all of your components.
Verify every part of your recipe.
Then load - from the bottom up.
Before you charge a case- make 5 dummy rounds using fully prepped brass, and seat the bullet to the length you want them at.
Measure them. Length, width at three points on the case, neck diameter.
Chamber the rounds. One at a time. Look for marks- extractor on case, case on chamber, rifling on bullet, anything untoward whatsoever.
If you find marks, find out what they are, and how they are getting on your piece...
We can certainly help you- but as everyone has noted, we need to know exactly what you have, what you've done, and what you haven't.
What manual are you using ? What rifle ? What brands/headstamps of brass ? Is it cold where you are at ? Is it hot ?
Reloading is a lot of finding out what you like and are comfortable with, and what your rifle likes and are comfortable with. Its a process, and there is a lot to learn. Like a fine lady, they all have tells. Unfortunately, you just jammed to third base on her doorstep. Didn't work out that well, eh ?
S'ok- many have done it. Get 'er some flowers ( Clean the gun and all mechanisms. Look for points of undue wear and tear- and allow yourself extra time for chamber inspection, and internal surface cleaning) , and lets smooth out the wrinkles, shall we ?
