I went to the range and tried some 7x30 loads. I loaded 154 grain bullets with 31 grains of RL-15 and some with 33 grains of IMR-4064. Both loads resulted in sticking cases in my contender. The brass was a mix of Remington and PPU. I didn't expect sticking cases from loads below max. Is this common for the 7x30 waters.

P.S. The primers are also flattened a little. The rounded primer edges are nice and square.

I run Varget in mine and have shot with a max load without any extraction problems. I found a load that is about a grain under max that is pleasant to shoot and accurate. Primers get a bit squared off, but really I don't consider that an issue.

According to my Hornady 8th edition, the max charge of RL-15 and 4064 is 32.1 and 33.0 grains, respectively. You probably need to back off the charge weights.

I had interesting day at range with my 7x30 waters. Even with powder charges reduced the cases still stuck with most of the 154 grain bullets. I reduced charges of BL-C2, IMR-4064, and RL-15 to 4 grains below max. The only charge that didn't stick was 29 grains of IMR 4064. I give up on the 154 bullet.
The 140 grain nosler ballistic tip did well with BL-C2 all charges from 31 grains to max of 34 grains. None of the BL-C2 loads stuck even at max load. The only charge of RL-15 that didn't stick was 30 grains and that is below starting load in some of my information. The IMR 4064 stuck with lowest charge of 32 grains. I didnt try any other loads after that.
I'm surprised at the velocities I see posted around the web for the 7x30 waters. All charges I have tried anywhere near maximum cause the cases to stick and I have trouble opening my contender.

Any idea on what to look for to explain why I have pressure issues with low powder charges?

P.S. The primers are flattened too.

Who made the barrel and are you seating th he bullets into the lands without knowing it, especially on the longer 154gr. bullet?

The barrel is a TC factory Suoer 14". I bought the barrel used. The overall length is less than the max listed in hornady loading manual. But I will check to be sure bullet is not in lands. I seat the 140 and 154 the same. The overall cartridge length is same with both bullets.

Both of these bullets weigh 120 grains and are seated so they are .015" off the lands in my Waters barrel. If I were to load the one on the right to the same OAL as the one on the left I expect I'd see some pressure issues.

Flat primers can be caused by excess headspace also. Id look at size die adjustment as well.
....n with that many light loads, the stickiness may not be high pressure.
Easy open model frame?

I do not know how to check if this is easy open frame or not. I did verify my powder scale. I checked various bullet weights on scale. The frame is a old style contender frame.

I may have found my problem. I have been crimping the bullets. It has been light. I'm going to crimp one and leave one un-crimped and see what happens. I smoked and round last night and put it in barrel. It does not hit lands in barrel.

"Easy open" models started above serial #195,000. They also have the externally adjustable rotating switch on the hammer.
I do not crimp rifle rounds and there shouldnt be any advantage to doing so most likely.

The old style frame had the pivot pin for the break down lever at the front of the frame covered by the forend. The easy open frame has the pin almost midway on the frame.
If its pinned at the front its and old style frame, midways easy open.

I would start by not crimping loads also.

Why are you crimping the bullet? It is a single shot--

I finally made it to the range again. The crimping seems to have been problem. No cases stuck with RL-15 or BL-C2. I did have sticking with IMR-4064.
Thanks for your help.

Now time to work on accuracy load.

Very interesting how crimping can make that big of a difference.

Wonder how the military loads get away with it?

Easy open frame has a center pivot trigger guard.