I'm just starting load development for my Bergara B-14 HMR. I use a Hornady OAL gauge and run it in 10 times I throw out the obvious bad ones and the high and the low and get an average of 2.261 off the ogive. The OAL with the ogive on the lands is 2.8645 which is .039 (lets just say it's an honest .040) over the listed OAL of 2.825. I don't see anyone going much more than 2.810 OAL and .020 off the lands would be 2.844 OAL and I'd like to be at .015 or 2.849-2.850 but that will never fit in my mag. Is the solution to just shoot single shots and manually load each round. That wouldn't bother me a bit if its the only way to do it. But, if it's not going to shoot any better, then why would I bother.

Yes, you single feed rounds longer than magazine length which is usually approximately SAAMI spec length.  There are detachable mags that exceed SAAMI length...  SAAMI max COAL for 308 is 2.810" but my Bergara B-14 HMR uses AICS mags from Magpul that I measured at ~2.875".  So my mag length loads for that rifle are ~2.87".  My 180 grain load for that rifle is 3.00" so it is single feed only.

You might consider measuring the mag in your HMR - it's probably longer that SAAMI spec although I don't know if it will fit the loads you are considering.

Most box magazines in "production" rifles are ~SAAMI length.  Custom rifles can have pretty much any mag length you like.

Buy a different mag, like an AI, that gives you more room.

Some bullets are jump tolerant, some aren't. Moving it closer to the lands may improve accuracy.

130 hybrid berger bullets don't really seem to care.  142 smk seems to like .030 in my rifle.  I load 140 berger match hybrids to .020 for best results in my rifle (COAL 2.885").

NRA long range matches are all fired slow fire. People load one round at a time. Some rifles with long throats simply cannot feed appropriately sized rounds from a mag.

As has been mentioned, certain bullet designs are very jump tolerant.

Thanks for the great responses. I setup a couple of dummy rounds after I posted and they will not fit in my current mag but that's o.k. with me. I think I will try to start at .015 off the lands and then work my way backwards to the average length of the Norma Match that I used to break it in, (haven't checked that yet). It is shooting 1/2 MOA and less off the bench at 100 yards which I consider to be excellent for an off the shelf rifle.

My goal is to shoot 140g Barnes "Barn Burners" out of Lapua brass with either H4350 or RL-17 better than what I already have which is setting the bar pretty high. Once I have some fire formed Lapua brass I'll make a new test case for use with the OAL gauge.

The rifle is off the shelf and I will be truing the action and bolt face at some point, all depends on how much snow we get and how bored I am.. LOL..
Thanks again,
Steve