7mm Rem Mag general COAL question

[UCO___]

Finally getting the numbers on my rifle and getting ready to start making my OCW loads. Using an ELD-X 162gr bullet and a once fired modified case, I am getting a MAX OAL of 3.5875" and a magazine MAX length of 3.5". The spec calls for 3.290". That will be a HUGE jump to the lands. Should I start just shy of 3.500"? That is going to have a negative impact of advertised velocities if I understand the relationship to seating depth vs pressure vs velocity.

Suggestions and Thanks in advance.

 

[Aletheia]

Load to the length that will feed from your magazine, and start testing. Or decide you have a single shot and load to the chamber length. I don't see any other choices. Some experimenting with loads may well find one that works well. Why are you so emotionally attached to the ELD-X?

 

[UCO___]

Want a single load for target, deer and elk. Plus I have 500 of them. Also have a few hundred of the 150 ELD-X destined for my 7mm-08 and/or 280 Rem.

 

[Woolecox]

I am getting a MAX OAL of 3.5875" and a magazine MAX length of 3.5".

I am guessing that this is the OAL that the bullet touches the lands? If you don't get acceptable results seating to an OAL that functions in the magazine, I would suggest getting a new stock with a longer magazine. For example, a 7mm Rem Mag uses the same detachable magazine that the 300 Win Mag uses. The 7mm cartridge is shorter and their will be no issue reaching the lands from there.

My 7mm shoots Berger VLD's better than anything, seated .003" off the lands.

 

[Varminterror]

COAL should be the shorter of:

1) Kiss length - desired jump
2) Mag box tolerance for reliable feeding

The second class applies for your rifle.

 

[climbnjump]

COAL should be the shorter of:

1) Kiss length - desired jump
2) Mag box tolerance for reliable feeding

The second class applies for your rifle.

And if you can't get good accuracy with the ELD-X's with choice number 2, then you might simply try another bullet. Some rifles are particular about what they like.

I have a Ruger RPR in .243 Win that loves the 108gr ELD-Ms but absolutely hates the 103gr ELD-Xs. I keep trying to find a load that works with the 103gr ELD-X bullets (as long as there are still some in the box), but I won't shoot any unless I have the range to myself because the groups so far are too embarrassing... But that's one rifle and I know folks who love the ELD-Xs in their rifles.

 

[UCO___]

Thanks for all the feedback. My biggest surprise was the delta from published OAL to my chambers max OAL. Am I correct is saying that as the OAL grows, the pressure/velocities are going to go down?

 

[climbnjump]

Am I correct is saying that as the OAL grows, the pressure/velocities are going to go down?

In general, yes. However if your magazine max is 3.50 and published OAL is 3.29, then you aren't going to lose that much - probably on the order of 50-100 FPS depending on the powder and charge weight you are going to use.

Now, if you decide to chase the lands and load beyond magazine length for single shot use, then the difference would be greater.