Thread: 7mm mag and 180gr ELDM

Originally Posted by ChrisW

Yea all that is getting a bit too much hassle for me. Im not really keen to get into any sort of wildcat, or another cartridge with expensive brass or unique loading requirements.

Your plan seems very good. With the advantages you are giving the RM with the long magazine and barrel, it should be cool.

Hopefully I don't get kicked off the internet for saying they gains on other cases suggested are pretty trivial and not worry the extra hassle.

I'm soon to try the same projectile in a much smaller rifle.

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@Tussock You understand my logic

What will you be running them in?

Originally Posted by ChrisW

@Tussock You understand my logic

What will you be running them in?

A Ruger M77 stainless laminate I paid the princely sum of $600 for. It shoots well with factory ammo so it has earned some reloads.

I have not checked if I can actually run 180s with whatever twist rate it has.

Just checked the mag length and I will have a case full of projectile. No dramas as I don't need a lot of velocity.

I think i might try to use one of the .338 mags so there are no limits on COAL.
Was checking this morning and I think it'll hold a 7mm rem mag case with some minor inwards bending of the feed lips. Its real close already, the belted rim is captured, the front of the lips would just need to be bent inwards a mm or so both sides.

3000fps should be achievable out of a 30" 7mm rem mag and slower powder, will chronograph mine when I have time to shoot it again but I would guess it's going 2800-2900fps out of my 24" with a mild load of AR2217.
ADI 2225 is listed as max of 2914 in the manual (24" barrel, 3.29coal)
Stability calculations are pretty similar to a 162gr ELD and seems to go fine out of my 1in9.5

@Cooper thanks for the info. I picked up a couple jars of ar2225 today.
Rifles now been sent off to the smith

I got the rifle back yesterday and worked out my lengths etc.
COAL is 91.25mm, which is just back from the lands. Perfect.
I loaded a little ladder test to test for pressure - got up to 72gr ar2225 and its still not compressed. (wont be able to shoot this weekend due to Sika show)
ill load up some pics later

I got out yesterday morning to break in the new barrel, and while I was at it try to get some meaningful data out of the process.

I loaded up 14 rounds using AR2225 with the 180ELDX seated way out. Starting at 66gr and increasing in .5gr increments up to 72.5gr.
The intention being to try to find my max powder charge/checking for pressure signs, while chronographing each load & looking to identify any flat spots in velocity, and also get a baseline of what sort of velocities we are working with relative to powder charge..all while undertaking the mundane barrel break in process.

Anyway, these are my results. Velocities acquired with Magnetospeed v3 chrono.

66gr - 2788fps - fist round ever down the barrel
66.5gr - 2842fps - second round ever down the barrel after a quick clean, etc etc
67gr - 2857fps
67.5gr - 2820fps
68gr - miss (chrono was not plugged in)
68.5gr - 2879fps
69gr - 2936fps
69.5gr - 2943fps
70gr - 2957fps
70.5gr - 2997fps
71gr - 3036fps
7.5gr - 3046fps
72gr - 3093fps
72.5gr - 3092fps

Pressure looked fine throughout and there are some decent flat spots in velocity to focus my load development around. Will focus initial efforts around 69-70gr, and 72-73gr.
Velocities are well up there with what I was hoping for.

Looking forward to getting a real load worked up and seeing what it can do.

Originally Posted by ChrisW

I got out yesterday morning to break in the new barrel, and while I was at it try to get some meaningful data out of the process.

I loaded up 14 rounds using AR2225 with the 180ELDX seated way out. Starting at 66gr and increasing in .5gr increments up to 72.5gr.
The intention being to try to find my max powder charge/checking for pressure signs, while chronographing each load & looking to identify any flat spots in velocity, and also get a baseline of what sort of velocities we are working with relative to powder charge..all while undertaking the mundane barrel break in process.

Anyway, these are my results. Velocities acquired with Magnetospeed v3 chrono.

66gr - 2788fps - fist round ever down the barrel
66.5gr - 2842fps - second round ever down the barrel after a quick clean, etc etc
67gr - 2857fps
67.5gr - 2820fps
68gr - miss (chrono was not plugged in)
68.5gr - 2879fps
69gr - 2936fps
69.5gr - 2943fps
70gr - 2957fps
70.5gr - 2997fps
71gr - 3036fps
7.5gr - 3046fps
72gr - 3093fps
72.5gr - 3092fps

Pressure looked fine throughout and there are some decent flat spots in velocity to focus my load development around. Will focus initial efforts around 69-70gr, and 72-73gr.
Velocities are well up there with what I was hoping for.

Looking forward to getting a real load worked up and seeing what it can do.

Nice one! How did all rounds look on target? Assuming you fired all at the same POI was there a gradual rise in POI as powder charge increased and did the POI level out at the velocity flat spots etc?

Originally Posted by stagstalker

Nice one! How did all rounds look on target? Assuming you fired all at the same POI was there a gradual rise in POI as powder charge increased and did the POI level out at the velocity flat spots etc?

Na I didnt, I shot the odd few at the same target (69 and 69.5 went in the same hole) but I was cleaning in between shots and also adjusting scope to sight it in at the same time so there was not much useful info as far as accuracy goes.
Next time ill be shooting for groups

7mm blaser 3060 1 8 twist have to measure coal 26" barrel currently going down to 22" my guess would be 2920ish will post numbers in a week or so

68gns rl 26 or 69 will have to check up on that iv only just finished my first 50 rounds done by the gunsmith

Originally Posted by Kelton

7mm blaser 3060 1 8 twist have to measure coal 26" barrel currently going down to 22" my guess would be 2920ish will post numbers in a week or so