Thread: clarification 7mmRm + ar2217 + hornady eldx 150g

Hey guys,

I have just made up several different loads forn my 7mm, and my 300 win mag.

I loaded up my 7mmRm first, as per the min and max powder amounts and loaded up 5 rounds of each going up .5g each lot of 5 rounds, after I made up 10x lots of 5 I went onto the 300winmag, 168g + 2217 again, although after loading the first few, I realised the casing was 85 -90% full before seating the projectile. After a quick bit of research, I realised that compressing the powder was normal but it made me think about the 7mmRm, and I knew the cashing were only 50% full, which meant no powder compression once seated.

So, I picked up a loaded round and shook it, I could hear the powder shaking around.... this is worrying me as I have made up 50 various rounds. Is this a problem? I stuck to the load data published by hornady, for the 150g eldx and the h1000 powder ( h1000 powder is equivalent to the ar2217 ).

Have I stuffed somthing up?

These are my first hand loads.....

Also is .5g a good amount to go up in weights by when developing a ladder load test? I also went to the maximum size - .20mm that the mag would allow for col.

Fire a few and find out.

.5gr increments is sensible

I would have thought your 7mm mag should be a lot more than 50% full with 2217. I use to use 71.5gr 2217 with a 162gr a-max. 300 win mag with a 168gr might need a faster powder than 2217.

If you are firing over a chronograph then 5 of each load at .5gr increments will waste a lot of rounds and give you a pretty sore shoulder.
With my 7mm mag I would load up 1 at each powder weight and fire over the chronograph. I would then start looking at the loads that gave the velocity I wanted and load 3 up at about 3 powder weights. Shoot those and go from there. Doing this I would usually get a 0.5-0.75 MOA load in about 20 rounds.

Originally Posted by stug

I would have thought your 7mm mag should be a lot more than 50% full with 2217. I use to use 71.5gr 2217 with a 162gr a-max. 300 win mag with a 168gr might need a faster powder than 2217.

How full was your 162g a-max? Mine was probably 1/2 to 2/3 full with the 150g eldx.

2217 was a recommendation to work for both rounds.

71 gn 2217 is >95% case capacity in 7mmRM. How much 2217 have you loaded in your 7mmRM Loads ??

61-67g of 2217,

Hornady shows that 61 -67g of h1000 which is an equivalent of 2217

Seems way too low for 150gn pills? For 162 AMAX like @stug says you’d expect to be running 71-72 gn 2217. So for 150gn rule of thumb says add 1gn powder for 10gns pill weight - so more like 72-73gn 2217 with a 150gn pill, but always work up from lower charge. I’d be starting at 69gn and working up, watching for pressure

Bugger messing round with loading up and testing that many rounds, just do a 10 shot ladder test and job done

I load 71 grs of AR 2217 with the 150 gr ELDX for 3071 fps COAL is 84.5 mm. These loads have a slight bit of space once the bullet is seated. You should always try and select a powder that will fill or near fill the case as this gives better ignition and burning which is desirable.

Hey guys
Just reading ur info about the 7mm Rem Mag
Hey im running 68 grains of 2217 , its doin 2700 muzzle velocity but is extremly accurate , question being should i be looking at trying to get this thing to be running faster or just leave it ? I do eventually want to shoot deer out to a K
Thoughts ????

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Sorry guys running the 162 A-max projies

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I have brought a buller puller and will pull these projecties and start at a higher amount of powder. So... a good range would be starting at around 68g of 2217, and go 69g, 70g, 70.5, 71g, 71.5g, 72g, 72.5g and 73g? Would 4x rounds of each be sufficient for a good group test ? or 3 or 5 ? With a bullet puller, Can I still use the projectile again ? or is it best not too? I will do some more of these developments next week when I am home so gettin all the information by then would be great.

Originally Posted by Larskramer

I have brought a buller puller and will pull these projecties and start at a higher amount of powder. So... a good range would be starting at around 68g of 2217, and go 69g, 70g, 70.5, 71g, 71.5g, 72g, 72.5g and 73g? Would 4x rounds of each be sufficient for a good group test ? or 3 or 5 ? With a bullet puller, Can I still use the projectile again ? or is it best not too? I will do some more of these developments next week when I am home so gettin all the information by then would be great.

I would not start that high. Its going to suck if you get to the range and find your start load is over pressure or close to, and you cant shoot any of the other 45rounds...

This is what I would do.
Load a ladder, one round of each, going up in .5gr increments from 64gr up to 72gr.
Start by shooting the 64gr cartridge and work your way up keeping an eye on pressure. Once you reach pressure signs you now know that your reloading efforts should be focused under that threshold.
Ideally you would also have a chrono, then during the initial pressure test you could look for flat spots in velocity and focus your loading efforts around those points.

If you must shoot some groups or test "accuracy" on your first outing/test, then I would highly suggest only taking multiples of lower powder charges. eg take like 5 x 64gr, 5 x 64.5gr, 5 x 65gr.... certainly don't take multiples from 69gr up to 73.... that's asking for a short day at the range. To be clear you are proposing to start at the book max and only work up higher from there. I understand others run slightly above book max, but that's not a starting point.
There are just as many people who cant reach book max without pressure, so there is a chance that ALL of your rounds will be un-shootable in your rifle which would make for a very inefficient load development process.

I would start at 64gr and go up from there.

Thanks Chris, So starting at the lower book limit would be good, but only go up 1 round of each until I see pressure signs, then back down to the previous load.
But from then, once I have found a good amount of powder - How do I go about working out somthing to give me better accuracy ?