7prc Neck Tension ADG Brass

[bowrunner81]

Hello All,

I have a 7prc that currently shoots Federal 175gr Eldx ammo very well. All of my handloads have shot good with it, but I like tinkering and want to find something great. I reloaded some of the factory Federal cases but start getting loose primer pockets after just a couple firings. So, I bought some ADG brass and started to reload those. I have noticed the bullets seat in the ADG brass very easily compared to the Federal brass. I am not a super skilled reloader and have only been into the basics really thus far.

How do I know which is the proper neck tension around the bullet? I have gotten fairly high SDs and ES but the groupings are good. Do you think the neck tension could be the issue with that? The dies I am using are the Hornady custom die sets. Any info is appreciated.

Thanks,

Joey

 

[wapitibob]

You'll have to test it to see. I'm at .004 others are at .001.

 

[bowrunner81]

Most of mine are at .002. So maybe that’s not an issue. Outside diameters are .313-.311 = .002”

 

[SloppyJ]

Most of mine are at .002. So maybe that’s not an issue. Outside diameters are .313-.311 = .002”

That's typically a pretty safe zone to be in. Have you ran powder charge tests to see how your numbers changed?

 

[bowrunner81]

Yes. Here is some data:
H1000, CCI mag primer, 175gr eldx, 7prc ALG brass, 5 shots fired at each grain weight

Really, I dont think this is bad at all. But the factory Federal shot better in all areas. The best shot group was 66.9gr, but all I think were under an inch.

65.8gr - 2797.8 avg vel, std 14.2, spread 40.0
66.2gr - 2816.3 avg vel, std 10.5, spread 34.5
66.6gr - 2826.4 avg vel, std 13.6, spread 38.4
66.9gr - 2854.7 avg vel, std 15.1, spread 38.4
70.2gr - 2837.1 avg vel, std 20.1, spread 56.0

 

[SloppyJ]

Those numbers are pretty rough. I'd recommend trying a different powder. Maybe N570 or Retumbo. Not sure if N565 lines up with the 7prc but might be worth a look too.

If you're not shooting far then you might be set if they're sub MOA. Might be something to see between the 66.2 and the 66.6 charge too.

 

[bowrunner81]

Would a different primer make much of a difference? I do have some Federal 215M primers I could try.

 

[SDHNTR]

Yes. Here is some data:
H1000, CCI mag primer, 175gr eldx, 7prc ALG brass, 5 shots fired at each grain weight

Really, I dont think this is bad at all. But the factory Federal shot better in all areas. The best shot group was 66.9gr, but all I think were under an inch.

65.8gr - 2797.8 avg vel, std 14.2, spread 40.0
66.2gr - 2816.3 avg vel, std 10.5, spread 34.5
66.6gr - 2826.4 avg vel, std 13.6, spread 38.4
66.9gr - 2854.7 avg vel, std 15.1, spread 38.4
70.2gr - 2837.1 avg vel, std 20.1, spread 56.0

You will never be able to shoot so precisely so as to discern any of those from anything else putting up half those numbers. But I also gotta ask, how many shots were fired of each charge to produce those numbers?

 

[skip189]

Just loaded some new ADG brass for the 7PRC with 175 ELDX. Used N560 and ran it up to max where got the best SD. Shot right at .5MOA 100 yards. I did check the neck tension with the new brass and was right around .002. I did notice that some bullets seemed to seat easier. I did run them through a mandrel before seating. I wasn't too worried about it as was fireforming it and looking to the next load.

 

[bowrunner81]

Just loaded some new ADG brass for the 7PRC with 175 ELDX. Used N560 and ran it up to max where got the best SD. Shot right at .5MOA 100 yards. I did check the neck tension with the new brass and was right around .002. I did notice that some bullets seemed to seat easier. I did run them through a mandrel before seating. I wasn't too worried about it as was fireforming it and looking to the neck load.

The only thing I worry about N560 is temperature sensitivity. Maybe it’s not that bad tho.

 

[bowrunner81]

You will never be able to shoot so precisely so as to discern any of those from anything else putting up half those numbers. But I also gotta ask, how many shots were fired of each charge to produce those numbers?

Those are 5 shot groups. If you think they are good enough, would you say just pick the best and go with it? I’m hunting with this guy and 600 yards is my max range.

 

[SDHNTR]

Those are 5 shot groups. If you think they are good enough, would you say just pick the best and go with it? I’m hunting with this guy and 600 yards is my max range.

Yes, but I consider 10 shot strings minimum to provide statistically significant info. Nonetheless, you will never ever see the difference in any of those at 600 yds.

 

[Fireflyfishing]

What’s the round count through that new ADG brass? I don’t get serious about load development until I have a couple firings through them. One firing at the bare minimum.

Honestly, I don’t measure my neck tension. I run a Redding body die to properly size for headspace, a lee neck sizing die, and then a lee factory crimp at the end (very light crimp). I’m getting single digit SDs using this method.

 

[bowrunner81]

What’s the round count through that new ADG brass? I don’t get serious about load development until I have a couple firings through them. One firing at the bare minimum.

Honestly, I don’t measure my neck tension. I run a Redding body die to properly size for headspace, a lee neck sizing die, and then a lee factory crimp at the end (very light crimp). I’m getting single digit SDs using this method.

The first loads were all the first firing, with the last two being a second firing.

 

[SDHNTR]

The problem with a SAAMI chamber and multiple firings of ADG 7prc brass is you may run into some clickers!