7 SAUM load advice

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I just prepped some brass and want to shoot with the 175 eldx tomorrow but I am seeing a big range in load data with H1000. These are not the same bullets, but both 175gn. The Nosler load is the ABLR and the Hodgdon load is a 175 sp. Not sure where to start with the 175eldx and how high to load to on a pressure test ladder. And advice?

Nosler:
1663467847673.png

Hodgdon:
1663467931239.png
 

Mark at EXO

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The Hodgdon data is more realistic. 61g is a safe starting point for sure. A 10-round ladder at half-grain increments that starts at 61 would be a safe an effective way to learn your rifle. Depending on your OAL/seating, you may run into compression before the end of the 10 rounds.
 

Ucsdryder

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fresh brass? I would load up to around 65. I bet you hit pressure somewhere around 63-64 but I alway go high so I don’t have to come load more. 60-61 should be a safe starting point.
 
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MuleyFever
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The Hodgdon data is more realistic. 61g is a safe starting point for sure. A 10-round ladder at half-grain increments that starts at 61 would be a safe an effective way to learn your rifle. Depending on your OAL/seating, you may run into compression before the end of the 10 rounds.
Its throated for the 175 so the boat tail junction is at the bottom of the neck.
 
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MuleyFever
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fresh brass? I would load up to around 65. I bet you hit pressure somewhere around 63-64 but I alway go high so I don’t have to come load more. 60-61 should be a safe starting point.
Yeah, new Norma brass.

I didnt make it out today, really windy when I woke up.
 
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I settled between 63.5 and 64.1 on a couple long throated saum barrels and ADG brass with the 175 eldx.

Not sure how exactly ADG compares in case capacity to Norma on the 7s. I did have Norma 7 saum brass necked down to 6.5 and found the same charge in that fired Norma brass was a little faster than virgin adg 6.5 SAUM brass so I assumed they were likely close in capacity.

The published data is probably based on much shorter COAL and chamber throats.
 
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Ucsdryder

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Mine is throated for 180’s and I am using 65.1 grains of H1000. I’d start at 61 and go up to 66-67 range personally.
Dang! That’s a lot of powder. I was at 64.2 for a while and had to drop because I started to see pressure signs as the barrel sped up. Still getting ejector marks at 63.7 but it shoots well so I’m hunting it at that load. I’ll mess with it next spring.

Adg brass
180 eldms
 

tdbaugha

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Dang! That’s a lot of powder. I was at 64.2 for a while and had to drop because I started to see pressure signs as the barrel sped up. Still getting ejector marks at 63.7 but it shoots well so I’m hunting it at that load. I’ll mess with it next spring.

Adg brass
180 eldms
180 hybrid. 3.050 COAL jumping ~.120” to the lands. I think the large jump is allowing that much powder.
 
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MuleyFever
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The Hodgdon data is more realistic. 61g is a safe starting point for sure. A 10-round ladder at half-grain increments that starts at 61 would be a safe an effective way to learn your rifle. Depending on your OAL/seating, you may run into compression before the end of the 10 rounds.

fresh brass? I would load up to around 65. I bet you hit pressure somewhere around 63-64 but I alway go high so I don’t have to come load more. 60-61 should be a safe starting point.

I settled between 63.5 and 64.1 on a couple long throated saum barrels and ADG brass with the 175 eldx.

Not sure how exactly ADG compares in case capacity to Norma on the 7s. I did have Norma 7 saum brass necked down to 6.5 and found the same charge in that fired Norma brass was a little faster than virgin adg 6.5 SAUM brass so I assumed they were likely close in capacity.

The published data is probably based on much shorter COAL and chamber throats.

I ended up getting a swipe mark and hard bolt lift at 62.5gn. I thought I would get to 63 at least. Speed was 2719 (20in barrel).

I am seated .02 off the lands. Would it be worth trying to seat them deeper?
 

tdbaugha

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Bummer. 20" for me also. ADG brass though. 2830 fps with 180gr hybrid target.
 
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Mark at EXO

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Do you have other powder options? I run the 175 ELD-X around 2900 (22" barrel) with RL-23 in ADG brass.
 

Ucsdryder

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I ended up getting a swipe mark and hard bolt lift at 62.5gn. I thought I would get to 63 at least. Speed was 2719 (20in barrel).

I am seated .02 off the lands. Would it be worth trying to seat them deeper?
I didn’t run the 175 so it’s not apples to apples. You are also using different brass with different capacities. The 175 versus the 180 ELD have different bearing services which can lead to different pressures as well.

I wouldn’t get too excited about any data until you’re using at least once fired brass and preferably have 80 to 100 rounds down the barrel for barrel speed up. I am having issues right now with increased pressure and basically having to start over.

If I were you I would not push close to pressure because you have nowhere to go from there. Find a nice easy shooting load work on some tentative load development and get some rounds fired down range. You should see 80-100 ft./s barrel speed up once you get closer to 100 rounds down the pipe.
 
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z987k

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I ended up getting a swipe mark and hard bolt lift at 62.5gn. I thought I would get to 63 at least. Speed was 2719 (20in barrel).

I am seated .02 off the lands. Would it be worth trying to seat them deeper?
.02 or .20 off the lands? Big difference.
 
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MuleyFever
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I didn’t run the 175 so it’s not apples to apples. You are also using different brass with different capacities. The 175 versus the 180 ELD have different bearing services which can lead to different pressures as well.

I wouldn’t get too excited about any data until you’re using at least once fired brass and preferably have 80 to 100 rounds down the barrel for barrel speed up. I am having issues right now with increased pressure and basically having to start over.

If I were you I would not push close to pressure because you have nowhere to go from there. Find a nice easy shooting load work on some tentative load development and get some rounds fired down range. You should see 8200 ft./s barrel speed up once you get closer to 100 rounds down the pipe.
I think I am only about 50 rounds through it so far. I am also not a long range shooter so even at 2700fps it stays above 2000fps out to 700 yards which would be pushing my max right now.
 
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I have H4350 and H4831SC. I have not looked to see if they are good options for the 175's.

They are good options for accuracy/consistency but neither is going to net impressive velocities.

H4350 is a popular powder among benchrest/fclass guys who shoot saums with 180 hybrids. It just seemed a little on the fast side to me for the heavies. It's what i use with 145 CEB lazers.

H4831 should be a good powder for 175/180 class bullets. The best load i had with a HCA carbon barrel was 180 scenars over H4831 SC. Speeds were around 2750 IIRC w/ 22" barrel.

If you're seating 20 thou off the lands, i would not expect a bigger jump to have an impact on the pressure signs if that is what you were hoping for.
 
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I ended up getting a swipe mark and hard bolt lift at 62.5gn. I thought I would get to 63 at least. Speed was 2719 (20in barrel).

I am seated .02 off the lands. Would it be worth trying to seat them deeper?

That doesn't surprise me. I think i was a little hot @ 64.0 grains and backed off on mine too. It's likely that norma has slightly less capacity on top of being softer brass than ADG and thus more likely to show pressure. I was 2820-2840 through a broken in 22" barrel so with less case capacity, softer brass, and 2" less barrel length that hasn't fully sped up, you're right there.
 
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