7PRC Partition wont chamber

[V00D00]

Alright, got some solid data. And I could really use all your help, and opinions on what I should do. Is the chamber too short, would u send it back? I’m not real sure what to do but I bought some 175 gn eldx bullets, and some 175 gn Nosler Accubond LR bullets. I found the lands with the Accubond LR 2.432 CBTO which equaled 3.077 Coal
The 175 gn Hornady eldx is 2.427 CBTO at the lands. I also measured the coal which equated to 3.131 coal.

I loaded a ladder test with both bullets that I haven’t shot yet.

175 gn Accubond loaded 0.060 off lands is 2.372CBTO, 3.013 coal

175 gn eldx loaded 0.040 off lands is 2.387 CBTO, 3.094 coal.

To demonstrate here is a pic of each bullet loaded to the specs above, along side the manufacturers book length. Am I missing something? This seems extremely short. Am I overthinking this?

 

[mtnbound]

Alright, got some solid data. And I could really use all your help, and opinions on what I should do. Is the chamber too short, would u send it back? I’m not real sure what to do but I bought some 175 gn eldx bullets, and some 175 gn Nosler Accubond LR bullets. I found the lands with the Accubond LR 2.432 CBTO which equaled 3.077 Coal
The 175 gn Hornady eldx is 2.427 CBTO at the lands. I also measured the coal which equated to 3.131 coal.

I loaded a ladder test with both bullets that I haven’t shot yet.

175 gn Accubond loaded 0.060 off lands is 2.372CBTO, 3.013 coal

175 gn eldx loaded 0.040 off lands is 2.387 CBTO, 3.094 coal.

To demonstrate here is a pic of each bullet loaded to the specs above, along side the manufacturers book length. Am I missing something? This seems extremely short. Am I overthinking this?

The ones on the left look too short. Are the manufacturer's specs the ones on the right?

 

[Ucsdryder]

Alright, got some solid data. And I could really use all your help, and opinions on what I should do. Is the chamber too short, would u send it back? I’m not real sure what to do but I bought some 175 gn eldx bullets, and some 175 gn Nosler Accubond LR bullets. I found the lands with the Accubond LR 2.432 CBTO which equaled 3.077 Coal
The 175 gn Hornady eldx is 2.427 CBTO at the lands. I also measured the coal which equated to 3.131 coal.

I loaded a ladder test with both bullets that I haven’t shot yet.

175 gn Accubond loaded 0.060 off lands is 2.372CBTO, 3.013 coal

175 gn eldx loaded 0.040 off lands is 2.387 CBTO, 3.094 coal.

To demonstrate here is a pic of each bullet loaded to the specs above, along side the manufacturers book length. Am I missing something? This seems extremely short. Am I overthinking this?

I’m so freaking confused. Factory Hornady eldx chamber fine and shoot sub 1”? Then load your reloads to the same specs and go to town. Why are you loading them so short? Looks like they just got out of the pool.

 

[V00D00]

I’m so freaking confused. Factory Hornady eldx chamber fine and shoot sub 1”? Then load your reloads to the same specs and go to town. Why are you loading them so short? Looks like they just got out of the pool.

Because both bullets like a lil jump. They’re only loaded 0.040 and 0.060 off the lands for a ladder. That’s a happy medium before seating depth. Why would I have a rifle built, and invest in equipment to mimic a factory load that shoots .9 is a better question.

 

[BCsteve]

If your load with the 175gr ELDX is:
"175 gn eldx loaded 0.040 off lands is 2.387 CBTO, 3.094 coal."

How did the factory 175 gr ELDX with a coal of 3.291 chambered without issue?

 

[V00D00]

If your load with the 175gr ELDX is:
"175 gn eldx loaded 0.040 off lands is 2.387 CBTO, 3.094 coal."

How did the factory 175 gr ELDX with a coal of 3.291 chambered without issue?

Thank you! Someone is paying attention. Unfortunately I do not know the answer unless the oal guage is just that inaccurate?

 

[BCsteve]

I don’t think your OAL gauge is set up properly or maybe user error ? Like someone said, what happens if you load a 175gr ELD-M to the factory ammo length of 3.291? It should chamber. If not, it’s not a bullet hitting the land issue but a brass resizing issue.

 

[V00D00]

I don’t think your OAL gauge is set up properly or maybe user error ? Like someone said, what happens if you load a 175gr ELD-M to the factory ammo length of 3.291? It should chamber. If not, it’s not a bullet hitting the land issue but a brass resizing issue.

If I load to book length, it won’t chamber. It’s brand new unsized adg brass.

 

[Ucsdryder]

If I load to book length, it won’t chamber. It’s brand new unsized adg brass.

But factory will?

 

[V00D00]

factory did chamver. but factory had a coal of 3.291 and book length uses 3.320

But factory will?

 

[ckleeves]

You may not be pushing hard enough with the oal tool. The tight throat dimensions on the PRC’s can feel a little funny if you’re using the Hornady tool and there is some fouling in the throat. You may feel a soft stop, give it a solid push and you might feel the bullet slide with some resistance thru the freebore giving you a touch length that should be about .040-.050 longer then book length. Might be worth a quick cleaning before you try also just to make things easier if the throat has some fouling.

The weird thing is it chambered and fired factory ammo fine, in my experience (not me, seen it happen) when a guy fires factory Hornady ammo in a short freebore chamber you get some pretty massive pressure sighs when it’s jammed that hard.

 

[wapitibob]

This is a 175 ELD-X, COAL, to the lands in a 7PRC chamber.
I don't know who's reamer chambered this rifle, but the COAL is slightly longer than what Furman posted in his 7PRC Cartridge Guide. Both are significantly longer than what you are posting.

 

[PanhandlinPat]

OP maybe someone said it already, but measure the neck if your fired brass vs loaded. I’m wondering if you have a super tight neck. Also, why not have the smith throat it to your desired COAL? Pretty straight forward job and you can get your desired results. Just bring in a dummy round at your desired length.

 

[wapitibob]

For comparison, my ADG brass, fired neck OD is .317-.318, loaded necks are .3125 - .314 +/-.

 

[V00D00]

This is a 175 ELD-X, COAL, to the lands in a 7PRC chamber.
I don't know who's reamer chambered this rifle, but the COAL is slightly longer than what Furman posted in his 7PRC Cartridge Guide. Both are significantly longer than what you are posting.

View attachment 1052144

if my lands were near that i would have never even made a post.

 

[V00D00]

You may not be pushing hard enough with the oal tool. The tight throat dimensions on the PRC’s can feel a little funny if you’re using the Hornady tool and there is some fouling in the throat. You may feel a soft stop, give it a solid push and you might feel the bullet slide with some resistance thru the freebore giving you a touch length that should be about .040-.050 longer then book length. Might be worth a quick cleaning before you try also just to make things easier if the throat has some fouling.

The weird thing is it chambered and fired factory ammo fine, in my experience (not me, seen it happen) when a guy fires factory Hornady ammo in a short freebore chamber you get some pretty massive pressure sighs when it’s jammed that hard.

and this is what im trying to figure out. is the problem me, or the throat

 

[V00D00]

OP maybe someone said it already, but measure the neck if your fired brass vs loaded. I’m wondering if you have a super tight neck. Also, why not have the smith throat it to your desired COAL? Pretty straight forward job and you can get your desired results. Just bring in a dummy round at your desired length.

i can do that , but... the only fired brass i have is hornady and im loading virgin adg.

 

[Ucsdryder]

Take a fired round and pop the primer. Try a few different fire rounds until you find one where the bullet slides in and out of the neck with just a little resistance. You can pinch the neck with your fingers to make it oblong to increase a little bit of pressure.

Seat the bullet long then softly close the bolt. It will seat the bullet to the lands. Repeat 10 times until you get a consistent CBTO. That will give you an idea of your distance to the lands.

 

[PanhandlinPat]

i can do that , but... the only fired brass i have is hornady and im loading virgin adg.

it shouldn’t matter the brand of the brass, measuring the outside of the neck. It will fire form to the neck diameter, even if the chamber neck is undersized.

Reason I say this is I’ve got a Remington 700 classic 7x57 with a tighter than spec neck. Batch of norma brass gave the same results your facing, managed to chamber some and fire and the fired neck outside diameter was .001” smaller than the loaded round.

 

[V00D00]

it shouldn’t matter the brand of the brass, measuring the outside of the neck. It will fire form to the neck diameter, even if the chamber neck is undersized.

Reason I say this is I’ve got a Remington 700 classic 7x57 with a tighter than spec neck. Batch of norma brass gave the same results your facing, managed to chamber some and fire and the fired neck outside diameter was .001” smaller than the loaded round.

ok i have some hornady cases once fired that ill measure the diamater of the neck tonight and ill report back. thank you.