7Prc not grouping

[sifer1]

good day. so i got a custom rifle built with a heller arms EV5 26 inch barrel in 7prc.
got about 40 rounds in it now. have tried 3 different types of ammo that i could lay my hands onto.
hornady precision hunter 175gr, hornady outfitter 160gr, and hornady eld match 180gr.

shot all 3 boxes twice now. hornady precision hunter grouping 1.09 or worse, hornady 160 outfitter grouping .689 or worse, hornady 180gr eld match 1.91 or worse 10 shot groups. any suggestions. the only thing is for sure is that the outfitter rounds dont always chamber. have 6 out of a box of 20 that would not chamber.
second pic is of the second day.

any suggestions would help!!
thanks

 

[davsco]

.689 TEN shot group, send that pos back!

What were your 5 shot groups?

 

[hlee]

.689 TEN shot group, send that pos back!

For real. That’s gross.

But really, measure the rounds that didn’t chamber. I’d be surprised if Hornady is sending out ammo that is on the bleeding edge of max saami spec.

 

[DocRDS]

.689 10 shot group in a PRC? Send it me, I'll "fix it" for ya. Even 1" in a PRC 10 shots is pretty good. That kind of recoil is tough to tame without solid fundamentals.

Outfitter not chambering would definitly throw some red flags for me. Factory ammo should always go in smooth.
1st option is it ammo or rifle? since other ammo chambers, suspect ammo. Try it in another 7PRC or case guage. You can try and measure but I've never had good luck trying to figure out why rounds don't chamber via measurements.

 

[sifer1]

.689 TEN shot group, send that pos back!

What were your 5 shot groups?

posted

 

[sifer1]

.689 TEN shot group, send that pos back!

What were your 5 shot groups?

that was the outfitter rounds that dont always chamber

 

[sifer1]

For real. That’s gross.

But really, measure the rounds that didn’t chamber. I’d be surprised if Hornady is sending out ammo that is on the bleeding edge of max saami spec.

sent hornady a email with pics now waiting to see what they say

 

[sifer1]

also its a 1 and 9 twist barrel

 

[DIBBS]

What are you expecting for accuracy from factory ammo? What does the rifle weigh, and what is your experience shooting heavy recoiling rifles? They do take getting used to. I would be happy with 1" groups from factory ammo, particularly in the PRC. Very happy.

 

[Baron23]

For real. That’s gross.

But really, measure the rounds that didn’t chamber. I’d be surprised if Hornady is sending out ammo that is on the bleeding edge of max saami spec.

I wouldn't be surprised...had some boxes of 140 ELD-M that were oversized and a bitch to chamber. Left a lot of brass in the chamber to clean out. And this is on a gun with a SAAMI chamber, which never had an issue with chambering a round, and chambered other ELD-M and Federal without issue.

 

[Thump_rrr]

What profile barrel and what is the purpose of this rifle?

If it is to be a hunting rifle which I suspect it is I would focus on cold bore shots and 3 shot groups. If you have a repeatable cold bore shot and a decent 3 shot group I would call it good.

I would also try a different brand of ammunition.
I have a rifle that hates Federal Gold Medal Match with 140gr SMK’s but loves Sierra Custom Competition with the same 140 SMK’s.

 

[Supersubes]

Zero info on heller arms website, except they do say “The most accurate barrels on the planet”.

 

[Maurygold]

Did you build this or a “gunsmith”?

 

[sifer1]

Did you build this or a “gunsmith”?

was built

 

[sifer1]

will post pic tomorrow

 

[sifer1]

https://hellerarms.com/ev-5-custom-bolt-action-barrel-with-barrel-nut-wrench-and-muzzle-brake/

 

[Maurygold]

was built

Never go back to that gunsmith. So many other barrels and actions out there that are proven to work - zero reason to have ended up with that barrel.

 

[PappyM3]

Never go back to that gunsmith. So many other barrels and actions out there that are proven to work - zero reason to have ended up with that barrel.

I think he sought out that barrel. He bought a Heller barrel last year in 6.5 CM. The only reason I know is I was trying to do a web search for Heller barrels and his post on Snipershide about his 6.5 CM one was one of the only non-store results. Seems like a lot of money for an unknown-quantity barrel to me, but to each their own.


Anyway, @sifer1, the first groups you showed a picture of seem totally reasonable. The second set of pictures less so. But honestly, I’ve not heard/seen great things about people’s group precision with factory 7 PRC (nor factory 7 backcountry). I’d recommend trying some non-Hornady ammo. Also, for groups, I wouldn’t shoot more than a few shots and then let the barrel cool down. You can always make note of the group center location relative to your POA to make sure that your 3 round group accuracy is good along with the precision. Paying attention to group center location across groups in relation to POA mitigates the statistical issues with 3 round groups. But you need to make sure your parallax and/or sight alignment is perfect from group series to group series. When setting parallax, do the rough check to make sure the target is in focus, but then fine-tune it as you wiggle your head to ensure the reticle doesn’t move on the target.

 

[Roadrace33]

Id be happy with .75 moa out of that thing with factory ammo. Id probably be more than happy actually. My AI's in 300 prc and handloads im pretty dang happy with 1/2 moa..so .75 is totally acceptable given the variables.

 

[PappyM3]

Id be happy with .75 moa out of that thing with factory ammo. Id probably be more than happy actually. My AI's in 300 prc and handloads im pretty dang happy with 1/2 moa..so .75 is totally acceptable given the variables.

If you look at the second picture, his groups can range from 2-2.7 MOA.

 

[Roadrace33]

If you look at the second picture, his groups can range from 2-2.7 MOA.

Ah i see. Ya, that is shit.

 

[Ledzep]

also its a 1 and 9 twist barrel

SAAMI is 1:8. Might explain some of the issues with the heavy bullets.

Try 162s.

 

[TheJeanyus]

A friend of mine has an Origin action with a Proof 7 PRC prefit (steel comp contour). It shoots 2-3 MOA with factory Hornady ammo and under 3/4 MOA with hand loads (Berger 180 hybrids). He pulled the 180 ELDMs from some of his left over factory ammo and hand loaded them, and it shot about the same as the Bergers. The rifle is probably fine. That factory Hornady ammo just sucks.