6.5 PRC group size

[jmkasza]

I’ve read (and heard) lots of opinions on group size. Typically I shoot 5-shot groups for my target rifles and when doing load development. I’m a casual target shooter and avid deer hunter; for the most part I’ve figured out what works for me.

18 months ago I bought a 6.5 PRC (Savage 110 High Country) for a potential mule deer hunt. I haven’t got the tag yet so it hasn’t become a big priority to get load sorted out. Free time has been in short supply too. It started off very promising, but I’ve ran into issues with huge group sizes. Here is the story:

2/25/24 Purchased new and cleaned bore

3/17/24 Shot 5 and gently cleaned. Bore was not very dirty.

Group size not measured, shot Hornady Match 147gr​

3/22/24 Shot 10 total, Hornady Match 147gr

0.749” group with 5 shots​

0.483” group with 3 shots (different group)​

Cleaned bore, rifle sat untouched till August​

8/30/23 Shot 10 – group size exploded!

2.620” group with 5 shots Hornady Match 147gr​

3.259” group with 5 shots Hornady Precision Hunter 143gr​

Cleaned bore​

Checked for loose screws, found none, verified correct torque on all​

12/13/24 Shot 5 again, group size even worse. Was pissed, did not measure.

Hornady Precision Hunter 143gr​

12/21/24 Swapped scope from a Vortex Viper PST 5-25 to a Zeiss 4-16

12/27/24 Shot 16 rounds, Hornady Precision Hunter 143gr

Huge group sizes, did not measure (wish I did, but too frustrated at the time)​

Cleaned bore​

12/28/24 Put the Vortex scope back on, removed the action from stock and reinstalled

Verified torque. Checked and torqued bases and scope rings.​

12/29/24 Shot 8 rounds, Hornady Precision Hunter 143gr

3.259” group with 3 shots​

Cleaned bore​

3/16/25 Tested a batch of handloads and more Hornady PH 143gr

1.256” group with 5 shots Berger 156gr EH​

1.699” group with 5 shots Berger 156gr EH​

1.139” group with 5 shots Berger 135gr CH​

0.506” group with 5 shots Berger 135gr CH (was shocked)​

3.840” group with 5 shots Nosler 129gr ABLR​

Ran bore snake​

5/23/24 Finished testing handloads

1.499” group with 5 shots Hornady PH 143gr​

3.211” group with 5 shots Hornady 143gr ELDX handload. Had a flyer, group would be 1.277” without it​

3.047” group with 5 shots Nosler 129gr ABLR​

1.148” group with 5 shots Berger 140gr EH​

1.355” group with 5 shots Berger 140gr EH​

2.286” group with 5 shots Nosler 140gr AB​

2.568” group with 5 shots Nosler 140gr AB​

Cleaned bore​

Out of all this.. I wish I would have saved targets. The Berger 140gr Elite Hunter showed promise so I loaded up 15 more for tomorrow. The 135gr Classic Hunter had the best group by far, but that’s my Creedmoor bullet I wanted the PRC to shoot heavier bullets. Evidently it does not care for the Nosler bullets I tried. Most of the dispersion has been vertical, on the handloads anyway. On the 3+ inch groups it’s been all over.

I shot next to a guy doing load development for this 6.5 PRC last time and he was doing 3-shot groups. Maybe I need to do this? Maybe I’m not letting it cool enough and it starts to walk.. I don’t know.

Could be me too as I haven’t been shooting much lately. When switching to a different rifle I seem to be just fine. I’ve been conscious of technique and getting setup the same every time. Shooting off bags, front and rear, from a bench.

Or if anyone has intimate knowledge of the 110 High Country I’d love to hear it. I really felt it had great potential at first, now with 120 rounds down the tube I’m not so sure.

-Jake

 

[kyotekiller25]

I would do 3 shot groups on a lightweight hunting rifle. That's just my thoughts. On a heavier barreled target/varmint rig then I typically do 5 shots.

I fully understand how frustrated you must be. I think anyone would be at that point.

 

[Idaho-Lefty]

If, the 135 grain, Classic's shoot "Well",. USE them and Don't Look, back !
They will kill Big Game ( even Elk ) ,.. just,. Fine at, 6.5 PRC, Velocities !

 

[Bill Norris]

First thing I would do is check the bore with a scope and see what the coppering looks like.

 

[Idaho-Lefty]

This ^^^ And,. get All of, the Carbon, Out of, the Throat Area !
Bronze Brush and JB's,.. IF, Necessary !
Then CLEAN Thoroughly or, you'll Have, very Heavy,.. Bolt lift !
Shoot 3 shot group's and,.. Let COOL if, wanting to shoot 5 shot Group's, take,.. 2 Rifles.

 

[Bill Norris]

This ^^^ And,. get All of, the Carbon, Out of, the Throat Area !
Bronze Brush and JB's,.. IF, Necessary !
Then CLEAN Thoroughly or you'll Have, very Heavy,.. Bolt lift !

Absolutely, carbon is an accuracy killer as well. Get the barrel clean, go thru your loading practices and equip. to see if there is anything amiss.

 

[Idaho-Lefty]

This ^^^ Bullet "Run-out", is cut down to, Near Zero,.. w/ FORSTER Dies.
Grandson Uses N-565 Powder, 140 gr. Elites, ADG Brass, Forster Dies and getting, 5 shot group's, in the 3's and 4's with his Savage 110 Lite Hunter ( w/ Proof Barrel )

 

[jmkasza]

If, the 135 grain, Classic's shoot "Well",. USE them and Don't Look, back !
They will kill Big Game ( even Elk ) ,.. just,. Fine at, 6.5 PRC, Velocities !

If I can't get the heavies to shoot, that's what will happen. I got the 156's specifically for this rifle, but if they don't shoot they don't shoot. I can use the 140's elsewhere.

 

[jmkasza]

First thing I would do is check the bore with a scope and see what the coppering looks like.

Definitely will focus on the cleaning aspect. So far this barrel has been pretty easy to get clean, but now that you mention it getting an eye on the bore scope makes total sense.

 

[Bill Norris]

If I can't get the heavies to shoot, that's what will happen. I got the 156's specifically for this rifle, but if they don't shoot they don't shoot. I can use the 140's elsewhere.

Great attitude. Sometimes a barrel simply won't shoot a particular bullet and you can't make it work no matter how hard you try.

 

[Idaho-Lefty]

I use, a 2 Step Cleaning Process,. First w/ Sweets 762 or, Barnes C-10 ( Wet Patches, Soak 20 Minutes and Bronze Brush, One Way ) to Get the Copper, Out.
THEN, I use BoreTech Eliminator to, get the Carbon Out.
I clean my Barrels every 60 to 80 rounds to be, Safe ( Hate, Carbon Build Up ! ) and to Get, Top accuracy.

 

[Straightshooter1]

If I can't get the heavies to shoot, that's what will happen. I got the 156's specifically for this rifle, but if they don't shoot they don't shoot. I can use the 140's elsewhere.

Hmmm??? Sometimes, one just gets a barrel that doesn't do well. Even so, I'd think you should be able to get much better than what you've described. Something just seems very wrong to get that kind of results at 100 yds (assuming you were shoot at that distance???).

I'd definitely scope the bore to get a good idea of what I'd be looking at. Now that you've got enough rounds down the tube, it should be broken in nicely. But be sure it gets a good cleaning where you get not just the copper fouling out, but also the carbon. . . particularly any carbon ring. And while checking out the bore with a scope, I'd take a good look at the crown.

I'm not a fan of bore snakes, as the idea of them (in my mind, though I've never used them) suggests they can easily damage the crown and not take care of the chamber's lead area??? ¯\_(ツ)_/¯

 

[jmkasza]

Hmmm??? Sometimes, one just gets a barrel that doesn't do well. Even so, I'd think you should be able to get much better than what you've described. Something just seems very wrong to get that kind of results at 100 yds (assuming you were shoot at that distance???).

I'd definitely scope the bore to get a good idea of what I'd be looking at. Now that you've got enough rounds down the tube, it should be broken in nicely. But be sure it gets a good cleaning where you get not just the copper fouling out, but also the carbon. . . particularly any carbon ring. And while checking out the bore with a scope, I'd take a good look at the crown.

I'm not a fan of bore snakes, as the idea of them (in my mind, though I've never used them) suggests they can easily damage the crown and not take care of the chamber's lead area??? ¯\_(ツ)_/¯

Yes, groups are all at 100 yards.

Ran the bore scope, it was a pretty clean actually, but I had cleaned it after the last range session. I went ahead and cleaned it (with copper killer this time) and ran the scope again. No concerns with what I can see and it looks very clean. No carbon ring.

Plan is to shoot tomorrow, 3-shot groups and a longer cooling period in between.

 

[Coyotefurharvester]

1. I would strip down the bolt and clean/inspect, something may have changed ignition wise.
2. Clean/inspect bore, look at the muzzle carefully.
Your activity notes suggest, A significant change after second range/cleaning.
Or something during storage(check firing pin/spring) and for corrosion.

 

[Clancy]

Sounds like pin drag or a screw or two is too long. Is your torque wrench good? Could you be crushing the scopes?

 

[Straightshooter1]

Sounds like pin drag or a screw or two is too long. Is your torque wrench good? Could you be crushing the scopes?

That reminds me of a shooter a couple years ago that was at a table next to me trying to sight in his new scope and just couldn't get it to shoot consistently for sighting. His frustration caught my attention and I went over and having some friendly discussion, I mention it could be the amount of torque he used, since he didn't use any kind of torque wrench. I happened to have my Wheeler Torque Wrench in my car and we loosened the screws, torqued it to a spec I happened to use on my scope rings (much lighter than he done). It turned out, he was crushing his scope and with the lighter torque on the screws, the results on paper was way better and he was able to get his scope sighted in.

 

[lawman29]

I can't comment as there is a lack of information on your testing protocol. Nor on powder, primers, case brand, seating depth etc. Also the 110 is a short action?? And limit for coal??

 

[jmkasza]

1. I would strip down the bolt and clean/inspect, something may have changed ignition wise.
2. Clean/inspect bore, look at the muzzle carefully.
Your activity notes suggest, A significant change after second range/cleaning.
Or something during storage(check firing pin/spring) and for corrosion.

Did this yesterday, no visual signs of damage or defect to either.

 

[jmkasza]

Sounds like pin drag or a screw or two is too long. Is your torque wrench good? Could you be crushing the scopes?

I hope it's good. Wheeler fat wrench. I'd have to dig up the specs, but I believe they are torqued in the 20-25 in/lb range.

 

[Clancy]

I hope it's good. Wheeler fat wrench. I'd have to dig up the specs, but I believe they are torqued in the 20-25 in/lb range.

I’d check it.