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Look at that crown - new crown needed?
- Thread starter 9.3x62
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- 6.5creedmoor crown gunsmith howa
The first who didn't read the post and responded?
Yes OP. You have a bad crown and need a new one. That may or may not be why your rifle shoots "terrible groups."
Before venturing down the crown path, check your scope base, rings/mount, etc for tightness.
Then check your action screws.
Check the simple stuff first.
Then check your action screws.
Check the simple stuff first.
I did that of course. I even removed the action from the stock twice while at the range and tried it with the same torque setting and with a different setting as well.
I've attached pictures. I know that 3-shot-groups are not ideal, but you get the idea. Why do you think, that the crown is not the problem?
I shot 8 x 3 shots.
Thanks for all the quick replies. I appreciate that.
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If that was with the same ammunition then you have a scope mount problem or a parallax issue.
Or both
There's no reason for your impacts to be that inconsistent from group to group unless you have a mechanical or parallax problem.
You said you checked the BA to stock torque.
Did you ever check the mounts, rings and/or base screws.
Or both
There's no reason for your impacts to be that inconsistent from group to group unless you have a mechanical or parallax problem.
You said you checked the BA to stock torque.
Did you ever check the mounts, rings and/or base screws.
Define "terrible"... No pics or measurements in the first post.The first who didn't read the post and responded?
Yes OP. You have a bad crown and need a new one. That may or may not be why your rifle shoots "terrible groups."
Post with pics show someone not knowing what they are doing. Five three shot groups att different point of aim (probably).
No distance to target and factory ammo.
"How does it shoot?" is not a question asked to evaluate the shooter, but to evaluate the rifle.
One point of aim for at least five shots to a group. With that scope a corner of a 1 by 1 cm square is a breeze at 100 m. At least two, but preferably more, types of ammo (unless reloading).
So, when he follows your advise, get it recrowned and still shoot terrible groups. What is your next step..?
It's not about reading the post, or to reply to it with not enough data. It's about to know enough to ask the correct question. Or to give the correct advise.
@9.3x62
Did you try shooting some Hornady 140-grain ELDM? Worth a box to see if the results change. The 147-grain bullet has given me a little bit of trouble in the past.
What torque did you apply to the cross bolts of the ERA TEC mount? I use one on one of my AR10s and they require a torque of 80 inch pounds.
Did you try shooting some Hornady 140-grain ELDM? Worth a box to see if the results change. The 147-grain bullet has given me a little bit of trouble in the past.
What torque did you apply to the cross bolts of the ERA TEC mount? I use one on one of my AR10s and they require a torque of 80 inch pounds.
I adjusted elevation and windage after "picture 1". Yes, everything else was checked as well.
No, I did not. Maybe I should give that a try first. All torqued to the correct Nm.
@CerebralDistortion
My usual way of things would be to try out different ammunition. But since the crown looks the way it does, I thought I would get opinions on that first.
So either crown, scope, or ammunition.
The easiest way will be to try out another type of ammo. Then I can use a different scope and so on...
One can clean up the crown with a tool from Brownells, Numrich, etc. Compare price to gunsmith charge to see if it's a cost effective option. The crown might not be the sole issue to lack of precision, but the condition isn't doing the rifle any favors.
The last rifle I troubleshooted had everything perfect, but the twist rate turned out to be too slow to what was printed on the barrel. Of course I checked twist rate last...That will be one of the first checks from now on.
The last rifle I troubleshooted had everything perfect, but the twist rate turned out to be too slow to what was printed on the barrel. Of course I checked twist rate last...That will be one of the first checks from now on.
There look to be some burrs and non concentric areas on that crown. I would be suspect that it is causing accuracy problems. I have a McGowan 243 barrel sitting next to me with a similar crown that shoots about 3 MOA. It would not be the reason the groups are moving up and down the paper.
Attachments
Even mediocre ammo won't move all over the paper.
REcheck all of your mounting points. Be sure to push the optic and rings forward into the pic rail, or the unimount forward into the rail that is on the rifle before you tighten the screws.
If it doesn't group, try another scope.
REcheck all of your mounting points. Be sure to push the optic and rings forward into the pic rail, or the unimount forward into the rail that is on the rifle before you tighten the screws.
If it doesn't group, try another scope.
Wow, who would have guessed that. Honestly, would't come in my mind.
I used the Q-Tip method to check for any burrs and couldn't feel any.
I hope that is not the case.
I just did that.
Hopefully I can get to the range this week. I'll try the Hornady and another type of ammunition as well. If that doesn't work out, I'll try another scope. Last step would be to remove the muzzle break.
Thanks for all the input.
Cheers,
9.3x62
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So, I made it to the range today. This time no tinkering around. I did not try different torque settings for the chassis (that explains why the position of the groups changed last time). Furthermore no changes in the elevation, or windage of the scope.
100m
5 Shot groups
So, I'm thinking it's either the muzzle brake, or it's the barrel/crown. What do you guys think?
My next step would be to try it without the muzzle brake. I'm not thinking, that the scope is at fault, but I would try a different scope as well.
Cheers,
9.3x62
100m
5 Shot groups
So, I'm thinking it's either the muzzle brake, or it's the barrel/crown. What do you guys think?
My next step would be to try it without the muzzle brake. I'm not thinking, that the scope is at fault, but I would try a different scope as well.
Cheers,
9.3x62
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Did you check the twist rate?
Did you torque the Oryx action screws to MDT instructions? (Possibly 60 inch lbs)
Everything looks consistently terrible until the Norm 143gr and I see where one can draw a straight line through the 4 shots. This is typically indicative to shooter error.
I wouldn't think crown or muzzle break would cause this drastic of open grouping.
Here is a new test - have you established your Distance to Lands (DTL) and the bullet jump? Does the rifle have a short throat and you are shooting Jam + conditions? Does it have a long throat and there is excessive jump?
Did you torque the Oryx action screws to MDT instructions? (Possibly 60 inch lbs)
Everything looks consistently terrible until the Norm 143gr and I see where one can draw a straight line through the 4 shots. This is typically indicative to shooter error.
I wouldn't think crown or muzzle break would cause this drastic of open grouping.
Here is a new test - have you established your Distance to Lands (DTL) and the bullet jump? Does the rifle have a short throat and you are shooting Jam + conditions? Does it have a long throat and there is excessive jump?
If you get that much of change in POI when changing action screw torque, I would say you've found the problem.
I've had POI shifts when reassembling rifles, but not to that extent (a cm or two).
Check action screw length and make sure they do not bottom out. Check bedding, if any.
I've had POI shifts when reassembling rifles, but not to that extent (a cm or two).
Check action screw length and make sure they do not bottom out. Check bedding, if any.
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The correct question to be asked is: Who the hell has a 9.3 Mauser and shoots a fucking creedmoor?
Ok...at least you are consistently in the same quadrant. That is a start. I would not be messing with any more torque on any of the screws on the chassis. Definitely try it without the muzzle brake.
There ain't no way that dispersion is caused by a bad crown. Not even if the muzzle was cut with a hacksaw.
If dispersion changes with torque settings, you either not using enough torque, or the bedding is suspect.
Muzzlebrake, bad ammo, bad barrel, bad bedding, bad scope and/or mounts or bad technique. Dealer's choice on order of likelihood.
If dispersion changes with torque settings, you either not using enough torque, or the bedding is suspect.
Muzzlebrake, bad ammo, bad barrel, bad bedding, bad scope and/or mounts or bad technique. Dealer's choice on order of likelihood.
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I checked the twist rate and it's correct.
The bullets are not touching the lands. I checked that. I don't have the tools to measure the DTL at this time.
Ain't enough clicks on my scope to shoot the 9,3 out to a kilometer
.Factory barrel.
So I was at the range again today.
Before that I torqued everything to specs. Before that it was less. I read here??, or on a different forum that some rifles are very picky, when it comes to torque.
At the range I shot 5-shot groups at 100m.
Cheers,
9,3x62
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Seems like it.
No offense taken. Yes I did/do. That's basically the reason I started this thread. Because I can't figure out what's going on and therefore need advice on the best steps to take.
Yes, it's a factory barrel. Seems like I wasn't that lucky on that one. Most of these barrels are not available where I live. Even through the local Brownells store it is not possible.
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I know. I've got two.
@9.3x62
It seems to me, now that it is torqued to specs, it did not like that brake.
And it looks like you are on the right path...
It is possible to ck the throat length (circa), and the DTL without specialized tools. Sans ejector, and best to remove extractor. Dummy, fired but unresized cartridge, blacken bullet with felt tip marker, chamber, carefully remove cartridge, perhaps with cleaning rod from muzzle end, ck length. You would pinch cartridge neck slightly to hold bullet without alot of tension. Next, flat base bullet backwards in case, same test to ck freebore length.
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He's not reloading. He's shooting factory ammunition.
No need to waste time testing something that won't change his factory ammunition.
No so fast! I was shooting factory on a used 70s Remington ADL, impacts were all over the board. Come to find out the throat was VERY short. I was was running a box of, I believe 175gr partitions, to gain some brass for reloading. My reloads of 140 BTs posted at 0.3 MOA @ 100 yards. Measured the throat. Sure enough, VERY short throat.
So what have you to say now?
This was my first thought, too... with the wandering groups. Early in my "development" of precision shooting experience, I learned the lesson about parallax. One day my groups were very inconsistent and wandering. I forgot to adjust the parallax from a previous range trip (and a different distance). Whoops!
I'm still quite the amateur compared to the esteemed and skilled shooters on this forum. And my 6.5 Creedmoor "rig" is rather modest: Ruger Precision Rifle with Vortex Viper HST and Harris bipod. The OP's scope cost more than my entire rig by a good margin!
I also shoot factory ammo, and Hornady ELD-M 140-gr is my rifle's favorite flavor. And even with 4,000 rounds through the original barrel, I can shoot a 10-round group like this.
The same day, my 18 year old daughter did this 5-shot group:
So, I'll be following this thread to see what the problem is determined to be. I'm very curious!
Get a Lothar Walter cut and chambered by someone who knows how to cut the tougher steel (or chambered by Walther Lothar and just headspaced by your smith), it should last longer than the 416 butter the Americans use.
Funny you mention this. I've been building a suspicion that 416 is used mainly for manufacturer's benefit/purposes rather than the shooters/customers.
I chose a smith here because he actually shares process stuff on his page, had a really good discussion around techniques required to work the different steels, 416 is incredibly forgiving on speed/pressure/coolant/lubricant. If you run pressure fed lubricant and the right cut rates you can chamber tougher steel fine.
I have to say you have missed what the OP is saying and my apparently lost attempt to help you understand something.
The OP is not currently reloading. He is shooting factory ammunition.
He's not going to be bothered with BTO measurements or any other handloading method. He probably doesn't even have the necessary tools.
You want him to take measurements.
Do you expect him to pull the projectiles?
For what purpose?
Do you expect him to seat them deeper?
For what purpose?
I could go on and on with the questions, but it's pointless.
He is shooting factory ammo
He is shooting FACTORY ammo.
He is shooting FACTORY AMMO.
NOT HANDLOADS.
Until he decides to start reloading, if he ever does, nothing you wrote applies to the OPs issue.
I'm sure he appreciates your attempt at help, but advice needs to be relevant or it's wasted effort.
With factory ammo he could check for short throat with the tool-less gravity method. Take a factory cartridge, muzzle to the sky, and press it into the chamber with pinky on the case head. If the cartridge falls out when pinky released, then the rounds are not sticking in the rifling. If a short throat is the culprit, then worse case, the OP either buys ammo that fits, or best case, he has a chambering issue and gets that addressed professionally.
I just recently walked a guy through this with his Fierce rifle. Everything was sticking in the gun. Said the factory rounds were sticking the bolt upon firing, and recoil was, uhm, "something fierce". I figured the throat was just cut short and given Fierce Firearms horrible customer service advised he take it to a smith in his area. Turns out the barrel didn't even have rifling! (Second reported instance of this to date)
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Yassir, I didn't want to get too deep in the weeds with the particlars in this thread, but also:
If a hand loader, check to make sure the sized case is not sticking somewhere and giving false stick read.
And like most 7mm chambers with throats cut tight (.2845) that rub/stick the bullets prior to the engagement of the rifling...
Me thinks you have a problem with comprehension. "I" was shooting factory loads! The throat was SHORT, factory loads, factory gun! What don't you understand?
OP. Fix your crown. Then check. Simple, huh? Check the throat, and other things mentioned in this thread. Simple, huh?
You're telling him to check the throat length/Freebore using a tried and true method.
Cool, he's got fired brass.
Does that fired brass fit in his chamber without interference?
Probably not.
He needs a projectile.
Does he have a bullet puller?
Probably not.
Does he have a caliper or any other case/projectile measuring tools?
Probably not.
It doesn't matter what YOU did, it's a matter of what he CAN do.
The OP is asking about his crown and you're trying to offer advice about measuring throat/freebore length.
He's not having pressure spike issues. He's not having issues chambering factory ammunition.
He has some issues with expected accuracy.
The technique you offered him is sound. It's just not relevant to his issue.
I'm not trying to shit on you. I'm merely saying you've gone in a direction that isn't helpful to his situation.
Awesome! I was hoping for something like that.
Thanks for following the the thread.
I found a gunsmith who uses Shilen barrels. At the moment I am not planning to go that road, but it sure is a possibility for the future.
Cheers
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