Cold gun issues

[WiscGunner]

There has been a lot of suggestions about problem solving scope, rings, bedding, screws etc. Could you please privide a picture of the rifle? Scope ring placement on the dcope tube can cause lots of wierd issues. Unlikely in this case but important to eliminate especially is this receiver is more curved that the previous reciever the scope was mounted upon.

There has been no discussion on how the barrel was installed. We are ASSUMING the barrel is headspaced and Torqued sufficiently. Could you please tell us a bit more about your barrel installation?

Also, I am curious how you removed bedding compound without damaging the original bedding of the stock. Could you please provide pictures of the various bedding attempts?

 

[mrmolar119]

Here is a group I shot at lunch. This is 3 shots with the new scope mounted, and using Hornady ammo. I didn't measure but looks about 1/2" 3 shot group. This was with a warm gun sitting in the house, and was the first 3 shots fired 5 hours after sighting in the new scope.

I will leave it out tonight to test the gun cold in the morning.

There's no reason at this point to believe he has a problem with the barrel. Everything indicates a problem with torque or the scope/mounts.

 

[CRNA]

I would bet the rifle has nothing to do with it. My money is on you. I would bet your cheek pressure is varying or your grip, etc. Once YOU get warmed up, you can obviously shoot well.
My suggestion is to check you natural point of aim meticulously before trying it again. Make sure you have a good edge to edge sight picture.
Try dry firing twenty rounds EXACTLY like you would fire if it were a live round. I bet once you get "dug in" to your comfy spot you will shoot just fine with a cold rifle.

 

[jpope02]

Lots of things will cause bullets to rise( usually), as barrels heat up. Harmonics pressure points in barrel channel, torque on action screws, chamber temp....etc..etc. faulty scopes, loose scopes, temperature sensitive powder in your loads Tinkering with any or all of these may help or Not. Sometimes you just have to punt if your patience wears out. I have had a couple of times and the answer was to put it on the consignment rack and build another dream rifle. Hope it works out. Good Luck.

 

[jpope02]

The barrel is free floated.

might put a business card under the barrel to see how it responds to pressure points at different places along the barrel.. Hint: try 7" in front of action 1st. and work out from there.

 

[HOT TUNA]

Have you mapped your muzzle velocity variation due to temperature with the loads you shoot? Colder powder means lower muzzle velocity which means lower impacts if not accounted for. Vertical stringing can be caused by your ammo being heated up in a hot chamber prior to being fired because the ammo gets heated up; in turn causing higher and higher muzzle velocity with each shot.

When the gun is cold and the ammo is the same temperature as the gun. Try this. Fire your first shot. Then keep the bolt of the rifle open until you are on target and ready to make the next shot. Then chamber your next round and fire it as fast as you can while still executing proper shooting fundamentals, and see if your second shot groups with the first one. Then fire the rest of your group in this manner (not chambering your round until your ready to fire). This will keep your muzzle velocities consistent by not allowing your powder to heat up. If this fixes the problem then you need to map your muzzle velocities at various temperatures and use them for your DOPE.

 

[WildRose]

Unfortunately, every Barrel maker makes mistakes.

Ask the Benchrest competition folks, this is with what they call a BAD barrel.

Having owned 3 Ruger MkII rifles in Various calibers, I agree that torque of action screws is very important.

BUT A good Barrel has always been more important.

BTW-- Ditch the Ruger rings(especially if they are not brand new built in the last 2ish years) and Get Leupold.

It doesn't matter how good or bad your barrel is if your action is being stressed due to improper torque. You can't make a flexed or twisted action shoot accurately no matter what you do.

 

[PApa Black]

I have ran into an odd situation. I have done a lot of testing in the past two weeks trying to figure out the cause. I have gotten it better but still has an issue.

To start with I had acquired a Ruger M77 MKII 22-250. I replaced the barrel with a Mcgowen in Sendero profile, lightened the trigger, and put it in a Hogue full aluminum bed stock. I did the standard load testing and came up with a very accurate load shooting 53gr v-max. I thought I would try making it more accurate and bedded the action, but really didn't result in any improvements and cause some headaches.

The problem I have is when the gun is warm, such as a 70-80 degree day (when I did load development) the gun will shoot great. However, if the gun is cold the first shot is always low out of the group. Then the next few will settle down and shoot in the normal group.

To test what the cause of the large spread I have done several test first thing in the morning. I would leave either the gun and ammo, just the ammo or just the gun outside so it would be cold. I would fire 3-5 rounds and see how they performed. The ammo grouped the same whether cold or hot, but if the gun was cold it always shoots the first shot low. When the gun is warm I don't see the issues.

I have included a picture of this morning's test. I also labeled the shots. Normally they aren't vertically strung out this perfect.

What would cause this? I was almost to the point of ordering another stock, but there really aren't many options for Ruger stocks with a heavy profile barrel.

Any ideas or suggestions on where to go? When warm, this gun is one of the most accurate guns I have. However, i built it as a coyote gun and i have no confidence in the first shot.

GPR23: I've experienced the same problem with : 1972 Winchester mod 70 300WM, Ruger M77 Mark II 280 Rem, Savage Axis .223 & Savage Weather Worrier 308. I tried everything suggested in this conversation and nothing worked. Then I tried a $10 LimbSaver De-Resonator and it cured the problem on all 4 rifles; which makes me believe the problem is a harmonic issue that changes with barrel temperature. Good luck!

 

[DENWA]

It doesn't matter how good or bad your barrel is if your action is being stressed due to improper torque. You can't make a flexed or twisted action shoot accurately no matter what you do.

WildRose,

I give this guy some credit. Different stocks different scopes, Same identical results is very hard to replicate, even the same exact TORQUE on screws in different stocks would act slightly different.

FWIW-McGowan Barrel on my uncle's 300 WSM was a ***. They replaced it because the Fluting on it was done by a 12 year old on his first day of work. I'm sure he could have done more on load development but the barrel really was a bit too picky compared to others IMHO.

 

[Danny Butler]

GPR23... what is your cleaning regime and are you using a temp sensitive powder like IMR 4064?

 

[Danny Butler]

It's been my experience that when your groups are stringing 12 to 6 or vertical.. that's indicative of a light powder load for the rifle.

 

[Danny Butler]

In the past I have had first round issues because I wasn't placing the stock in the pocket of my shoulder correctly. After the first round it would correct itself after recoil. I solved this by using a fully adjustable stock and moved the recoil pad over to the left. I'm a right handed shooter.

 

[GPR23]

Here are a few answers to your questions.

It is not stock, action screw torque, ammo, or scope/rings related. I have switched them all, and tried multiple variations of each to no avail. it is not shooter, as I have now had someone else shoot to verify. I also will shoot other guns right before shooting this one, so I'm warmed up ready to go. Also i have tried a cleaned vs dirty barrel and it made no difference.

It is either the barrel or the action, not sure which. I'm not in love with this gun as i got it on a trade, then put the stock and barrel on it. I have wasted enough time and energy, it is time to send this gun down the road. I don't have much free time, and I'm tired of spending it testing this gun instead of hunting.

Thank you all for the help and suggestions.

 

[KiwiKeith]

Agree with Azrael that the barrel is the likely cause. After all, it was the barrel change that started this whole episode. One thought I had is whether the bore is actually centre of the barrel. With unequal material on one side of the bore as opposed to the other there's likely to be an uneven amount of material expansion causing the barrel to bend when it is heated up after the first shot. This will shift the POI. Wondering whether you need to talk with the barrel manufacturer, explaining all the problems you have had, and the measures you've taken to try to mitigate the issue.