300 win mag trouble with accuracy

[arizona1650]

Just installed a new vary x 3 I had laying around. Checked torque on all screws. I'm only going to shoot factory ammo and just see if there is any improvement. Also I measured the groups i'm getting with a caliper and they are 1.5-2" groups. They just look really freakin big!!

 

[AZShooter]

If you are in Tucson I could look at your barrel with my bore scope.

Here is my checklist for a new rifle:

Borescope inspection can tell you plenty. I always check the throat, rifling and crown. I encountered a new weatherby barrel with one land smashed flat in the throat! Have seen nasty crowns and even saw one rem barrel with a 1/4" of land missing mid barrel!



Forward screw of front base touching threads of barrel shank. This is a sneaky one. remove rear screw of front base and tighten front screw. If it hits the barrel the base will be loose. Shorten screw till it doesn't hit barrel threads.

Leupold windage style base windage side screws not tight


Action screw holes in stock too small, drill larger so sides of action screw won't touch

Bolt handle touching stock

Mag box must not bind

Recoil lug making early contact in bottom of bedding (rocking action)

Trigger group must not touch stock

Trigger guard must not touch trigger

Uneven bedding--- tightening one action screw to see if the action pulls up at other end.

Action screws properly torqued

Barrel having adequate clearance where it is supposed to be floated

Clean bore


Ross

 

[arizona1650]

If you are in Tucson I could look at your barrel with my bore scope.

Here is my checklist for a new rifle:

Borescope inspection can tell you plenty. I always check the throat, rifling and crown. I encountered a new weatherby barrel with one land smashed flat in the throat! Have seen nasty crowns and even saw one rem barrel with a 1/4" of land missing mid barrel!



Forward screw of front base touching threads of barrel shank. This is a sneaky one. remove rear screw of front base and tighten front screw. If it hits the barrel the base will be loose. Shorten screw till it doesn't hit barrel threads.

Leupold windage style base windage side screws not tight


Action screw holes in stock too small, drill larger so sides of action screw won't touch

Bolt handle touching stock

Mag box must not bind

Recoil lug making early contact in bottom of bedding (rocking action)

Trigger group must not touch stock

Trigger guard must not touch trigger

Uneven bedding--- tightening one action screw to see if the action pulls up at other end.

Action screws properly torqued

Barrel having adequate clearance where it is supposed to be floated

Clean bore


Ross

Ross, I really appreciate the offer! I plan on shooting Saturday morning, is there any chance of meeting in the evening or Sunday? I stay in Star Pass with my in laws. If not maybe we can shoot for another weekend?

 

[AZShooter]

Where are you shooting Saturday morning? In Tucson? How about shooting together at Pima Pistol Club? They have a nice rifle range. PM coming with my phone #

 

[arizona1650]

Where are you shooting Saturday morning? In Tucson? How about shooting together at Pima Pistol Club? They have a nice rifle range. PM coming with my phone #

Sounds great! I had actually planned to go there with a buddy Saturday morning. I'll give you a call tomorrow and discuss. Thanks again.

 

[Marble]

It's nice seeing guys reaching out to help another shooter out.

 

[AZShooter]

Saturday sounds fine. Talk soon

 

[FEENIX]

It's nice seeing guys reaching out to help another shooter out.

Yep, it don't get no better than that!

 

[gspman]

i had the same problem, did a cast of the chamber and verified that there was a minute flaw in the rifling. One of the lands didn't completely contact the chamber space as did the others. I made the assumption that this would cause the bullet to launch funcky.

I am rebarreling in a couple weeks.

 

[AZShooter]

I inspected the bore of the suspect rifle and met a great guy at the same time.

Throat, entire bore and crown were fine. We talked about the setup and I discovered that Az1650 used quite a bit of torque on the action screws. I suggested we loosen and retorque to a lower setting. The group size became smaller. I suggested that the bedding might be an issue.

After 1650 shot the rifle a few times, I tried shooting it with a bi-pod with rear bag vs a regular front rest and rear bag. Tried tight and loose holds for both ways of support. There were differences in the size of the group with the different methods. We concluded that the bedding needs some work. 1650 will be doing some changes to the bedding like floating more of the barrel and opening up the bedding material in the pillars holes so the action screws are not touching any bedding as they go through the pillars and into the action. We will know more when 1650 gets those things done.

We shot paper and had plenty of conversations on handloading coues wt hunting and some techniques of handloading. We also bantered with his two friends that came with him. We ended up at the range for hours and had a great time. Looking forward to seeing my new friends at the range again in a couple of weeks.

Ross

 

[el matador]

Hope you get it figured out. Maybe this sounds dumb but I don't think it has been mentioned...how often are you cleaning the gun? My factory Rem 700 could only go about 10 shots before accuracy went to crap. It was a very picky barrel and would only shoot under 1" with the most perfect of handloads. Some barrels will shoot 150 rounds without needing to be cleaned while others need it quite frequently. Also some barrels are just super picky! Trying 5 or 6 different bullet/powder combos may not be enough. I finally got fed up with my picky Rem barrel and it's being replaced by Pac-Nor. Most of them will shoot well with the right load but not all of them.

If you haven't already:

Get a good trigger or trigger job
Bed the entire action AND chamber portion of the barrel
Work on precision handloads - neck size, weigh powder charges, etc.
Try quality brass such as Norma

These things all helped tighten up my Remmy a little.