This is where I would explore. If the threads were single point chased and enlarged then you will need a custom barrel that will only work with your rifle.
Help- my gun won’t group
- Thread starter Stringstalker
- Start date
Help Support Long Range Hunting Forum
I always grab for the low hanging fruit first before I start pulling the rifle apart. These steps are time consuming and monotonous but tend to eliminate a lot of sources of problems usually cost little more than time and, again,all before the rifle gets torn down.
1) Get some premium factory ammo.
a) Measure the COAL with a dial micrometer.
b) Record your measurements in a notebook.
c) If the first shot always goes where you want it to
i) Something is moving during recoil.
2) Let someone you trust shoot it.
a) How much time between each shot. I realize that carbon barrels are supposed to negate much of the temperature issues but 24" is a long tube, What is the taper?
b) If the first shot is ALWAYS where he wants it.
i) Then there is probably nothing wrong with the chamber/barrel
ii) If the first shot is ALWAYS two inches off of POA then the chamber/barrel is likely a problem.
3) Do not use the magazine, manually feed each round.
a) If step 3 tightens up the group.
i) Then If you reload your neck tension is insufficient.
ii) To prove this load up the magazine and fire a string.
iii) Mark each round with a sharpie numbering its place in the magazine.
iv) Measure COAL of round 1, Write that in the notebook.
v) Fire round 1, Remove all rounds from the magazine and measure all
vi) Note in notebook.
vii) Put the rounds in the magazine the way you have them numbered so they are always in the same order.
viii) Repeat this with all rounds in the magazine.
ix) If your recordings show the COAL increasing with each shot then recoil is causing the bullets to jump forward, and your distance off the rifling is changing.
4) If you are reloading, is this new brass or previously fired (in this rifle).
a) What kind of press are you using? Is it single stage, old, new?
i) Check the ram for wear throughout its entire length of travel grab it and try to wiggle it in the bushing in the press frame. You should not perceive any movement at all.
b) Do you have access to a runout gauge? If so, check runout on new brass if you have any. Record your measurements.
i) Measure again after you size the brass, measure runout and record the results.
ii) Load a few rounds, measure and record the runout results. Number them with a sharpie so you don't lose track of which is which.
iii) In a safe place, manually chamber and completely close the bolt, carefully cycle the bolt; remove the round and measure and record runout again.
iv) Load the magazine with these rounds. Cycle the bolt chambering and ejecting the rounds one by one, measure runout and record results.
If you have any questions about what any of these steps will prove for you please IM me and I will explain.
1) Get some premium factory ammo.
a) Measure the COAL with a dial micrometer.
b) Record your measurements in a notebook.
c) If the first shot always goes where you want it to
i) Something is moving during recoil.
2) Let someone you trust shoot it.
a) How much time between each shot. I realize that carbon barrels are supposed to negate much of the temperature issues but 24" is a long tube, What is the taper?
b) If the first shot is ALWAYS where he wants it.
i) Then there is probably nothing wrong with the chamber/barrel
ii) If the first shot is ALWAYS two inches off of POA then the chamber/barrel is likely a problem.
3) Do not use the magazine, manually feed each round.
a) If step 3 tightens up the group.
i) Then If you reload your neck tension is insufficient.
ii) To prove this load up the magazine and fire a string.
iii) Mark each round with a sharpie numbering its place in the magazine.
iv) Measure COAL of round 1, Write that in the notebook.
v) Fire round 1, Remove all rounds from the magazine and measure all
vi) Note in notebook.
vii) Put the rounds in the magazine the way you have them numbered so they are always in the same order.
viii) Repeat this with all rounds in the magazine.
ix) If your recordings show the COAL increasing with each shot then recoil is causing the bullets to jump forward, and your distance off the rifling is changing.
4) If you are reloading, is this new brass or previously fired (in this rifle).
a) What kind of press are you using? Is it single stage, old, new?
i) Check the ram for wear throughout its entire length of travel grab it and try to wiggle it in the bushing in the press frame. You should not perceive any movement at all.
b) Do you have access to a runout gauge? If so, check runout on new brass if you have any. Record your measurements.
i) Measure again after you size the brass, measure runout and record the results.
ii) Load a few rounds, measure and record the runout results. Number them with a sharpie so you don't lose track of which is which.
iii) In a safe place, manually chamber and completely close the bolt, carefully cycle the bolt; remove the round and measure and record runout again.
iv) Load the magazine with these rounds. Cycle the bolt chambering and ejecting the rounds one by one, measure runout and record results.
If you have any questions about what any of these steps will prove for you please IM me and I will explain.
Last edited:
I think you covered it very well. Good work.
- Joined
- Jan 26, 2015
- Messages
- 1,533
Going a little deeper into the action. When you say "trued", what exactly does that entail? Waspocrew and sedancowboy touched on the receiver threads. You said then the bolt wouldn't close. On my last 700 truing, I had the receiver threads single point cut (requiring custom threads), receiver face trued, bolt face, receiver and bolt lugs all trued to receiver face and the bolt retimed. Truing can encompass a great deal.
Rflshootr
Well-Known Member
It's hard to tell from the pictures, but is the bottom of the trigger touching the inside of the trigger guard at any point in its movement? It looks very close. Also check to see if the sides of the trigger are touching the sides of the bottom metal or inside the stock. Something tells me there is much more to this story than has been said. Who trued the action and who did the stock work? What was the reason the bolt wouldn't close and you had to have the bolt handle moved?
xsn10s
Well-Known Member
- Joined
- Mar 7, 2016
- Messages
- 7,333
I'll have to go with the others and look for the threads being chased for trueing. Also if the bolt wouldn't work properly after trueing the action then I'd say that's the first area I'd look for the problem. My guess is you'll need a new action if you want to use the remage barrel.
Roger_Roger
Active Member
Take it to the Train Station, keep the scope and mounts.
It sounds like you've done most of the basic stuff. The suggestion to switch scopes is a good one, but I've never had a bad NightForce. One thing, the older Rem 700 actions were very good to excellent, the recent ones, not so much. I've got 700s from 20 to 30 years ago that shoot 5 shot, 100 yard groups under 1" all day long. My VSSF 22-250 shoots 1/2".
sierracharlie338
Well-Known Member
If it makes you feel any better OP I had a Ruger M77 (newer model) that would not shoot sub MOA, best it would do is about 1.5. It took me years and lots of money to get it sorted out. Basically a whole new gun and two bedding jobs later it shoots 1/2 inch groups. If it was a sentimental rifle, it would have been down the road kicking rocks a long time ago.
My 7mm Rem Mag wasn't quite as bad as 2" at 100 but some loads would approach 1.8". Today it shoots 0.215" to 0.334" with 180gr Berger VLD hunters at 100 (yes I know, Berger says the twist rate on my Sendero is marginal for these. I agree. I'd rather see 0.100" to 0.000" groups but these'll do). Longer range testing to come. I replaced of the old school brake with ports 360° around. That helped some. After shooting 1,500+ rounds thru various rifles this year I've improved my shooting skills. That was a lot of it. After I pull the trigger on my Rem Mag, I'm still on the scope and the scope is still on or very near the target. Before I fine tune me, that was not the case, at all.
Munch
Well-Known Member
A lot of good suggestions have been mentioned above and worthy of investigation.
A thought from looking at your images....
Are you absolutely sure your Pic rail is properly torqued to the action and Loctite 242 applied to screws?
The Marine Corps generally uses a HD ring/base up front, the 6 screw cap type on optics mounted to the M40.
Mounting scope bases to a Picatinny rail requires a scope alignment rod in order to torque the bases down into the Pic rail slot. It is pretty rare needing to lap rings from well known, reputable manufacturers.
Also, when you mount the bases with alignment rod into the Picatinny rail, you want the muzzle facing upwards. With a small plastic faced mallet very gently tap the ring bases to firmly set into the face of the Pic slot to the rear of the base.
There is a very specific technique to torquing the bases into the Pic rail as well as the scope in the rings to maintain alignment in order to achieve absolutely no movement or torque on the optic's tube. Further, 0.001 inch of scope movement will cause about one MOA of scope reticle movement on the target. Once you have the proper installation, a repeatable zero is easily achieved if the scope/base assembly is removed from the Pic rail. Assuming the optic assembly is reinstalled on the Pic rail correctly to eliminate all movement.
In your second post you stated you are getting 2" groups...so the rifle is grouping, just not a tight of a group as you had hoped.
Hopefully you can identify the issue. If not, I would send the rifle to Matt (a fellow Marine) at Short Action Customs for analysis You have a fair amount of coin invested in the project, might as well have one of the best bolt action gunsmith in business today take a look at it. And no doubt there are many other fine "rifle 'smiths" capable of identifying your rifle's issue.
I bought all the components for my PRS rifle; sent everything to Matt for working his magic. I have a solid 1/2 MOA rifle.
Quality components should yield the results you desire. I'm a tinker'er as well, but, I knew I needed a gunsmith like Matt to build the rifle I desired.
Good luck!
A thought from looking at your images....
Are you absolutely sure your Pic rail is properly torqued to the action and Loctite 242 applied to screws?
The Marine Corps generally uses a HD ring/base up front, the 6 screw cap type on optics mounted to the M40.
Also, when you mount the bases with alignment rod into the Picatinny rail, you want the muzzle facing upwards. With a small plastic faced mallet very gently tap the ring bases to firmly set into the face of the Pic slot to the rear of the base.
There is a very specific technique to torquing the bases into the Pic rail as well as the scope in the rings to maintain alignment in order to achieve absolutely no movement or torque on the optic's tube. Further, 0.001 inch of scope movement will cause about one MOA of scope reticle movement on the target. Once you have the proper installation, a repeatable zero is easily achieved if the scope/base assembly is removed from the Pic rail. Assuming the optic assembly is reinstalled on the Pic rail correctly to eliminate all movement.
In your second post you stated you are getting 2" groups...so the rifle is grouping, just not a tight of a group as you had hoped.
Hopefully you can identify the issue. If not, I would send the rifle to Matt (a fellow Marine) at Short Action Customs for analysis You have a fair amount of coin invested in the project, might as well have one of the best bolt action gunsmith in business today take a look at it. And no doubt there are many other fine "rifle 'smiths" capable of identifying your rifle's issue.
I bought all the components for my PRS rifle; sent everything to Matt for working his magic. I have a solid 1/2 MOA rifle.
Quality components should yield the results you desire. I'm a tinker'er as well, but, I knew I needed a gunsmith like Matt to build the rifle I desired.
Good luck!
I've gotten real sloppy and not used my alignment rod with the last couple of installs. Thanks for the reminder.
cheeseburgersfearme
Member
I recently had new rings that had a burr inside one of the top mounts that acted like a thread and allowed my scope to shift (turned clockwise about 7 degrees) kept noticing my verticals was off and I'd remount the scope so my 100-200 seemed fine but distance was off of course with any dialing. Was over it and in the process of changing rings when I noticed the screw wouldn't just fall freely thru the upper mount. Was a new set of rings from a reputable company.
