Sudden accuracy issues

[5RWill]

So I'm scratching my head with this one and maybe it's self induced. This is with my XM3. The first groups it ever printed were astounding easily a 1/4 minute group with norma golden target 175gr. Since the first picture I had the flash hider loosen when trying to take the can off. Took it home and intended to torque it back in place with my barrel vice. I was missing my torque driver set so couldn't remove the barreled action from the stock or just didn't have the right hex screw. I decided to torque it down anyway. Since then it has printed groups like below. I'm starting to wonder if I damaged the bedding? I didn't see anything physically but it just has me perplexed. I thought maybe it's just me and I'm out of practice. However printed the 5 shot group in the attachments today with the LMT LM8 and I'm by no means a proficient gas gun guy.

Example A:

This was resighted with the norma in the center (horrid) and load development of 168gr TMKs over varget after remounting the flashider, Settled on 45.3gr. I since remounted and timed with the barrel in my barrel vice. Test seating depth today. Should've grouped the norma again but forgot to. The last two pics are setting depth groups I shot today.

 

[hafejd30]

How often was it shooting a 1/4”? Was it just a group or consistently?

Consistent 1/4 moa guns are few and far between. If it was just a group that shot 1/4” especially only 3 shots it may be that those 3 landed in a 1/4” but the gun may be a 1/2 or 3/4 moa gun and the following groups may be a better representation of that

Otherwise remove the stock and retorque the action screws and muzzle device. Also check crown for damage but highly doubt that’s the issue

 

[5RWill]

How often was it shooting a 1/4”? Was it just a group or consistently?

Consistent 1/4 moa guns are few and far between. If it was just a group that shot 1/4” especially only 3 shots it may be that those 3 landed in a 1/4” but the gun may be a 1/2 or 3/4 moa gun and the following groups may be a better representation of that

Otherwise remove the stock and retorque the action screws and muzzle device. Also check crown for damage but highly doubt that’s the issue

That was the initial 4 but i honestly hadn’t printed it on paper until the flash hider came off. Crown looks fine. Bedding looks fine. I’ll retorque it i guess. But the Norma hasn’t remotely grouped under a minute since which is why i was perplexed

 

[hafejd30]

That was the initial 4 but i honestly hadn’t printed it on paper until the flash hider came off. Crown looks fine. Bedding looks fine. I’ll retorque it i guess. But the Norma hasn’t remotely grouped under a minute since which is why i was perplexed

It’s really hard to say it’s changed based on the initial 4 shots being the baseline.

I’d bet more that the rifle’s true capability is shown currently.

Doesn’t hurt to retorque stuff but I’m 99% certain it’s not a 1/4 moa rifle

 

[5RWill]

It’s really hard to say it’s changed based on the initial 4 shots being the baseline.

I’d bet more that the rifle’s true capability is shown currently.

Doesn’t hurt to retorque stuff but I’m 99% certain it’s not a 1/4 moa rifle

Yeah I get your point, and that is fine, i never really said it shot 1/4th MOA all day long. I stated that was the first group. My point is the groups are still sub optimal for a custom build though, by any standard. Maybe it's the TMKs and the 1in10 twist. I'll shoot groups again in the morning with the rest of the Norma I have, some 175gr AAC, and load some more 168gr TMK tonight. Don't get me wrong i wouldn't be shocked if I didn't pull off that group again with the norma 175 but to open up the way it did in the center of the 2nd photo, is nuts to me.

Looking at the bedding looked like one of the trigger retaining pins was making contact with the bedding so I adjusted that and retorqued. Friend of mine is suggesting to remove the flash hider to rule it out, so might be doing that as well.

 

[dms416]

Friend of mine is suggesting to remove the flash hider to rule it out, so might be doing that as well.

I’ve had the Surefire slip-over style muzzle devices on 3 bolt guns (2 brakes. 1 hider)

Every single one caused me problems with either accuracy and consistency. Not sure if it’s the reduced profile it requires or carbon build up on the crown…they have done me no favors (though they look awesome)

 

[5RWill]

I’ve had the Surefire slip-over style muzzle devices on 3 bolt guns (2 brakes. 1 hider)

Every single one caused me problems with either accuracy and consistency. Not sure if it’s the reduced profile it requires or carbon build up on the crown…they have done me no favors (though they look awesome)

That friend mentioned just that about surefire OTB cans and brake/flashiders.

 

[Huskydriver]

What scope?

 

[5RWill]

What scope?

NXS 3.5-15x50 F1

 

[diggler1833]

What scope?

+1

Have you checked the torque on all of your scope rings and bases as well?

 

[Huskydriver]

NXS 3.5-15x50 F1

Between the muzzle device and the scope /mount that's where I would start

 

[5RWill]

+1

Have you checked the torque on all of your scope rings and bases as well?

Between the muzzle device and the scope /mount that's where I would start

Gotcha I’ll double check them as well

 

[stanley_white]

My priority for sudden accuracy loss, if I am confident it isn’t me, goes as follows:

1. Check muzzle device.

2. Check action screws.

3. Check all screws related to my optics.

4. Check bipod / rail.

5. Check for excessive dirtiness.

6. Check shot casings / ammo.

7. Have anothwr shooter, who I know is better than me, shoot and see if the rifle behaves the same.

-Stan

 

[5RWill]

I think I’ve narrowed it down to cheek weld of all things. Noticed when i relaxed normally. I’d have a little scope shadow on the right side of the image and am constantly readjusting, reticle moving left to right. So going fix my cheek weld and start over.

8 shots with the Norma 175.

 

[dms416]

I know you're not a newbie here, but what do you normally shoot? Gas guns? Chassis bolt guns?

 

[5RWill]

I know you're not a newbie here, but what do you normally shoot? Gas guns? Chassis bolt guns?

Bolt guns and gas guns. More often than not bolt guns. Traditionally all my bolt guns have been in manners. Currently running a ATX on my tempest.

I might just be in denial that it’s the rifle but i can’t help myself. Never had a custom perform so poorly especially in 308. Hence the attachments. Ranging from 6.5x47-7 Sherman short mag. Don’t get me wrong it’s depreciating. When i come back from a long absence it takes a while to get back into the swing of things. I’ve certainly don’t shoot like i used to cause i just don’t have the time due to residency. However i like to think my fundamentals are pretty sound.

 

[dms416]

Bolt guns and gas guns. More often than not bolt guns. Traditionally all my bolt guns have been in manners. Currently running a ATX on my tempest.

I might just be in denial that it’s the rifle but i can’t help myself. Never had a custom perform so poorly especially in 308. Hence the attachments. Ranging from 6.5x47-7 Sherman short mag. Don’t get me wrong it’s depreciating. When i come back from a long absence it takes a while to get back into the swing of things. I’ve certainly don’t shoot like i used to cause i just don’t have the time due to residency. However i like to think my fundamentals are pretty sound.

Thought so, that's why i'm not going to hit you with the "check your scope rings" stuff.

Since you mentioned cheek weld/positioning, it took me longer than I'd like to admit to get back into shooting a "traditional" fiberglass stock gun after a decade of AI's and gassers. The limited rail space for the scope, limited to no stock adjustment was a kick in the dick.

And though it is BAD ASS, the XM3 is a bit of a leap backward for most of us in terms of tech...

 

[5RWill]

Thought so, that's why i'm not going to hit you with the "check your scope rings" stuff.

Since you mentioned cheek weld/positioning, it took me longer than I'd like to admit to get back into shooting a "traditional" fiberglass stock gun after a decade of AI's and gassers. The limited rail space for the scope, limited to no stock adjustment was a kick in the dick.

And though it is BAD ASS, the XM3 is a bit of a leap backward for most of us in terms of tech...

The A1-3 certainly has a hell of a comb to it with a narrow ass point. I might reset the diopter as well just to be double sure.

 

[TheOE800]

Maybe it's the TMKs and the 1in10 twist.

168gr TMK is my go to 1:10 308win.

 

[5RWill]

168gr TMK is my go to 1:10 308win.

Makes me feel better cause i really couldn’t find any load data on this bullet. Seemed like it had been abandoned tbh. I put some risers in the stock pack and feel much better about it now. When i first fired though original groups it was winter and i was prone. I really am hoping it’s just been a cheek weld issue that i overlooked.

You running varget?

 

[TheOE800]

Makes me feel better cause i really couldn’t find any load data on this bullet. Seemed like it had been abandoned tbh. I put some risers in the stock pack and feel much better about it now. When i first fired though original groups it was winter and i was prone. I really am hoping it’s just been a cheek weld issue that i overlooked.

You running varget?

Federal T308T, actually. Data over several hundred rounds has been very promising.

 

[5RWill]

Federal T308T, actually. Data over several hundred rounds has been very promising.

I’ve never heard of that. Is it new? I bought some staball match a while back so i could move the progressive to LA and load just haven’t gotten around to using it. I’ll have to check it out.

 

[TheOE800]

I’ve never heard of that. Is it new? I bought some staball match a while back so i could move the progressive to LA and load just haven’t gotten around to using it. I’ll have to check it out.

Federal T308T Tactical TRU - 308 - 168 Grain Tactical Tip MatchKing - 20 Rounds

Bereli.com has the best deals on the web for ammunition, firearms, tactical gear & more. We offer free shipping on all orders, even guns & ammo!

www.bereli.com

 

[supercorndogs]

Have you run a dry patch looking for tight spots in the barrel and confirmed the barrel is free floating?

 

[5RWill]

Have you run a dry patch looking for tight spots in the barrel and confirmed the barrel is free floating?

Yeah confirmed barrel is free floating. Haven’t run a dry patch.

So this was yesterday afternoon 10rd groups 168gr tmk loads on the top 175gr Norma golden target on the bottom.

This right now. 7 shots with the TBAC same 168gr tmk loads. DMS might be on to something and I’m just not at stable as i am with my heavy ass chassis guns. Cause outside of that initial flyer to the right, which was the first shot. It doesn’t look half bad

 

[Hawk in WY]

Hmmmmmm

You shot better groups in winter than now in summer

I would back off your charge weight in .3 grain increments and see if that gets your mojo back.

All other suggestions are good, but I suspect you had unrealistic expectations based on your first group that may have been a statistical anomaly.

Good luck

 

[supercorndogs]

What kind of barrel is it? Does the xm3 use a factory remington barrel cut down?

 

[5RWill]

What kind of barrel is it? Does the xm3 use a factory remington barrel cut down?

Hart XM3 contour. I think it might just be me and getting back in the saddle with a stock? I also moved the scope way back last night. LOP with the spacer is pushing it but i can’t take it out cause the screws are too long for the 1/2” decelerator to sit flush. Or the surefire setup was wonky with a little debris under the flash hider setting on the outer recess of the crown. I’m gonna put the surefire back on after i run these 15 TMKs out then i have to get back on the road.

Same TMK load

 

[5RWill]

So right now i think it’s a myriad of issues. Fitment being the biggest one that i don’t think i realized early on setting it up and running it quickly. Another would be my consistency. As i said it’s a depreciating skill and I’m not shooting as much as i used to. I’m still unsure on the difference between the surefire and TBAC

 

[supercorndogs]

If you run a patch down to the end you can get better look at the crown. Also using zoom instead trying to put the camera closer helps.

The groups look like what I tend do when shooting ar15s.

 

[5RWill]

If you run a patch down to the end you can get better look at the crown. Also using zoom instead trying to put the camera closer helps.

The groups look like what I tend do when shooting ar15s.

View attachment 8454088

I know right? Ironically my LM8 is printing better right now

Forgot to mention before the fiasco with the flash hider being removed this was 1000yds with the 175gr golden target. Which is currently looking better than my 100yd groups lmao

 

[Terry Cross]

I think I’ve narrowed it down to cheek weld of all things. Noticed when i relaxed normally. I’d have a little scope shadow on the right side of the image and am constantly readjusting, reticle moving left to right. So going fix my cheek weld and start over.

You said you are running an NXS 3.5-15x50 F1.
You are not new to rifle shooting so we have to assume that you are aware of the big knob on the left side of that scope and how to use it.

If you are using the big left knob correctly, you head position will not matter

at all

in the least

and have zero effect on your POI shifts or groups.

 

[5RWill]

You said you are running an NXS 3.5-15x50 F1.
You are not new to rifle shooting so we have to assume that you are aware of the big knob on the left side of that scope and how to use it.

If you are using the big left knob correctly, you head position will not matter

at all

in the least

and have zero effect on your POI shifts or groups.

Agreed haha. Parallax has been fine now that the rifle fits groups are looking much better. I put the surefire back on. I actually need to bring it to you Terry for the CMP installation.

I really think it was a combination of fighting the gun and just being out of practice.