Gunsmithing My groups went from 0.5" to 3.0", no idea why, ??

[1000yard]

I have a Rem. 700 SPS Tactical 223rem. The gun was a real good shooter, consistent .5 moa, then yesterday I went out to shoot it with a suppressor, to check for POI shift, with /without can. I put 1 round through it, to check zero, it was off low and right, adjusted scope and shot again, was near x-ring(100yd sight in target)then I put 2 more rounds through the gun,it looked like a shotgun pattern.I checked the scope mount,rings,action screws, flash hider/adapter, all tight.the barrel is threaded .5-28
Moved to other side of target, shot 5, low and scattered.
Changed scopes, sightd through bore. Put 1 through the gun @ 100, adjusted scope, the put 5 on the target, same thing scattered. I have looked at the crown, I can't see anything out of whack, no burrs felt, all looks good. But it just went to hell in a hurry.The barrel doesn't have 200 rd through it.
Any ideas, suggestions? Or someone locally that can check it.

 

[bohem]

Re: My groups went from 0.5" to 3.0", no idea why, ??

I'm assuming this is the same ammo that shot well before, correct?

When's the last time it was cleaned? I have a factory Rem barrel that shot very well for about 75-100 rounds and then went to shit, cleaned with WipeOut (1 hr and then 12 hr of soak time) and it came right back into sub MOA groups after 2 fouling shots.

90ish rounds later, shotgun groups again. It was copper fouled big time.

 

[Chiller]

Re: My groups went from 0.5" to 3.0", no idea why, ??

All your bolts torqued?

The barrel floated or an contact on the barrel?

The barrel tight you mentioned a supressor..??

 

[300sniper]

Re: My groups went from 0.5" to 3.0", no idea why, ??

did you try it again without the suppressor?

 

[KYS]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Check every bolt on your gun. If they are not torqued correctly you are suffering there.

Check the suppressor for proper seating and is it concentric? Did you get a baffle strike?

hand loads or factory ammo?

Is your action bedded? is the barrel contacting the stock at all? especially when fired?


Answer these and we can help you more

 

[1000yard]

Re: My groups went from 0.5" to 3.0", no idea why, ??

All bolts torqued, everything tight, no baffle strikes, barrel is clean. No contact with stock. I am totally confused on this one. I am shooting the same ammo I was shooting previously.I tried again after removing the can, still bad. It went from tackdriver to shotgun overnight.I am going to take to APA and let them borescope it, and see what they think. I am headed there after lunch. I'll post results when I get them.

 

[Lumpy Grits]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Crown?
With 'pressor on you could/may have the bbl and stock "kissing" from time to time during recoil, BTDT, BTW.
'pressor is off C/L and you can't see the bullet strike/marks.
Respectfully,
LG

 

[USMCj]

Re: My groups went from 0.5" to 3.0", no idea why, ??

What scope are you using? Try another scope, or even another shooter.

 

[High Binder]

Re: My groups went from 0.5" to 3.0", no idea why, ??



I had this happen to me about a month ago and after a quick investigation found that I had forgotten to tighten the bolts holding my action to that stock, once tightened it was back to bug-holes.

 

[jrbet83]

Re: My groups went from 0.5" to 3.0", no idea why, ??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">did you try it again without the suppressor? </div></div>

exactly......shoot it without the can and see if it sucks back. that should have been step one. since you still said it shoots like crap. has it ever shot good with the barrel threaded. if everything is in spec (bolts, free float etc). I'd make sure it's not copper fouled.

 

[1000yard]

Re: My groups went from 0.5" to 3.0", no idea why, ??

I checked and double checked all the bolts, swapped scopes, tried without suppressor and/or flash hider/adapter. same results, bore was clean.I dropped it off at APA this afternoon, to let them check it out and borescope it. I could't visually see any defects with naked eyes. I will leave it in their capable hands to figure it out. As far a changing shooters, I only had one available, I can usually take a good rifle and shoot minute of prarie dog out past 1000 yards, so a sight in target at 100 yards with my .223 shouldn't give me too much trouble. Something in the milk ain't clean, I just can put my finger on it. As soon as the folks at APA tell me something, I'll report it here. Thanks for the input.

 

[USMCj]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Well you sure did take it to the right people! If they anyone is capable of figuring out what went wrong its Jered and crew.

If everything els is as you said, then it could be a defective barrel where a chunk of land broke off and is causing all kinds of hell in the bore. Its more common with stainless barrel than CM but it should only happen to a barrel with a LOT of rounds through it.

 

[1000yard]

Re: My groups went from 0.5" to 3.0", no idea why, ??

I got my rifle back yesterday, Jered inspected the barrel and saw problems with the crown. He contacted me to discuss the problem with the gun, and I said to go ahead and recrown it as well as correct an issue with the flash hider.. I got to go to a public range near my home this morning to shoot it. I am totally pleased. The rifle is shooting great again. I may have to play with some different loads, but I have some Atlanta Arms 77 grain match, and @ 100 yards I shot 5 that you can cover with a dime.
I can't say enough good things about APA, just great guys and great service and workmanship. Thanks agin, everybody for the input. Now it's time to hunt some critters, with confidence.

 

[Jayman_10X]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Good to hear you got it back on track! I recently purchased an APA-built rifle, and can also testify that Jered and his staff are 1st rate. He has a customer for life.

 

[USMCj]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Glad you got it worked out! and +10000 on APA!

 

[Greg Langelius *]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Late to the topic, glad you found the solution.

As I was reading along, I came to the conclusion that changed performance indicates a changed system.

I was going to suggest that there may be issues with harmonic mass, which very likely changed with the addition of a suppressor; and with crown integrity, which <span style="font-style: italic">might</span> have changed.

 

[GRIM]

Re: My groups went from 0.5" to 3.0", no idea why, ??

I was going to suggest re-crowning it as I remember Frank White (Compass Lake Engineering) once has a similar problem in his son's rifle. Went from shooting well to shotgun like patterns. They looked at it under magnified power and still couldn't see anything wrong. He re-crowned it and back to shooting tiny groups afterwards.

You did everything else that could have been the culprit so that is all that was left. The worst thing is not having confidence in your stick to hit what you want.

Nice shooting too!

 

[new_guy]

Re: My groups went from 0.5" to 3.0", no idea why, ??

Just goes to show ya... I would have tried the scope first, and I would have been wrong.

 

[Clark]

Re: My groups went from 0.5" to 3.0", no idea why, ??

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">the barrel is threaded .5-28..tried without suppressor and/or flash hider/adapter. same results</div></div>

My experiments with crowns and my reading other people's experiments with crowns suggest to me that crown do not have a measurable effect in the 0.5" to 3.0" group range.

I have a .223 I built with a 22LR barrel and 1903 Turk action that I have ~ $100 into + scope, that averages ~ 0.95" 5 shot groups at 100y.
I expect that if I hack saw off 1/2" the muzzle while at the range, that the group size will not change.

But if I hit the muzzle with a hammer and peened some material into the bullet path, then I would expect a measurable change in group size.

My understanding could be all wrong about crowns, and I just have not tried the crown that is bad enough yet.

Do you have pics of the crown before and after fixing?