Did my SWFA 3-9 take a dump on me?

[willfrye027]

Ive been shooting a few new tikkas and chasing my tail with one of them (22 creedmoor). To make a long story short, it’s been wandering in zero and once or twice has been completely off the paper at 100 yards. It would work fine for a nice, 10 shot 100 yard zero…dial out to 660 and ring the steel, and then back to 100 and it’s completely missing paper.

List of components/what’s been done:

1. Alterra carbon hunter, swapped to KRG bravo all properly torqued down (thought it was the bedding in the alterra, but reproducing the results in the bravo)

2. Sportsmatch T084, degreased and loctite/torqued down to 45lbs and 20lb for ring caps

3. Swfa 3-9 from one of the newer production runs. I had it briefly on a tikka 6.5cm and had a few head-scratcher zero shifts but didn’t think much of it.


Today after meticulously re-verifying action screws, scope mount, etc I attempted to re-zero. This barrel has been reliably producing 1.3” 10 shot groups at 100 yards.

Scope does not seem to track quite right..I had a hard time getting a perfect zero so I shot this group:




Then I (gently) gave it a few thumps. Nothing crazy. 3-4 inch drops, and a foot drop onto the but pad without letting it fall all the way.

Then shot these two, missing left of the group.




Next step is swapping scopes from a dead-nuts reliable 25 creedmoor. I switched the bushnell LRHS onto the offending 22 creedmoor and put the SWFA on the reliable 25 creedmoor.

If it keeps losing zero I can try another set of sportsmatch rings, otherwise I feel like it’s the scope.

Any other thoughts on my method here? FWIW, I have a few other tikkas that have never missed a beat. Wearing a mix of bushnell LRHS, nightforce SHV, and previously some of the older SWFA 3-9s

@Formidilosus ?

 

[KenLee]

I'd bet on scope "shit the bed"

 

[Formidilosus]

@Formidilosus ?

Swap scopes and see. There are no scopes made with a 0% failure rate. Some have extremely low rates of failure, most extremely high.

 

[willfrye027]

Swap scopes and see. There are no scopes made with a 0% failure rate. Some have extremely low rates of failure, most extremely high.

SWFA has been very good for me in the past, will be surprised if it’s truly a dud but hey that’s why you trust but verify..

 

[Antares]

I had a 6x shit the bed on me a few months ago. Reticle came loose and would rotate inside the scope body while lightly thumping the side of the rifle with the palm of my hand. SWFA promptly offered refund or replacement. Hard to get too upset given the price. Stuff happens. Just glad I was training not hunting.

 

[Formidilosus]

View attachment 575552

Thankfully, the center is still the center…. grin

 

[walk2112]

Curious to see what you learn/conclude here. I’m about to start a testing/load development journey with one of the newer production batch scopes myself, will try and add to the pool of drop test data soon if things pan out.

Hoping they didn’t build the latest batch on Friday before a holiday weekend (ha).
Will test to be sure.

 

[JCMCUBIC]

I've had one of the SWFA 2.5-10x32's turn into a rattle and the reticle turn with a distorted view. SWFA sent a replacement asap.

The details listed on the 3-9 in the op seem like it's jacked up. I'd probably replace it with a known good on the rifle and put the 3-9 on a different rifle and test both just to verify...but I'd be surprised if it was suddenly good.

 

[willfrye027]

Well, as much as I’d like to blame the ugly kid on the block (swfa)…looks like it’s NOT the scope.


First thing I did was swap the bushy onto my .22 creedmoor. 5 shot group after adjusting for zero.


Put the SWFA on the 25 creedmoor and got close enough to zero



Smacked the 25 creedmoor with SWFA around a bit, dialed a couple hundred mils back and forth, confirmed it was tracking correctly on a tall target (didn’t take pics). Damn thing comes right back to zero like it’s supposed to. So my conclusion is probably not the scope.

So WTH is wrong with the .22 creedmoor??

I remember accidentally smacking the barrel against my floorboard before it lost zero on a previous occasion. So I replicated that with a few more thumps for good measure. This is with the reliable, proven bushnell scope on the troublesome .22 creedmoor.



You can see the next 4 shots are all over the place, missing high and wandering.

I’m thinking it may be the barrel nut setup and possibly not torqued down well. The same type of zero shift happened in another stock so I doubt it’s an issue there.

@Formidilosus have you seen issues with barrel nuts and zero retention?

Next up strip the gun down, put it in a vice and torque that sucker down to see if it fixes things.

 

[Formidilosus]

@Formidilosus have you seen issues with barrel nuts and zero retention?

Next up strip the gun down, put it in a vice and torque that sucker down to see if it fixes things.

Yes. Barrel torque is a thing. As soon as I read that the scope was working, barrel being loose is the most likely candidate.

 

[4th_point]

I would check the muzzle device as well, if using one.

 

[sndmn11]

I just had a new to me barreled action throw some terrible groups when everything should have worked fine. I thought it was bullet related but when tightening the magnetospeed on, spun the barrel off. Definitely learned that lesson now.

 

[willfrye027]

Yes. Barrel torque is a thing. As soon as I read that the scope was working, barrel being loose is the most likely candidate.

torque was probably the issue. Put the action in a vice and gave it some muscle on the barrel nut this time. Probably should buy a torque wrench..

Can’t remember how many shots in this group. Re-zeroed and thumped the barrel in between every 1-3 shots. Looks like it’s holding zero. The bottom left shot was from another day.

Need to swap back to the 3-9 SWFA on this gun and re instill some confidence in the setup over the next few hundred rounds.

SWFA, sorry I doubted you

 

[Formidilosus]

I just had a new to me barreled action throw some terrible groups when everything should have worked fine. I thought it was bullet related but when tightening the magnetospeed on, spun the barrel off. Definitely learned that lesson now.

View attachment 575954View attachment 575955

If dudes understood how fragile their “bad azz custom rifle” was with 35 ft-lbs of barrel torque was, they wouldn’t be so happy.

 

[sndmn11]

If dudes understood how fragile their “bad azz custom rifle” was with 35 ft-lbs of barrel torque was, they wouldn’t be so happy.

You forgot the pound signs.

1kSteelBang

 

[willfrye027]

If dudes understood how fragile their “bad azz custom rifle” was with 35 ft-lbs of barrel torque was, they wouldn’t be so happy.

Begs the question: do you torque your barrels to a specific ft/lb?

 

[Formidilosus]

Begs the question: do you torque your barrels to a specific ft/lb?

Tight. Start at 100 ft-lbs and go up from there. Tikka factory is about that as well.

 

[JCMCUBIC]

Nice to hear it's not the scope. Interesting on the torque.

I've a couple of Defiance actions that I've installed prefit's on. Torque umbers I saw listed were all over the board. I ended up going with 50 ft-lbs and haven't had a problem. I've only been using one of them a couple of years and about a year on the other, though I used it for a year previously with a different barrel. These are fixed headspace so it's just barrel to action with no barrel nut on these...which I'd guess would be less likely to have issues(?).

Glad the OP found the issue.

 

[4th_point]

If I recall correctly, Tac Ops has progressively increased their barrel torque over the years. Not sure what it is now, but hundreds of foot-pounds rings a bell.

 

[4th_point]

Regarding loose nuts, anyone heard of issues with issued MRADs? Not sure of the details but sounds like barrel to receiver problems.