DTA SRS Return to Zero issue

[tridiumk]

Having issues with my DTA regarding changing barrel and returning to the same impact point.

In the attachment (shot at 200 yards), the scope isn’t touched at all during the 4 shots. If i don’t touch the barrel, i can sight it in, and shoot sub 0.5MOA all day. As soon as i change the barrel, it goes way off, like waaaay off. You can see in the attachment, its moving like 5 to 7 inches or more every time i change it. Basically means every time i change the barrel, i need to sight it back in again.

I know that between the different barrels i have different impact points, i’m fine with this, but this problem is something really frustrating.

I know that this is not supposed to happen, and DTA claim it is meant to return to impact point... Any thoughts? anyone experienced the same thing ?

 

[Abq-Defense]

Sorry, to ask, but its best to start with the basics.... Are you torqing down the 4 screws to the same 70lbs each time?

Are you setting the lock screw?

 

[tridiumk]

I use the following method:

1. Put in barrel
2. put in Bolt, engage bolt into closed position
3. engage lock screw (although once i didnt do this, but not sure what difference it would make as it is loose and just turns that stopper in front of the barrel)
4. do up 4 screws hand tight to about 35 pound so that the barrel is held firm before going to 70 pound
5. go back over each screw to 70 pound.

 

[Abq-Defense]

Well it sounds like you are installing the barrel correctly. I don't have any other ideas aside from ensuring that your scope mount and rings are tight.

 

[tridiumk]

ensuring that your scope mount and rings are tight.

Yeah, no issues there. Using La Rue 50 cal mounts and a $4000 March Scope. When not changing the barrel, it shoots sub- 0.5 MOA all day, so the scope and mount are behaving perfectly for repeatability.

 

[BLDTYLRY]

Anything to do with Cold Bore?

My cold bore shots are ~1" High and ~1" left at 100yds. I have 4 caliber conversions and I write down the scope adjustments for each caliber conversion in my notebook for multiple distances. So far, all of my change outs have only deviated at most 0.1 mil in elevation but this could be due to outside temp/pressure. The windage adjustment is seldomly ever effected.

 

[tridiumk]

tried on a hot bore and cold bore, same same. Will see what DTA says, no doubt it will involve a massive dick around of having to send the gun back for testing or something.

 

[BLDTYLRY]

I'd recommend doing your caliber swap testing at 100yds. Stick four 1" dots on a paper target and shoot the following strings and post your results:

Caliber 1 - Shoot a 1st group of 5
Swap calibers
Caliber 2 - Shoot a 1st group of 5
Swap calibers
Caliber 1 - Shoot a 2nd group of 5
Swap calibers
Caliber 2 - Shoot a 2nd group of 5

Otherwise, just seeing four shots on a single target leads me to believe it's anything but the barrels/rifle.

 

[BLDTYLRY]

BTW - Do you have a Gen1 or Gen2? Reason I ask is if it is a Gen1 and the locator pin is broken, consistency is going to be an issue.

 

[tridiumk]

BTW - Do you have a Gen1 or Gen2? Reason I ask is if it is a Gen1 and the locator pin is broken, consistency is going to be an issue.

Gen 2.. the A1 version. Brand new in December 2013..

 

[SRSDriver]

You are using a torque wrench, correct?

 

[tridiumk]

Yeah, they come with preset 70 pound torque wrench tool in the kit


Sent from my iPhone using Tapatalk

 

[sib1948]

Contact Desert Tech. I had issues with my barrels sticking when trying to swap them. Sent it in and had it back in less than 3 wks with issues resolved.

 

[tridiumk]

spoke to them today, they want to see 5 shots in 338, 5 in 260, then 5 in 338. all video'd. THey claim there hasnt been a single complaint in this regard, so i suspect i have had a brain lapse somewhere along the line in the barrel swapping... i'll try it again, take 2 video cameras to show real time at the target and me at the shooter in changing the barrels. i hope its just my stuff up !


Sent from my iPad using Tapatalk

 

[BLDTYLRY]

Did you get this resolved?

 

[orkan]

I would avoid turning that barrel lock until you get the barrel torqued down. I never use that barrel lock on any of my chassis. I'd test it without using the lock, and see if that helps. Also, make sure you are using the same torque sequence on the bolts. I start front to back each time.

We have never heard of this happening to anyone, or any of our customers either. So far, they have all repeated zero to within 1/2moa or better.

 

[tridiumk]

Ok, ill try doing it that way... Thanks!


Sent from my iPhone using Tapatalk

 

[VKC]

Did you try inserting the bolt and making sure it indexes well with bolt?


Sent from my iPhone using Tapatalk

 

[tridiumk]

Before I tighten the 4 screws, I engage the bolt..


Sent from my iPhone using Tapatalk