Possible bedding of a MDT ACC chassis?!

[Desert Rat]

Hey y’all I had a quick question….. I switched my barreled action from an XLR to an MDT chassis and the accuracy has completely gone off. Now a little background the barrel has 2300 rounds of 6.5 Creedmoor on it and I did a heavy clean of the barrel. I then put 200 rounds through it and it still is not shooting the half MOA groups I was used to. Is it possible that I would have to bed an aluminum chassis? I also was able to borescope my rifle and did not see a carbon ring. The scope is tightened on rings as well to spec. Thanks for your help. Basically I’m wondering if my barrel hasn’t gone out could it be the chassis?

 

[Shoots 700's]

I have a .308 that is doing the same thing. Have you checked to see if the action is moving when you torq the action screws?

 

[Ericsl2]

How is it grouping now compared to the half moa groups you have been getting in the past? Substantially larger or just a hair larger?

 

[FrozenFingers]

Probably the barrel

 

[Desert Rat]

I have a .308 that is doing the same thing. Have you checked to see if the action is moving when you torq the action screws?

The action screws I have checked after both Range sessions and cannot detect any movement whatsoever and they are torqued down to spec 65 inch pounds

 

[Desert Rat]

How is it grouping now compared to the half moa groups you have been getting in the past? Substantially larger or just a hair larger?

Oh it’s not even in the ballpark …… 2MOA groups maybe

 

[Vodoun daVinci]

I wouldn't bed an MDT Chassis for any reason. The issue is elsewhere.

VooDoo

 

[stello1001]

Play with torque settings. Even though manufacturers usually give you a specific setting to torque to, sometimes the rifle will like something else.

 

[Ericsl2]

Oh it’s not even in the ballpark …… 2MOA groups maybe

Have you ever burned out a barrel before? Are you getting sporadic flyers, significant changes in velocity, the usual signs of a shot out barrel? If you drop the barreled action back in to the xlr do groups tighten back up? Did you check that the barreled action is properly installed in the acc, and action screws are the correct length and not a touch too long?

 

[Mike Casselton]

Check the front action screw length. Make sure it's not touching your lower bolt lug.


Otherwise, probably your barrel.

Try your old chassis.
Try another scope.
Make sure your scope rail is torqued correctly.

Don't bed the new chassis

 

[HousePlant]

My MDT chassis, which I bought used, was bedded for the same action as mine (Impact). The gun shot like shit. Because the chassis itself wasn't straight anyway (the barrel channel was slightly twisted but not touching the barrel), MDT graciously replaced it at no cost. MDT, as far as I'm concerned, really earned my respect. They never put up a fight, nothing. But with the new chassis and no bedding, the gun shoots bugholes. One thing that got me when assembling the rifle was that I forgot about the washers for the action screws. Went to the range and found the gun not shooting that great (and my bolt was sometimes hanging up on the front action screw). Took it apart wondering if PROOF gave me a shitty 6CM barrel or if I had another bad chassis or something and that's when I realized I forgot the washers (oops!). Rebuilt the rifle and - poof - it shoots amazing and I'm really proud of it. I have since put a Kelbly's Atlas Tactical action in that MDT chassis with a 6.5 CM Kreiger barrel attached to it and it also shoots well, just a teeny bit larger groups than my Impact/PROOF combo now in an XLR chassis (and it shoots the same bugholes in that chassis and I cleaned a few stages in a PRS match for the first time ever.)

That is all to say, you should not have to bed an aluminum chassis. Something in the assembly is wrong or your barrel is done.

I suppose there is a chance your MDT chassis is not mating to the recoil lug well. Frankly that's where I'd look first given the situation.

 

[spife7980]

OP- put it back in the xlr and see if the accuracy loss follows it.

Bedding it won’t make it shoot worse.

 

[KhaymKhaym]

Hey y’all I had a quick question….. I switched my barreled action from an XLR to an MDT chassis and the accuracy has completely gone off. Now a little background the barrel has 2300 rounds of 6.5 Creedmoor on it and I did a heavy clean of the barrel. I then put 200 rounds through it and it still is not shooting the half MOA groups I was used to. Is it possible that I would have to bed an aluminum chassis? I also was able to borescope my rifle and did not see a carbon ring. The scope is tightened on rings as well to spec. Thanks for your help. Basically I’m wondering if my barrel hasn’t gone out could it be the chassis?

Considering the round count, your barrel is probably shot out man. Thats a lot of rounds for a 6.5 CM tube

 

[Raffy]

Considering the round count, your barrel is probably shot out man. Thats a lot of rounds for a 6.5 CM tube

I know there are some round counts on 6.5cm barrels with higher counts than that and arent shot out yet, but im with you its definitely either getting or gotten long in the tooth. Id be getting a new barrel spun on first before i would bed an mdt chassis. If the new barrel wont shoot then you probably could make a case for bedding it. In which case you might consider asking the gunsmith to give your old barrel back in case it does still have life left in it.

 

[Matagorda308]

Don’t you hate it when they just leave you hanging?…

 

[Raffy]

Absolutely

 

[TreyMeTrey]

Hey y’all I had a quick question….. I switched my barreled action from an XLR to an MDT chassis and the accuracy has completely gone off. Now a little background the barrel has 2300 rounds of 6.5 Creedmoor on it and I did a heavy clean of the barrel. I then put 200 rounds through it and it still is not shooting the half MOA groups I was used to. Is it possible that I would have to bed an aluminum chassis? I also was able to borescope my rifle and did not see a carbon ring. The scope is tightened on rings as well to spec. Thanks for your help. Basically I’m wondering if my barrel hasn’t gone out could it be the chassis?