Barrel accuracy

[LA Hog Hunter]

I bought a 20” fluted ELD barrel in a Grendel Upper kit from Delta Tactical. I assembled it and had really good results at the range, 1” MOA or less at 100 yards with Hornady Black 123 ELD.
My hunting buddy was impressed with the accuracy of this barrel and wanted the same setup for hog hunting. Unfortunately, Delta was out of the 20” fluted barrel. He ordered an 18” ELD barrel and installed the barrel and a new Davidson Defense Mod Pro 15” hand guard on his gun.
Once at the range, this 18” barrel would not group at all with the same load. The shots at 40 yards were 2” apart and 7”-10” at the 100 yard distance. The barrel is tight and free floated. The gun functions fine but the gun will not group.
We tried with or without the Super Compensator muzzle brake with no change. Normally, I would try other loads to eliminate bullet weight, but the groups are so large and all over the place. We also have eliminated scope variables. We both shoot an ATN X-sight 2 and the same bullet. We swapped out scopes with similar results.
Could this be barrel harmonics causing these huge groups or should I suspect another cause?

Thanks,
LA Hog Hunter

[kmon]

Could be several things but I would not expect it to barrel harmonics for that large of groups. A friend had one that was shooting that way in a bolt action he bought used and in trying to figure it out I took it to a friend that re did the crown on it. Accuracy was about 1.5 MOA after that. Turned out the crown was not square with the bore. Just one example of something you do not expect.

I would double check assembly and call the manufacture and see what they have to say if nothing is found with the check

[LA Hog Hunter]

Thanks,
My plan is to reassemble and check the barrel nut torque. My friend wants to reorder a 20" barrel and just go with it but his has me stumped.

[VASCAR2]

Delta Team Tactical has been the topic of conversation on this and a couple of other forums. Here is a previous discussion.


http://www.65grendel.com/forum/showthrea...ns-on-them

[oyster]

You also can't necessarily expect two barrels to shoot the same bullet the same even from the same manufacturer. Has he tried any other loads?

[Mad Charlie]

You also can't necessarily expect two barrels to shoot the same bullet the same even from the same manufacturer. Has he tried any other loads?

7-10" groups! Somehow I don't think tweaking a load is gonna help much. That rifle needs attention.

[trace]

I'd bet the crown is jacked up. Can you take a close-up picture of it?

[lazyengineer]

Something is defective

[ARErector]

I don't want to offend you or your friend, but are you sure the barrel was installed properly? I had an upper that grouped really badly like that. I had bought it from Delta Team Tactical as well. After inspecting it, the barrel nut was not tight. It actually rattled on the gas tube! After disassembling and properly reassembling the upper it worked fine and had decent groups. Just something to check.

[NugginFutz]

I don't want to offend you or your friend, but are you sure the barrel was installed properly? I had an upper that grouped really badly like that. I had bought it from Delta Team Tactical as well. After inspecting it, the barrel nut was not tight. It actually rattled on the gas tube! After disassembling and properly reassembling the upper it worked fine and had decent groups. Just something to check.

I don't mean to disappoint you, but the OP has only ever posted twice, both times in this thread. A quick check reveals that they haven't been on the site since the day after their 2nd post, so I doubt you will offend either the OP or their friend.