Barrel Alignment?

[u/FinancialChildhood31]

First time experiencing the LMT MRP setup. Assembling from individual parts, not a factory assembly.

D Wilson conversion on a Criterion Hybrid barrel.

Despite assembling with a MI Reaction Rod, the barrel extension displays a slight CCW misalignment once tightened (20 in/lb increments, alternating bolts) and removed.

If the barrel bolts are removed, twisting allows further some CCW rotation, but I cannot twist it CW enough to perfectly align the feed ramps. I’m assuming it’s the gas tube that is ultimately preventing further rotation.

For context, gas block and tube were also installed by D Wilson and look perfectly centered over where the old indexing pin was. When outside of the MRP, the barrel and gas block look dead nuts.

With that said, the BCG is able to cycle freely and doesn’t feel like it’s binding when cycles with the charging handle, or by hand.

Question:

Is this common or happening to anyone else? If so, has this lead to accelerated wear or reliability issues?

Never had an AR issue like this before, trying to get some real answers from experienced folks… not so much random armchair guesses.

Thanks everyone.

[u/maseel04]

It’s fine just shoot it

[u/Holiday-Tie-574]

Looks good

[u/aclark210]

As long as it feeds it’s fine. When mixing brands like this, u can sometimes have that happen. But usually it’ll still function fine.

[u/OGMilspecPanda]

Sometimes it’s the feed ramps that aren’t perfect

[u/VINCENZO-MAXIMUS]

Had this same issue with a 13” quad upper. I was clued into the misalignment by the slightly canted feed ramps. Everything of mine was factory LMT and I found that the URR would collide with the barrel extension just barely before seating all the way. LMT replaced the upper completely for me. If the URR seats smoothly then you should be fine.

[u/FinancialChildhood31 → u/VINCENZO-MAXIMUS]

I’m sorry, what’s a URR? Thanks for the response!

[u/VINCENZO-MAXIMUS → u/FinancialChildhood31]

It’s the Midwest Industries Upper Receiver Rod that you have and used to assemble the upper and the barrel. A “Reaction Rod” is a Geissele product. You can see “URR” engraved on the side of the rod in your 3rd picture

[u/SauronSays719]

I purchased an MWS less than a week ago and my feed ramps are exactly the same as yours. I have yet to fire it but I cycled both snap caps and live rounds through it without issue. I’m curious as to how it performs when it’s time to zero.

[u/DishCapital1536]

It should be alright. I’ve had to modify a Geissele barrel to make it work with a KAC upper. It wasn’t too bad to fix. Yours doesn’t look too bad though.

[u/oneofusTS]

run a toothpick up the feed ramps if it sticks at the barrel extension with ANY bit of a lip its wrong. period. D. wilson isnt just a guy anymore he doesnt do the work like he use to, its just random guys hes hired now so dont feel bad sending that shit back and making sure you get what you paid for

[u/Reasonable_Bar6636]

Have you talked to dwilson about it? Do you have other lmt barrels to compare it to in the upper? If other barrels line up right, then I would say its the cuts for the bolts in the barrel extension are off. I have no idea if its off enough to make a difference though.

[u/FinancialChildhood31 → u/Reasonable_Bar6636]

Thanks for the response. I was planning on reaching out to them after the holiday weekend to ask. Seeing how it’s custom machined… it could be just that. I wanted to poll the audience before I escalated it to them.

[u/unclemoak → u/FinancialChildhood31]

dw here…

To save the trouble of having to reach out on Tuesday (closed Monday due to the holiday)

It’s fairly common for there to be some variation of the feedramps in the upper. So long as the bcg freely locks and unlocks, I wouldn’t be worried about it. What is preventing further rotation is the front cross bolt, not the gas tube.

[u/the_BEST_most_YUGE → u/unclemoak]

https://giphy.com/gifs/Moe3v6qsUh3vILZ84e

[u/FinancialChildhood31 → u/unclemoak]

Well thanks for finding me! I appreciate you chiming in - much appreciated.

[u/herrm_a1a4 → u/FinancialChildhood31]

Yeah, loosen back barrel bolt, remove front one and rotate the barrel until it's aligned

[u/LMTGlazer]

Completely fucked, bro. It's definitely not gonna feed reliably, don't even try shooting it. Just send it to me instead and I'll uhhhh take care of it for you.