Coffin mag too tight

[Grant435]

Has anyone tried a coffin mag in there max31 upper and it was extremely tight fitting? I received my first coffin mag yesterday and wanted to insert in upper. It only went in like 1/3 rd of the way and I thought of course usually my luck. I noticed there’s a guide rail on front side of coffin that’s not on drums or zmag-s. I had to remove and keep trying until eventually I got it inserted. Seems like every time I want to insert it I have to regrip and work it in. Definitely no fast smooth mag changes like a zmag or drum. I got 4 more coming in with really nice finish and would hate to file anything or maybe those will fit. Is this a common issue and what did you alter to fix it? Thanks

 

[Fulautotank]

I have 5 coffin mags and a max10/31. All the mags fit fine and are more on the loose side.

 

[Gaujo]

Bro you just destroyed a $150 magazine's resale value. I'd check the ones coming in, and if they also don't fit something's wrong with the magwell.

 

[JohnnyE]

Bro you just destroyed a $150 magazine's resale value. I'd check the ones coming in, and if they also don't fit something's wrong with the magwell.

I read his comment a bit differently to mean that he repeatedly removed and reinserted the coffin mag into the magwell to get it to seat, not that he removed any metal from the coffin mag. I hope I'm right.

 

[gun.bro]

I had a problem where the raised channel on the mag did not fit the recessed channel in the lage upper, i CAREFULLY dremmeled the channel on the mag a little skinnier.. works and fits fine now!

 

[Grant435]

I read his comment a bit differently to mean that he repeatedly removed and reinserted the coffin mag into the magwell to get it to seat, not that he removed any metal from the coffin mag. I hope I'm right.

Correct, I didn’t remove any metal just removed mag and reinserted. I got home late from work so I didn’t really dig into it but I heard a bit of grit when first inserting so I figured ok there’s some residue in magwell rail guide or on mag. Did quick wipe and got further but still surprised it was struggling. I didn’t feel any residue in there but I’ll take a q tip to really clean in the corners of it. I just thought I would ask if these mags are known for tight tolerances. Even if there is minor residue I was surprised for it to cause such an issue. I’ll do more thorough inspection and cleaning when I get a chance later tonight. Appreciate the replys so far

 

[llamasabound]

I dremeled three coffin mags (sorry future!) before I gave up and widened the channel slightly on my 10/31. Everything fits now!

 

[DistalRadius]

File > Dremel

 

[CRofMel]

I'm selling 18 coffins and a 4 coffin leather pouch for sale if you wanna buy another to try.

 

[gun.bro]

I'm selling 18 coffins and a 4 coffin leather pouch for sale if you wanna buy another to try.

price?

 

[CRofMel]

$145 shipped upper 48. Got (3) loaders, $120 shipped.

 

[Concorde]

Has anyone tried a coffin mag in there max31 upper and it was extremely tight fitting?

Yes... I sent them with the new MAX31 back to Richard Lage to check them out... he said that my Coffins had been refinished and had too much Cerakote thickness on them

 

[Grant435]

Well here’s the close up picture. Seems like the recessed channel on upper is not as wide as the raised channel on coffin mag. I should be getting 4 more coffins in about a week. I will try those to see if it’s the mag or upper. After reading some of your reply’s I see it’s not uncommon.
https://i.imgur.com/L4J0l2C.jpg

 

[Grant435]

Pic of mag also
https://i.imgur.com/h1ahvz5.jpg

 

[gun.bro]

Well here’s the close up picture. Seems like the recessed channel on upper is not as wide as the raised channel on coffin mag. I should be getting 4 more coffins in about a week. I will try those to see if it’s the mag or upper. After reading some of your reply’s I see it’s not uncommon.
https://i.imgur.com/L4J0l2C.jpg

Exact same as mine. There was no extra finish/cerakote on mine. I had too much metal. I shaved off a little on each side and they now fit correctly. As for future value, they stay the same if they stay paired with the Lage upper..