Mag fed Dominion Grizzly jamming issues

[5h00ter]

Hey guys so I just got myself a 12.5" 12 gauge mag fed Dominion Grizzly from Canada Ammo, I've heard that there were jamming issues with it so I tried cycling some ammo through it. I have two types of ammo, Score 00 buck shot, and Federal Truball rifled slug. Both of them are in 2 3/4".

For some reason, while I was cycling through both types of ammo, the Score shells occasionally get stuck on the feed ramp and jam. It always seems to be the exact same shells regardless of what order I load them in the mag. However, I have no problem with the Federal shells.

I have both the aftermarket steel mag and the mag that the gun came with. No difference

Not sure if it's the ammo, or the shotgun itself. I think either the ammo is the issue, or the fact that I haven't really broken it in yet. Has anyone had similar issues? I kind of don't want to go through the hassle of sending this back to CA if the gun is actually the issue.

 

[Tachead]

It is the ammo(well, maybe the cheap magfeed gun too as they are known to be much less reliable) .

Score ammo is garbage(especially their buckshot) and is known to cause feeding issues due to the poorly done crimp and loading procedures they seem to use. There is a thread on this just below yours...

https://www.canadiangunnutz.com/for...oking-for-a-decent-price-on-00-buck-and-slugs

https://www.canadiangunnutz.com/forum/showthread.php/2004025-Score-12g-00-buck-feeding-issues

 

[yank]

Its a well known issue with the gun. There are a few things you can do, mostly modify the follower in each mag with a raised dimple. Do a search here and you will find it. Its a great idea for a gun but needs work to keep it funtioning reliably.

 

[Butcherbill]

Its a well known issue with the gun. There are a few things you can do, mostly modify the follower in each mag with a raised dimple. Do a search here and you will find it. Its a great idea for a gun but needs work to keep it funtioning reliably.

This^^^

It could be the Score ammo but I’ve always found the mag is usually the culprit 90% of the time if there is a jam while feeding a shell with 2 3/4” shells. Either the feed lips are too tight or rough, or the follower needs to be dimpled. Dimpling it gives the nose of the shell a higher angle as it try’s to enter the feed ramp and chamber opening.

Adjusting the lips and adding a dimple usually solves one or a combo of both issues, the mag fed Grizzly’s weak link is the mag. Otherwise it’s as rock solid as the tube fed version.

 

[Butcherbill]

Like so.

 

[rebelent]

What did you use to dimple the mag?

 

[Jon.]

I solved my issues by selling the damn thing. I had a half dozen mags and tried every trick in the book and nothing would work the least bit reliably.

 

[Butcherbill]

What did you use to dimple the mag?

I used the largest punch in my punch set, I took a block of wood and drilled a shallow hole in it and set the follower on top of the block. Hammer and punch and pounded the dimple into the hole in the block of wood.

 

[Tachead]

I solved my issues by selling the damn thing. I had a half dozen mags and tried every trick in the book and nothing would work the least bit reliably.

Good plan imo. Grab a real pump shotgun to try next time(870P, 590 A1, Fabarms, Benelli) and I hope you are issue free going forward. You get what you pay for a lot of the time imo/e.

 

[grumpyguy]

Like so.

Bill, were you able to get yours to run reliably with these mods?

 

[Butcherbill]

Bill, were you able to get yours to run reliably with these mods?

Yes, mine now functions 100% with 2 3/4” loads. High and low brass feed fine, I have done other things as well that improved feeding and function of it. Mainly de burring and polishing the action bars, feed ramp. I opened up the chamber mouth and mirror polished it as well as polishing the mags prior to adjusting feed lips. PM me if you have any questions and I can give you some tips or send you pics of the chamber mouth.

I find 90% of the time I had a ftf malfunction it was mag related, it just takes some tuning. Springs had to be cut shorter on a couple aftermarket metal mags I bought to match the factory metal mag mine came with, I’d say an hour or two with a dremel and some wet dry sandpaper and it’ll be all tuned up. It’s never going to load 3” shells 100% but that’s totally a mag issue, it’s not long enough to strip a 3” shell reliably. They hit the front of the mag and jam.

 

[hollowedpoint]

I did this mod and it works great!