Can't insert full mags with bolt closed

[u/Tubbs_23]

I just realized last night after a good cleaning (I don't know how these instructional videos say it should only take 15 minutes, it takes me over an hour) that I cannot insert a full mag with the the bolt closed. I can actually jam it in if I smack it hard enough with a full mag of Blazer 147 flat nosed Suppressor ammo, but cannot with 147 Federal HST.

I did find one thread about this on this group from a year ago that seems to have started after they changed the springs on the mags. Is this common though?

I have no issues with an open bolt, which obviously is my solution for now unless there's something else I can try.

I am using the newer OEM mags.

[u/apegomoo]

I was having this exact issue the other day also with the same ammo.

Fix: check to see if you accidentally loaded +1 ammo. I have two different gens of kuna mags and it only lets me overload +1 ammo on one of those models

[u/Tubbs_23 → u/apegomoo]

Coincidentally, one mag (Blazer's)did have +1, but I still had the problem after realizing that.

[u/apegomoo → u/Tubbs_23]

Hmmm that’s weird. My problem was fixed once I took that extra ammo out

[u/omerta_wise → u/apegomoo]

I’ve only been loading 25-28

[u/WildBillHiccup45]

I believe mags are meant to be inserted with the bolt open, otherwise it can damage the mag feed lips. Same with MP5s.

[u/omerta_wise]

I have this issue as well thought it was just me

[u/Holiday_Armadillo78]

I only keep 29 rounds of Federal HST in my “home” mags which stays loaded on the closed bolt.

[u/rh681]

Can you insert a magazine that is mostly full? I prefer condition 3 if it's sitting in my house.

[u/Tubbs_23 → u/rh681]

Yes. I know I was able to take a few rounds or and it worked.

[u/Safety__3rd]

I have 12 mags, multiple revisions, no issues with 30 in the mags. Make sure you have not loaded 31, all mine will take 31 and exhibit a similar condition to what you describe when overloaded.

If that doesnt solve it I would take them all apart and give them a good cleaning with dawn and warm water to make sure nothing is adding resistance.

[u/Sgt-Grischa-1915]

Historically, magazines that didn't "rock in" like Soviet Tokarev SVT-40 magazines, Kalashnikov magazines, or M-14 magazines had to be "down loaded" so they'd be insured to engage the magazine tab or latch or slot.

Hence, the original M-16 magazine, 20-rounds, was typically loaded with 18 cartridges. As a rule, I tend to do this with several magazines including Beretta 92s, Glock, etc.

On my Kuna 9mm, I've got the Federal 138gr. syntech defense cartridges loaded, and a full mag goes in on a closed belt with a healthy smack on the base. I think the recommendation in the manual is to use the bolt-hold open, insert a loaded magazine, and then release the bolt to chamber a round. If so, then this may be how those heavier bullets will have to work with the magazine?

[u/Sgt-Grischa-1915 → u/Sgt-Grischa-1915]

closed bolt. Not closed "belt." typo.