So I took out my new SR22 to the range today & ran about 350 rounds through them. All rounds ran flawlessly, both Thunderbolt & some Remmington I think.

But when I would load a new mag with the slide back & try to release it via slide release, the round seemed to get stuck on the feed and just wouldn't go. I always had to manually push or bump the slide forward a bit for it to push the round in the chamber.

I had to do this every time I loaded a new mag, with both types of ammo. Once it was loaded it raw flawlessly, but I would obviously like to address this issue right away.

Any thoughts on what it could be?

JS,

An SR22P should chamber a round from the magazine using the slide release.

You are using the worst ammo on the planet, ThunderBolts, which often coat the inside of a barrel with lead.  The other Remington is an unknown.

By 350 rounds of ThunderBolt, you gun is rather dirty and crudded up.  I would suggest this:

1)  Clean the entire firearm including disassembling the magazines.

2)   Lube the pistol and leave the inside of the magazine tubes dry.

3)   Find some other ammo, CCI MiniMags, CCI Blazer, WW36HP, WW40RN, NOT any Federal as it is usually too weak and not any modern Remington.

4)   If your gun is not leaded up, set the ThunderBolt aside and don't use it.  Likewise if it is leaded up.  Clean out the lead and don't use the ThunderBolt.

5)  Clean and lubed, try it again with different ammo.

You might see the references to ammo used in:       http://www.ar15.com/forums/t_5_4/148288_Beginner_Level_Set_Up_Of_A_New_Pistol.html

The other real question is:  Does it chamber a round if you retract the slide and just let it fly from fully rear?  If it does that, it should do it from slide lock.  If it won't chamber a round from fully rear, clean and lubed, it time to ask Ruger CS.

The subject of the other post was a SR22P.  It was only loaded from slide lock and worked every time with the ammo noted in the post.  A couple thousand rounds by now.

LSA

Remington ammo is really cheap dirty stuff. I agree that you just probably just need to clean that sucker good after putting that many rounds of those thunderbolts through it. I'd take Lampshade's advice and see how that works for you...

I wouldn't blame the ammo for making the gun dirty as the gun was brand new and had issues from the first round.

I will give it a clean soon and try to run other ammo through it, but the ammo didn't seem to be the issue since it was a brand new gun.  

Some guys over on Rugerforums said this is normal and it's not a slide release but a slide catch? Either way I figured it would work.

With any gun but especially a 22 first step is try different ammo. I use Remington 22 only if my choice comes down to use rem or do not shoot. Easily the worst quality 22 ammo on the planet!

Happens to mine with CCI minimags and Aguila copper HV rounds as well, not a fan of slide release on any gun either way.