kurtm

Hold hard and favor the center

Well I'm a limited guy and that made my head hurt too! 300 yard zero with iron sights and just aim at the top of at the card from 400 on out. Oh sorry, I forgot we were talking about Intense magnification....carry on!

Well the tube doesn't care how long the shells are. In general it is harder to get the 3.5" guns to run 3-gun type shells we use reliably, but it can be done. I myself prefer a smaller port, but I don't load like you. Everytime I try a "long" receiver gun I feel like I'm throwing a hotdog down a hallway!

So if that bushing isn't in place you have less spring compression? Kind of like running a reduced or lightened recoil spring? And there is more bolt bounce? That's just crazy talk, where's that salt water? On an aside, I'm not sure adding weight to the carrier will help with bolt bounce, and more than likely the opposite. The 3" shell allowed more deceleration of the bolt group as it was closing due to drag, not because of weight. What the weight will do is allow the carrier to remain in place during recoil longer which in turn compresses the inertia spring more. More weight equals less power needed to cycle so in theory you can use lighter shells either in weight of shot, or less velocity.

I don't know about all Stogies, but a lot of them do bounce a tiny bit. As long as it doesn't fully unlock your fine. I think you will find that the light springs don't help, and can in some cases hinder. I would no sooner put in a lighter recoil spring in a shotgun than I would soak it in salt water for a year.

Not saying one isn't flatter than the other, just pointing out the physics thing. Kind of like saying my 1911 is much flatter shooting than my 1873 Colt single action. The grip is much lower on the single action so it flips up more.

If you really want to compare, they would have to be the exact same set up, so in your case flatter means nothing.

I can see why. The shoulder pad of the stock on the J.P. is sitting under the recoil tube, while the cobalt stock is sitting over an inch higher. Simple physics says your pivot point is a lot different, causing the J.P. to jump more!

Hmmmmm, was it Carter Miller by chance?

I think it's the locking head/locking pin....bolt. I think all the rotation on a Stoeger is done by the bolt head and pin put in the carrier, but I haven't played Stoeger in a long time.

I'm thinking new locking pin and carrier, but I'm not a stoeger guy. All I am is a guy who has done a little playing with inertia guns.

I really don't know. I know on Benellis a heavier spring made it worse because it compresses the inertia spring even more. On that.gun, the guy had dremmeled the slot in the carrier so there was no step at all. It closed really smoothly, no hitch at all, but it had a very madining intermittent click. It took me almost a week to find the cause, because he said he hadn't done any thing to the gun except polish a couple rough spots. After that it's the first thing I check for the feeder inertia click!

Yes, where the bolt rotates. Don't do anything in there! Some guys try to re profile that area so it rotates real smooth. Problem is, if it doesn't have that hesitation in it, it can bounce back out of battery because when it closes it compresses the inertia spring a bit. Sounds to me like it is suffering bolt bounce. Quick test. Lock it back, hold it horizontal right in front of your face and trip the bolt release. Watch the bolt slam forward, if it bounces back at all that's your problem. It should close and not move back at all. If it does something in your camming system is worn. Also make sure that the retaining pin for your ejector is tapped all the way in and not dragging.

Did you by chance polish the cam pin slot in the bolt carrier? Knock the edge off that kind of flat spot on the carrier where the cam pin hits when it first is closing?

I would and always have gone J.P. Most innovations that have happened in the AR world have started at J.P. most the others copied.his ideas and added a twist or two which sometimes works and sometimes doesn't. If you want the one with the most proven R&D behind it....J.P.!!!!