Since it's obvious that few folks on the forum have any experience with this new offering from Mossberg, let me be the first to report on my experience with it.

I bought one the other day because I really liked the lines of the rifle. I was looking for a deal on a TC Encore when I saw one of these in the gunshop. It really caught my eye. Mossberg utilizes really good wood in the stock and the lines are very clsssic. Since it was priced close to half of what an Encore would be, I went ahead and bought one in .30-06.

When I put it together, it was awfully tight, but that is to be expected in a brand new break-action gun. It came with a one-piece Weaver scope base, so I simply mounted an old 3x9-32 Vari X II that I had in the gun room waiting for a home. It even had Weaver rings still attached, so scope mounting was easy.

I bought a couple of boxes of Winchester Super X 180-grain Power Points to use as a starting point in the rifle(and to create some brass that I can neck size). I also went to work in the loading room. I dug out a bunch of old Winchester brass of an unknown number of firings and cleaned it up, trimmed it to uniform size and set about loading. Since I am going to use this gun as plains game rifle in Africa, I am requiring it to shoot 180-grain premium bullets. So I broke out the Nosler Patitions and the Speer Grand Slams.

For powder, at first I decided to stick to H 4350, since this seems to be the powder of choice in a bunch of manuals for the .30-06. On a whim, however, I decided to load up a few rounds with IMR 4831. In retrospect, it was a smart move.

At the range, I fired the first group with factory ammo and cleaned the bore -- a very unimpresive 3" group. I then fired another three inch group with the same ammo . After each firing, the rifle was extreamly hard to open requiring maximum exertion. Obviously, the case is expanding in the chamber and pushing back on the receiver, causing this problem. Also, the primer looks more like it was struck with a needle rather than a firing pin. It also looks like it may be trying to back out a little. It's a very unusual looking primer (remember, this is factory ammo).

After another cleaning, I switched to the hand loads. First I shot one of the 4350 rounds with a partition. It was way too hot, chronoing over 2900 fps. When I tried to eject it, it took everything I had to break the action. Once it broke, the ejector refused to budge the empty. I had to use the cleaning rod to remove the case. and this was two grains below max load.

I then decided to clean the gun and try a group with the 4831. I was apprehensive because all I had loaded up with this powder were max loads. The first three shot group I fired measured .857-inch. I then fired one that measured right at an inch. Then my 16-year-old shot a group smaller than my first one. All three groups were with 57.5 grains of IMR 4831 and 180-grain Nosler Partitions. After these three goups, We had to switch to Grand Slams with the same powder, and the groups opened up a bit. Obviously, this rifle is very particular about what you feed it. (I will add that one of the Partition/IMR rounds did stick in the chamber, requiring a rod to free it.)

I went back to the 4350 loads to see if the first shot was an anomaly. It wasn't. Again it was way too hot a load for the rifle and the case again stuck. Forget H 4350 for this rifle.

Having exhaused all the "good" handloads, I went about shooting up the rest of the factory rounds. Three and four-inch groups are the best it would do. None of the factory rounds suffered a stuck case, but some sure acted like they wanted to stick. This kind of scares me, especially considering that I want to neck size, which makes for a tight case to begin with.

Bottom Line:

I think I will back off about a grain with the 4831 and see if I still get tight or stuck cases. It was chronoing close to or right at 2800 fps, so a little fall off won't hurt me. I will also make sure that we hunt with only new brass, which will minimize the chance of a stuck case.

The rifle, with the right load, shoots outstanding groups, but follow-up shots are going to be difficult unless the action loosens up a bit. It is also a loud action to chamber, so it will have to be chambered long before game is in close proximity. This is something guides (and Dads) really hate for safety reasons, but we have no choice.

The trigger really sucks. Don't yet know how hard it will be to fix this.

The fact that it is so particular about what it shoots could be because I am requiring it to shoot 180-grain bullets. .30-06s generally shoot 165s much better than the heavier alternatives. I'm fortunate that I was able to stumble upon a bullet/powder combination that it likes so quickly.

Don't know what to make of the primer signs, but, then again, I've never owned a break-action rifle before.

All in all, once I tackle all of the idiosyncrasies, it might just turn out to be a pretty good rifle.

Sounds like you may get that Mossberg to shoot well for you. Thanks for the report.
It does concern me that you started out fresh with max. loads, though. Not a great practice, IMO>
T.D.

Ditto on the max loads to start. Should of bought a 300 Mag instead of trying to turn your '06 into one. Try H4350 at 3 grs. less than your previous load, and you're ejection problems will probably go away.

I liked the looks of the SSI too,not too many cals though.
I too think you should start low and work up finding the right load.You said you got 2900+ using 2 grs less than max w/180 gr bullet,something don't sound right,according to the speer manual H4350 58C max,2grs less 56grs should be somewhere around 2700 fps.Hodg. sugests 57.5 to give 2798,maybe this is why things are a little sticky????
I am using IMR 4350 and 57.5 grs w/165gr bullet and only get avg.2860 fps but it will drive tacks.

Who said I shot a max load of 4350? I started two full grains below my max. This is where I start most loads, unless it is a really fast burning powder. This is the first time that I have ever shown "pressure" problems doing this -- and I load for 24 different rifles.

With 4831, on the other hand, being a still slower powder, I doubt that you could put enough in a case to do any serious damage. It is one of the safest powders around.

I took a couple of the spent factory loads to a local gunsmith, who said he believes the gap between the barrel and the receiver is too great, causing the case to slam back and swell. You can see the perfect indentation of the firing pin hole on the primer and the primer is packing out. Remember, this is factory ammo.

I have contacted Mossberg by e-mail and am waiting for a reply.

with any new loads or new gun, all loads should be started at 10 percent under max..... then work up......

steve

About the action being tight,
My H&R was like that for a while. I shot about 2 boxes of ammo in it, and just worked it open and close for a while, now it's smooth as silk.

Maybe it just needs to be broken in?

Thanks for the report. Good luck getting it right.