Hello
So after wringing out this SPX with buckshot ammo, I thought I should give it a whirl with rifled slugs.

I collected several samples of rifled slugs, five from Winchester, five from Remington, seven from Federal and three from Brenneke.  I mainly wanted to see what kind of velocities I could get with an eighteen inch barrel, but while I was at it, might as well see what I can do at 50 yards with the factory sights.











These were all shot off a Caldwell Rifle Rest at 50 yards.  Targets were 5½" circles. Sight settings were not changed during this shoot. I wanted to see how they all shot relative to each other. The only thing that changed was where I put the front sight.  Starting off with Win/Rem loads I was able to cover the circles with the front sight. But as light conditions changed, it was better to shoot with a six-o'clock hold for the remaining ammo. All five rounds in each box were shot.

Velocity data was taken with an Oehler model 33.  Skyscreens centered at 15'.








I had a weird chronograph issue come up while shooting the Win/Rem ammo, targets #3 and 7 only one round registered correctly. All the others were registering in the high 3000's FPS.  After a conversation with Mr. Oehler it was determined that the jacks and sockets needed a cleaning.  That solved the issue.
So, the one that did register is on the target.

As was the case with the buckshot ammo, all the 'managed recoil' ammo did not cycle in this gun.  The Federal offering actually did cycle some rounds, but not all five.

It's interesting, that the Win and Rem 3" mag ammo turned in the best groups.  The Rem 2¾ 1oz didn't do too bad either.  The Federal 2¾ Truball 1oz had four almost touching with one flyer.  I wonder if that was just me..  The worst group goes to the Federal 3" Power-Shok 1¼ oz load.

The fastest 2¾ 1oz load was the Brenneke KO.  With all the Brenneke loads, the advertised and actual velocities were very close.  The most accurate 2¾ 1oz load was the Remington and the Federal Truball. That's how it turned out today anyway..

I have three more Brenneke ordered;  the 1¼ oz Green Lightning, the 1oz ATS, and the 3" 1 3/8oz Black Magic Magnum.  That one should be fun to shoot...  So I'll shoot those as soon as I get a chance to complete this project.

Here is a little summary of advertised and actual velocities so far.




The range;



The Brenneke ATS, Green Lightning and the 3" Black Magic Magnum rifled slug ammo arrived so I shot them this morning, thus completing this project. The pics on the original post have been updated.

There was an apparent wad separation with one of the ATS rounds, which I'm thinking is the reason for the flyer off to the left..
The Green Lightning did very well. The last round wandered off low. Velocity was very consistent.
With the 3" Black Magic Magnums, the velocity was all over the place.  But even so, any one of those would be very effective.  Good bear medicine.

So, some observations about this Mossberg 930 SPX.

As mentioned before, the gun will not cycle 'low' or 'managed recoil' ammo.
If you are going to keep the gun un-chambered with rounds in the magazine, with the intention of racking a round when the gun is called upon, just make sure you rack it in hard.. Don't baby it. If you do the round might not make it in the chamber and you'll have to assist it in. This usually happened when I failed to remember this. . Not a good scenario in a high stress situation. Using full power ammo this gun experienced no feeding malfunctions at all.
During the slug shoot, I noticed most of the slug groups started out very good, then as the barrel heated up the slugs #4 and 5 started wandering a bit.  This isn't that unusual with firearms and that was certainly the case here. Three round groups would have made the groups look better.

Well other than that, the SPX is a pretty solid shotgun. I'm happy with it.



Well hopefully this was helpful or at least interesting. 

Thanks RDub01, for the detailed slug fest shoot out.  Very nice documentation and nice range to shoot from.
I have been loading the Lyman 525 grain Cast slugs in 2 3/4" hulls and velocity of 1425-1450 fps from the Remington 20" BBL.

Maybe I missed it but you didn't say if the barrel was a slug barrel or an open choke. The slug barrel makes an incredible difference in slug performance. If you have an open or modified choke barrel, you won't believe the difference shooting that same gun with a slug barrel. The State of Texas was looking for a better way to shoot hogs from a helicopter and since my little brother was in the prime country for hogs, we got to work the project together. We tried the open and modified barrels and they work great for the intended use as long as it was with buckshot. Slugs, not so much. When we went with a slug barrel for the Remington 870, it was a completely different ballgame. We ended up using the Barnes #57500 1 oz saboted slug on top of 34.0 grs of Blue Dot in Federal Match brass using a roll crimp. Velocities increased almost 30% vs a modified choke barrel. Recoil went up considerably too. Accuracy......get this, at 100 yds was 2" groups. I couldn't believe that kind of accuracy from a shotgun but after looking into it, there are folks shooting shotguns at 100 yds and shooting groups at an inch and some smaller. I had no idea that a shotgun could be that accurate. If slugs are going to be the game, a slug barrel is primo. It was a unique experience getting to play on taxpayers money. The learning curve was mind blowing. But be careful, it was a very expensive, habit forming, experience for us. FWIW, they make shotgun scopes too and yes, they work fabulous.

Hi.. Very interesting experience!
I've watched Utube vids of guys shooting hogs from helicopters and wondered what ammunition they were using. Don't recall any actually specifying. At the distances they were shooting, it would have to be either something like Fed or Horn Flight Control 00Buck, or slugs.

The SPX only comes in open bore, no choke..  That's why I was curious to see what rifled (foster) slugs mainly intended for smooth bores could do.
I suppose one could get an aftermarket rifled barrel, but I haven't looked into that. Of course as you are aware, buckshot won't work well in a rifled bore.

The State here settled on a Benelli pump 12 ga and #4 buckshot to shoot from the helicopters. The decision made was mostly because few shooters are able to really handle any gun from the outside of the chopper. It's like sitting in a tornado and attempting to hit a moving target that's running 30MPH while the chopper is also moving and not necessarily in the same direction. For the ORVP project we shot hogs using an M1a. Little brother is a natural shooter. He doesn't have to work at it like most folks. The boy can literally pick up any weapon and shoot it accurately. But the adventure into slugs was an eye opener. Mossberg makes a slug barrel for your shotgun if you have any major intention of shooting slugs. You won't believe the difference it makes. I don't recall how much velocity we were getting but it was just under a 458 Winchester for a 400 gr bullet. Seems like it was 2200'ps but that might not be right since I'm not sure. I know it was hard on recoil as the 432gr saboted slug went down the 20" slug barrel. Shooting slugs out of a shotgun though is a hoot. There are many types out there. For little bro, for store bought ammo he preferred the Remington Premium saboted HPs. He claimed they were a better hog killing ammo. Hope you have a bunch of fun with the project. It was an experience I enjoyed a lot. Glad you posted your experience.

Shot the three Brenneke loads this morning I ordered. Original post is updated, completing the project.