2 3/4" /Mosseberg 935

[brian]

There has been some postings here and elsewhere about the Mosseberg 935 not being able to cycle 2 3/4 " low brass. I personally witnessed my buddy cycle a half of a box of 2 3/4" low brass Federal with only one failure to cycle, today. I told Brian89 that I would check this out. This is what I observed.

We did this test in a sereis of 3 shells per round. Only once did the gun fail to lock the bolt open after the last shell was fired. It will cycle this round, not at a 100 % but it will do it.

As far as the pattern, it holds true to the statement that, firing a 2 3/4" shell out of a gun designed to chamber 3 1/2" destorts the pattern. The pattern of the gun with the 2 3/4" low brass is horrid.

[THE GOB-FATHER]

I'm assuming this happens because of the powder discharge buildup and low amount of gas energy working the action appropriately?

[moordeer]

i tried several times to get 2 3/4 shell to work in my 935 with no success at all. not once would it even kick the shell out.

just my experience with it.

[brian]

Are you talking about the pattern? Mr. Wakeman explains it better than I ever could.

What Chamber Length for Your Shotgun?
By Randy Wakeman

Good question, as most shotshells have been lengthened far beyond their original design parameters to allow more room for componentry. The patterning board proves that this "more is more" school is not always the best, or even a reasonable approach.
If we accept that every shotgun has two forcing cones, one at the breech and one at the muzzle (the choke), shooting a 2-3/4 inch shell in a 3-1/2 inch chamber is just asking for problems, and I've seen them. For example, the accoladed Browning Citori XS, XT, and Citori 525 clays guns all have 2-3/4 inch chambers. So do the Sporting Clays Browning Gold versions, and the cost of separate barrel inventories for these models strongly suggests that it is not by happenstance.
When hot gas pushes a wad down the bore, the shot mass wants to expand. Giving a smooth transition from hull to bore with minimal shot deformation and upset is the primary requirement of good forcing cone design. If we fire a 2-3/4 inch hull in a 3-1/2 inch chamber, what happens during the unsupported "jump" is obvious: our shot mass wants to migrate out to hull outside diameter size. It tries, and then is immediately reconstricted, and overly constricted, when the forcing cone ramps the mass down to the inside diameter of the barrel.
If you measure the outside diameter of a 12 gauge hull you'll find it to be around .800 inch. Our chamber, which must be a "slip fit" for the hull, is necessarily larger than that. Starting out at over .800 in., we expect our wad to seal at that unsupported level, and all the way down to a 12 gauge bore diameter which varies from .729" (American designation) or .725" diameter (European designation).
A .075 jump is a lot to ask of a plastic wad, and some gas blow-by is to be expected. Shooting 2-3/4 inch shells in a 3-1/2 inch chamber is opening a can of worms, and just asking for poor pattern efficiency.
There is a lot to be said for shooting the shell length that matches your chamber length. The same effect is also present in shooting 2-3/4 inch shells in a 3 inch chamber, but with only one third the gap, is far less pronounced and problematic. I've shot outstanding patterns from 2-3/4 shells out of 3 inch chambers, and many hunters either don't care or feel that the potential reduction in pattern efficiency is not significant compared to the added flexibility a 3 inch chambered field gun offers them.
Most manufacturers agree, as the majority of field guns sold today in 12 or 20 gauge are fitted with 3 inch chambers. There are exceptions, though, and they include almost all competition guns (trap, skeet and sporting clays models). Again I'll cite Browning Arms. The Citori O/U Superlight Feather, clearly a dedicated upland field gun, comes with 2-3/4" chambers; so do most "London best" side by side field guns made today. In years past, many 12 gauge London guns were built with 2 inch or 2-1/2 inch chambers. The short shells and light loads simply pattern better than heavy "over square" loads.
Only the patterning board reveals it, but unless you think you need a steady diet of 3-1/2 shells for something (and I sure don't), it is wise to steer clear of 3-1/2 chambers. That is one of the reasons all my 3-1/2 inch chambered shotguns have found homes elsewhere.
Advances in shot, such as the popular Hevi-Shot, have in large measure negated the need for the 3-1/2 chamber, certainly when hitting something as fragile as a turkey head. For long range pass shooting at geese they might have a place, but you will likely pay a performance price with that same gun on the dove field. Like the re-rise and demise of the 10 gauge due to the early, comparatively poor steel shot loads, the sun is setting on the 3-1/2 chamber in 12 gauge for general use.
Three inch chambers remain a reasonable compromise in 12 and 20, and are not available in 16 or 28 gauge. Yet another reason, I believe, that both gauges generally pattern better than they are "supposed" to.

[xtremesportsman]

I don't know what the outcome on a patterning board would be but I do know this; I have a Winchester Super X2 that has trouble cycling 2 /34 shotshells. Anything from 7.5 federal to 6 winchester Super X loads. At first I cleaned the gun at the shoot and then instead of taking a chance I switche dto my O/U for the bird shoot. when I brought the gun to work the next open day we did a comllete and thorough cleaning on the gun. Trigger and bolt removed for the cleaning as well... I had a friend shoot it in a round of skeet that same day and he said it cycled but felt sluggish.

That weekend I went squirrel hunting with my nephew and tried the gun on a pine cone in the tree. The gun would not cycle after the first shot. I talked to the gunsmith at the shop and he thinks the cold weather may be freezing the oils in the gun so we clean it again and put very little oil one the slide. I will try again on a warm day and see what happens... Bottonmm line is on a frigid day in January while goose hinting with 3 inch #2's I had not one hang up...... I will keep it posted on what happens on my warm weather shoot... Sure will be funny if that is my hang up problem on the 2 3/4 shells.

As for the SuperX2, when the gun was cycling roperly I was dropping pheasants with it like it was nobodies business. So I don't think the X2 had a patterning problem with the 2 3/4. Definately had a cycling problem though, seems when it is cold for sure.

[moordeer]

not talking about the pattern. talking about the gun cycling the 2 3/4 shell. the 935 I had wouldn't do it. it wouln't even throw the empty hull out of the gun. but had no problem with the 3 or 3 1/2 "s

[THE GOB-FATHER]

moordeer said:

not talking about the pattern. talking about the gun cycling the 2 3/4 shell. the 935 I had wouldn't do it. it wouln't even throw the empty hull out of the gun. but had no problem with the 3 or 3 1/2 "s

Were the 2 3/4's low or high brass?

[brian]

Low

[moordeer]

admin said:

moordeer said:

not talking about the pattern. talking about the gun cycling the 2 3/4 shell. the 935 I had wouldn't do it. it wouln't even throw the empty hull out of the gun. but had no problem with the 3 or 3 1/2 "s

Were the 2 3/4's low or high brass?

GF , I tried both high and low brass in it no differance.

[xtremesportsman]

maybe because it is a 3 1/2 gun the extractor isn't grabbing the shell. It may be just a hai short.... I am going to have to try 3 inch shell nad see what happens. I bet it is the extractor isn't grabbing the empty shell.

Sort of like buying a 3 1/2 barrel for a gun that was originally meant for 2.75... If you can even get a 3 1/2 shell in the chamber it may be too big for the exit or the extractor, this could be the same but instead of bigger it is too small for the extractor.

[xtremesportsman]

what happens if you manually pump the rounds out, does it extract okay?
Maybe the 2 3/4 are being pushed in too far and can't be grabbed.
I am baffled with this...

[moordeer]

Yeah it would grab them a pull them out, but I no longer have the gun. sold it. not because of this problem I just wanted another gun and didnt need 2 shotguns. But I have to say that it patterned the best out of the turkey guns I have seen with the 31/2's .