Pump Shotgun, action opens slightly with heavy loads, dangerous condition?

[wink_man]

I have a Winchester 1300 pump, in 20 gauge, and when I fire slugs from the gun, the action doesn't stay locked in place, it partially opens, in essence, the bolt moves back a little. I bought the gun used, so can't say it ever stayed locked in place. I've heard of this before with pump shotguns, but I'm being told this is a dangerous condition? I've fired the gun many times with no problems, and it's extremely accurate with slugs. Can anyone tell me wether this is really a dangerous condition or not, or more like 'normal' for a gun firing heavy loads? The bolt moves back in the action maybe 1/4 inch upon firing, rather than staying locked in place, actually making it very easy and swift to chamber a second round. Any input from anyone in the know would be appreciated.

[SHOOTALL]

try holding backward pressure on the forearm while shooting , the reason to try this is most modern pump shot guns must have a very slight forward movement before it will move back . Most don't notice because it happens with recoil .
you can check by dry firring the gun to omit recoil altogether . i have been told the slide release by-passes this .

[The Gamemaster]

Take it to a authorized Winchester Service Center.

A good gun shop can tell you where yours is located.

Your problem probably is due to misaligned parts or something is wore or out of adjustment.

Yes I would be concerned that there is a problem with your shotgun - due to the fact that it concerns you.

Your guns condition is something that is not considered normal for a working gun in good condition.

Take it, have it examined and fixed before it gets worse.

No matter how good it shoots, is your life worth putting it in jeopardy?

[SHOOTALL]

with heavy recoil and tight hold you may be opening the action and not realize it . slugs do recoil a bit more than bird shot !
the little test will allow you to determine if repair is warrantied !

[wink_man]

Shootall, thanks for the dry firing tip.

I just dry fired 5 pump shotguns holding backwards pressure on the forend, 2 Remington 870's, and 3 Winchester 1300's. One of the 1300's is NIB  and unfired.

Both 870's the action stays locked in place until I release the backwards pressure on the forend, and all 3 1300's the action opens upon dryfiring with backwards pressure on the forend.

As I said, I've fired this gun many times, no problem, and in light of the fact that one that is NIB unfired functions the exact same way, I assume it's a design feature of the gun?
 

[bull]

Winchester claims that their pump guns (mod. 1300, 1200, 12, 97 etc.) are the fastest pump guns on the market. Working properly, brand new , they will perform as you have discovered. The model 12 and 97 guns can be fired simply by holding down the trigger and pumping the forearm.  It sounds as if the gun is working properly. If you are concerned take it into a reputable smith for a check up. It's a pretty simple action.

bull

[gunnut69]

Your shotgun is working normally. If the action was blowing open with pressure in the barrel the pump handle would most likely be blown from you hand. This would be very unusual indeed with the winchester rotating bolt. It's a fairly common problem with the Mossberg 500 series guns. Especially with heavy use..

[wink_man]

Thanks for the feedback gentlemen, I appreciate it. I didn't really think it was a problem, but someone was trying to tell me it's a dangerous condition, so I figuered I'd throw it out here and get some feedback and opinions, again, appreciate the input.