View Full Version : Clueless noob shotgun question

August 7, 2005, 03:47 PM
OK, since I have never owned a shotgun until now, I have a dumb question to ask:

What are the little grooves (flutes) on the shotgun shells for?

A presume that they help extraction?

Reason I ask is that my cheap Chinese Ithica M37 clone works great with smooth 2 3/4" snapcaps but sometimes fails to feed normal (grooved i.e. non-smooth) light load wally world bird shot.

I have not tried smooth shelled birdshot shells yet but plan on it in a week or two.

Any info or insight would be appreciated.

August 7, 2005, 05:31 PM
Is it failing to cycle unfired live rounds or fired rounds.

Death from Afar
August 7, 2005, 05:45 PM
I may be wrong, but I always thought the grooves were a way of saving costs on cheaper shells. For example, you dont have the grooves on the Winchester AA trap loads, which do need to relaible ( yet another reason to own a pump, not an auto) - the shells with the grooves tend to split after reloading.

August 7, 2005, 06:49 PM
They are failing to feed from the tube magazine. Extraction is not really a problem AFAIK.

I cock it and it randomly goes click on every third round or so because there is nothing in the chamber (FTF).

If I cock it again it usually feeds the one that didnt want to go in, but I do feel a little resistance when it finally loads into the chamber.

Snapcaps do not do this and feed almost 100%. Only difference between the snapcaps and real ammo that I used were that the snapcaps were smooth and I think slightly undersized in radius than the real thing. Real ammo also had the grooves (flutes?) on it's plastic.

One suggestion I got is to dissmantle tube magazine and clean and oil it lightly. Did that so I will see if that fixes it on next shooting trip.

I will also try using Winchester AA smooth plastic ammo to see if that helps.

Just looking for other things to try before I go as a range trip is expensive for me.

Big Yac
August 7, 2005, 10:51 PM
I cant think its the hull thats giving you troubles, I'm gonna say its something internal, something in the gun, what though I'm not sure, sorry for being such a big help :) I'm just saying this because if you start using the premium ammo, unless you reload its almost a waste.

August 8, 2005, 09:10 PM
A smooth tube, good spring, and a good non-binding follower should guarantee reliable feeding with any ammo.

I clean out my tube regularly with a little solvent then wipe dry. I don't like oil in there. I am always making sure the surface of the follower is wiped clean. You'll notice that gunk accumulates on the follower where it rubs against the tube--keep it clean. More than one fellow has polished his mag tube and/or follower just enough to remove any burrs and solved feeding problems.

I'd suspect the design of the brass head on the ammo you're using before the "lined" plastic case.

August 9, 2005, 05:33 PM
The grooves are a way to reduce the contact surface of the shell against the cylinder, to help extraction on plastic shells. Paper shells never needed that because there is no pressure swelling in the paper hulls unless they are already wet or at least softened by moisture.

Plastic shells react to the heat and pressure of firing differently than paper, tending to want to bulge and re-form tight to the cylinder. Big loadings of slow powder will cause even these grooves to heat, blow out, and flatten, so the plastic hulls can wind up acting like a cork shoved in a bottle, air-tight.

Handloaders who have packed their rifle brass with too much powder are familiar with this little problem, which causes us to revert to the ram-rod to extract tight cartridges after the bolt ejector claw has let go of them........... such fun. :D

August 9, 2005, 11:18 PM
Differences exist in the manufacturing and components of plastic shotshells.

The most famous hull ever - smooth.

Do a search sometime on Mike Jordan with Winchester.

Find an older shotshell reloading book showing the various hulls, and what recipes work with what powders, wads, loadings. This will show some histories and developments over the years.

What one IDs and learns is a Hull, may be of a certain construction and used across various lines in a shotshell mfgr line - And - sometimes used for private branding. For instance in the old days a shotshell might have the Sears, Montgomery Ward, or a Farm Supply store name on the box/ shell.

Knowing how to ID allowed one to make informed choices on buying new shells ( hard shot, soft soft, worth reloading, or not...similar/same as factory loading that had patterned/ not patterned well in their gun...etc)

When the plastic hull came about different qualities of plastic were used. So different types of equipment used to make the Hull were avail.

Winchester Literally changed the plastic shotshell industry with the One Piece Compression Formed Hull 40 years ago. This hull was used in target loads to many of the better hunting loadings did many things. This Compression formed hull literally RULED for 40 years. Everyything was and still is compared to this hull. [ see note to follow**]

Tidbit - at first it failed. Too thick, so tweaks were make in composition of plastic,, thickness, skiving the mouth of hull...etc, then Win hit upon the famous result.

This Compression formed hull allowed many folks to shoot more because they could reload - for many reloading had been reserved for only the elite, or trap, skeet shooters. This allowed regular folks to shoot clay games more, and allowed regular folks to reload to save monies for hunting birds small game,ducks and waterfowl ( before non- toxic shot) a learned benefit was allowing one to get a load that patterned best in THEIR gun for Task...remember guns back then had fixed chokes.

**The equipment that made this Famous Compression formed hull finally wore out. Winchester weighed the cost of replacing this equipment, new dies, and everything. Decison was made to NOT spend the monies, The new AA hull is a two piece hull nowadays.

--Activ shotshells had NO metal - except for the primer. All one saw was Plastic. This was a great shotshell, yes it was reloadable. I reloaded many of these.

The height of the brass has no effect on velocity - great mental/ psychological deal for selling tho" . Many of us have reloaded buckshot loads in AA target load hulls ( low brass) as well as reloading the Heavier Magnum loads [ 1 1/2 oz , grex buffered, #4 hard shot] for waterfowl. IN the same note, I have / others have reloaded the 1 oz target loadings in high brass hulls...makes no difference.

Grooves - actually more of a result of mfg choice of plastic, the equipment, how the hull, brass basewad...components were put together.


Most common failure seen on a shotgun - no matter what platform. Dirty Chamber.

Wisps of 0000 [ 4 aught] steel wool or the finest grit of Scotchbrite pad wrapped around a brush, battery drill will take out the plasticized crud from chambers.

Even by hand will work.

We did NOT have this problem with the old paper hulls btw.

I still likes and shoots the paper hulls...


3 weelin geezer
August 10, 2005, 12:47 AM
Then why do they make two different sizes of brass? Why brass at all? I have seen some all plastic shells at the range. Personally, the last time I used the longer brass shells I felt less recoil. Don't remeber what the specs of the ammo were though since I go to wallmart and get the cheapest boxes just to bust clays and the trash people leave there.