You will find that moon clips are easiest to load on round one, and hardest to load on round five. The reason is due to the tension created by each successive round being snapped into place.
I know for certain that Winchester factory ammo snaps into place with ease.
I SUSPECT that once-fired, reloads will have trouble going into moon clips because their base diameter has been expanded just enough...and even normal resizing won't fix this, so the finished rounds are dimensionally too large to fit in factory spec moon clips!
Sorry, but you suspect wrong. All modern cases are of the solid head type (as opposed to the old balloon head cases) and as such are solid brass at the extractor groove. It would take considerable pressure (dare I say, overpressure) to expand a case at that point.
To see if this is true I took four ten case lots of .45 ACP ammunition.
Lot 1 was brand new, loaded Federal Ball (230 gr).
Lot 2 consisted of empty Federal cases, once-fired that were factory ball.
Lot 3 consisted of empty Federal cases that were fired unkown times with an unknown load (range pick-ups).
Lot 4 consisted of empty, mixed headstamp cases, that were fired unknown times with unknown loads (range pick-ups).
The extractor grooves, of all cases in the above lots, were measured using a TESA digital vernier caliper. Each lot was then averaged. Here are the results.
SAAMI spec for the extractor groove is .4000"
Lot 1: .3951"
Lot 2: .3947"
Lot 3: .3954"
Lot 4: .3950"
A maximum variance of .0007" - which is more likely attributed to production tolerances rather than any external forces imposed on the cases.
Personally, I have never found it harder to insert a case into a specific position of the clip, more so than any other, regardless of number of rounds loaded. Also, as evidenced by the above, never found it harder to insert reloaded rounds, as opposed to new.
Some may say that my results may not hold true for a higher pressure round like the .357 Magnum - to them, I say: Prove it.
I want to also note that there will be a greater variance among different manufacturers of rimmed cartridges than the rimless. That is because there is no SAAMI spec for the groove (and it's not really an extractor groove) at the head of a rimmed cartridge, so manufacturers make their own determination - thus a clip that may fit Winchester brass well, may be problematic with another manufacturer's brass.
Rimless cartridges do have a SAAMI spec for the extractor groove because it has to be very specific so that it can accommodate the extractor (able to slip under it when chambering, but having enough purchase to hold it against the breech face and pull it from the chamber during cycling).
To optimize your use of moon clips, get the right ones for the ammo that you are using. For rounds like the .45 ACP, the inexpensive moon clips work just fine for any brass ($.35 - $.40 ea direct from Ranch Products and other suppliers). The short case and heavy round nose bullet lend themselves well to quickly recharging a cylinder.
For the rimmed cartridges, use a clip specific to the brand of brass. You can look on TK Customs or Revolver Supply websites (both manufacturers of clips) for detailed specs and recommendations.
Lastly, stop with the fingers and pliers for loading and unloading the clips. Buy and/or make the proper tools. You spend mucho dinero on the gun and the ammunition, don't cheap out on the proper tools. The Deluxe Moonclip tool (just Google it) is only about $40 +SHI and if you want to buy the screwdriver handle type demooner (highly recommended) they are only about $18 to $20 + SHI from Brownells and other sources. I have fired literally thousands, maybe tens of thousands, of moon clipped rounds. I have always used the proper tools to moon and demoon the brass, and I have never bent a moon clip.
The BMT tool mentioned earlier in this thread is super slick, but they are gun and caliber specific so if you have multiple moon clip guns of different calibers or sizes, the BMT tools can add-up fast. There is no better tool for the 8-shot revolvers.
Your moon clip compatible guns will be much more fun to shoot if you have the proper tools to load & unload the clips.
More than you ever wanted to know about moon clips.
HTH
Adios,
Pizza Bob
