Cycled ammo discussion, I decided to test it

[dc dalton]

We had the thread here last week (can't find it) about cycling ammo over and over and it becoming dangerous to shoot due to the head being pushed back into the shell.

I even discussed it with Rich Warner the other day and he said if he cycles a round he will fire it or remove it from the the gun.

Well call me a skeptic, my mechanical engineering days made me really wonder about this actually happening. So I needed a new caliper anyways and picked on up at Lowes. I pulled the mag from two guns here that I KNOW have had at least 2-3 rounds cycled through during loading unloading etc. I also got the box of the ammo each one was loaded from to get a test basis. This is what i found.

Federal 9mm 147 grain tactical hydra-shock.

I measured 15 fresh out of the box, the rounds ranged from 1.100 to 1.103

Measured all the rounds in the mag (as I said I know several have been cycled through several times) and they all came up in the 1.101 - 1.103 range

Fiocchi 32 Auto 60 grain semi jacketed hollow points

Again I measured 15 fresh from the box, they ranged from .924 to .929

Measured all the rounds in the mag, now on this particular gun I know for a fact the gun is unloaded and reloaded 3 times a week and has been, with this same ammo for quite few months. Again all rounds from the mag came in at .924 - .929 with one oddball coming in at .930

So I'm not saying it doesn't happen, I'm no gun engineer but based on these two guns and knowing the ammo has been cycled quite a bit the measurements do not support the conclusions I have heard ... curious to hear from others here.

[Shawn.L]

while you are testing can we get some more specifics?

what guns?

could you grab one of theose 9mm's and cycle it through a couple dozen times then measure it again?

[dc dalton]

while you are testing can we get some more specifics?

what guns?

could you grab one of theose 9mm's and cycle it through a couple dozen times then measure it again?

Yup I can do that, will actually be interesting to try it.

The two guns I measured were a KelTec P-11 and a P32 but since we are going to do some actual tests I will pull out the G27 and run some through it too.

Give me a half hour to run tests and type up the findings

[ReconLdr]

I was under the impression this "set back" condition was almost exclusive to bottle necked cartriges and the .45 GAP. Most of the reports I have seen are .40, .45GAP, and .357SIG. I have not seen any other calibers with multiple kbs.

[autotech6506]

keep us updated. I may have to borrow some calipers from work and do a test on my 1911.

[thelemite]

I have seen it happen to 357 sig over time. Need to watch the bottlenecked stuff.

[Pa. Patriot]

Setback, or lack thereof, depends on the ammo and the gun.
It definitely happens, seen it many, many times myself. It really is not a big huge controversy. Moral of the story is to keep an eye on your top round, compare it regularly with a fresh round. When and if you see any setback, discard.

[dc dalton]

OK, here's what I did

1 round, measured before, after 5 cycles and after 10

9mm - Federal 9mm 147 grain tactical hydra-shock.

Keltec P-11 - before 1.102, same at 5 and 10

Berretta 92 FS - before 1.102 same at 5 and 10

Glock G26 - before 1.100 same at 5 and 10

32 Auto Fiocchi 32 Auto 60 grain semi jacketed hollow points

Keltec P-32 - before .925 same after 5 and 10

Speer Gold Dot 40 S & W 180 grain GDHP

Glock 27 - before 1.119 same after 5 and 10

[o1dakota440]

+1 just did the same with one of my g17's but cycled the same round 42 time and found no differance. 1.103 before and after. and before someone asks why 42 times, my hand got tired ok

[d90king]

It does happen with .45's. That said I think those cases occur when it is done daily over a long period of time. Think of the guy who clears his weapon everyday for long periods of time using HP's. It is also more common when guys try and go 8 +1 on a 1911...

I have laying around somewhere a few bullets with obvious set back one was pretty significant.

I have found if you check sometimes you can spot some out of spec, right out of the box. I had 7 in a 100 rnd box of WWB one time.

The above could also be some of the issues reported as setback, with out realizing it was out of spec from the get go...