Testing Self Defense Ammo in Auto vs. Revolver

Many people say you need to test an autoloading pistol with x number of your intended carry ammo (200 rounds seems popular). Does the same apply to revolvers given that feeding issues are far more remote?

What would you recommend for an auto vs. a revolver in regards to number of rounds of carry ammo tested?


Edit: This is not a discussion about breaking in a pistol or doing general reliability tests, but rather carry ammo specific.

 

In a revolver, you are simply verifying the point of aim with a specific ammo. So, with defensive ammunition, you only need to shoot a cylinder full. 5, 6, 7, or 8. Done!

 

I don't know if I totally agree with that statement. I have seen too many revolvers over the years with a very tight barrel cylinder gap that bind after a cylinder or two. There are other things that can go wrong with a revolver as well. You certainly don't need to run 200 rounds through it but I would at least run several cylinders through it.

 

There are ammo malfunctions that can put a revolver out of action. The most common is jumping crimp. As you fire a revolver, the bullets in the unfired cartridges want to stay at rest, while the revolver recoils away from them. Try marking one round, firing the rest of the cylinderfull, then reloading and trying it again -- you may find the bullet in that one round has crept forward. If it goes far enough forward, it will tie up your revolver.

For this reason, if you fire your revolver, you might as well fire a full cylinder full -- don't carry ammo that has been subjected to recoil.

Another problem is primers backing out. This can be caused by pressure being too high, or too low. The reason is, that on firing, the primer always backs out, but a normal load will then recoil and reseat the primer. If you see signs of primers backing out, you have an ammo problem.

 

I've had more revolvers fail than semi's. There is a lot more to go wrong. If either type doesn't work right I've found that problems will show up fairly quick.

 

Since I reload it is easy for me to test my revolvers with a few hundred rounds. After it proves reliable with my reloads then I will run a box of carry ammo through it.

 

I test carry ammo with a few cylinders or mags full. If there is going to be an ammo related issue chances are it will show up right away because ammo problems are usually things like bullets jumping crimps in revolvers and feeding due to bullet shape or cartridge OAL in autos.

 

I remember reading an article about bullets "jumping crimp" when subjected to repeated recoil events. However, except for defective qualities in the ammo itself, I have every bit of confidence that a typical round will "survive" at least as many events as one less than the number of chambers in the revolver.

The article, which included an essay on bullet "setback" in autoloading pistols, was cautioning revolver-carriers not to be too confident that, just because "bullet setback" is unique to autos, they were not immune to recoil-induced ammo failures.

But, I couldn't help wondering, how often does one repeatedly shoot all but one or two of their rounds from their revolver, reload, and repeat, making sure not to fire those same exact rounds?

 

Crimp jumping risk increases as gun weight decreases or cartridge power increases. Crimp jumping is therefore rare in a GP100 firing .38 specials, but a bit more common in a J Frame titanium .357 Magnum. I did extensive testing with several different ammo brands in my 642 by reloading the same defensive round through at least 5 cylinder fulls of cheap ammo (to save money). I repeated with several more defensive rounds and found very little bullet pull (.002 at most) with 135 +P Speer Gold Dot, 125 grain +P Double Tap Gold Dot and 158 +P LSWCHPs from Federal and Remington. But it can happen, so it is important to test. I still do the test for my heavier .38s and .44s (firing specials, I don't do magnums for self defense), but not to the extent I did with the little pocket blaster.

Another consideration is cases sticking. I've encountered exactly 1 brand of centerfire ammo that refused to be ejected from one of my revolvers (686) without the aid of a small mallet and a dowel rod (yes, the cylinder and crane were supported during the delicate procedure). IIRC, it was Winchester SuperX .357 Magnum. So you want to make sure you chosen defense ammo will eject cleanly. And preferably you want to do that test when the gun is dirty, such as after firing at least 50 rounds of practice ammo.

In the end though, my revolver ammo testing is much less extensive than for my autos. The big thing on the autos is verifying the reliability of each magazine you plan to use with your defensive ammo. Maybe not 200 rounds through each, but a good number. And of course, I make sure the gun (either platform) will eat a bunch of my cheap reloads before I even think of feeding them the expensive stuff.

 

really I test the ammo more than the gun. I have shot a couple cylinders worth leaving the same round in one chamber to test for bullet pull. I also shoot some to test POA vs POI. All in all I usually shoot at least 50 rounds of carry ammo and a couple hundred reloads through a revolver before I really trust it.

 

Based on your question both gun(s) have passed my mandatory 500 round test without any problems caused by the test ammo.

With a semi-auto 200 rounds sounds like a good number. It gives me a chance to check functioning (ftf, fte) and the magazines. Due to cost of factory amm it is unlikely I will do this testing in one range session so in the meantime I 'll carry FMJ'S.

Revolvers are much more forgiving so I would probably start carrying after 50 - 100 rds.

Note that I reload so my prior 500 rounds for revolvers will be loadd close to the specs of the ammo I plan on carrying.

 

If you want to test it for crimp jump, just keep two or three of the same rounds in the cylinder and then fire the other three cylinders, reload those three, repeat. Measure COL as you go for the 3 unfired rounds. Do that for maybe 12 or 18 firings, and if they haven't jumped crimp by then, I doubt there is much to worry about.

 

Eldon's post describes a great way to check for crimp jumping. If none of the three test rounds jumps at all even after shooting 12 to 15 rounds from the other cylinders then it's pretty likely you can trust the last of 6 not to jump crimp. Although there's always the risk of that one lone defective round.

There's a few other reasons to test your defensive ammo in a revolver for more than just point of aim. You want to test for fouling and related binding for starters. Then you also want to shoot enough of it that you KNOW that you won't get a light strike on a primer.

For the binding issue if you can shoot at least a full box of 50 rounds without any signs of binding of the cylinder during DA shooting or of rounds not wanting to shuck and load easily you're gold. Who's going to shoot even that much in a personal SD situation? You don't need your SD ammo for this either. But I would suggest that you shoot 50 reloads then finish with a cylinder of the SD ammo just to ensure that the sizing of the SD ammo is such that it still slips in easily and shucks out easily.

As for trusting the primers to go off each time I don't see much option but to shoot at least 100 of your preferred option.

 

In a revolver I usually send 3 to 4 cylinders downrange to test POI and IMO that's good.

 

I have always urged the firing of at least 200 rounds of the carry ammo through each carry magazine for auto pistols. For revolvers, I would consider 50 rounds of the carry ammo sufficient, mainly because revolvers are not prone to the magazine and feeding problems that tend to plague auto pistols.

But note the emphasis on the words "carry ammo". All too often, folks tend to take a new gun to the range, fire a few rounds of reloads or the cheapest ammo they can find, load up with their choice of carry ammo (usually more expensive), and go about their business, never thinking that the carry ammo might not work. I have seen that situation several times, and in a couple of cases, the carry ammo failed rather badly, though the cheap stuff worked fine.

I know the tendency is to save money and not shoot up the "best" ammo, but that attitude is "penny wise, pound foolish". It is actually worse than not testing the gun at all, because it gives the illusion that the gun is reliable when, in fact, it is not.

Jim

 

Much much easier in a revolver.

Load it with the desired ammo, make sure the cylinder spins freely. Fire 18 or so rounds to verify sight aliment and ignition. Then... you are good to go.

Even the best semi-autos take more than that, even Glocks, to be sure.

And with ammo 1 to 2 BUCKS a SHOT, this can be significant. Yea 200 rounds of DPX would cost about what the gun cost.

Deaf

 

Unlike JMR40, I only had one revolver malfunction. I've had many semi-autos, (finicky things IMHO) fail. My only revolver problem was when I didn't crimp MY reloads properly getting the 'crimp jump' you've been reading about here. I usually test two cylinders of my Carry Rounds for accuracy is all. Oh... been shooting over 40 years. Carried a piece daily for work too.

 

I agree with Jim K's post.

Doesn't matter semi or revolver, I think that you should always shoot-up your carry ammo at least once a quarter and replace it with fresh defensive ammo afterwards. Even revolver ammo can get dinged-up or worse over time. Hate to find out the one time you may need it, that the SD ammo got fudged-up.

Even though I shoot a lot of practice rounds (typically Win. white box), they fire much differently than my hotter, heavier defensive loads. Once every 3-4 months isn't too bad to run a cylinder or magazine of your SD loads.

 

Since I regularly shoot a 1911 5" Full size
and a S&W 625 .45 ACP w/full moon clips -or- .45 Auto Rim

Carry Ammo in stock
.45 AR
225 gr. Auto Rim w/Barnes XPB all copper HP
.45 ACP
+P Hornady 230 gr. XTP @ 950 fps

Both are close enough in velocity for POA/POI

The revolver - once hung up on a .45 ACP shotshell and the
firing pin stuck in the expended primer. and last Saturday
the thumblatch came off as the female screw backed out but I found
both parts - indoor range and it's back together.
and it likes Federal primers

1911 - broke the thumb safety once & plunger came loose but
it kept firing

I've also got some of the new Barnes TAC XPD
+P 185 gr. HP @ 1,000 fps I'm
needing a few mote boxes - for a Commander I will
be getting around May.

R-

 

For semi's a couple/few hundred flawless rounds. For a revolver, one full box of SD ammo and one cylinder of the same SD ammo from a second box. Use the rest of the 2nd box as SD ammo for that revolver.

 

My carry ammo IS my practice ammo: generally RN FMJ.

I don't buy the marketing hype on "SD Ammo", as I do not have an expendable income to blow over $1 a round at the practice range.

I do practice shooting a lot for SD scenarios, practicing head shots. Aim small, miss small, and practice on a regular basis.

Now, if I were an uber-rich dude, and I had extra money to purchase $$$ pallets of Xx brand name ammo? Sure.