View Full Version : Revolver Checkout procedure - How to tell if a particular specimen is any good.

05-05-2010, 9:44 AM
This is an old post from The Firing Line (http://thefiringline.com/forums/) forums authored by our very own 1JimMarch; I don't recall when it was first posted. Originally posted February 18th, 2001 (wow has it really been that long?) It's been invaluable when checking out a used revolver and I think it's excellent information to have handy.

Revolver checkout:
How to tell if a particular specimen is any good
So you're buying a revolver. New, used, doesn't matter, you want a good one, right?

How do check one over without firing it, right at the dealer's counter or gun show table?

This is how. All of this works with DA or SA wheelguns..."close the action" on most DAs means swing the cylinder in, on SA types, close the loading gate, on breakopens, close 'em. UNLOADED.

WARNING: Most of these tests require violation of the "finger off trigger" rule. Therefore, be extremely careful about safe muzzle direction and making sure the gun is unloaded ahead of time, PERSONALLY, as you begin handling it.

Note: Bring a small flashlight, something small and concentrated. A Photon or similar high-powered LED light is perfect. You also want feeler gauges if you're not used to eyeballing cylinder gaps; at a minimum, bring a .002", .004" and .006".

Note2: No dry firing is required or desired at any point. It just pisses off the gun's current owner.

Cylinder play 1) With the gun UNLOADED (check for yourself!), close the action.

2) Thumb the hammer back, and while pulling the trigger, gently lower the hammer all the way down while keeping the trigger back - and KEEP holding the trigger once the hammer is down. (You've now put the gun in "full lockup" - keep it there for this and most other tests.)

3) With the trigger still back all the way, check for cylinder wiggle. Front/back is particularly undesirable; a bit of side to side is OK but it's a bad thing if you can wiggle it one way, let go, and then spin it the other way a fraction of an inch and it stays there too. At the very least, it should "want" to stop in just one place (later, we'll see if that place is any good). The ultimate is a "welded to the frame" feeling.

Cylinder gap 4) Still holding the trigger at full lockup, look sideways through the barrel/cylinder gap. If you can get a credit card in there, that ain't good...velocity drops rapidly as the gap increases. Too tight isn't good either, because burnt powder crud will "fill the gap" and start making the cylinder spin funky. My personal .38snubbie is set at .002, usually considered the minimum...after about 40 shots at the range, I have to give the front of the cylinder a quick wipe so it spins free again. I consider that a reasonable tradeoff for the increased velocity because in a real fight, I ain't gonna crank 40 rounds out of a 5-shot snub.

If you're eyeballing it, you'll have to hold it up sideways against an overhead light source.

SAFETY WARNING: This step in particular is where you MUST watch your muzzle direction. Look, part of what's happening here is that you're convincing the seller you know your poop . It helps the haggling process. If you do anything unsafe, that impression comes completely unglued.

Timing 5) You really, REALLY want an unloaded gun for this one. This is where the light comes in. With the gun STILL held in full lockup, trigger back after lowering the hammer by thumb, you want to shine a light right into the area at the rear of the cylinder near the firing pin. You then look down the barrel . You're looking to make sure the cylinder bore lines up with the barrel. Check every cylinder - that means putting the gun in full lockup for each cylinder before lighting it up.

You're looking for the cylinder and barrel holes to line up perfectly, it's easy to eyeball if there's even a faint light source at the very rear of both bores. And with no rounds present, it's generally easy to get some light in past where the rims would be.

Bore (We're finally done with that "full lockup" crap, so rest your trigger finger. )
6) Swing the cylinder open, or with most SAs pull the cylinder. Use the small flashlight to scope the bore out. This part's easy - you want to avoid pitting, worn-out rifling, bulges of any sort. You want more light on the subject than just what creeps in from the rear of the cylinder on the timing check.

You also want to check each cylinder bore, in this case with the light coming in from the FRONT of each hole, you looking in from the back where the primers would be. You're looking for wear at the "restrictions" at the front of each cylinder bore. That's the "forcing cone" area and it can wear rapidly with some Magnum loads. (Special thanks to Salvo below for this bit!)

Trigger 7) To test a trigger without dry-firing it, use a plastic pen in front of the hammer to "catch" it with the off hand, especially if it's a "firing pin on the hammer" type. Or see if the seller has any snap-caps, that's the best solution. Flat-faced hammers as found in transfer-bar guns (Ruger, etc) can be caught with the off-hand without too much pain .

SA triggers (or of course a DA with the hammer cocked) should feel "like a glass rod breaking". A tiny amount of take-up slack is tolerable, and is common on anything with a transfer bar or hammerblock safety.

DA triggers are subjective. Some people like a dead-smooth feel from beginning of stroke to the end, with no "warning" that it's about to fire. Others (myself included) actually prefer a slight "hitch" right at the end, so we know when it's about to go. With that sort of trigger, you can actually "hold it" right at the "about to fire" point and do a short light stroke from there that rivals an SA shot for accuracy. Takes a lot of practice though. Either way, you don't want "grinding" through the length of the stroke, and the final stack-up at the end (if any) shouldn't be overly pronounced.

Detecting Bad Gunsmithing: 8) OK, so it's got a rock-solid cylinder, a .002" or .003" gap, and the trigger feels great. Odds are vastly in favor of it being tuned after leaving the factory.

So was the gunsmith any good?

First, cock it, then grab the hammer and "wiggle it around" a bit. Not too hard, don't bang on it, but give it a bit of up/down, left/right and circular action with finger off trigger and WATCH your muzzle direction.

You don't want that hammer slipping off an overly polished sear. You REALLY don't want that . It can be fixed by installing factory parts but that'll take modest money (more for installation than hardware costs) and it'll be "bigtime" unsafe until you do.

The other thing that commonly goes wrong is somebody will trim the spring, especially coil springs. You can spot that if you pull the grip panels, see if the spring was trimmed with wire cutters. If they get too wild with it, you'll get ignition failures on harder primers. But the good news is, replacement factory or Wolf springs are cheap both to buy and have installed.

There's also the legal problems Ayoob frequently describes regarding light triggers. If that's a concern, you can either swap back to stock springs, or since you bought it used there's no way to prove you knew it was modified at all.

In perspective: Timing (test #5) is very critical...if that's off, the gun may not even be safe to test-fire. And naturally, a crappy barrel means a relatively pricey fix.

Cylinder gap is particularly critical on short-barreled and/or marginal caliber guns. If you need every possible ounce of energy, a tight gap helps. Some factory gaps will run as high as .006"; Taurus considers .007" "still in spec" (sigh). You'll be hard-pressed to find any new pieces under .004" - probably because the makers realize some people don't clean 'em often (or very well) and might complain about the cylinder binding up if they sell 'em at .002".

The guns in a dealer's "used pile" are often of unknown origin, from estate sales or whatever. Dealers don't have time to check every piece, and often don't know their history. These tests, especially cylinder gap and play, can spot a gun that's been sent off for professional tuning...like my snubbie, the best $180 I ever spent.

As long as the gun is otherwise sound (no cracks, etc) a gunsmith can fix any of this. So these tests can help you pick a particularly good new specimen, or find a good used gun, or help haggle the price down on something that'll need a bit of work.

Hope this helps.
Jim March

05-05-2010, 10:49 AM
Thx for posting ... would have been nice to have seen this prior to buying my Taurus 66 late last year ... the gun is POS ... this will help me do my write up before I send it in to Taurus

05-05-2010, 10:58 AM
Excellent post, thank you.

05-05-2010, 5:41 PM
It's "March", not "Marsh".


05-05-2010, 5:47 PM
Seriously, I want to also refer people to the original thread:


There's additional commentary and discussion there worth looking at.

And yes, I'm planning a revised/updated version including at least some model or gun-specific notes.


05-05-2010, 7:56 PM
Thanks for posting!

i just happened to read this earlier and didnt even realize you just posted it today :)

my new 686ssr is good-to-go. :cool:

05-05-2010, 9:17 PM
It's "March", not "Marsh".

Oh damn, apologies for that Jim. Fixed it.

05-05-2010, 9:54 PM
Ain't a biggie :).

05-05-2010, 11:27 PM
That was an enjoyable lesson...ty

05-05-2010, 11:37 PM
Thank you for posting. I used this guide an year ago when I was checking out a revolver. :)

06-12-2010, 11:15 AM
This is awesome. Thank you for this info. I want a .38 snubie and now I can buy one used and save some money with this information.

08-27-2010, 5:10 PM
There is a comparable post, I think, by Xavier at XavierThoughts (http://www.calguns.net/calgunforum/showpost.php?p=2289918&postcount=6) regarding used 1911s.

09-21-2010, 5:43 AM
thanks for posting
some great info
this sure makes me feel better when buying a old gun

12-06-2010, 10:51 AM
Fantastic write up! Thank you Jim for the original content and for Chris for cross posting it here. :)

I have found a helpful writeup which supplements Jim's writings. It's a piece by Kirk Hayes. (http://urbanevasion.com/firearms/98-what-to-look-for-in-buying-a-revolver)

02-13-2011, 6:37 PM
. this will help me do my write up before I send it in to Taurus ..

05-21-2011, 3:16 PM

At 12 pages worth of PDF file, the "revolver checkout" just got a major update. There's pictures. There's side-notes on everything from special needs for black powder, reloading tool compatibility, make and model-specific data, and at the end a one-page outline of what kind of recoil and ammo performance you should expect with various weight classes of 38Spl and 357 guns.

There's special notes scattered throughout on various gun types, everything from the Colt Walker to breakopens to aluminum-frame snubbies.

There's...a lot :). Page 12 is a one-page re-hash of the whole checkout procedure as quick bullet points to take with you to a gun show, gun shop, post-apocalyptic back alley or whatever :D. Despite this "short form" I recommend reading the whole thing once, to get the various theories and advanced notes down before going shopping.

It's too big for an attachment so I have it at google docs where it can be viewed without a PDF reader if needed:


NOTE: you can download it locally - look for the "file" menu, top-left corner area below the color google logo. This is also where you can print it cleanly.

And yes, I promise, there'll be an update in 2021 :). With any luck, there'll be a special section on magazine-fed gas-eject single action revolvers that I got rich off of inventing :D.

(Or not.)

A quick moment: if you’ve found this guide useful, please consider chipping in $20 or less – not for me, but to fund a really important election-related lawsuit in Arizona that has national implications. See also:
https://www.wepay.com/donate/AZCARE – THANKS!

ADMINS: can we move this post to the top?

06-11-2011, 10:16 PM
Was looking at some revolvers at MBR today, and thought I needed to review this post. And now I find that 12 page PDF. Awesome! Thanks Jim.

07-27-2011, 6:22 PM
Better late than never...for me reading it anyways. I am in the market for a revolver and this has definitely educated me. Thank you very much!

08-31-2011, 8:48 PM
Cool Post! I've always checked gap, but never really thought about the tuning aspect. I always just wanted to know if the gap was less than .006 with judgement favoring the idea of the lower the better until .002 gap. Never gave it a thought other than that. Now that you mention it though, A lot of the really tight gap tolerance guns I've seen also seemed to have well above average slick triggers. i always just attributed it to the factory "luckout" and the trigger being really well broken in.

09-01-2011, 11:14 AM
Yeah, what you sometimes see looking like "just another old gun" on the dealer's shelf is actually somebody's former pride and joy. Maybe a dead somebody, widow sold it not having clue one it was worked over by a top gunsmith. There's way more critters like this floating around than you can imagine.

09-13-2011, 11:39 AM
This is excellent. Particularly for a newb in the market for a revolver like myself.

Thanks for sharing!

09-13-2011, 7:47 PM
Cylinder gap Still holding the trigger at full lockup, look sideways through the barrel/cylinder gap. If you can get a credit card in there, that ain't good...velocity drops rapidly as the gap increases.

I wanted to check my GP100. I haven't done the full lockup thing yet, but I sure hope that changes things because right now I can get 2 credit cards in the gap! :eek:

09-13-2011, 8:51 PM
I wanted to check my GP100. I haven't done the full lockup thing yet, but I sure hope that changes things because right now I can get 2 credit cards in the gap!

It *might* change things. It does on some guns, not on others. Rather than spend pages and weeks of research figuring out which are which, I went with "do the full lockup thing" :). Sorry, but it was the practical answer. As best I could, I wanted one procedure that would work on anything from an 1836 Paterson Colt forward (NOT that you'd do it on a genuine antique Paterson(!) but Uberti has made replicas...).

10-21-2011, 6:33 PM
Very, very, helpful! The post with the 12 page reference should be at the top. Thanks!

01-11-2012, 9:24 PM
Well I guess better late than never to the party . Thanks for some great info , My father-in-law has an old service revolver I want to check out and see what kind of shape it's in .....

01-29-2012, 2:59 PM
Jim, since youre trying to raise some cash, why not offer a check-out clinic 3-4 times a year? Ive read and enjoyed the "12" but still some things im not familiar with, or lets say have the right experience/feel for to really know if a weapon is Ok or not. Id pay for your on the spot check-out, wouldnt others, too?

01-30-2012, 12:07 AM
Huh. Well one option would be to schedule a mini-class at one of the big AZ gun shows - towards the beginning :).

Not a half bad idea, that...

Flyin Brian
01-30-2012, 4:35 PM
I'm looking at an early Python right now that has very little cylinder gap, actually there are light rub marks on the front of the cylinder where the forcing cone is making contact or has in the past. All of the other checks come out great... is this a major issue or not?

03-07-2012, 2:22 PM
Great read! Thanks Jim March for sharing your insight and knowledge. I'm keeping my eyes open for my next revolver and this will be invaluable.

ETA: Thanks QuarterBoreGunner for sharing it too. :-)

03-12-2012, 1:33 PM
Thanks a lot for posting this. I just went through your check list with my Python I bought used about 4 years ago. At the time the gun seemed clean and 600 bucks was too good to pass up. Your write up confirmed I got a good deal.

03-21-2012, 10:30 PM
Hi Chris and Jim March:
My eight-year-old "near virgin" Taurus Model 605 passed with flying colors all but the full lock up cylinder-to-barrel gap which is around 0.012 inches! (Ideally it should be closer to 0.002") It has only had around 250 rounds through it and was probably that far out of spec. when it came out of the box from the gun dealer in Redding, Calif. in 2004.

I will use the great info to bend Taurus' arm when I return it to them. They claim their revolvers have a lifetime warranty... we'll see if they are liars!

Thanks for a truly great post! Very good info. :)


03-21-2012, 11:55 PM
At .012 you're going to lose a LOT of velocity. In 357 I don't like more than .004" if I can avoid it, while in .38 I like it even closer although the gains in velocity aren't really that great between, say, .004" and .002".

There's a few cases where you want a big gap, up to about .008" or even a hair over if you're shooting "Holy Black" in a SASS black-powder-cartridge class (larger soot particles, and you want them to blow loose, and peak velocity isn't a concern). But .012" should be WAY past spec on anything.

01-25-2015, 12:15 PM
Your procedure doesn't check the cylinder timing well enough. IMHO.

I would bring along a full set of snap caps and dry fire the thing slowly at first, then as fast as possible, for at least fifty additional times.
Pointing the gun at a normal shooting angle, not up at the sky.
If the revolver is out of time, it will lock up. Will lock up more often in actual shooting, so any hiccup dry-firing is a very- very bad sign.
Had this problem with a Colt DA revolver. Factory service didn't help for long. Sold it. Let someone else deal with the lack of quality.

01-31-2016, 1:04 PM
great thread ! I be sure give those function check and check the gap with feeler gauge too . thanks