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Discussion Starter #1
Last week I shot my new (used) 8-in. Python for the first time and was a bit disappointed in hitting the target. Shot a 4-in. group at 15-yards with occasional shots off the paper.

When running a brass brush thru' the bore, it felt snug at the muzzle, less snug mid-barrel, and snug again near the breach. Fearing that the piece had a buldged barrel, I mic'd the outside diameter: At the muzzle=0.7447; measuring towards the breach 2.5-in.=0.7434; at 4.5-in.=0.7432; at 5-in.= 0.7425; 6.75-in.=0.7404. So there appears to be no outward indication of a buldged barrel.

So I can only conclude that: 1- There might be a slight barrel buldge not outwardly detectable, 2- The piece didn't like the .357 SWC reloads, 3- My shooting skills need improvement, or 4- All of the above.

All comments will be appreciated. Thanks.
 

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I know that the older Pythons had a tapered barrel which was tighter at the muzzle. I'm sure other people here will have more info.
 

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Wow, anyone that can read 10ths on a Micrometer would HAVE to know what they're talking about.
Being that the bulge is not visible from looking down the tube, I'm not sure how you could check that. Do they make bore mikes that small ?
A telescoping guage won't work due to the rifled barrel.
You could try dropping a pin guage in that's the same I.D. as the Muzzle and see if there's any wiggle to the pin as she gets deeper inside the bore.
Although, isn't the bore of the Python barrel supposed to have a very slight taper as to squeeze the bullet out of the barrel ?
Does the crown look OK ?
Because that will through the whole shooting match out the window.
That's very unusual that you would feel that in the brush. I'm sure you would not feel a couple thousanths on a brush. At least I wouldn't think you could.

I'll be interested to find out how you make out on that one.

Jeff (GUNKWAZY)
 

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They make air gages for checking barrels. Also, I agree that you probably can't tell a slight difference by a brush.
 

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WoodSmith, Sounds to me like it is #2 or #3. I would change ammo and try again. If it were me shooting I would probably vote #3.
 

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WoodSmith, pinch the barrel between your thumb and index finger and slide it down if there's the slightest bulge you will feel it. You can also take a light and shine it across the breech end while you look through from the muzzle, a bulge will show up as a dark ring. Don't shine a bore light directly into it. make sure it's clean and shiny inside tho.
 

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by GUNKWAZY:
Wow, anyone that can read 10ths on a Micrometer would HAVE to know what they're talking about.
Jeff (GUNKWAZY)
<HR></BLOCKQUOTE>


Micrometers are read in increments of .0001
not 10ths
 

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Pinch the barrel REBEL ?

C-mon, The man just gave you the O.D. of the barrel in what's known as 10ths of thousands of an inch or what you are clearly pointing out as being a 4 place decimal.
Please don't correct if you don't know what the heck your talkin' about.

****REBEL727
.001 is known as one thousanth of an inch.
.0001 is known as one tenth of a thousanth of an inch.

Most people in the real world can't even read a micrometer, yet alone take it 4 digits and be able to read tenths.
Should I explain millionths or will you incorrectly correct me there too ?



Jeff (GUNKWAZY)

[This message has been edited by GUNKWAZY (edited 04-28-2005).]
 

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So I tapped an extra zero and didn't catch it. I worked in a machine shop, I know how to read a mic. He only measured it in four places. You can feel a bulge no matter how small. Don't get your panties in a wad. LOL!!!
 

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Discussion Starter #10
Gentlemen, thanks for your comments.

At the next opportunity I plan on trying several brands of factory jacketed ammo (the lead SWC may be leading the barrel), and marking each cylinder to identify a possible mistimed cylinder bore. Also, I will work on refining my holding and aiming technique for better consistency. It's my goal to shoot a respectable group beyond 25 yards (with 2x scope).

FYI, it IS possible to detect varying resistance while running a brush thru' the bore, at least for this particular 8-in. Python. And it is NOT difficult to mic to 1/10,000 of an inch with the proper instrument.

I will keep everyone posted on progress, and thanks again for your comments.

-Bob
 

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Hi Bob,
I would think that being the barrel does not have any kind of bulge on the exterior that it probably would be either a ammo or crown issue.

As far as the brush goes, are you sure it does not feel bigger once the brush/bristles are fully inside the barrel ?
That could be the confusion I would think.
Do you have another 357 to compare it to ?

Just a thought.

Jeff (GUNKWAZY)
 

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Discussion Starter #12
GUNKWAZY,
Yes, I ran the same brush thru' a 6-in. Python that shoots well, and the resistance is consistent. Also, I have a 4-in. Python that I believe is a police turn-in that has ALOT of wear everywhere and the brush has very little resistance thru' the bore. The crown appears to be OK.
-Bob
 

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>I worked in a machine shop, I know how to read a mic. He only measured it in four places. You can feel a bulge no matter how small.<HR></BLOCKQUOTE>

Rebel...
It's obvious you DON'T know how to read a Micrometer if you don't know that .0001 is one tenth of a thousanth of an inch.

You probably worked in a carwash too, but that don't mean you know a darn thing about cars.

Jeff (GUNKWAZY)
 

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Bob,
I guess you'll have to change ammo and see.
Some guns do act funny with different ammo.

The crown can have one small ding and throw everything out of whack.

Keep us posted as I like to learn these things for when someone else has these problems.

Thanks and good luck, Jeff (GUNKWAZY)
 

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by GUNKWAZY:
Rebel...
It's obvious you DON'T know how to read a Micrometer if you don't know that .0001 is one tenth of a thousanth of an inch.

You probably worked in a carwash too, but that don't mean you know a darn thing about cars.

Jeff (GUNKWAZY)

<HR></BLOCKQUOTE>

Whatever makes you feel good, go with it.I'm not getting bent over it.
 

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Discussion Starter #16
Unspellable, Yeah it sounds possible that the bore diameter at the breach could be constricted by crush fitting the barrel. Perhaps Dfariswheel can comment.

Diamonback68, I didn't think Colt would machine within 1/10,000-in. either. I just tried to get an indication of an outward barrel buldge by measuring the OD as tight as possible.

Will try a variety of factory jacketed ammo at next opportunity.

Thanks all.
-Bob
 

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So what's one tenth of a mil?

Don't know if they still do, but at one time it was said Colt made a tapered barrel. This would make it smaller at the muzzle.

Now there is a hypothisis that a crush fit barrel such as the Colt has suffers from the breech getting squeezed down when it is installed as opposed to the pinned barrel that S&W used to have which was not a crush fit. Any possibilites in this?
 

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WoodSmith,I'd try the light at the breach and see if you can detect a ring inside the barrel. If not, that clears the inside and the outside. I would not rely on a bunch of little brass bristles as an indicator.
Trust me, Colt doesn't hold tolerances to a tenth of one thousand.
Sounds like you have an ammo selection problem, it happens on most guns.

------------------
Dick

The watchwords for all mankind are.....Liberty and Freedom.
 
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