SW 625 question

[abbafandr]

I have 2 625 revolvers. 4 inch  and a 5 inch barrel.  The 4 inch model just keeps tumbling bullets and keyholes most shots.  The 5 inch is a tack driver. 

At first I thought it was because I was using some .451 bullets, thought maybe use .452.

I took both  to range along with a bottom feeder .45.

Using the same ammo, the 4 inch tumbled like a circus clown at 15 yards, while the 5 inch and the bottom feeder punched nice holes in the cardboard.  So that pretty much ruled out the ammo possibility.

Any ideas?

[Toolguy]

Most likely something with the barrel. Maybe bad forcing cone, bad muzzle crown, constriction in the barrel, bad rifling, or a combination.

[21 shooter]

Toolguy has listed the most likely problems.   The only other thing I can think of is a badly leaded barrel.  A 625 is one of my favorite revolvers.  

[BHBret]

I have Blue Bullet and SNS coated RN you can try. Also 230 grain FMJ Blazers, if you like. 
 

 

[gargoil66]

11 hours ago, abbafandr said:

I have 2 625 revolvers. 4 inch  and a 5 inch barrel.  The 4 inch model just keeps tumbling bullets and keyholes most shots.  The 5 inch is a tack driver. 

At first I thought it was because I was using some .451 bullets, thought maybe use .452.

I took both  to range along with a bottom feeder .45.

Using the same ammo, the 4 inch tumbled like a circus clown at 15 yards, while the 5 inch and the bottom feeder punched nice holes in the cardboard.  So that pretty much ruled out the ammo possibility.

Any ideas?

AF:

 

Given the cylinder is in alignment with the forcing cone so you aren't shaving lead, and you are not leading up the barrel, try another visual inspection of the barrel.

 

Crown is easy enough.  Simple glance would show if something that bad was wrong with it to cause every bullet to tumble.  It would be a really big notch in the crown and even then I doubt it would make a 230 RN tumble so inspect the rifling.

 

Take out the barrel from your .45 and look at its rifling then compare it visually to the 625.   If both look pretty much the same, then see if the bore in the 625 is oversize or has a tight spot.  

 

I would find a tight fitting patch and run it through the 625 barrel and then the 1911 barrel and compare the difficulty in punching the two barrels, or if the 625 has a high spot in the barrel.   If the 625 is grossly easy compared to the 1911, or hits a tight spot -- you probably found the problem and may want to slug the barrel to make sure. 

 

If it were my blaster, and I suspected the barrel was the issue, I would not hesitate to buy another barrel and get it installed.  

 

GG

 

 

 

 

[625]

How old is the gun and has it always keyholed when shot.  For the bullet to be sideways in 15 yards, is a lot of rotation.  Picture of the target might help.

[TNWilliams]

Plus one on leading/fouling

[abbafandr]

Thanks for the input.  I measured the inside of the barrels and the 4 inch was about 6 thousands of an inch wider.  Not positive my calipers were the correct tool I tried something else for fun.  I took a projectile and dropped it in the forcing cone end of the barrel. The 4 inch let the bullet drop well into the cone and fell right out when I lifted the gun up.  The 5 inch(which I can't get posted dropped in snugly but didn't go all the way in.  I had to use a pencil to tap it out when i lifted the gun up.  Maybe the barrel is out of spec? 

[JohnT-73401]

I realize that you said that you tried .452 bullets, but I had the exact same problem with undersized cast bullets from a Lee mold. They measured .451. I switched to an NOE brand mold that drops bullets .453 to 454 as cast and problem went away. My throats measure .453 and the forcing cone is gigantic. I get leading with .452 sized bullets but they don't tumble. Are you sure your bullets actually measure .452 ? 

[abbafandr]

22 minutes ago, JohnT-73401 said:

I realize that you said that you tried .452 bullets, but I had the exact same problem with undersized cast bullets from a Lee mold. They measured .451. I switched to an NOE brand mold that drops bullets .453 to 454 as cast and problem went away. My throats measure .453 and the forcing cone is gigantic. I get leading with .452 sized bullets but they don't tumble. Are you sure your bullets actually measure .452 ? 

I don't cast them. I buy them so I guess I'm at the mercy of the bullets manufacturers.

[gargoil66]

27 minutes ago, abbafandr said:

Thanks for the input.  I measured the inside of the barrels and the 4 inch was about 6 thousands of an inch wider.  Not positive my calipers were the correct tool I tried something else for fun.  I took a projectile and dropped it in the forcing cone end of the barrel. The 4 inch let the bullet drop well into the cone and fell right out when I lifted the gun up.  The 5 inch(which I can't get posted dropped in snugly but didn't go all the way in.  I had to use a pencil to tap it out when i lifted the gun up.  Maybe the barrel is out of spec? 

AF:

 

I don't really like trying to measure groove diameter with a calipers however I think you may have found your problem.  What did you get for the overall groove diameter?

 

I have had bullets tumble from rifles when using a bullet too long for the twist but a 230 RN is almost a round ball and it ain't about to tumble unless you are shooting it out of a smoothbore.   

 

GG

[abbafandr]

1 minute ago, gargoil66 said:

AF:

 

I don't really like trying to measure groove diameter with a calipers however I think you may have found your problem.  What did you get for the overall groove diameter?

 

I have had bullets tumble from rifles when using a bullet too long for the twist but a 230 RN is almost a round ball and it ain't about to tumble unless you are shooting it out of a smoothbore.   

 

GG

The 5 inch was .4415 and the 4 inch was .4465.

[BHBret]

What are the throats of the chambers in your cylinder? If they’re skinny it might be sizing the bullets too small before the get to the forcing cone and the barrel.  
 

You can see if the bullets drop through the cylinder chamber or if they get “squeezed”

[gargoil66]

48 minutes ago, abbafandr said:

The 5 inch was .4415 and the 4 inch was .4465.

AF:

 

.45 ACP groove diameter should be .450 give or take a very little.  Bore diameter diameter .442 give or take just a little. 

 

Hard to measure accurately unless there there are equal numbers of lands.  Don't have my 625 near me to check but I doubt it.  

 

I still suspect oversize bore and I think your measurements seem to indicate it.

 

I also think that BHB has a damn good idea of checking the cylinders to make sure they are not way undersized and are sizing the bullet down a huge amount before it enters the forcing cone so by all means, take a look or measure them.  

 

Easy way to see if the barrel is doing its job is to either shoot a round or two into a soft medium and recover the bullets to inspect the engraving by the rifling, making a chamber cast and pounding it out of the barrel or what has to be about the biggest PITA which is pounding a slug through the barrel.  Cerosafe will give a guy a really nice cast and is easy to use but with all of them, measuring the slug is not easy unless there is an equal number of lands / grooves.  

 

All this said though, if I thought it was the barrel and proved it to myself, I would save myself the frustration and just buy a new one.  

 

Now to turn this over to Warren because it has hit the max of my expertise and mechanical ability!

 

GG

 

 

 

[gargoil66]

Just remembered owning a Webley Top Break that was capable of taking half moon clips of .45 ACP or .45 Auto Rim.  Groove diameter was technically .455.  Shot .452 cast bullets out of it and never keyholed.  Accuracy was pretty rough though.  Bet it was as much as shooting a undersized bullet as the monstrous trigger pull.  Still, no keyholing.  

 

Doesn't take much engraving to put a spin on a bullet is what I found out with that Webley.  Ditto for shooting cast bullets through barrels with Medford styles of rifling. 

 

 

 

 

[BHBret]

ABBA Fan (love that name), here is some info that might help from my 625JM 4" that is very, very similar to yours (except the tumbling bullets). Last year I fired a squib load (Blue Bullet) that got lodged in the barrel. The base of the bullet was just inside the barrel and I had to thump it out with a rod. That bullet (seen in the pictures) measures 0.450". I also was able to push SNS coated bullets (0.452") with minimal pressure into the cylinder chambers from the front. I'm going to guess that the chamber throats are 0.452" diameter.  All of which is probably as it should be.

Edited April 8, 2022 by BHBret
grammar

[pskys2]

Have you tried Jacketed .451" bullets?  

Shoot at least a cylinder full of high pressure Jacketed loads.  Then shoot another cylinder full of .451 Jacketed Bullets, don't have to be high pressure though, for accuracy.  If you don't see tumbling, switch to some .452 coated bullets and after doing a serious bore scrubbing test the .452 coated bullet loads for accuracy/tumbling.  If they don't tumble anymore and are reasonably accurate just start using .452 coated bullets or .451 Jacketed.

If it's still tumbling, get a reamer from Brownells, or find a 'smith (Carmoney or Warren you out there?) to recut the muzzle crown and maybe the forcing cone.  And have them check the Cylinder Throats.  

The solution may be as simple as using only Jacketed or a larger sized bullet, clear up to .454 if the throats are oversized.  

Most 625's do best with .452" bullets, 1911's aren't as picky.  

[BHBret]

I forgot to take this picture until now. It's a 230 SNS sitting in the forcing cone. This looks the same as you described your 5", which didn't go all the way.

[abbafandr]

2 hours ago, pskys2 said:

Have you tried Jacketed .451" bullets?  

Shoot at least a cylinder full of high pressure Jacketed loads.  Then shoot another cylinder full of .451 Jacketed Bullets, don't have to be high pressure though, for accuracy.  If you don't see tumbling, switch to some .452 coated bullets and after doing a serious bore scrubbing test the .452 coated bullet loads for accuracy/tumbling.  If they don't tumble anymore and are reasonably accurate just start using .452 coated bullets or .451 Jacketed.

If it's still tumbling, get a reamer from Brownells, or find a 'smith (Carmoney or Warren you out there?) to recut the muzzle crown and maybe the forcing cone.  And have them check the Cylinder Throats.  

The solution may be as simple as using only Jacketed or a larger sized bullet, clear up to .454 if the throats are oversized.  

Most 625's do best with .452" bullets, 1911's aren't as picky.  

I had my gunsmith cut the crown.  I've been using some .452 cast and plated (Berry).  The bullet drop into the cylinder just fine on both.  Going to shoot it this weekend, gonna try some .454 a friend will let me try.

[gargoil66]

2 hours ago, abbafandr said:

I had my gunsmith cut the crown.  I've been using some .452 cast and plated (Berry).  The bullet drop into the cylinder just fine on both.  Going to shoot it this weekend, gonna try some .454 a friend will let me try.

AF:

 

Remember to make a couple of dummy rounds using the .454 bullet and your brass to make sure they will drop into the cylinder and can be removed easily. 

 

GG

[gargoil66]

16 hours ago, abbafandr said:

I had my gunsmith cut the crown.  I've been using some .452 cast and plated (Berry).  The bullet drop into the cylinder just fine on both.  Going to shoot it this weekend, gonna try some .454 a friend will let me try.

"I had my gunsmith cut the crown."

 

AF: 

 

Question.

 

Why was that?  Did this revolver keyhole before it was re-crowned?

 

GG

 

[abbafandr]

On 4/9/2022 at 7:46 AM, gargoil66 said:

"I had my gunsmith cut the crown."

 

AF: 

 

Question.

 

Why was that?  Did this revolver keyhole before it was re-crowned?

 

GG

 

Yes it  keyholed before he recut the crown.

[gargoil66]

On 4/17/2022 at 4:34 PM, abbafandr said:

Yes it  keyholed before he recut the crown.

 

Hmmm.

 

Something tells me the oversize bullets didn't work either.

 

Seems like a new barrel is probably in order.  

 

I would be pretty upset if this happened to me.

 

GG66

[pskys2]

Just curious what crimp are you using?  If you're using .452" bullets in a Revolver  I like no tighter than a .468" Taper Crimp.

 

I had a similar issue when using 45 Plated Bullets at Major PF back in the day, I was over crimping them and had tumbling issues.

[GMM50]

Another easy test is to put any bullet into the cylinder throat upside down. 

They should all go in the same amount.  If one (or More) go in further than the others, then you have throats of different sizes and perhaps they are too small.

Edited April 20, 2022 by GMM50