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How to tune primers and extraction for 8 shot revolvers


MattInTheHat
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I had my first range session in about 3 years, and have barely been out since 2014 or so due to lots of joint and muscle problems. I recognize that 8 shot is the only viable option so I'm trying to tune everything so that it works like my good old .45s.

 

The two big issues I'm running into are lots of clicks and empty moonclips jamming up against the frame, grip, or ejector on reloads. I cooked up a batch of light, medium, and heavy primer stroke ammo but haven't found a recipe yet, trying from .01 to .015 depth in the pocket. I've shaved back the left side of the grip to give as much clearance as possible but I still get clips tangling on the ejector.

 

That last part is probably something I can work through with mixtures of shaving, gun position, and different clip tensions, but I'm always open to suggestions.

 

More to the point, does anyone have a sweet spot for primer depth on a 627 with Starline short Colt brass and Federal SPP?

Edited by MattInTheHat
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You loading on a 1050 where you can set your depth ?

 

How heavy are you running your trigger with what rebound ?

 

I'm loading starline long colts, on a 1050. I set.it to .009 below flush. Some come out 008, some 010. But works fine. 

 

As a reference, my triggers are about 5.5 - 5.75 lb with an 11 lb rebound spring. 

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I load on 550s and I just firmly seat the primer in the pocket.The 550 has a good feel for primer seating. I never worried about measuring the depth and mine all work fine. They DO have to be firmly set to the bottom, but I never crushed them past that point. That might make them more sensitive, I don't know. Try different things and find what works for you.

I have found through experimentation that a .500 to .505 firing pin with a full radius nose works the best ( of the ones I've tried), and a Carmonized (at least hammer spur bobbed) hammer will give reliable ignition with a lighter mainspring. I'm running about 5.5 down to 2.5 pound D/A trigger with 100% on Federal primers with my 627s.

 

For the extraction problem, you have to get the gun fairly vertical, then hit and release the extractor very quickly. If you hold the extractor out, the cases tend to not fall freely.

Edited by Toolguy
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New prototype hammer I'm getting ready to patent. The trigger pull gets lighter as you pull it back. The last 1/8" or so of the trigger pull is the same as a S/A pull would be, based on whatever rebound spring is in there. You can dial it up for whatever primer you're using, but it always ends up the same at the end. The Federals start at 5.5 to 6, CCI starts around 9 to 9.5. There are not hard numbers because every gun is different, springs vary, pull gages are not all the same, etc. and measurements aren't exact. I'm getting about 2-1/2 with a 12 lb. Wolff rebound. 

 

The rebound springs give from around 2-1/4 for a Wolff 11 lb. to 3-3/4 to 4 lb. for a S&W factory. All the other Wolff ones are somewhere in between. This is measuring the pull weight of the trigger with rebound only, with hammer and mainspring out.

Edited by Toolguy
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Darn Matt good to see you back!  

Deciding on biting the bullet, so to speak?, and use an 8 shot in Revolver? Great fun and a lot less battering to the body than the Major 45 ammo!

 

I like to relieve the left side grip too, also did it for the 625.  I even played with removing the upper left tang on my 45's at one point, but it just beat my thumb joint up more.  It did help with the ejection though.  

I've not found a lot of difference between the 625/627, might just be the guns but both my 627's are more reliable than my 625 was.  

Never measured the actual depth, set the primers so I can feel the primer below the case rim.

But my actions are all 5.5 +/-.  Any lighter and I can't seem to keep one reliable for any length of time.  

What moon clips are you using, TK or HearthCo's are what I use.  They are tight (a lot tighter than the old Ranch 45 clips) but, unless stepped on & twisted, they don't give me any troubles.  Dave Hearth is on this Forum, might PM him if you need some more clips.  I've had more issues with loose clips with the short colts than the tight ones.

 

So are you going to campaign in Revolver Division, or ICORE, when this pandemic hysteria wanes?

Good Luck!

 

 

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20 hours ago, alecmc said:

You loading on a 1050 where you can set your depth ?

 

How heavy are you running your trigger with what rebound ?

 

I'm loading starline long colts, on a 1050. I set.it to .009 below flush. Some come out 008, some 010. But works fine. 

 

As a reference, my triggers are about 5.5 - 5.75 lb with an 11 lb rebound spring. 

Just a 650, but then mic'inc out a batch to test with, back in the day I could get a pretty consistent .01 to .014 depth by feel but those were Federal LPPs and I was probably shooting a pound heavier than most, usually clocked at 6.5 by a cheap pull scale. That said, they were 1/1000 reliable.

 

Best case is always lightest possible pull through with strongest possible reset, and the 627 I shoot right now is not my own trigger job, it's very thin at the top so not much mass at the end of the lever.

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5 hours ago, Toolguy said:

I load on 550s and I just firmly seat the primer in the pocket.The 550 has a good feel for primer seating. I never worried about measuring the depth and mine all work fine. They DO have to be firmly set to the bottom, but I never crushed them past that point. That might make them more sensitive, I don't know. Try different things and find what works for you.

I have found through experimentation that a .500 to .505 firing pin with a full radius nose works the best ( of the ones I've tried), and a Carmonized (at least hammer spur bobbed) hammer will give reliable ignition with a lighter mainspring. I'm running about 5.5 down to 2.5 pound D/A trigger with 100% on Federal primers with my 627s.

 

For the extraction problem, you have to get the gun fairly vertical, then hit and release the extractor very quickly. If you hold the extractor out, the cases tend to not fall freely.

I've always run bobbed primers but I don't know what the factory pin length is. I tried an extended pin on the .45 and had immediate failures so backed off. A SPP might be a different thing since there's theoretically a smaller diameter of similar metal to deform, this my question. Maybe an extended pin works better for the smaller primer?

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The right length of firing pin works the best. There are many variables involved here. Some of the main ones are endshake, primer seating depth, headspace, rim thickness, moonclip thickness, etc. The longest factory pin I've seen is .495, the shortest was .482, and everything in between. The .495 is also the shortest length that seems to work reliably. Whatever pin is in there has to be long enough to make a deep enough dent in the primer for the combination of variables in that particular gun. In a perfect world, all parts of all guns and ammo would be exactly to drawing specs. In the real world, there will always be minor variations from the ideal desired perfection. The longer firing pin will help "flatten the curve" of deviations from the ideal. Some guns don't need an extended firing pin, some do. You can easily take the FP out and measure it to see what you're working with.

 

I like to see the firing pin stick out about the thickness of a dime when the hammer is down. Make sure endshake is at a minimum. I use a #8-32 x 1/2" setscrew and blue Loctite for the strain screw. Tighten the mainspring lightly at first, shoot, advance in 1/8 turn increments, shoot, etc. until no misfires. Then another 1/8 turn to catch that 1 in 100 misfire. Then find the lightest rebound spring that gives a good trigger return feel. Then you will have the lightest trigger pull for that gun without extra parts or gunsmithing. You can usually get into the 6 to 7 pound range with factory parts that way.

Edited by Toolguy
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Ok hope this helps.

 

I'm loading on a Super 1050 now. 

The primer depth is .009.  Pretty much the same as when I was loading on the 550.

 

627 PC & 627 Pro with Hammers NOT bobbed, factory FP (think it measured .495 or .505) I have on hand several C&S,  Apex & the factory  FP's that came in the 627's.  I like them in the reverse order.  My 625 had a .475 FP (if I remember right) & I started using the Apex with good results.  I've been told SPP are easier to light off?  I've had better results with the SC rimmed rounds & SPP than I ever had with acp rimless & LPP though.

I use HearthCo Moon Clips for Starline Short Colts, they are very tight with no discernible movement in the cartridges.

 

My hammer drop weight is 40 ounces (measured with an older RCBS spring Trigger Gauge) on both 627's, with 11 lb rebound springs-2 coils for an Action Weight of 5.5-6 lbs measured with an old fishing scale (rated from 1 lb to 10 lbs).

If I go below 5.5 lbs I will see an occasional light strike.  And I do like a positive rebound, but not one that pushes my finger hard.

The current thought on CF Revolvers is a lighter hammer has more snap to set off the primers (opposite with RF though?).

One thing to check with a real thin hammer would be for a crack somewhere.  I've seen a few reports of them being over Carmonized & cracking.

Maybe take one out of another Revolver and see if it helps?

 

 

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On 5/10/2020 at 7:16 PM, pskys2 said:

Ok hope this helps.

 

I'm loading on a Super 1050 now. 

The primer depth is .009.  Pretty much the same as when I was loading on the 550.

 

627 PC & 627 Pro with Hammers NOT bobbed, factory FP (think it measured .495 or .505) I have on hand several C&S,  Apex & the factory  FP's that came in the 627's.  I like them in the reverse order.  My 625 had a .475 FP (if I remember right) & I started using the Apex with good results.  I've been told SPP are easier to light off?  I've had better results with the SC rimmed rounds & SPP than I ever had with acp rimless & LPP though.

I use HearthCo Moon Clips for Starline Short Colts, they are very tight with no discernible movement in the cartridges.

 

My hammer drop weight is 40 ounces (measured with an older RCBS spring Trigger Gauge) on both 627's, with 11 lb rebound springs-2 coils for an Action Weight of 5.5-6 lbs measured with an old fishing scale (rated from 1 lb to 10 lbs).

If I go below 5.5 lbs I will see an occasional light strike.  And I do like a positive rebound, but not one that pushes my finger hard.

The current thought on CF Revolvers is a lighter hammer has more snap to set off the primers (opposite with RF though?).

One thing to check with a real thin hammer would be for a crack somewhere.  I've seen a few reports of them being over Carmonized & cracking.

Maybe take one out of another Revolver and see if it helps?

 

 

Helps a bunch bud, I really appreciate the time and knowledge that went into that. The first question I have is that .009 used to be my minimum on .45, are you getting a good visible anvil bulge in your primers at that depth? I found that below .007 failed just as past .015 did, assumption being that one didn't let the pin accelerate enough and the other was depth challenged. Like I mentioned I'm looking for about 1 in a 1000 failures so I'd like to dial it in pretty well.

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2 hours ago, MattInTheHat said:

Helps a bunch bud, I really appreciate the time and knowledge that went into that. The first question I have is that .009 used to be my minimum on .45, are you getting a good visible anvil bulge in your primers at that depth? I found that below .007 failed just as past .015 did, assumption being that one didn't let the pin accelerate enough and the other was depth challenged. Like I mentioned I'm looking for about 1 in a 1000 failures so I'd like to dial it in pretty well.

At .009 the seated primer looks normal, no crushing with a normal looking rounded dome.  In the past I seated them so when I ran my thumb across the rim and could feel a slight ridge at the case rim above the primer.  That's about what this also feels like.  

I've not had any issues other than getting used to the 1050.  Had one click and the primers weren't being seated below flush.  I fiddled and fussed and couldn't figure it out.  When I had first gotten it everything was great.  Then I changed to 9mm and had all kinds of issues.  Kept adjusting and nothing changed.  Finally really looked at the system and duh I was adjusting the wrong thing.  I now have it figured out.

I just changed back to 38 short colt and the primers were seating to .011, left it at that and will see how this batch of about 1,000 and see if there's any issues.  It shows a very little flattening of the primer at this depth.

Now that you've got me checking, and I've figured out the 1050.  I'm getting a little OCD about it!

 

I'm retired and just finished my basement, the wife now has about 500 sq ft of the basement for a Quilting Studio with her Machine Quilting Rack (good story at her Retirement visit with HR I  was gabbing away as always and mentioned I wanted to get one for her as a gift.  The HR gal told us of one, long story short got it for $600, and I had to almost sneak around and get it as she didn't want to spend that much.  Checked last week with the manufacturer and found out this machine was a special order and the original owner spent just under $20,000 on it in 2015!!! 

I've only got a bit over 200 sq ft for my Reloading Room, but it's plenty of room for my 8' bench, safe, 8' presentation bench, mini fridge plenty of shelves.  There's plenty of room left to rattle around.  Now if I can just keep my stock of components up!  Going out back to my Range at least once each day is starting to eat into my supplies!

Sorry for rambling though!

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