Roll crimp for moon clips?

[Mcfoto]

Newb questions continue: spent a frustrating evening last night trying different moon clips and brass combos that I couldn’t get to seat easily in my cylinder. Finally loaded a clip of snap caps and walla! They flew in. So now thinking the straight taper crimp is the hang up. Using coated bullets so been told to taper crimp back to straight. Now wondering if I need a roll crimp to help get the edge of the cases over the ridge of the cylinder.

[ffl]

you should always use roll crimp on  revolver rounds.  they help keep the bullet from moving while shooting.  taper crimps don't keep the bullet from moving back unless you crimp really hard and then the accuracy goes away.

 

 

[revoman]

I use Lee factory crimp die on all my moon clipped revolvers and have never had a problem with loading or bullet movement. 

[PatJones]

Which revolver? Which caliber?

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[MikeyScuba]

Are you gauging your rounds first?

 

I'm no expert but I don't think the crimp is your problem.

[Mcfoto]

13 minutes ago, PatJones said:

Which revolver? Which caliber?

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627, .38 sp. eventually going short colt

[Mcfoto]

1 minute ago, MikeyScuba said:

Are you gauging your rounds first?

 

I'm no expert but I don't think the crimp is your problem.

 

Of course. I gauge every round as it comes off the press.

[Dr. Phil]

1 hour ago, ffl said:

you should always use roll crimp on  revolver rounds.  they help keep the bullet from moving while shooting.  taper crimps don't keep the bullet from moving back unless you crimp really hard and then the accuracy goes away.

 

 

Pretty difficult with bullets without a crimping groove. I taper crimp and have no problems as well. Might try setting your crimp up with a factory round in the die? Crimp can be touchy so experiment. And maybe don't load 1000 till you get it worked out?

Good luck and welcome to the dark side!

[pskys2]

If you roll crimp without a crimp groove, or over a driving band you can bulge the case and cause seating issues.  If you taper crimp too much you can also cause trouble with shedding plating or if it's a jacketed it can collapse the case leading to a bulge and seating issues. 

I've used both to good effect.  But have seen no great advantage to a roll crimp especially with no crimp groove.  Further the taper crimp will actually help reduce loading issues.

If you shoot minor it's less of an issue than you'd think.

You might make sure you don't have shavings from not enough belling of the case, or worse of all seating and crimping at the same station.  The shavings can cause rounds to not seat.

 

[radny97]

^^^^^^Yep. Taper crimp has worked well for me on coated bullets. 

Edited October 30, 2018 by radny97

[PatJones]

I'm currently using the 158 grain round nose from S&S Casting because it has a crimp groove. I do prefer a roll crimp. That said, my 625 runs just fine with a taper crimp.

My 627PC has the chambers chamfered from the factory and needed to modification. Is your cylinder chamfered? It doesn't take much, just enough to clear the thickness of the case.

Could it be something else? During dry fire recently I noticed the moon clip was hanging up on the cylinder release. I use a SDM cylinder release, the checkering is very sharp and comes all the way to the edge. I put a slight radius on the edge of the release and my reloads are more consistent. I've been chasing a problem with my reloads hanging up intermittently for several years, and this solved it for me.

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[revoman]

All the bullets I use are coated lead  without a crimping groove and never have had problems with leading or loading. Comes down to how much crimp you use. Again this is minor loads so just a little is needed. 

[kimmie]

I had the same problem with a 2nd 627 that I just bought and discussed it in another thread.  Original 627, moon clipped .38sp rounds dropped right in 100% of the time.  New 627, same rounds and they were getting hung up on the edges of the chambers and I had to wiggle them in. Both cylinders just had the factory chamfer, which is pretty much, none. I use a tapered crimp.  Sent the cylinders out to be chamfered by a forum member here and problem solved.  I can throw them at the gun from across the room and they fall right in, lol.

[Mcfoto]

15 minutes ago, kimmie said:

I had the same problem with a 2nd 627 that I just bought and discussed it in another thread.  Original 627, moon clipped .38sp rounds dropped right in 100% of the time.  New 627, same rounds and they were getting hung up on the edges of the chambers and I had to wiggle them in. Both cylinders just had the factory chamfer, which is pretty much, none. I use a tapered crimp.  Sent the cylinders out to be chamfered by a forum member here and problem solved.  I can throw them at the gun from across the room and they fall right in, lol.

 

Good point. It’s going for the after-break-in tune next week. I’ll have the smith do some chamfering.

[MWP]

13 minutes ago, Mcfoto said:

 

Good point. It’s going for the after-break-in tune next week. I’ll have the smith do some chamfering.

I am so curious what is included in the "after-break-in" tune. 

 

Is there a pre break in tune? How long is break in?

[Mcfoto]

1 minute ago, MWP said:

I am so curious what is included in the "after-break-in" tune. 

 

Is there a pre break in tune? How long is break in?

 

The guys I deal with want a couple hundred rounds down the pipe before doing the stoning and spring work. That way, there's wear patterns established to know where to remove metal. Plus, that way I get to play with the new toy before it goes away again for a couple weeks... ;o}

[BallisticianX]

As previously said the crimp is not the issue. Clear up some misinformation first:

-- I taper crimp my target revolver rounds without an issue and holds the bullets in place just fine with no bullet deformity and is the proper type of crimp for smooth body bullets!.

-- Roll crimping is only used if you have a crimp groove/cannulure on the bullet and is mostly beneficial for heavy recoiling magnum loads.

-- A roll crimp applied to a bullet without a crimp groove will roll and bury the case mouth into the bullet with deformity, and with lead bullets loose lead shavings to increase barrel fouling.

 

Your problem: Many things effect moonclips just dropping in.

1. Brass: In your case .38 Brass brands have different extractor groove dimensions, there is no SAAMI standard for extractor grooves on .38's so they are all over the place between brands. So properly mating brass brand to moonclip is important. Your brass should spin freely once seated into the clip, if it cant spin or is loose enough to barely be held in place it will be a problem. TK Custom has the most comprehensive line of clips to match to what brands (TK's are the Smith factory supplier of clips). keep brass clean. Dirty brass (like dropped in the dirt or sand) or corroded brass can jam up a clip drop too.

2. Clip straightness; a bent clip causes rounds to lean in or out and will stunt the drop in...check clips for straightness using a known perfectly flat surface and if bent replace them!

3. Cylinder Charge hole condition; a 627 extractor is notorious for its cut not lining up on the inside (closest to the ratchet) with the charge hole in the cylinder body itself. You end up with a knife edged "ledge" protruding out just below the extractor. This will catch a case and stop the clip dead. You need to break that edge with a fine stone or a bullet point fine polishing bit. Also visibly check that the charge holes walls inside are smooth without burrs, carbon rings, grit etc. With what happens at Smith these days its a crap shoot how good or bad the finish is in there. If you get tightly spec'd charge holes due to tooling wear this is going to require clean cylinders moreover for reliable clip drops. I always polish the charge hole walls with an 800 grit Flex-hone cylinder honing brush (400 if there esepecially tight or rough then finish with 800). Only takes a few seconds in a power drill to each charge hole and makes a big difference in moonclip drops and extractions. 

 

Hope this helps   

 

[Mcfoto]

Thanks everyone for the helpful suggestions. I just heard today from my gunsmith. He assures me all is well. A bit of chamfer-ing went a long way and he is suggesting being about .002 more aggressive in my my crimp. I was backing off a little using coated bullets not wanting to cut into the coating. He had some plated factory stuff  that's sliding right in. I pick up the 627 at the end of the week and I'll let you know how it goes...

[ajblack]

I've found that a slight taper crimp (.002-.003) works well for 38 specials when using a bullet without a cannelure. The 160 grain SNS is a good example. I've shot these out of an LCR and didn't see any bullet jump so I figure they're good to go in a heavier gun like a 686. This is at 110 pf.

Edited December 5, 2018 by ajblack

[Mcfoto]

Checking in with resolution to this issue. The 627 just came back from the second trip to the gunsmith - had issues with light strikes that turned out to be bad Wolff springs. After the first go round in chamfering it was much improved but every once and a while I'd get a clip full that would stick and need a wiggle. Since it was coming back anyway, I asked him to be a bit more aggressive on the chamfer. Yesterday, I got the gun back and wow. EVERYTHING is flying into that cylinder. I even did the worse case scenario and loaded up some .38 special in a set of cheapo thin Speed Beez clips I had and despite the floppiness, even those slid right in. I'm all set up with Short Colts but honestly, if my cylinder had come in this shape, I'd probably wouldn't have bothered. BTW, back to crimp, I've been using a slight taper crimp with great success.

[BallisticianX]

On 1/17/2019 at 1:12 PM, Mcfoto said:

Checking in with resolution to this issue. The 627 just came back from the second trip to the gunsmith - had issues with light strikes that turned out to be bad Wolff springs. After the first go round in chamfering it was much improved but every once and a while I'd get a clip full that would stick and need a wiggle. Since it was coming back anyway, I asked him to be a bit more aggressive on the chamfer. Yesterday, I got the gun back and wow. EVERYTHING is flying into that cylinder. I even did the worse case scenario and loaded up some .38 special in a set of cheapo thin Speed Beez clips I had and despite the floppiness, even those slid right in. I'm all set up with Short Colts but honestly, if my cylinder had come in this shape, I'd probably wouldn't have bothered. BTW, back to crimp, I've been using a slight taper crimp with great success.

Glad to hear your all fixed up. I am curious to ask what was your gunsmiths determination for bad wolf springs? Ive never had a bad main spring from them, Ive had them weaken and settle, basically wear out over many thousands of cycles. Im curious to hear what happened.....

[pskys2]

4 hours ago, BallisticianX said:

Glad to hear your all fixed up. I am curious to ask what was your gunsmiths determination for bad wolf springs? Ive never had a bad main spring from them, Ive had them weaken and settle, basically wear out over many thousands of cycles. Im curious to hear what happened.....

Same here, I've had to re-bend a few at some point but unless cracked or heated up for some reason (trying to adjust the bend?) the main spring seems pretty hardy.

[BallisticianX]

42 minutes ago, pskys2 said:

Same here, I've had to re-bend a few at some point but unless cracked or heated up for some reason (trying to adjust the bend?) the main spring seems pretty hardy.

Kinda what I meant, I dont think it was a bad spring as he told you. Just a mis-adjusted one that was too light. It happens. When you arch the mainspring I look to go about 4-5 ozs higher than where I want to be to account for the spring to settle in after a few dozen cycles. SO if he set it for 6lbs out of the gate, after you ran a few cylinders down it's possible to settle into 5lb 12oz and just be on the edge of the necessary energy range for your setup. But once they settle in they are good for many thousands of cycles before they may start to settle again. I have Wolf Type 2 springs I've ran for years without issue. If you dont have one, get a trigger pull gauge. Once your confident this spring is set for 100% ignition, check and note the DA pull weight.  Then check your DA once a month, you can catch a problem or see nothing changed for piece of mind. 

[swordfish]

Just checked some 929 rounds today, there is a .020" jump in length with rounds scavenged from partially fired moons. Shot some 6 shot arrays at the last match and loaded the unused rounds in new moons for practice tonight. One decided to stick in the checker, which is weird because they've all been gauged before and passed. So I got out the calipers.

Using Blue Bullets, so no cannalure. Didn't measure the taper crimp, but it's pretty deep to allow for easy loading. I think the longer OALs can be affecting power factor sometimes, which would account for one or two performances of scraping the floor at 125.4pf. Now I load all my stuff to 135pf but I can only imagine accuracy might be inconsistent with the different velocities, if there is indeed a difference (I would assume so since I've tested different length OALs with a similar load out of an automatic). I'm having not the best of luck with 50yard groups, handheld. In my auto they're much nicer.

 

So what is my next step? Is the roll crimp die a completely separate thing, or do you just crank the taper crimp die down until it starts to roll in on itself?

[mchapman]

8 hours ago, swordfish said:

So what is my next step? Is the roll crimp die a completely separate thing, or do you just crank the taper crimp die down until it starts to roll in on itself?

Chris , Lee has a 38 short colt die set that has a roll crimp die. I use that for my short colts and my 9mm for my 929, not a heavy roll crimp just a slight one and it works for both with no adjustment.