Failure to fire & extended firing pin for Taurus .45 ACP

[Sim G]

I'm afraid I think you may have over done it on machining the cylinder. The 456 was designed to accept moon clips as it was, there was no reason to have the work done in order to run properly. They can run without clips but the reliability isn't great due to the cartridge head spacing on the case mouth. Your ammo has to be really good for any sort of consistancy. The Taurus clips are regarded as thin and a little flimsy. There is a practice in the US to have the back of the Taurus cylinder machined so they will accept the thicker moonclip, 0.040", of the S&W 625, as opposed to 0.025" thickness of the Taurus Stellar clips.

Before messing with firing pins I'd try some S&W clips or some thicker custom moon clips.

[IsleShoot]

I had the problem pre-moonclip milling and I also had issues with the cylinder fouling which I believe was due to the cartridge being at the maximum OAL and the step inside each chamber being too high/different.

I'll get the micrometer onto the moonclips I've got but they're nice and thick, I'm pretty sure they're most likely matched to S&W tolerances?

What I think I have done by having the cylinder moonclipped is I've ripped up my warranty and any hope of ever getting the cylinder replaced if I can actually isolate the fundemental issue(s)?

Does anyone have a schematic drawing for a long barrelled Taurus and any tolerance/dimensional data? I'm starting to think I've got the Friday afternoon gun as there are other issues that potentially suggest all is not well, namely expansion of the cylinder after six/twelve shots. Spent cases eject with a tap (not slam) on the extractor but live cartridges will not fit into the cylinder? Bearing in mind I taper crimp all my .45 rounds.

[Sim G]

Live cartridges won't slide into the chambers?

[Sim G]

Got to ask, what are those bullets loaded in the picture?

[IsleShoot]

Thats right! First set of 6 no problem, fire them off, eject the cases and the next 6 won't drop in! Only thing I can think if is the cylinder is expanding due to heat??? My initial thought was it was an over pressure issue but I'm using 8.0 grains of HS6, which is the min load for a 230g head. I've reduced the OAL to 1.215 but theres still plenty before you get to the min OAL and max load for HS6 is 8.6 grains.
I haven't tried another powder yet but I was thinking about getting some Ramshot Zip which has a much bigger spread load wise in terms of weight so I could isolate any possibity that it might be an over pressure issue?

The bullets are Ares, they're plastic coated in lieu of copper, very slightly faster than FMJ but they don't lead/copper the barrel so keep it clean. I get them from www.IPSCstore.eu, cost about £25 per 250 plus shipping which isn't cheap but if you buy enough its worthwhile! I believe there a guy in Northern Ireland whos the UK supplier but haven't gone down that route yet.

[Sim G]

Well, you've certainly given me something to think about all day! I'm going to try and write my take on it all, but, if it sounds like I'm being judgmental or condescending, please accept my apologies now as that is not the tone I'll be writing this with...

I think you've wrecked your revolver. As I said earlier, the Taurus 456 is designed to shoot .45 ACP utilising the Taurus Stellar moon clips. It can also shoot without the clips, but reliability is effected unless the ammunition is really good in terms of OAL so it head spaces correctly on the cylinder throats.

The first issue has been the light strikes. Did you adjust the mainspring tension? The Taurus' Sillouhette/Target models, which are the base for the UK LBR's have a facility to adjust the tension of the single action and double action trigger pull and hence, the strength of the hammer fall. I suspect you haven't. That would probably have solved it immediately.

The second thing is your ammo. HS6 isn't a really good choice for .45. I still use it in heavy .38s and 1oz slug. It was one of the ones that I tried in the old pistol days in .45 to try sync reduce the number of types of powder I held. Like .45 ACP, I found it didn't work well in .45 Colt or .44 special. Great in smaller, high pressure cases such as 9mm or .357, but was very dirty and left loads of residue and unburnt powder with the large cases.

I cannot see six rounds of .45 being able to heat a revolver cylinder where it actually expands! And if it did expand, the charge holes of the chambers would be bigger and subsequent ammo would be easier to load. Are the first six loaded into clean chambers? The fouling I've come to know with HS6 may very well be preventing a "clean" insertion.

Sticking with the ammo, you bought secondhand cases. Some of these could easily have been around for 20 years having been hammered during the pistol days. Likewise, you've gotten moon clips that you didn't know what they were for. Taurus clips would not have required any machining of the cylinder. Smith clips would have done, it's actually in vogue at the minute. But, there are also a load of other clips available of varying thicknesses. Hopefully, they are S&W 625 clips and purely by chance you had the cylinder machined to accept these. At least these clips are freely available.

But that's not the biggest mistake you've made with this. The biggest mistake has been to have a machinist, because he surely couldnt have been a gunsmith, to have "taken down" the cylinder throats. That's what those ridges are in the chambers, the throats. The purpose of these is to set the bullet up properly to exit the chamber and enter the forcing cone of the barrel. In an automatic cartridge chambered revolver, the throats are what the cases headspace against. Auto cartridges use the case mouth to headspace as opposed to the rim. The ammo has to be right, such as correct, uniform length and uniform taper crimp. There is a practice where throats are hand lapped to within one thou above barrel groove diameter, but I get the impression that the machinist didn't do this....?

Likewise, I can't imagine at all that the chamber throat dimensions were so out of spec. Taurus, even though not S&W or Ruger, still make a relatively quality product, to specifications as stipulated by regulatory authorities. I strongly suspect this machinist had difficulty in measuring. And when he "took down" the throats, what condition did he leave the chamber walls? Bad enough that debris and dirt sticks like pooh to a blanket, or slippery smooth so the rearward thrust in recoil of the case damages the clips of standing breech?

Yep, I agree, your warranty is right out of the window. You've used a sledge hammer to crack a nut. A simple adjustment, some different ammo and appropriate moon clips may never have seen you in this situation. Adjust the mainspring and you might get away with this if the clips work and different ammo feeds better every time. If this doesn't work, I really can't see you being able to get another Taurus cylinder as the Hunter/Sillhouette models have been dropped from the Taurus catalog and do are cylinders may be hard to come by. Perhaps a custom cylinder could be fashioned by Westlake or someone.

[IsleShoot]

No offence taken Sim, just a big gulp...

You're bang on about the HS6 it is very dirty and no (hangs head in shame) I haven't adjusted the main spring!

Thank you for your thoughts, an excellent example of what a valuable resource this forum is to the UK shooting community.

Well I've certainly got a worse case senario to work from now, best thing I can do is work through the list of variables I think starting with a good clean of the gun and then some factory ammo followed by different primers & powder for home loads. Hopefully I'll be able to find a combination that works?

As an aside, I've noticed when looking for Taurus spare parts that Brownells UK have Taurus moonclips for sale, D'oh!

[A.J.P.]

Let us know how you get on Rich, hopefully you'll be up and running reliably again soon. Unfortunately neither Brownell's UK or US stock Taurus (TK Custom) moonclips in 45ACP for the 456.

[Sim G]

With your ammo, try HP38, Win 231 or Bullseye. Target loads of around 5.0gns for 231 and HP38 and 4.5gns for Bullseye with a 230gn lead bullet will give you around 825fps, which as you remember from your IPSC days, will give you a major PF of 189.

CCI primers will be perfectly fine once you've fettled the mainspring tension and sorted headspacing and the rest. But get some new brass and prep them all the same first, it won't do any harm at all to do that!

And, in case you don't have one, I've found an instruction manual on t'interweb for Taurus revolvers....

http://www.taurususa.com/pdf/revolver-manual.pdf

Good luck!

[bradaz11]

I thought winchester WST works very nice in 45acp, there just isn't a huge amount of it around. burns nicer than bullseye