Leading problems in a Taurus 24/7 Pro C DS .45acp

[steve in kc]

I recently started reloading and shooting rounds for my 24/7 Pro Compact DS . 45acp

I've used the following recipe on two batches:
Projectile: Missouri Bullet Company - 230 LRN "softball" .452, BHN=18*
Brass: Assorted between PMC once fired and Winchester, Remington, Speer Range brass (all cleaned up of course)
Powder: Red Dot
Charge: 5.0gr and 4.5 gr
Primers: CCI 300
OAL: 1.265
All rounds go into battery and feed from the clips without a hiccup. When dropped a dummy round into the barrel (removed from the gun) it seats flush with a 'clunk'.

After shooting 50 rounds of each this past weekend, my barrel was so leaded, grooves were almost FULL of lead. It looked like I had a smooth bore! In fact, there were very small thin shavings of lead clinging to the inside of the barrel.

I've got it all cleaned up now and all the lead is gone, but I have a LOT of these bullets left over.

I'm wondering if the following could be a culprit:
1) BHN is 18: Is this too hard of lead for my barrel?
2) Barrel could possibly be .001-.002 larger than .450 - has anyone slugged this barrel? I haven't yet, but plan on doing so. The reason I bring this up is that gas cutting could be the culprit.
3) Could my OAL be too short? I measured against a PMC 230J FMJ for seating depth, after I had shot 150 rounds of that ammo without a single failure to feed/fire or jam.
4) I did NOT check the diameter of the projectiles against a caliper. I assumed (yes I know what that means) that they were spot on as .452 since they were professionally manufactured.

Thanks in advance.

[jbc]

I would guess that size is your biggest problem. I have a full size 24/7 pro that leaded badly when I first got it mostly because of a REALLY ROUGH barrel. I did some serious hand lapping with some materials that I wouldn't admit to and re crowned the barrel for accuracy and it straightened right out. Auto barrels are the easiest to slug because they can be removed and set on a block of wood to start the slug so I would try that first and if the size is good then I would look to see how rough the inside of the barrel is.

[Gee_Wizz01]

I have a PT145 Pro that does the same thing. I haven't bothered to slug it yet, but its moving up the to do list. After about 10 shots with various .452 sized bullets, I have strings of lead hanging out of the grooves. I normally use jacketed bullets in it, so I have ignored it. I am getting ready to cast up some .45 boolits, so I will probably slug the bore to see what the problem is. My bore is relatively smooth, therefore I suspect the bore is a little large.

G

[steve in kc]

I have a PT145 Pro that does the same thing. I haven't bothered to slug it yet, but its moving up the to do list. After about 10 shots with various .452 sized bullets, I have strings of lead hanging out of the grooves. I normally use jacketed bullets in it, so I have ignored it. I am getting ready to cast up some .45 boolits, so I will probably slug the bore to see what the problem is. My bore is relatively smooth, therefore I suspect the bore is a little large.

G

I'm going to slug it tonight. I'll let you know what I find out.

We basically have the same barrel, however, mine is just a tad longer. :groner: Sorry, had to. ;)

I do think I found that after measuring a little bit ago, that my problem may actually be found in the OAL. I THOUGHT I was seating to a length of 1.265 per the recipe, however, they run from 1.2585" to 1.261"

When I set the caliper's to 1.270 on the nose, there was a tiny, but visually noticable gap when I put a loaded round in them. If I can SEE the gap, then I more than likely am getting gas cutting on these loads.

I'm going to work up some dummy rounds tonight at the proper OAL and cycle them then work up a small batch of new loads starting with 4gr Red Dot to see what happens.

[yondering]

I do think I found that after measuring a little bit ago, that my problem may actually be found in the OAL. I THOUGHT I was seating to a length of 1.265 per the recipe, however, they run from 1.2585" to 1.261"



The OAL is not your problem, and will not cause gas cutting. While it may not be optimum, it's perfectly acceptable for the bullet to make a small jump to the rifling.

Your leading issue is likely a result of bullets too small for the bore, a rough bore, or both. Your load is fine (although I much prefer to use a slower powder than Red Dot for 230gr bullets), hardness should be fine, and .452" diameter is pretty much the standard for 45 ACP cast bullets. Your bore may be larger.

[steve in kc]

well, I've narrowed some things down....

I slugged my barrel, and it came in at .4660"

my projectiles are .451"

I"m .016 undersized

I've got some gas cutting going on .

[Crash_Corrigan]

Adding .008" to that .4455 gives you a groove diameter of .4535 so you should mold your boolits at .4545 to .4635 to be within .1" of groove diameter.

Can you chamber accept a boolit of that dimension? If the boolit does not seal off the barrel in the gun when fired then gas cutting becomes a problem.

Experiment with some bigger boolits and see where you are at. When you slugged the barrel did you measure across the fattest part of the boolit, the grooves or did you mike the skinny bore part? Normally the bore is .08 smaller than the deepest part of the rifling (the grooves) and your boolit needs to be at least as big as the grooves and up to .002" bigger for good accuracy.

It depends on your chamber dimensions and what works for your gun.

I load my .45 Taurus 1911 with boolits cast at .456 or bigger and size them down to .452 for this gun when I lube them. If I use the Lee RN 230 GR TL mold I do not size them down at all. I lube them 2 x with LLA and JPW and after drying I load them over about 3.8 gr of Clays. No leading and excellent accuracy with a clean barrel and a mild report and recoil. I have never slugged the barrel in this gun but I believe it has very shallow grooves and I have never had a leading problem with it.

[yondering]

well, I've narrowed some things down....

I slugged my barrel, and it came in at .4660"

my projectiles are .451"

I"m .016 undersized

I've got some gas cutting going on .

Wow, if that's correct, Taurus most definitely needs to replace your barrel. That is not an acceptable bore!

When you slugged the bore, did you push the slug all the way through the barrel, or just in from the chamber end then back out again? Any chance that's the chamber dimension? If you didn't push the slug in far enough from the chamber, you may be measuring the chamber diameter, or possibly a very generous throat.

Your bullets should drop right through your barrel if those dimensions are correct.

[steve in kc]

Adding .008" to that .4455 gives you a groove diameter of .4535 so you should mold your boolits at .4545 to .4635 to be within .1" of groove diameter.

Can you chamber accept a boolit of that dimension? If the boolit does not seal off the barrel in the gun when fired then gas cutting becomes a problem.

Experiment with some bigger boolits and see where you are at. When you slugged the barrel did you measure across the fattest part of the boolit, the grooves or did you mike the skinny bore part? Normally the bore is .08 smaller than the deepest part of the rifling (the grooves) and your boolit needs to be at least as big as the grooves and up to .002" bigger for good accuracy.

It depends on your chamber dimensions and what works for your gun.

I load my .45 Taurus 1911 with boolits cast at .456 or bigger and size them down to .452 for this gun when I lube them. If I use the Lee RN 230 GR TL mold I do not size them down at all. I lube them 2 x with LLA and JPW and after drying I load them over about 3.8 gr of Clays. No leading and excellent accuracy with a clean barrel and a mild report and recoil. I have never slugged the barrel in this gun but I believe it has very shallow grooves and I have never had a leading problem with it.


Sorry, I had edited my last post after you responded. The land to land diameter was .4455. The groove to groove was .4660.

[steve in kc]

Wow, if that's correct, Taurus most definitely needs to replace your barrel. That is not an acceptable bore!

When you slugged the bore, did you push the slug all the way through the barrel, or just in from the chamber end then back out again? Any chance that's the chamber dimension? If you didn't push the slug in far enough from the chamber, you may be measuring the chamber diameter, or possibly a very generous throat.

Your bullets should drop right through your barrel if those dimensions are correct.

I slugged it from the muzzle. I didn't go all the way through. But I think I'll give it a shot just to be uber accurate.

[steve in kc]

alright, well, I screwed up....
I'm a tester by trade, so I knew better than to go off of my first read.

I replaced the batteries in my calipers to ensure I had fresh juice.
I then slugged all the way from the throat out the muzzle.

I fully admit I was wrong. :)
I am slugging at .4515"

So, bullet size/bore size are ok.
I double checked the bullets too and they are spot on at .4515

So I"m just a wee bit undersized, but not enough (IMHO) to cause gas cutting. :)

If I had to point a finger, I would do so at Taurus for a rough barrel instead of too hard a bullet. The reason I say this is that after some more research, I've found others that have reported having to re-crown and lap as well due to roughness.

[Gee_Wizz01]

Well this peaked my interest and I finally slugged my PT145 Pro. It slugged at .4568 with my vernier micrometer. I was a little suprised but slugged it twice. I suppose that answers the leading problem with .452 boolits. I slugged from the muzzle to a point half way down the bore, then pushed it back out the muzzle. I lubed the slug with Synthetic ATF fluid and I upset the slug in the bore with dowel rods.

G

[dubber123]

A friend also has one, and reports a leading problem. He says the bore has a very rough appearance. It might be time for some lapping.

[shotman]

one thing you can get a bore lapping kit from Brownells that works good has 3 size grits. It worked good on a S&W 460. also would try Unique or tite group Red dot is more for a compressed charge and could be gas cutting in a rough bore

[steve in kc]

one thing you can get a bore lapping kit from Brownells that works good has 3 size grits. It worked good on a S&W 460. also would try Unique or tite group Red dot is more for a compressed charge and could be gas cutting in a rough bore

I couldn't find what you're talking about. can you post a link?