Throat erosion with 2400 and 4227?

[crabo]

A mold maker, who is faily well repected, made this comment about powders in the 357 cases with 180 grain boolits. Have you found this to be accurate in your revolvers and lever guns? I have never heard this before and don't want to accept it without ample verification. Is this comparison of stick, flake and ball powders accurate?

"A lightly compressed load of either H110 or 296 is what I recommend. 4227 and 2400 will both give good velocity, but they are stick powders and cause far more rapid throat erosion than ball powders, while also being more sensitive to temperature induced pressure changes. The above load will be running real close to 40,000 psi at room temperature. H110 and 296 both give a straight line pressure climb all the way to 100,000 psi, as loads are increased or as temperatures increase, whereas the stick powders and all the flake powders I've used, give a very rapid pressure spike once pressures reach about 40,000 psi."

Comments?

Thanks,

[Boomer Mikey]

Ball powder burns cooler and has more retardants added to control the burn rate; those retardants also make the powder harder to ignite well especially in lighter than magnum charges... the warnings not to reduce below recommended levels.

2400 is a double base powder and 4227 is a single base powder; both burn well in reduced charges.

My experience with these is that 296 and H110 are very stable and linear at or near maximum charges and unstable below recommended charges (hang fires).

I've never pushed 4227 beyond recommended limits and I've not experienced instability or peaky pressure spikes using it or 2400 either.

I've not experienced gas cutting of top straps with any of these powders; I have experienced top strap flame cutting with 680 in the 357 Maximum. 296 and H110 has shown more forcing cone erosion in my 44 and 41 Magnum revolvers than H4227 using jacketed bullets.

With cast bullet loads I haven't experienced any difference... maybe the bullet lube/lead wash in the forcing cone protects it.

The peaky ones for me are Titegroup, Bullseye, and Red Dot.

Generally, the faster the powder burns the more you can expect pressures to peak (spike) faster.

Boomer :Fire:

[Bass Ackward]

Don't limit the effects to certain powders. Lead is a polisher. It will continue to smooth as it polishes and then virtually stop as it get the full surface down to the same level much as sand paper does when you first start out with a new grit. That is unless you chase this chance with a larger diameter bullet. Antimony is the abrasive which is why the old timers shot lead and tin only. And tin will counter the abrasiveness to a degree.

So anything you do to rough that surface up, (powder / pressure / heat) will allow lead to polish it away. The more obturation force that you produce the faster the smoothing effect takes place. Eventually the space that is being polished (forcing cone or throat) will elongate and stabilize once balance has been achieved.

If you are shooting soft or PB bullets, you will produce more obturation than with a check. Heavy for caliber bullets produce more obturation. The powder speed you select will move and elongate / shorten the location the obturation takes place. If you are running a slower powder, the farther out this point will be.

This effect is magnified the larger the diameter bullets that you shoot over bore size and the higher the pressure. Question is, should you worry about it? I say no because everything causes wear. It's a fact of shooting. Makes a case for shooting hard bullets though if you have any antimony in them and sizing as small as possible.

It's also an excellent reason to slug every so often to keep an eye on what changes are or aren't taking place.

[Dale53]

Using proper powders for velocity desired, AND proper alloy for lead bullets and it has become a "non issue" for me.

I use fast burners for target loads, medium burners for "medium" loads and slow burners for heavy loads. Examples are:
Fast - Bullseye, 231, Red Dot
Medium - Unique
Heavy loads - H110, 296, and WC 820

These are only examples. I now tend to use mostly ball powders as they measure so well.

I have LOTS of loads (in the tens of thousands, in some cases, through a variety of revolvers and autos) and erosion has NEVER reared it's ugly head.

I do NOT abuse my handguns, but would consider "wearing one out" if it should happen as a normal situation (just like tires on a car). As a matter of fact, it has NEVER happened to me or my handguns. I have in excess of a 100,000 thousand rounds through a .45 ACP 1911 and it is still of match grade.

FWIW

Dale53

[felix]

I personally don't consider erosion an ugly head, but something I can take advantage of, especially with "new" guns. As BA suggested, we have to learn to manipulate erosion by optimizing it per location, and that would depend on where the problems exist for your boolit of choice. Heat nitrides steel, which makes it hard. The harder it becomes, the more flaky it becomes, making it look like sun dried gumbo mud. It is those rough edges that need to be smoothed, and that is taken care of by the antimony in the boolits. So, this is one good reason to break in a rifle by using high heat generating loads, and, using condoms makes that job pleasurable. After every 250 rounds or so, high antimony boolts should be used for a progress indication. Eventually that gun will produce very good accuracy with lead, because the throat cracks from the erosion will be filled with lube, lead, powder which is taken advantage of. This is the main reason I don't throughly clean boolit guns, but just enough to prevent lube mixture there at the throat from becoming concrete over time. ... felix

[Boerrancher]

I myself am not worried about erosion/wear. I have worn out several pistols, as well as rifles. If it is a rifle I like I will re-barrel it and have the barrel tapered to where I can set it back a time or two as needed to remove the throat erosion. If it is not one of my favorites I just sell or trade it. I also have a couple of antique rifles that are in good shape, and I just don't shoot them a great deal. As far as cleaning the bore on any of my guns, that is something that rarely happens, unless I get a bad load that causes lots of leading or copper wash. I may pull a dry patch through the bore on occasion but that is about the extent of it.

Best Wishes from the Boer Ranch,

Joe

[Mugs]

IMR 4227 has always been one of my favorite powders for the .357. I've shot several thousand 180's and 200's with compressed loads of 4227 through a FA. Still shoots as good as it did new.
Mugs
IHMSA 5940L

[runfiverun]

i am hoping for some throat erosion on about 3 of my rifles,
and about the only time i clean a bbl is when switching from cast to jacketed or back.
unless there is some bad fouling.

[JeffinNZ]

Let's talk about Cordite. Now THAT's erosion for you!!!!! Thank goodness it is now more.

I have seen Lee Enfields with a throat that stopped an inch from the muzzle.

[Boerrancher]

I have seen the cordite remains and even got to shoot some of it we found in a cache of rifles and ammo. Probably been there for over a hundred years. Some of those Lee No 1's didn't look too bad. Would have been worth a fortune had we have been able to send both the rifles and ammo home, but since we couldn't ship the ammo we shot it.

Best Wishes from the Boer Ranch,

Joe

[kooz]

).

I've never pushed 4227 beyond recommended limits and I've not experienced instability or peaky pressure spikes using it or 2400 either.

296 and H110 has shown more forcing cone erosion in my 44 and 41 Magnum revolvers than H4227 using jacketed bullets.

With cast bullet loads I haven't experienced any difference... maybe the bullet lube/lead wash in the forcing cone protects it.

The peaky ones for me are Titegroup, Bullseye, and Red Dot.

Generally, the faster the powder burns the more you can expect pressures to peak (spike) faster.

Boomer :Fire:[/QUOTE]
+1 agree with all that Boomer Mikey has said as this has also been my experience. I would say without a doubt you will experience the greatest amount of forcing cone erosion with H-110/296 .

[felix]

Cordite and HiVel2 shared the same fate, once the culprit was found to be nitroglycerin over 30 percent. Cordite had something like 45 percent. Too much heat. Triple base powders were "invented" to deliver the same energy with reasonable heat. ... felix