Actually 2 cases separated on my this morning. Both where new (1st loading) starline 460 Smith & Wesson. The load was 39 grains of Lil Gun, 275 grain Barnes XPB, Winchester large rifle primer. In load development for this gun I got up to 40 grains of powder with out any problems and chickened out and dropped down a grain volatility was running 1615 FPS with the 40gr charge from my 5in revolver. The shots where normal, until I extracted the rounds and found the top half of one case had sheared off and was lodged in the chamber, and the top 1/4 of the other case was gone and no where to be found. Any thoughts on why this happened?

Quick load shows you at 55k PSI, well below the 62k Max. Do you have any left over? Can you pull a bullet and weight the charge just to make sure?

I pulled 3 rounds apart to day @ Antelope's suggestion. The charges where 38.6 to 38.9, and I lost a small amount of powder each time. the charges where originally thrown with my charge master. How ever it was extremely difficult to pull the bullets. So after making some dummy rounds I am now of the conclusion that I did not expand the cases mouths enough before I seated the bullets. Looking back it also took more force to seat the bullets then other cartridges I load for, but just wrote it off as a quirk of the new gun. So would under expanding the case mouth explain the suppurations?

Case separations are usually caused by excess headspace, not bullet pull. That or weak brass. I suspect that the rims of your cases are too thin, the revolver headspace is too generous, or a combination of both. If this is the case, there is not much you can do other than sending the revolver back to S&W for repair, or trying different brass.



.

quote:

Case separations are usually caused by excess headspace, not bullet pull

Ok, so Tx, I have a question. You can shoot .38 specials in a .357, and .44 specials in a 44 mag. Since we are talking about a revolver, how does this translate regarding your theory the problem could be excessive head space?

quote:

Originally posted by Antelope Sniper:

quote:

Case separations are usually caused by excess headspace, not bullet pull

Ok, so Tx, I have a question. You can shoot .38 specials in a .357, and .44 specials in a 44 mag. Since we are talking about a revolver, how does this translate regarding your theory the problem could be excessive head space?

Correct. My suspicion would be a problem with chamber dimensions or a loading problem. things to check:
Cases trimmed to correct length.
Bullet diameter.
Throat diameter.
Does it happen in every chamber?
Might have to cast each chamber in the cylinder.
It probably is a case of too much pressure, not from too much powder but because there is something binding up and not letting the bullet start down the barrel until excessive pressure builds up.
DO NOT SHOOT THIS GUN WITH THESE RELOADS UNTIL YOU FIGURE THIS OUT.

quote:

Originally posted by TX Nimrod:
Case separations are usually caused by excess headspace, not bullet pull. ... I suspect that the rims of your cases are too thin, the revolver headspace is too generous, or a combination of both.
.

Revolvers, and for that matter shotguns, rely on rim thickness for headspace not shoulders or case mouths. If the chamber is reamed a little deep or the rims are cut a little thin, the case expands at the mouth and grips the chamber and the head moves back toward the breach. In the case of .38/357 or the various .44's the rims are the same thickness the case is longer or shorter.

For older shotguns, the end of the camber can be reamed deeper and a ring set into it to cure this. For a revolver you'd probably need to replace the cylinder.

When the load is to hot, over pressure >

quote:

the case expands at the mouth and grips the chamber and the head moves back toward the breach.

causing case separations, as the brass stretches. Hodgdons website lists a 250gr BAR X at a maximum of 42.0 gr. A
, all-copper XPB bullets is going to make more pressure than a lead core jacketed bullet. The longer the bearing surface of a bullet, the more pressure. Reduce your powder charge.

All case lengths are 1.790 the trim to lengths in the Hornaday manual. I understand that the Barnes bullet is going to run higher pressures, the charge is based on a 325 JHP with a make charge listed as 41. Also Barnes manual lists a max charge of 39 grains of Enforcer which is a faster powder then Lil Gun (and a powder not carried locally. I know the charge is based on an educated guess but that is my logic.
Pulling the rounds apart I have found some that have taken over 100 hits with my inertia bullet puller. Others have taken 5 or 6. For some reason about every 4th bullet wants to stay in the case. Once I get the bullet out and re-size the case, and expand the case a seated bullet will come out in 5 or 6 wackes. This is why I think I didn't expand the case mouths enough. It is my theory that the "stuck" bullet is causing the case to stretch until it ruptures.

On heavy recoiling revolvers the expander can be as much as .004" under bullet diameter. This is to keep the bullet from jumping crimp. The belling of the case is to help start the bullets in to the case mouth. These are 2 different things. As the brass is worked from reloading/firing it will change, the case wall thickness will thin some.

quote:

the top 1/4 of the other case was gone and no where to be found.

This does worry me. When you say "top", do you mean the case mouth area? Had you previously been firing .45 Colt or .454 Casull in the revolver?[

100 hits with the puller?

Did your seating die move between the loading of the original loads of 40 grains, and the subsequent loading of 39 grains?

Here is a good thread with photos on the 460 http://www.thehighroad.org/showthread.php?t=514257

Hope this works 1st time trying to post pictures.

The first picture shows the 2 cases that separated flanking an unfired round.The bit of mangled brass is what I had to pry out of the chamber. The next picture is of the primers of the 2 cases that came apart. The finale picture is a close up of the seated bullet.

Gun is new about 30 rounds through it a mix of my hand loads and Hornaday factory all 460. 243winxb thanks for the link it sounds like I have the same problems as talked about in that thread although it happened to me on 1st loading. Makes you wounder if they have a good understanding of how these hand canons work. The seating die was change as I am working with 2 bullets, but stopped all shooting after the cases came apart.
Thanks for the insight guys!

Auke Bay:
Did you anneal your brass before 1st loading?


Dutch

The loaded round photos look good. No bulge at the base of the bullet that i can see. If the Full length die was sizing the brass down to much, you would see where the base of the bullet stops. You can check SAAMI measurements of a loaded round & chamber here>. http://www.saami.org/PubResour...20SandW%20Magnum.pdf Brass can stretch on the 1st firing and come apart when the brass grabs the chamber wall. If the powder charge was lighter, on firing the brass would just slide back.

I suspect your bullets have "cold welded" to your squeaky clean new brass. I had this happen to some .44 XTP 300gr bullets with virgin nickel plated brass... I pounded that bullet puller for 5 minutes.. only to have the lead core start to extrude out !? Never did get that bullet out...

cold welding
n.
The welding of two materials under high pressure or vacuum without the use of heat.

Properly annealed brass will inflate like a balloon and release the bullet. Noting the brand and it's reputation for being very hard at the mouth I would anneal it and be happy.
45-70 may have a point. Your nice new cases have no carbon inside the neck. Try a little graphite in the neck after you anneal them.

The Starline brass has already been annealed at the factory if you can believe this info. http://www.midwayusa.com/viewp...ductnumber=941112561 "Notes:

•A light "staining" may be found on the case neck of new brass. This is due to annealing. Annealing is a process, performed by the manufacturer, which involves rapid heating to a specified temperature followed by rapid cooling. This process imparts cases with the proper hardness to securely hold a bullet as well as gives flexibility to expand and contract upon firing and repeated forming. The "staining" is a residue from this process. This stain may be removed by tumbling before loading." Annealing is best left to the factory. To much heat and your brass becomes scrap. Not easy for the home reloaded to get it right. IMO. The factory has special chambers when brass is annealed. The gas in the chamber is such that very litte if any tarnish/carbon is left on the brass.Google it.

Try reading the Starline website info or better yet look at the brass in this thread. It shows no signs of annealing.

The Starline brass that I bought for the 40-65 is known to be hard.

Starline FAQ> How can I soften case mouth to allow case to properly seal when using black powder in 45-70, 45-90, 45-2.6 (45-100) and 40-65?
1.) Be aware this is not always necessary. Only if cases are extremely dirty and a lot of unburned powder is consistently found in chamber would you need to anneal.

2.) First place case in proper container filled with approximately 1 inch of water so head of case is submerged in water. (Reason is you only want to soften mouth of case and not head area as this can ruin strength at base and primer pocket where case must remain rigid to handle pressure.)

3.) Next heat case mouth (approx. top 1/2 inch of case) uniformly just to where it begins to turn a dullred and then knock over in water. A propane torch is usually used for heating device. MOST IMPORTANT: Remember if case gets too hot they are ruined and there is no way to make hard again. So, try a few out and get a feel for the proper color and softness required for your application. If they get bright red, you probably went too far. FYI Note: Black powder is a low pressure loading and may not expand brass to seal a chamber. A 460 s&w @ 50,000 psi will not have this problem. Modulus of Elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.

I am out of here.

If it took over 100 whacks to pull your bullets from the loaded cases it's apparent for whatever reason the case has a tremendous grip on the bullet. Thus the separation, that part of the case went with the bullet instead of releasing it.

I highly doubt Starline missed annealing the cases. This is an inline process...it's not like they take boxes of cases over to an annealing room or something.

Watch annealing cases because most people usually get them too soft and that's not good either.

quote:

Originally posted by 243winxb:
Starline FAQ> How can I soften case mouth to allow case to properly seal when using black powder in 45-70, 45-90, 45-2.6 (45-100) and 40-65?
1.) Be aware this is not always necessary. Only if cases are extremely dirty and a lot of unburned powder is consistently found in chamber would you need to anneal.

2.) First place case in proper container filled with approximately 1 inch of water so head of case is submerged in water. (Reason is you only want to soften mouth of case and not head area as this can ruin strength at base and primer pocket where case must remain rigid to handle pressure.)

3.) Next heat case mouth (approx. top 1/2 inch of case) uniformly just to where it begins to turn a dullred and then knock over in water. A propane torch is usually used for heating device. MOST IMPORTANT: Remember if case gets too hot they are ruined and there is no way to make hard again. So, try a few out and get a feel for the proper color and softness required for your application. If they get bright red, you probably went too far. FYI Note: Black powder is a low pressure loading and may not expand brass to seal a chamber. A 460 s&w @ 50,000 psi will not have this problem. Modulus of Elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.

I am out of here.

C Sounds like you never annealed a case in your life.

quote:

Originally posted by Auke Bay LT:
Actually 2 cases separated on my this morning. Both where new (1st loading) starline 460 Smith & Wesson. The load was 39 grains of Lil Gun, 275 grain Barnes XPB, Winchester large rifle primer. In load development for this gun I got up to 40 grains of powder with out any problems and chickened out and dropped down a grain volatility was running 1615 FPS with the 40gr charge from my 5in revolver. The shots where normal, until I extracted the rounds and found the top half of one case had sheared off and was lodged in the chamber, and the top 1/4 of the other case was gone and no where to be found. Any thoughts on why this happened?

I sent your problem into Barnes, took a while, but finally got a reply from them. This did not come from their call in techs, but from an engineer in the company:

Copper bullets don’t just “cold weld” themselves to a brass case. If they did we’d have similar problems with all our rifle and pistol loads – and we don’t.



From the photos posted on the forum, it doesn’t even look like he’s using much of a crimp. Over crimping doesn’t appear to be the issue. He does mention that it was hard to seat the bullet. If he isn’t deburring his cases and flaring the case mouth, he might be gouging the heck out of the bullet and the brass if a case mouth burr catches on the soft copper bullet. This might create a stress riser in the brass causing failure.



We’re not going to be able to provide a definitive answer based on the few photos and descriptions in the chat room. Unless he’s willing to send the ammo, brass, and perhaps even the gun to us for examination, there’s little we can do. He’ll have to come up with the answer himself. Best we can do is help him work through the problem.



I always recommend customers take a scientific approach to working through this type of problem. The key is to only change one variable at a time if you really want to zero in on the problem. For example, if the customer were to try H110 powder (which seems to work well with many of our XPB bullets in the revolver loads) and all his problems disappear, then its probably a pressure issue.



The most likely culprit is the brass. If he doesn’t want to switch brand, perhaps he could try another batch of Starline brass and see if it works better.



Both Corbon and Federal successfully load the 460 S&W with our copper XPB bullets – I don’t think it’s a bullet issue. If he fires some of this factory ammo through his gun and still experiences the same problem, then its likely a gun issue.







Tim Janzen | R&D Engineer
Barnes Bullets, LLC