Ruger om 44 convertible

[sixshot]

How many of you have ever seen an old model SBH convertible? Probably no one but I saw one today. A buddy of mine just got it back from Ruger, he had sent it in for a taller front sight & since it had an earlier conversion to the transfer bar & had broken, he had it replaced at the same time. This is a hard way to end up with a convertible!!
Ruger did a very nice job, they also reblued the old 3 screw & put a nice new set of factory laminated stocks on it. Even though the gun was a SBH it had been changed to a round trigger guard & aluminum grip frame, nice touch & the gun had shot very well before being sent in.
My friend called me early this morning & gave me the low down. He had went up into his upper pasture & started shooting it from the bench. His loads were 9 grs of Unique with a 300 gr GC bullet sized .431", also he had some that had 10 grs of Unique, again with the same bullet.
He told me he had fired 2 rounds & when he fired #3 he blew the top strap clear off & the top 3 chambers of the cylinder. The top of the frame that goes over the barrel was gone, also the back of the top strap including all of the rear sight.
He showed up at my house 2 hours later, I was amazed that he hadn't been hurt, not even a scratch on his hands. He couldn't find the top strap or any of the cylinder but he did hear it launch. The barrel actually looks like it can be reused, no crack in the forcing cone, etc. but for sure it will have to go back to Ruger, hopefully they can tell exactly what happened.
When he handed me the gun he again said that he only fired 3 rounds, 5 of rounds had fired & the sixth one was the next one up on the left side of center. The case had been ruptured badly & all the powder was out of the case but the cast bullet was still in the case!
I didn't pull the base pin but I actually think he had fired 5 rounds instead of 3, if I had pulled the base pin I could have seen if the primers had been struck but I wanted to leave the gun intact so Ruger could asses the problem.
The barrel was perfectly clean, so it hadn't been anything lodged in the barrel & the gun did exactly as designed when there is an overload......double charge, & that is, the cylinder let go on the top 3 holes. Its my guess that it had to be a double charge even though he said he was loading on a single stage press & weighing every charge.
I believe he failed to move his powder funnel, just a guess, & ended up with a double dose of a fast powder. He is a long time, 40+ years handloader.
I think the SBH 44's are maxed out in the reloading manuls at about 36,000 & proofed somewhere around 80,000 so what ever happened was an enormous pressure spike that could have been a disaster. Yes, he's out a $500 sixgun but still has both eyes & all his fingers, very lucky.
This is the second 44 SBH I have seen blown up in the last 3 years, glad I wasn't standing there watching either time. I pulled the bullet from one round & it held 9.9 grs of Unique, which is a pretty stiff load with a 300 gr slug. Heavy bullets are usually better with slower powders when you start to get into the higher end velocities.
When you blow the cylinder & top strap you end up with a convertible!

This is the original gun when I owned it a few years ago.

http://i84.photobucket.com/albums/k3/6shot_01/100_0348-4.jpg

This is the same gun today after it was remodeled into a convertible.

http://i84.photobucket.com/albums/k3/6shot_01/100_3238.jpg

http://i84.photobucket.com/albums/k3/6shot_01/100_3237.jpg

http://i84.photobucket.com/albums/k3/6shot_01/100_3239.jpg

AT this point there are more questions than aswers but I'm still leaning towards a double charge of Unique. Thoughts?

Dick

[quasi]

If he was using 2400 or 296 a double charge wouldd overload the case before seating the bullet. I will bet he was using unique , 231 , or something of that burning rate.

[saz]

What a shame. That was a purty 3 screw. Glad your friend is OK.

[MT Gianni]

Wow, I am glad he is OK. I vote double charge, though I opened the thread expecting to see a 44 mag/44-40 convertible.

[44man]

Darn, here we go again. Heavy boolits with Unique and heavy loads for the 300 at that.
Double charge is my thought too. He screwed up, end of story.
Only one other thing would do that. He missed the powder in one, stuck a boolit and shot another behind it.
Use loading block and look into every single case before you ever start to seat boolits.
A friend blew a .41 because he loaded one shell at a time. He was distracted, forgot the powder, seated a boolit in an empty case.
Use a loading block and use a flashlight if you must to see into each shell.
I am glad he was not hurt but he really is mentally, a fine gun destroyed.

[sixshot]

44man, I ask him about the possibilty of it being a squib but he said no, all the previous shots felt the same. Also, usually when a bullet is stuck in the barrel & another shot is fired it cracks the barrel/forcing cone, etc. This barrel looks perfect.
He was loading with a loading block but its still possible to leave the funnel on one case & forget to move it, thats what I think he did. I agree, if you want to use Unique, keep the loads midrange velocity. That was a fine old 3 screw that became a convertible.

Dick

[tek4260]

Mr Thompson, do you mind if I swipe the 3rd picture from the top? It would be useful in showing exactly how thin a single action is at the bolt notches. It comes up from time to time when discussing why a Redhawk can be loaded hotter than a Blackhawk.

[pietro]

[He screwed up, end of story.]

No, it's not - AND, you might want to cut him some slack, since I've personally seen TWO Ruger OM SBH's blow just like that one.

The thing is, the two I saw blew using factory ammo. :oops:

The two I saw occurred in the early 70's, and both shooters wouldn't have known a loading press from a steam iron - I knew them both, & neither knew squat about handloading.

Ruger replaced both revolvers, BTW.

.

[white eagle]

Glad your bud is ok Dick
I am with Pietro
there are no pat answers

[Mal Paso]

NO Way could 20 grains of Unique fit under that Boolit. 20g fills a mag case to 1/8" from the top!

If that's a 429650 You're going to have to lean on the press hard to get 12 grains of Unique under it.

I think 10g behind that boolit was too much for that gun.

[sixshot]

Tek, you're welcome to use the photo, no need to call me mister, I'm just an old fat guy!

Mal, the 300 gr slug was an LBT style. Another thing I proposed to my friend was that its possible for Unique to bridge over in a powder measure and drop only a partial charge in one case & perhaps a charge & a half in another. Ruger will sort it out, what ever happened went way beyond a proof load. Many shooter use 10 grs of Unique with a 300 gr cast slug.........I don't but I've seen it listed in several articles.

Dick

[colonelsanders]

Just a few thoughts on this. For Background I am a mechanical engineer with a heavy background in failure and fatigue.

I wonder if I could request a high quality photo of the fracture zone of the cylinder? I am specifically interested in the grain structure of the bolt notches.

I put fort the the following.

1) Firearms in general (the type we plebeians can get our mits one) are not designed for infinite fatigue life.

2) The Factors of safety used in firearms design are in line with low end of fatigue requirements (usually less than 10,000 cycles).

3) One of the funny things about fatigue is that each time you push the material past its original design point, you lower its expected life.

4) I am looking at this as an older gun with an unknown number of rounds through it. but based on its age a substantial round count seems likeley.

5) When these firearms are designed it is generally preferable for something else to go before the cylinder lets go and takes the top strap. Generally this takes the form of the gun wearing loose or the barrel wearing out. But they are designed to handle X rounds at standard pressures.

6) I see alot of folks calculate the strengths of Rugers, but these calculations are only ever performing an evaluation on a straight static pressure basis. This is wrong when trying to determine if a load is safe.

I attached a couple of marked up figures for your perusal.

[sixshot]

colonelsanders, I'll have to see if my friend has already sent it back to Ruger, if not I'll try to get some more photos. Going over there today.
The Rugers are designed with the cylinder as the weak link & they usually do just like this one did, top 3 holes gone. The others I've seen still had the top strap although it was severely bent. Thanks for the analogy.

Dick

[454PB]

You can see in the photos where the base of the boolit is located, and it takes up about half of the available powder space. If the case truly contained 10 grs. of Unique, it could be that the powder was compressed.

Still, a SBH is an extremely strong gun. My WAG is a bore obstruction of some kind.

[Swampman]

I shot some Lee 310 grain boolits over 10 grains of Unique today in my 4 5/8" New Model SBH. They were pretty snappy, but very accurate and gave no problems.

[gandydancer]

Mr Thompson, do you mind if I swipe the 3rd picture from the top? It would be useful in showing exactly how thin a single action is at the bolt notches. It comes up from time to time when discussing why a Redhawk can be loaded hotter than a Blackhawk.
I learn so much on this site from you all. I am two days older then dirt. my S S number is V (5) and a Ruger fan since 1959. mostly their single actions and have had many of them in all calibers. and still have a 1/2 dozen in my safe today. and I never realized how thin the wall is on the cylinder from the approach to the bolt lock up. Man that is thin. never had any trouble with any as far as a blow up. I did have a Ruger black powder revolver blow a hole on the inside cylinder wall. and when I went to reload six more shots using 24 grs of 3F as I poured it into the cylinder and saw the powder go down like it was falling out the back of the cylinder I looked it over with a light and saw the hole about the size of a eraser. sent it back and all was good. I don't like to think about what could have gone wrong. I was lucky. GD

[jwp475]

Sure was a beautiful SB before the conversion. I don't think that a double charge would fit under the bullet, but it would not take but another grain or two to produce an overload if the powder some how bridged in the powder thrower

[gray wolf]

I just looked at a Alliant reloading guide, it's from 2005 edition.
Unless I read it wrong--it shows 7.2 grains of unique for a 310 grain LSWC g/c bullet--965 Vel. 34800 p s i
If that is correct wouldn't 10 grains be a little hot ? and 10 X 2 would be
not a good day. Please correct me here so we all know.

sam

[tek4260]

How many blown revolvers have been attributed to H110 or some other slow powder?

It "always" is a light load doubled or some other mishap using faster powders that causes these catastrophic failures.

Moral of the story, load barn burner H110 loads and enjoy! When you want something lighter, grab your 22. :)

[W.R.Buchanan]

This got me to wondering also. I checked Alliant and Lyman 49.

Alliant had no Unique loads over 240 gr boolits, and then stopped at 10.3 gr. Only 2400 and similar powders made by Alliant for heavy boolits.

Lyman 49 also has no Unique loads for 300gr boolits, again slower powders like 2400 H4227, H110/W296.

For 429244 they list 8.9 to 12.1gr of Unique. 12.1gr is 36.4K psi !

I see too big a boolit with too fast a powder by a significant amount.

Really this is a testiment to the strength of the Old Ruger. It swallowed "two" way beyond max loads before it gave up.

However,,,,,,

I then pulled out Handloader #237 (Oct 05) which has an excellent article by Brian Pearce on "Midrange Loads for .44 Magnum." His test guns were a Ruger SBH 3 screw and a Smith M29-2.

He lists 9.0 gr of Unique with RCBS 44-300SWC at 988fps and 10.0 gr with the same boolit for 1098fps.

Your friends loads were right at the top end no matter how you look at it.

In Handloader #236 (Aug 05) Brian does an article on loading .44 Special. He has a 307 gr boolit at 1060 fps with 15.5 gr of H110 at less than 25K psi. No Unique here.

It would seem that the difference in powders (Unique and H110) has a dramatic effect on the pressure without much difference in velocity.

I'm seeing Unique for low velocity loads with lighter boolits and H110 for heavier boolits being the way to go.

The other factor I see here is a 50 year old gun. I know it is a Ruger, but nobody with a brain would say that the quality of the metals available in 1960 was anywhere close to the materials we have nowadays, even the same Cromoly is infinately better today. Heat treating is also better today.

A steady diet of max pop loads will eventually make anything fail, but I doubt anyone could have seen this coming.

I'd almost bet that since Ruger just redid the gun, they will give him a new one.

Randy

[Silver Jack Hammer]

In cowboy we see single action guns blow with very light charges of fast burning powder and light boolits in large capacity .45 Colt cases. Odd thing is a double charge of the fast burning powder under the lightweight boolits doesn’t generate enough pressure to fail the chamber. Yet the guns blow. So we don’t know why. Allen Jones of Speer has offered the best explanation, a double charge, not of powder but of boolits. Two 200 gr boolits is 400 gr and that will blow the gun with a light charge of fast powder. All the theories of the light charge of powder causing detonation rather that ignition blowing the guns hasn’t been able to be reproduced in the laboratory.

So, I checked an Italian Colt copy out of the property room to blow it up. The court had ordered it destroyed. I got some lightweight boolits and fired it with double charges of super light cowboy mouse flatulence loads of Red Dot, Bullseye, and Green Dot. The gun did not blow. A double charge of a light load of Unique didn’t blow the gun. I couldn’t double charge 2400 so I put as much powder in the case as I could, I didn’t think the gun would let go but it did. I figured it was metal fatigue from the previous loads that caused the gun to blow with an overcharge of 2400. Ultimately I felt I had learned very little, too many variables. I lacked proper measuring systems and American steel is not Italian steel. Don’t try this at home, I was behind a bunker and firing the gun by remote.

In 1978 I had a squib in a SBH new model I purchased new , got a 240 jacketed bullet stuck in the bore. I thought it was stuck in the case so I fired another shot without checking the bore. Young, dumb and lucky. I didn’t blow the barrel, I didn’t even bulge the barrel. The recoil was double but the gun was unharmed. Of course barrels are hammer forged and cylinders are just bar stock with holes bored in them and then heat treated.

Now I have an old model 3-screw SBH unconverted with a standard Blackhawk hammer, and fitted with a carbon blue grip off an Old Army and for stocks some custom purpleheart with Ruger medallions. If I blew this gun I would consider myself mentally injured even if it didn’t draw blood.

[tek4260]

A double charge of boolits? Is he saying this could happen with his ammo or with handloaders? That would require quite a bit of Murphy along with a taste of inbreeding to pull that stunt off for a handloader.

Not sure how the process runs in the Speer ammo factory and weather it could happen.

[dmize]

A double charge of boolits? Is he saying this could happen with his ammo or with handloaders? That would require quite a bit of Murphy along with a taste of inbreeding to pull that stunt off for a handloader.

Not sure how the process runs in the Speer ammo factory and weather it could happen.

I was thinking about the same thing,just was afraid to say it.

[Silver Jack Hammer]

Two (2) 200 gr boolits will fit in the .45 Colt case with the small charge of fast burning powder.

[dmize]

Two (2) 200 gr boolits will fit in the .45 Colt case with the small charge of fast burning powder.

And anyone that would actually make a "mistake" like that definately needs to quit reloading and handling anything more dangerous than a soda straw.

[L Ross]

dmize, you and I cannot imagine physically placing two bullets into a single case. However, think about this for a second. Cowboy action shooting was and maybe still is very popular and brought lots of new shooters into a game that needed a fair amount of ammo. This also caused folks to start reloading that never had before. Large numbers of ammo needed pushed people into using progressive reloaders and suddenly we began seeing no powder in loads and double charges and double bullets. I'm not saying at all that the OP's friend had any of these factors. I'm simply responding to the incredulity of some posters and the double bullet theory.

Duke

[dmize]

I know a lot of people took to that game for serious shooting but I always got the idea it was mostly a fashion show, so yea I can see your point.
After all we still drain gasoline out of diesel Super Duty's on an almost daily basis.

[Silver Jack Hammer]

Cowboy shooting is great. If you want to shoot pip-squeak loads, get a .38 Special and use a full weight boolit. If you are going to use a .45 Long Colt, remember it was designed to be a powerful black powder cartridge. It was never designed for a light boolit and a scant dusting of fast burning powder. Didn't we just recently have a highly altered P-51 crash pylon racing? The P-51 was designed for high altitude interception, not a low altitude tight turning game. The .45 Colt is great for deep penitration. Star-Line makes great Schofield brass and with a 230 gr boolit this would be a great cowboy load, I think. But so many guys are just asking for problems and as L Ross says, cowboy shooter go through a lot of ammo. I just did a 400 round match, my son and I so that's 800 rounds, then the next weekend another 200 round match. That's a lot of casting and loading. Stay away from the minimum and maximum margins that are there for our safety.

[dmize]

I was in my gunshop last night and wanted to get 45 brass different than Starline to load for my boys to shoot in my Uberti's. I got 4 boxes of emptys in Winchester "Cowboy Load" boxes..Still had price tag when new...I just about fell over.

[One Gun Andy]

I have to agree with L Ross and dimize; cowboy action shooting appears to be much more about the "cowboy" and not near enough about the shooting. Yes, they go through a lot of rounds, but how many of them understand the high-pressure explosion that's generated each time they snap the trigger? Another great discussion. We learn so much from each other's experience.

[MajorDude]

This is an interesting thread. I had never heard of blowing a SBH, mine was always my go to if I was trying something I didn't want to risk in a model 29. Guess you just can't be too careful!

[9.3X62AL]

This whole thread has been rather sobering to read.

[paul h]

Glad your buddy didn't become a convertable, man made devices can always be replaced, man, not so much.

I can only speculate as others have done. I've burned quite a bit of unique over the years and it is one of my favorite handgun powders for mid level loads. To me mid level loads are the mid weight for caliber bullets at ~1000 fps. When you try and use unique for the mildest ~700 fps loads it doesn't burn consistantly, and conversley if you try and use it to push the heaviest for caliber bullets it builds pressure rapidly.

While I've enjoyed Brian Pearce's articles over the years, I think publishing the unique load with a 300gr bullet was foolish. I woudn't be the least bit suprised that if one was to pressure test a 300gr cast 10gr unique 44 mag load and they tried different bullet designs and different primers they'd find that pressures in some combinations had dramatic pressure spikes. You're simply out of the realm of uniques sweet spot and there is good reason you are unlikely to find published data with that combo from the powder manufacturers or bullet manufacturers. There are some combinations where just a tad more powder, a different primer or a bullet seated a bit deeper can result in a dramatic rise in pressure.

To me if you're going to shoot 300 gr cast in a 44 mag, the only powders to use are H-110, 2400 and a few others of similar burn rate. To me unique with a heavy for caliber bullet is like the bumper sticker some women have on their cars, 49% sweethart, 51% female dog, don't push it. Unfortunately your friend learned the hard lesson that in handloading some combinations are much closer to the edge and can behave erratically with only minor changes to the recipe.

[Rockchucker]

Paul, you just make good since.

[Willbird]

dmize, you and I cannot imagine physically placing two bullets into a single case. However, think about this for a second. Cowboy action shooting was and maybe still is very popular and brought lots of new shooters into a game that needed a fair amount of ammo. This also caused folks to start reloading that never had before. Large numbers of ammo needed pushed people into using progressive reloaders and suddenly we began seeing no powder in loads and double charges and double bullets. I'm not saying at all that the OP's friend had any of these factors. I'm simply responding to the incredulity of some posters and the double bullet theory.

Duke

The way I have heard of the double charge of bullets is debris (shaved lead from previous rounds) or lube in the buller seater die causes the first bullet to lodge there.....in a progressive the loader just gets an empty case out the end and and may think "hmm I forgot to place a bullet" but the NEXT round gets two bullets, the one hand placed, and the one stuck in the bullet seater die. Just a reminder to clean your bullet seater dies often :-).

[rintinglen]

The way I have heard of the double charge of bullets is debris (shaved lead from previous rounds) or lube in the buller seater die causes the first bullet to lodge there.....in a progressive the loader just gets an empty case out the end and and may think "hmm I forgot to place a bullet" but the NEXT round gets two bullets, the one hand placed, and the one stuck in the bullet seater die. Just a reminder to clean your bullet seater dies often :-).
Having deliberately loaded multiple bullet loads on a number of occasions, It ain't as easy as some would have you believe. In a recent test while loading 3 110 grain NOE WC's in 44 Mag, I had to size the base wadcutter down to.428 in order to get the cartridge to chamber. In similar attempts to manufacture multi ball loads for 38 specials, I had to select the lightest cases to minimze the wall thickness to avoid similar problems. In this case, 2 300 grain boolits in a 44 case would be over 2 inches long. I don't own a revolver whose cylinder would chamber such a thing, though I suppose a BFR might.
I suspect that this was a result of catastrophic failure brought on by an overcharge of powder in a gun previously fired fairly extensively with heavy loads.
I wonder, were the remaining cartridges broken down and weighed? Perhaps some anomoly in loading procedure occured that may be present in the surviving rounds that could shed further light on this unfortunate (but fortunately not injurious) incident.

[Moonie]

I've used loads in my NMBH 45 Colt from Linebaugh, he shows load data up to 11gr of Unique with a 310gr boolit having pressure right under 30,000. I've got some loads with around 9.8gr Unique with 300gr boolits, rather energetic but nothing compared to the 22gr H110 loads with the same boolits.