HBWC base stuck in bore

[coyotejoe]

I was trying out some loads in an Enfield .38 revolver, one load being a Remington 148 grain hollow based wadcutter over 2.8 grains of Red Dot. Recoil was very light and shots were impacting in the dirt below the target. After the first shot my Pro Chrono went dark. I fired off the six rounds, all hitting in the dirt, and when I opened the gun and looked through the bore I saw only a .22 size hole. A bullet had separated, the nose was gone and the hollow base portion was stuck in the bore. I knocked it out and found the barrel was bulged in two spots. I can't imagine how that could happen, I mean how could a bullet pull in two in the bore?
  I found the front half inside the cardboard box on which I had posted my target. It was damaged from impacting the dirt but one could still see where it had torn. Apparently a bit of lead had also impacted my chrono right in the LCD display,  so it is dead as well. Not a good day all around and one of those things I would have said could never possibly happen, but it sure as heck did happen!

[coyotejoe]

sorry, double post

[hoggunner]

Glad you didnt get hurt! pretty wild what goes on in a chamber
Hogguner

[Mikey]

coyotejoe - here's how I think that happened:  Since I do not recall a .360 - .361 diameter hollow based wadcutter slug for the 38/200 (38 S&W) I think you were using the wrong diameter slugs in your loads.  If you were using standard 38 special wadcutter slugs the diameter would have been somewhere around .357-.358 - significantly undersized for the bore.

I think what may have happened is the first slug may have expanded in the barrel beyond its structureal capability and split at a weak casting point, probably at a lower lubricating band just at the top of the 'hollow-base', allowing for a 'first shot fragment' to clock your chrono as well as sending a short round down range.  The front part of the slug went down range, the 22 cal hole you mentioned is probably the fragment that mortally wounded your chronograph.  I think the following loads are the ones that may have bulged the barrel but the loads you were using were so light, even for that old cartridge that you may have stacked one on top of the other.

I think what may also have happened is that with the bottom half of the wadcutter slug ringing your barrel and causing the obstruction the remaining slugs may just have been driven through or down the bore - yes, they were 'short rounds' but because they passed through the lead ring obstruction in the bore.  Stranger things have happened.

I believe the cause of the problem in the beginning was using undersized slugs. 

I am glad you were not injured in this situation and send condolences on the passing of your chronograph.  I will not send condolences however on the passing of that revolver and if you ever decide to get another we can help you with proper load data.

A interesting note on some of these oldies is that the loads they used were of such low pressure that even 'full-house' loads aren't over pressured. 

That's what I think............. I could be all wet, but that's what I think......... Mikey.

[coyotejoe]

Yes, it is a .361" groove diameter barrel, that was the whole point of the hollow base, to expand .003" to fill the bore. These were Remington bullets, swaged, not cast, and of dead soft lead. Bullets pulled from Winchester factory loads measure .358", but solid based and those 145 grain roundnoses are loaded over 2.5 grains of what appears to be W-231 powder and chronographed about 600 fps. The powder charge of 2.8 grains Red Dot may seem very light but is a listed load and should have produced around 700 fps, which is about mid-way up the scale of listed loads for this round.
  It would seem that for a bullet to tear in half, the rear half must somehow have come to an abrupt halt, then the momentum of the front half would pull away, but why would the base just stop like that? The bore, prior to that shooting session, had been bright and clean, with no roughness or pitting at all. Why would a bullet base just stop, two inches down the bore, and stick so fast as to pull in two? This may indeed have happened more than once, there were two bulges in the barrel about one bullet length apart, but only one base remained in the bore after firing six rounds. The base I removed from the bore was not especially hard to drive out.
  Funny thing is, something exited the bore and hit the dirt after every shot, I had no reason to think a bullet was stuck and had this been any other revolver than the break top I probably would not have looked through the bore and may have fired a roundnose bullet into that stuck bullet base.
 All things considered, I don't get it!

[Savage]

I think Mikey hit the nail on the head. It seems logical that the hollow base expanded enough to cause it to separate the bullet at the bottom on the hollow base where it joins the solid body of the bullet. It would have been prone to separation at that, the thinnest  point,  due to increased drag at the base, and the heat of the powder burn.
Savage

[coyotejoe]

A fellow on another site came up with an explanation that makes sense. He feels that my choice of Red Dot powder was the main culprit, that it pressure spikes earlier than Bullseye and that the hollow base expanded into the very large forcing cone of the Enfield barrel and the bullet was torn in half at that point, even though the base I recovered was stuck about two inches down the bore. Even though Lyman lists that load for a 158 grain bullet and I was loading a 148 grain he said the pressure was too great for the hollow base and that combined with a large and abrupt forcing cone caused the separation. These bullets were seated out to crimp in the first lube groove and thus the COL was 1.135" or just a dad shorter than a flush seated wadcutter in the .38 special. A standard target load for the .38 special was 2.7 grains of Bullseye with the 148 grain HBWC and such separations are known to happen (but rarely) with that load in some revolvers with oversize forcing cones. It's a new one on me.
The expansion of .003" is zip, remember this is a swaged bullet of dead soft lead, nothing like the brittle alloys of "hard cast" bullets, I've no doubt that soft lead hollow base could be turned inside out without cracking.

[Savage]

Pretty much what I was trying to say. The heat of the powder burn effect on the lead at the thin hollow base caused the expanded base to pull apart when it hit the forcing cone. If you must shoot these bullets in that revolver, you could turn them around with the hollow base to the front, that should eliminate the problem. Just one other thing, Bullseye is a faster burning powder than Red Dot, therefore shorter pressure curve,  just mentioned that to set the record straight. Are the barrel bulges bad enough to have to rebarrel the revolver? That would be a shame!
Savage

[coyotejoe]

Indeed Bullseye is listed as faster than Red Dot, but in looking at actual handgun pressure tested data for identical charges I find Red Dot consistently runs a bit higher pressure. But that is not the whole story as it was patiently explained to me. This fellow claims that Bullseye is a progressive burning powder while he calls Red Dot regressive, meaning that pressure spikes immediately and it's all down hill from there. That combined with the very small capacity makes it very touchy, one tenth of a grain becomes a big deal. I'd likely have been OK with 2.8 grains of Bullseye or with 2.5 grains of Red Dot but 2.8 grains Red dot was too much for the 148 grain hollow based bullet even though some sources list up to 3.0 grains with a 158 grain solid base.  Jeeze, 40+ years reloading and still lessons to be learned.
 The bulges in the barrel are quite dramatic on both sides where the Enfield barrel is very thin, top and bottom look normal. This gun was no great collector's item, pretty much devoid of finish and I had no great investment in it.  It is always a shame to so damage any firearm but all in all, if it were to happen, I'd rather it happen to the Enfield than any other handgun I own, well, except for the Nagant.

[WILD_WEASEL]

Being an Enfield No.2Mk1** enthusiast myself I always look over any of these revolvers whenever I spot one at gun shows or shops.  Running my fingers along the barrels it is not surprising to me how many have bulged barrels, confirming the reports about the 178gr .380 military ball having a tendency t get stuck in the barrel.