Help me figure out what happened!

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ILikeLead

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Yesterday I decided to reload subsonic loads for 300blk to shoot in my Remington 700 AAC-SD.

Using 220 grain round nose soft point bullets I referenced the chart on the lee reloading die insert. I had used imr4198 in the past but the loads were too fast for subsonic (sonic crack). I decided to try H lil gun and see if they were sub-sonic. On the lee chart there is no range. It lists only one load for sub-sonic. For lil gun that load is 9.0 grains for the 220gn jacketed bullet.

I loaded 5 and shot them upwards into the trunk of an oak tree in the backyard about 50 yards off. No sonic crack, good to go.

I reloaded 20 more to shoot at 100 yards and test accuracy. The first 4 were loaded into the magazine with the muzzle down. Then I placed the gun on bags for shooting. The first round was noticeably louder and the bolt was stuck closed. After unloading the remaining live rounds I used a mallet to open the bolt and found the case severely expanded into the head of the bolt. No case head separation. No split neck. Just brass molded into the bolt face area. The bolt was cracked on the front rim. I machined out the brass but will have to have the gun repaired if it is at all possible.

here's the question. Was it detonation? I don't know. Suppose I did double charge the case with 19 grains of lil gun. THe 44 magnum shooting 220 grain bullet calls for 20.1 to 24.9 grains of lil gun in my Sierra manual.
Granted the lee chart lists lil gun for the 300blk and 135 grain bullet as 18 grains maximum.
(Case volume for .44 magnum is 35-40% more than 300 blk)
I just don't know. Luckily no human damage. Only damage is to gun.

Any helpful words of wisdom? I'll look for a more bulky powder next time for this purpose!

Also, Anybody know where I can get a replacement bolt? I've already emailed Remington and awaiting response.
 
The 44 magnum chamber is beefier than the 300 Blk. It could stand the overcharge, the 300 blk might not. The bolt may have just had a failure point that coincided with the charge. If you initially pointed the muzzle up, then lowered it to the horizontal, you should not have had detonation, all the charge would still have been in proximity to the primer.(Dang, just reread the post and realized that the cases might have the powder in the neck area and not at the primer.) I give up. I was about to say I've never heard of an actual case of detonation but this sure seems to qualify!

Bill
 
R.ph.... Yes the over pressure load would have had the powder near the bullet based on how I loaded the magazine.

243 win.... I was hoping for a factory type bolt for maybe 1/3 that price... Thanks!
 
As all I can do is guess. My guess is a double charge or possibly a long case (doesn't sound likely as you are just building loads).

Comparing the 300 Black to a 44 Mag is like comparing an apple to a bannan. That said, when I was working on finding a starting point with a new/not listed powder [Olin 630], I did a ratio comparison between 296 and 630 in the 44 Mag and extrapolated a starting point for the 300 Black. I only loaded one round and with a lot of puckering, fired it. This gave me a starting point.

My hottest/heaviest Lt'Gun charge using a 130 grain bullet was/is 18 grains and I only shot 2 of those. My prefered charge for this bullet is 17.5 grains for 2124 FPS out of my 16 inch AR type with a Carbine gas system.

Sorry about you mishap. Pleased you have all of you fingers.
 
I don't use that powder, but none of my powders would fit a double charge even at 9 gr in the case, and definitely not with that large of a bullet. Maybe you are seating them longer than I do though, as I'm trying to fit an AR mag.
 
Any helpful words of wisdom?
Click to expand...

There is always a thread going on about gun failures. About 35 + years ago a foreign company did some research. When finished they decided they did not know what caused the failures because they could not blow a gun up every time they pulled the trigger. They concluded it can happen, not every time but it can happen. After that they quit talking about it.

I follow their advise, I do not shoot reduce loads, I believe powder is position sensitive.

F. Guffey
 
found the case severely expanded into the head of the bolt.
Click to expand...
Same here.
Shooting factory new Winchester 55gr ballistic silvertips, this model Rem 700 locked up the bolt. A gunsmith had to remove the barrel to get the bolt open. The brass is welded to the bolt face. http://www.thehighroad.org/showthread.php?t=579068
Click to expand...
th_243WinFactoryAmmo.jpg
[/URL][/IMG]
 
Yesterday I decided to reload subsonic loads for 300blk to shoot in my Remington 700 AAC-SD.
Click to expand...

Shooting factory new Winchester 55gr ballistic silvertips, this model Rem 700 locked up the bolt.
Click to expand...


Sub sonic loads the other shooting new factory Winchester?

F. Guffey
 
New info... Absolutely not a double charge

Well fellas I got to thinking. I wondered last nite what a double charge would look like in the 300blk case. So this evening I loaded 18 grains of lil gun in the case and the powder came up all the way to the neck. I now know for a fact I did not double charge. I wouldn't have been able to seat the bullet,as it was a long 220 grainer.

I also weighed the charges on a rcbs charge master combo.


All It could be is detonation I suppose.
 
243win... That's exactly what it looked like except brass not nickel plated.




I was able to remove bolt from gun and machine most of the brass out of the bolt. But it's definitely damaged
 
I like Trail Boss for reduced velocity loads. It fills the case. I've shot hundreds of them in 308, 22250, 44 mag, 223, and 38, using jacketed and cast bullets. Hodgdon says the proper load for each caliber is fill the case up to the base of the bullet.
 
The 44 magnum chamber is beefier than the 300 Blk.
Click to expand...
I'm not sure I understand your statement, are you saying a S&W Model 29 is stronger than a Remington 700 and has thicker chamber walls?

I have no experience with, or particular knowledge of, Lil'Gun. I know it's close to H-110 on the burn charts, but that's about it. I can't recall ever seeing any warnings about reducing loads more than 3% like with H-110.

In any case, you're shooting a bolt gun and don't need to use a powder slow enough to operate a semi auto. In my experience, the faster a powder burns, the less noise your round will make leaving the suppressor. Faster powders are also generally safer as far as Secondary Explosion Effect is concerned. They are however, more dangerous regarding double charges. Very bulky powders like Trail Boss mitigate the double charge problem, but I've never gotten top accuracy using them.

Most of the information that I've seen regarding Secondary Explosion Effect was with slow burning rifle powders used in reduced loads with jacketed bullets. But I've seen references to it having happened with pistol rounds involving jacketed bullets and extremely reduced loads of relatively fast burning pistol powders.

My understanding of the phenomenon is that under certain circumstances (often involving a bore that has been fouled by previous uneventful firing of the same load), a bullet will stick in the bore. The powder will then smoulder in the chamber, producing gas which then detonates like a charge of high explosives with enough energy to wreck even a very strong rifle.

I've never heard about this happening when using cast bullets.

I've been shooting subsonic bullets from .308's, 7.62x39's and 30-06's for almost 20 years and I've never managed to stick a cast bullet in the bore. I stuck a number of jacketed bullets before I pretty much gave up on them for loading subs.

I know that subsonic loading has advanced a lot in the last few years and it's now easy to find subsonic load data for jacketed bullets, but I can't really understand why anyone shooting a non semi auto would use them. I can see why they're popular with .300 Blackout AR shooters, they generate more back pressure to operate the action and don't foul gas systems like conventionally lubed cast bullets can.

But in a suppressed bolt, lever or single shot, the modern cast bullet, well coated with powder paint to prevent fouling suppressors, holds all the advantages.

They're MUCH cheaper, equal or better in accuracy and can be customized to suit the needs of the shooter/caster. I'll absolutely grant that jacketed bullets are superior for long range shooting, but ".30 caliber", "subsonic" and "long range" don't work out very well together regardless of what bullet you choose.

A cast bullet can be made hard enough to blow a hole from skull plate to rectum on a big hog or soft enough to give explosive expansion when shot through the chest of a 60 pound whitetail. It's even possible to cast projectiles with a dead soft nose and the rest of the bullet hard enough to shoot through heavy shoulder bones.


Did I mention that I like cast bullets? :D
 
@ ILikeLead
You probably already know this, but make sure you get the headspace checked on your rifle when you get the new bolt.

Honestly, it might not hurt to have the whole action Magnafluxed before you shell out any money for new parts.
 
All It could be is detonation I suppose.
Click to expand...

Using 220 grain round nose soft point bullets I referenced the chart on the lee reloading die insert. I had used imr4198 in the past but the loads were too fast for subsonic (sonic crack). I decided to try H lil gun and see if they were sub-sonic. On the lee chart there is no range. It lists only one load for sub-sonic. For lil gun that load is 9.0 grains for the 220gn jacketed bullet.
Click to expand...

I do not shoot reused loads, I believe powder is position sensitive and I believe the foreigners when they say it can happen, not every time but it can happen.

When replacing the bolt there are critical dimensions. The third lug on the Remington is the bolt handle.

About the double charge, and when it is critical I believe the reloader should know the weight of the case, powder and bullet. When finished loading the total weight of the round should equal the weight of the components.

F. Guffey
 
Swampman,
Care to share some of your experiences with powder coated reduced loads such as loads, bullets, etc. for .30-06? The Cast Boolits threads on powder coating are all over the place and generally address pistol calibers.

I collect old milsurps bolt actions but live in a suburban area so I need rounds that are indoor range compatible (which generally these ranges frown upon lubed lead bullets) unless I only want to shoot once or twice a year at longer ranges.
 
Conclusion

Thank you all for your input. I spoke with the gunsmith Wednesday. He tried to take the barrel off with intentions to first visually inspect and then possibly magna flux the chamber etc.


He couldn't get the barrel off. Stated that he used a 3ft cheater bar on his barrel vise tool and still couldn't unthread it. Said that tells him the chamber is expanded. He's going to sell the floor plate and stock to a gun salvage guy in Oklahoma.

Gone is the Remington 700

Just picked up the ruger American tonite.

Thanks again to all!
 
This looks like the stuff we were just talking about late last month
http://www.thehighroad.org/showthread.php?t=792462

My take on it was posted in message #26

In a nutshell, slow burning powder piled up at the front of the case. Primer drives bullet into the rifling before the powder goes off. When the powder does go off, the pressure goes through the roof.

If you tilted the barrel back before shooting, chances are that you would have the loads you were expecting. If you tilted the barrel down again before shooting, you would probably experience another super high pressure shot and maybe a kaboom.
 
My take? When considering factors I would think the powder lying in the case from the case head to the back of the bullet would be worst. Powder burns slower than the primer, then there is the large flame front caused by the powder lying in the case.

I want my bullets to get out of the way before the burning powder gets serious. That is the reason I do not seat bullets to or into the lands, I want my bullets to have the 'running start', I do not want my bullets to hesitate.

F. Guffey
 
Detonation has never been reproduced with smokeless powder, and smokeless is specifically designed to burn at a controlled rate (not detonate). If it were me and my reloads, I'd be looking for a more realistic explanation and a corrective action, lest it happen again.

You might want to check that oak tree to be sure it has 5 holes.
 
A small amount of powder in a big case always makes me nervous. I load a lot of 300 BLK. I shoot 125's and 150's. I have never loaded a bigger load. While I do want to try heavy bullets I compare them not for loading (how much powder/primer/brass), I compare what a 220 does out the barrel compared to my 45 Colt. I used a Remington Model 7 AAC Blackout. I will note the experiences here and take care. Might have to try filler with such a lot. Too expensive to break a fine rifle. Thanks for share, although the experience was an expensive one.
 
I have never loaded 300 for subsonics, but Hodgdon lists 9gr as max load of Lil gun with a 220 gr. I loaded some with a 150gr bullet just last night and 14.3 gr was almost to the bottom of the bullet, so I wouldnt imagine 9gr with a big 220 gr bullet shifting much.
 
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