Unburned Powder in my Barrel

[USAFrox]

I need help from all you guys who are much smarter than me (most everyone here). I just built a new .50 Beowulf and tried it out for the first time with a new load I put together. Here's the load data:

335 grain Rainier plated hollow point.
34.2 grains IMR 4227
brand new Alexander Arms brass from MidwayUSA
CCI large pistol magnum primers

Barrel is an AR-Stoner 12.7x42 barrel from midway (this one: http://www.midwayusa.com/product/694634/ar-stoner-barrel-and-bolt-ar-15-127x42mm-1-in-20-twist-16-stainless-steel?cm_vc=ProductFinding)
upper and lower are no-name
gas system is mid-length
barrel is free-floated
used two magazines: one the Alexander arms .50 beowulf-specific magazine from midway, and the other was a thermold 5.56 magazine that I had lying around.

temperature at the range was about 45 degrees (fairly chilly), with slight wind.

Now here's the problem: when shooting it at the range, it never once fed the next round, and only ejected the fired brass about half of the time. This leads me to think that my load isn't stout enough. But then after the first 5 shots (all fired single-shot), I looked down the barrel, and it was LITTERED with unburned powder. I mean it looked like I practically took a teaspoon full of powder and just sprinkled it down the barrel.

So, if my load isn't stout enough, why is it not even burning up the powder that it DOES have?

I only ended up firing 13 rounds, having to manually charge it every time, before giving it up. Also swabbed all the powder out of the barrel every 5 rounds. I took some pics of all the unburned powder in the barrel that I'll try and upload later. Was also a lot of unburned powder in the chamber, on the bolt carrier, etc. It was just a big mess.

[Harter66]

The most likely explanation is that the powder didn't hit it's pressure curve . I haven't worked with 4227 ,but 4350 will do exactly that until it hits 30 kpsi and then it burns clean and completely. I will venture that the failure to feed is a result of low pressure short stroking but then I don't have enough AR experience to be 100% sure of that .

[country gent]

Cool temps, light load, possibly a crimp on the lighter side, all are can be a part of the problem. Un burnt powders can be due to to light a charge or powder distributed wrong in the case if not a dense enough loading. Primers can push the bullet forward into throat just before powder ignites causing ignition and pressure problems. A to light crimp allows the affore mentioned to take place easier. The function issues may be not enough pressure to completly cycle the bolt back far enough to pick up a loaded round. Check exiting data and see where your load falls into it. Im gyessing your on the kight side of starting loads in reality

[USAFrox]

The problem is that I cannot find existing load data for the combination I have. Alexander arms has published some load data (http://alexanderarms.com/images/pdfs/beowulf_reloading.pdf), but there are only like 4 powders on it (OK, there are actually 9). The only one of those powders that I can find in my area is the IMR 4227, but that one isn't listed on the bullet that I have. The only load they list for my bullet is Lil' Gun, which I cannot find locally. So I extrapolated using the powder I had, and the bullet I had. But obviously my guess was off.

So, if I raise the powder amount, it should get better? And maybe put a better crimp on?

By the way, I really appreciate the help so far!

[stephen m weiss]

Yes I agree. Unburned powder results from low pressure due to a fairly empty case and slow powder. If you measured the case volume you could use quickload and fudge in the case volume and bullet seating for slow rifle powder and see what it would take to get efficient burn.

I have an AR that will barely cycle at 16-17 grains of Alliant 1200r. If it ejects the case, but does not load another, its within a hair of cycling normally. With a 17 grain load, I cleaned my gun and lubed it with motor oil then it would cycle normally when before it would only eject. 15 grains never ejected at all, so its real close.

If you like testing more than calculating, make bags of 5 with one half grain more powder each, 34.5, 35, 35.5. It looks like a max load would be on the order of 35 grains (swag), so you are close. I bet they are being very conservative. Examine the primer after every shot. Check for the radii at teh pin indent to become sharper and sharper. When it gets to about .01 inch with large flat areas from the bolt face, its close to max pressure. If there appears a ridge around the primer pin indent, you are over pressure. One slightly overpressure shot isnt going to do much. Fatigue damage from stress runs as about the cube of the pressure, so 5% over pressure is like firing 1.15 normal pressure rounds. Not a big deal. Go way over pressure much, and you use up the life fast. For our pressure transducers, we would always give them a 150% overpressure cycle once to blunt any crack tips, then never again. Better life and stability that way.

[lefty o]

ive not loaded the 50B, but what you mention indicates it could use a little more powder, a faster powder, or a hotter primer. if you cant find some good published load data, give the sierra tech line a call, they are pretty good with helping you come up with a useable load.

[Harter66]

Remembering that I 50 Bowolf is a case mouth headspace cartridge.

You said you have a generic upper it is possible that the throat is generous and reducing pressures for you also . I think you can probably move on up with the loads reasonably safely in YOUR rifle. In this case the cycle threshold should be where you stop. In other words if you see pressure indicators or get a compressed load you should have been cycling freely. If it cycles and the accuracy is acceptable then stop there. The exposure I have had with ARs and gas guns in general points me to also ask if the new build cycles with factory ammo as I have read that occasionally 1 slips through that will fail to feed .... but again you're having unburned powder so back to low pressure.

[runfiverun]

ive not loaded the 50B, but what you mention indicates it could use a little more powder, a faster powder, or a hotter primer. if you cant find some good published load data, give the sierra tech line a call, they are pretty good with helping you come up with a useable load.

saving myself some typing.

[USAFrox]

Thanks! I'll pull the rest, and bump up the powder bit by bit until things start working out.

[tomme boy]

More powder. In my 45 Colt rifle I had. It left unburned 4227 until it got over a certain speed. Looking at the data they posted, you have two 350gr bullets. Go the the max of each and average the two maxes. Start 1 gr below that and work up till you feel it is max. Stay below the max shown for the 325 gr. I would go to about 40 as max. If it is working the action and have good accuracy, stop.

[blademasterii]

I wish they would expand the powder selection as well. I use 2400 for most of my cast loads and there is no load data for cast boolits of the weights I cast with any of the powders I can find. My powder is hercules 2400 also not the newer stuff. The 50B is touted as a 50 cal 45 70 round. Big boolit, low pressure. I am tempted to try to work up loads with red dot and 2400. I have a nice box of bright red powder coated lee 460g boolits and a large box of brass but nothing to put in between.

[runfiverun]

I'd try extrapolating some 45/70 data based on boolit weight and case volume.
if something like 20-24 grs of 2400 pops up in there, you'll be duplicating some decent 45/70 loads.

[Gelandangan]

Often using magnum primer would help on this issue.

[USAFrox]

Often using magnum primer would help on this issue.
As said in the first post, I'm already using a large pistol magnum primer.

[USAFrox]

I've been looking for the reloder 7, but can't find any in my area. Don't know how the powder situation is looking for all of you folks, but it's still pretty sparse in my neck of the woods.

[blademasterii]

Just looked again today and no reloader 7 here still. I still have factory rounds, but what fun is that? No usable powders at all for that round.

[Harter66]

I picked up 1 of my favorites last spring ,it was jus a 4000 mile road trip. It's looking better out here in the far west. It's thint but more choices than a yr ago.

[Moonie]

I was unaware the 50B used pistol primers...

[USAFrox]

Yeah, if you check out the published load data at the link above (post #4), they recommend the magnum pistol primer. From the data:

"Notes: .50 Beowulf® ammunition requires large pistol magnum primers..."

[Multigunner]

Have you checked the firing pin indentation on fired primers?
45 F is not cold enough to affect ignition or burning of the powder, but it might be cold enough to slow down striker impact if the lube in the firing mechanism isn't cold weather rated.

I've had incomplete ignition when using small pistol magnum primers with a .38 Special target pistol. the hammer fall just wasn't fast enough.

[TES]

I'm betting the crimp is not tight enough to allow pressure build on ignition.....any time I have seen un-burned powder it is a pressure issue. This is assuming you are using published data for your load and the components listed for the data that is published. Either COL is out of tolerance or crimp. If that is not it try using the right powder / components for your application.

[Multigunner]

Just remembered those were small rifle primers I used in those .38 Special loads not Small pistol magnum primers as I had said earlier.
Powder didn't burn well and one round the primer blast pushed the bullet up the bore to the muzzle where the core popped out of the half jacket, the powder didn't ignite at all. I was using a 310 nut cracker tool and no crimp so that might have contributed.

[USAFrox]

Have you checked the firing pin indentation on fired primers?
45 F is not cold enough to affect ignition or burning of the powder, but it might be cold enough to slow down striker impact if the lube in the firing mechanism isn't cold weather rated.

I've had incomplete ignition when using small pistol magnum primers with a .38 Special target pistol. the hammer fall just wasn't fast enough.

I haven't specifically checked the primers for the firing pin indention, but I'd be surprised if that is an issue. These are being struck by a rifle ignition system, which is typically much faster/stronger than a pistol ignition system. I was just using Rem Oil for lube on the bolt carrier ways and on the bolt/firing pin, etc. But it was certainly not cold enough to freeze it.

I will make a point to check the firing pin indentation when I get home, though, just to rule out any discrepancies. Only problem is that I've not fired any out of this gun in warm weather yet, so I won't be able to do an apples to apples comparison from the same gun - I'll just have to check to see if they don't look "normal", I guess.

[USAFrox]

I'm betting the crimp is not tight enough to allow pressure build on ignition.....any time I have seen un-burned powder it is a pressure issue. This is assuming you are using published data for your load and the components listed for the data that is published. Either COL is out of tolerance or crimp. If that is not it try using the right powder / components for your application.

Adding more of a crimp is one of the things I'm going to try. I just used the crimp that my seater was giving. I have the separate FCD for the extra crimp afterwards, but hadn't used it. I hadn't put any flare on the cases, so seating the bullets seemed to be getting them quite tight in there, since they were basically forming the cases around the bullet without the benefit of the flare to start it easy. Definitely something I can improve on with the FCD.

As far as your assumption that I'm using published data for my load - there is no published data for the bullet I'm using except for using Lil' Gun, which I can't find in my area. I'm using one of the other powders published for different bullets, but that's part of the problem - I'm trying to find my own load without the benefit of there being published data. I'd love to be able to use the published load, but with powder availability being what it is lately, there is no way for me to do that right now.

[TES]

So tighten the crimp....if that does not work then you need a faster powder.

[USAFrox]

Last night i pulled the 33 that I had left from that first weak load, and reloaded 15 of them with 34.5, 35, and 35.5 grains (5 each) to see if one of those works. If not, and it still looks weak, I'll keep going up unless and until I start seeing pressure signs. I'm hoping to get out to the range after work today to try out those 15 rounds. Hopefully I'll have more news after that.

As far as the primer indentations, they don't look abnormal, so I think that's not an issue.

I did complete the new lower receiver for this build since I shot those first rounds (using the lower receiver from one of my other evil black rifles) though, so it'll be out of a new lower receiver, but that shouldn't really affect anything. All the fun stuff happens in the upper receiver. ;-)

Oh, and I used the FCD to apply a better crimp on these 15 rounds.

[USAFrox]

Ok, just went shooting. Shot those 3 loads (5 rounds each). The 34.5 was just as dirty as the first ones I shot at 34.2 grains (no surprise there), and were just barely better in terms of cycling the action. Two of the five cycled the action. The 35 grain load was pretty much just as dirty, but cycled two also. Not much improvement. The 35.5 grain load actually burned almost clean (very little powder mess in the barrel), but only cycled 3 times out of five. It also locked back on empty for the first time!

No pressure signs on brass yet. Still nice radiuses on the edges of the primers, with little to no flattening.

Looks like I need to keep climbing, but I'm getting closer! Thank you all for the help so far!

[snuffy]

That ranier plated bullet has no cannelure, flaw #1. A new build on an AR frame takes some breaking in, flaw #2. How did you lube that assembly? Unless you had lube dripping from it, it may not function with normal pressure loads. I see a lot of AR's that fail because owners either use the wrong lube or not enough of it

A friend bought one that was built by Alaxander Arms, it would jam, fail to feed, fail to eject. This was with my handloads using the same Midway brass, H-lil gun and 350 XTP's and 500 RNFP. He bit the bullet,(no pun), bought a box of factory rounds, same story. The gun shop sent it back to AA, they said it functioned perfectly! It was evident it had been shot extensively while there, just needed to be broken in. Now it works great! It is also quite accurate.

[USAFrox]

That ranier plated bullet has no cannelure, flaw #1. A new build on an AR frame takes some breaking in, flaw #2. How did you lube that assembly? Unless you had lube dripping from it, it may not function with normal pressure loads. I see a lot of AR's that fail because owners either use the wrong lube or not enough of it

A friend bought one that was built by Alaxander Arms, it would jam, fail to feed, fail to eject. This was with my handloads using the same Midway brass, H-lil gun and 350 XTP's and 500 RNFP. He bit the bullet,(no pun), bought a box of factory rounds, same story. The gun shop sent it back to AA, they said it functioned perfectly! It was evident it had been shot extensively while there, just needed to be broken in. Now it works great! It is also quite accurate.

I hope that is the same for me, and a break-in will smooth things out after a while. For lube I'm just using Rem Oil (my old stand-by).

Now that I've gotten the powder to burn more cleanly, that's half the battle. I'm sure that just a little hotter and it'll all work well.

[USAFrox]

Ok, just went out and tried loads at 36, 36.5, and 37 grains (5 each). Accuracy is good, and EVERY ONE of the cartridges from each of those 3 loads fully cycled the bolt. There were no failures of ANY KIND!

I checked the barrel after each five rounds and wiped it out. I'm still getting too much unburned powder, though. Each of those loads left what I consider to be an unacceptable amount of powder in my chamber and barrel. The functioning is now 100%, and the amount of unburned powder is BETTER than it was, but still too much.

Is IMR 4227 just a really dirty powder?

This is is the first time I've ever used it. At the highest load above (37 grains), I was starting to see pressure signs beginning, as far as the primers flattening out. Not terrible yet, but I'm not sure I should go hotter. Should I just tighten the crimp? Do I just learn to live with a dirty load? What do you all think?

[snuffy]

Is IMR 4227 just a really dirty powder?

Yes it is!! Every time I have tried it, there was unburned powder in the barrel. These were all revolver loads, except for the .22 hornet, even that had some chunks left behind.

I don't think it matters much as far as accuracy goes, that powder is blown clear out of the barrel by blow by gases so it doesn't "get in the way" of the bullet/boolit.

[USAFrox]

Oh, that's good to know! I was thinking that I still must be doing something wrong.