Something that's worrying me-Krag shooting

[madsenshooter]

I've been shooting 20gr of Blue Dot fired with a Rem 9 1/2M primer under a 169gr cast boolit in my Krag. I'm seeing something on the fired cases that is worrying me. It appears that the majority of the Blue Dot is burning in the forward part of the case, and it's the same on all the cases. It begins .822" forward of the rear of the case. I can see a couple scenarios causing this. One, the magnum primer is blowing the 20gr of BD forward, compressing it some before it starts to burn. Two, this obvious pressure mark is also at the exact point where the receiver ring ceases to encase the barrel. Am I perhaps flexing the chamber that is outside the receiver ring with my load, and maybe taking a chance of ringing it? Anyone have an approximation of how much chamber pressure I'm generating with this load? I have an idea from the fact that a 23BHN bullet will shoot wildly, the same boolit oven treated shoots like a dream. That'd put pressure above 30,000psi, but how much above? Don't know just how hard the oven treated bullet was. This barrel shoots too good for me to ruin it, appreciate some input. Anybody else see this pressure mark on the forward half of the case shooting reduced loads?

[StarMetal]

Have you thought about using a lesser primer? Maybe even a pistol primer. Sounds like your gun had a SEE, a secondary explosion up in the forward part of the case. In some rifles you see rippled cases too. You could try the primer changes, maybe too a filler to help keep the charge in the back of the case. You'd have to reduce your charge if you use a filler. I'd say you're probably up in the 30k bracket.

Oh and keep an eye on your bolt lug for cracks too.

Joe

[JeffinNZ]

It is worth considering that where your pressure ceases is the same place the brass really begins to thicken up. It is possible that your load has only enough pressure to seal up on the thinner wall section.

[madsenshooter]

Have you thought about using a lesser primer? Maybe even a pistol primer. Sounds like your gun had a SEE, a secondary explosion up in the forward part of the case. In some rifles you see rippled cases too. You could try the primer changes, maybe too a filler to help keep the charge in the back of the case. You'd have to reduce your charge if you use a filler. I'd say you're probably up in the 30k bracket.

Oh and keep an eye on your bolt lug for cracks too.

Joe

It appears my Krag has too much firing pin protrusion for them, too many are pierced, tried em. Good results, but the case marks are just the same. If this is an SEE, then it's a controlled one, had about 80 so far. Jeff, that's a thought, something I hadn't considered, just seemed strange to me that it coincides with end of the receiver ring. It is surely something I'm going to watch, and I'll be using some more case filling powders in the future, but I have 4lbs or so of this Blue Dot to use up, and it works really good. Any of your Enfield cases look like this one?

[Bret4207]

The FP protrusion can be fixed. I'd section a case and see if that isn't where the brass thickens, look a bit high for that to me. I'd also check the chamber and see if there is any chance theres something there that might lead to this. A filler (dacron) should hold the powder to the rear if the scenario is playing out like you think.

[Cap'n Morgan]

Quickload estimates your load to a pressure about 35000 psi - well within the 47000 psi max for the Krag. Judging from the picture I would think the chamber needs a bit of polishing. I've seen something similar in guns with rusty and pitted chambers.

[madsenshooter]

I've got some new 303 British brass that I've sized for the Krag chamber, I think I'll load a few rounds with a more case filling powder like 4895 and see how they look. I'm really thinking that it's just where the Blue Dot is at when it releases its energy, but if that's the case, some of you other guys should be seeing it with 2400 and similar powders. There's no measurable bulging at the point where the pressure mark starts, extraction is easy. I'll let you know what the 303 cases look like. Ah, I was hoping someone would chime in with some Quickload estimates. Thanks, that means my hardened bullets that works so well are at least 28BHN, no rust or pits in the chamber, barrel looked like new when I got the rifle.

[Shiloh]

Do you think you could get the Secondary Explosive Effect with Blue Dot??

Its pretty fast
as a rifle powder. I agree that you may be over primered with magnum primers. I don't see the need for them with Blue Dot.

Shiloh

[madsenshooter]

Well, I was having an accuracy problem, changed 2 variables and it was no longer a problem, one, I hardened the boolits, and 2 I went to the magnum primer. The accuracy problem went away, but I think it was the boolit hardening that solved it. The 9 1/2M is reportedly the mildest of the magnum primers. They are presently about all I have, save for some old Herter's Large Rifle. Thanks for the input guys! I'd really hate to wreck this barrel!

[Bob S]

Quickload estimates your load to a pressure about 35000 psi - well within the 47000 psi max for the Krag.

The accepted maximum for US Krags is 40 KSI. US Krags have only a single locking lug ... the guide rib does not bear on the receiver, unlike Danish and Norwegian Krags. The standard US load was a 220 grain FMJ at 40 ksi, giving 2000 fps. In 1898, a higher velocity load giving 2200 fps at 45 ksi was tried for a short period of time, but the higher pressure loads resulted in a number of cracked locking lugs, so the service load went back to 2000 fps at 40 KSI.

Resp'y,
Bob S.

[swheeler]

Well, I was having an accuracy problem, changed 2 variables and it was no longer a problem, one, I hardened the boolits, and 2 I went to the magnum primer. The accuracy problem went away, but I think it was the boolit hardening that solved it. The 9 1/2M is reportedly the mildest of the magnum primers. They are presently about all I have, save for some old Herter's Large Rifle. Thanks for the input guys! I'd really hate to wreck this barrel!

Change one thing at a time, cast or jacketed, makes diagnosis much easier.

[madsenshooter]

The accepted maximum for US Krags is 40 KSI. US Krags have only a single locking lug ... the guide rib does not bear on the receiver, unlike Danish and Norwegian Krags. The standard US load was a 220 grain FMJ at 40 ksi, giving 2000 fps. In 1898, a higher velocity load giving 2200 fps at 45 ksi was tried for a short period of time, but the higher pressure loads resulted in a number of cracked locking lugs, so the service load went back to 2000 fps at 40 KSI.

Resp'y,
Bob S.

Hi Bob!

The 40,000 you're talking about would be CUP. Johan at Western powders also told me that the US Krag has a max of 47,000PSI in the more modern way of expressing pressures obtained via transducer. I was actually surprised to see someone else using the figure. The guide rib on my Krag also bears on the receiver BTW, someone set it up that way, has an uncut guide rib.

[BruceB]

Since the US Krags were built at Springfield Armory immediately before the low-number 1903s, I've long considered it logical to AVOID fast-burning powders in any rifles made in that time frame by Springfield. The same methods were used in creating the Krags as were used in the later 1903, and we all know about the woes of SOME low-number 1903s.

The same velocities we might obtain with a quick-burning powder are perfectly feasible with slower powders, too....it's just that the rate of pressure rise is slower and (*I* think) less likely to cause a problem if the receiver steel is brittle. The fastest powder I will ever use in my Krag or low-number 1903 is 4198. It works beautifully and avoids that hammer-blow to the steel that I envision with faster powders.

In my opinion, the RATE of pressure rise is the potential problem, not the ultimate maximum pressure of the load as long as it's within normal limits.

[StarMetal]

I'm going to take a look at my Krag's bolt and see if I can remedy your pierced pistol primer thing.

Joe

[JIMinPHX]

Pressure inside a cartridge case distributes evenly. You don't get more pressure in one part of a case than another. Since you say that the mark ends right where your receiver ends, I'm going to expect that your threads are a press fit & your chamber is getting compressed in that area. The threads may have been free running when the barrel was new & rust may have turned it into a press fit. I've seen that before on machined fits in other places.

As for your cartridge pressure, have you tried any factory ammo in that gun? Do factory cases get the same marks?

I don't know a lot about Krags, but I do remember reading in a book, many years ago, about how the Krags were built before metallurgy was as well understood as it is today & how the bolts were made full hard with no tempering afterword. That kind of makes me want to jump on the bandwagon with Bruce B & suggest that you might want to stay away from the heavy charges of fast powders in that thing. Full hard = brittle.

[bruce drake]

Get rid of the magnum primers. I've never had a need for them to ignite Blue Dot loads in my 303 Enfields.

[StarMetal]

Pressure inside a cartridge case distributes evenly. You don't get more pressure in one part of a case than another. Since you say that the mark ends right where your receiver ends, I'm going to expect that your threads are a press fit & your chamber is getting compressed in that area. The threads may have been free running when the barrel was new & rust may have turned it into a press fit. I've seen that before on machined fits in other places.

As for your cartridge pressure, have you tried any factory ammo in that gun? Do factory cases get the same marks?

I don't know a lot about Krags, but I do remember reading in a book, many years ago, about how the Krags were built before metallurgy was as well understood as it is today & how the bolts were made full hard with no tempering afterword. That kind of makes me want to jump on the bandwagon with Bruce B & suggest that you might want to stay away from the heavy charges of fast powders in that thing. Full hard = brittle.

Apparently metallurgy was well understood in Europe, Russia, and Japan.

I'm not sure I agree with that. Look at all the early Mausers that have been rebarreled to high pressure modern rounds and seem to do well like the 93's and 95's. Why would Germany know metallurgy and the U.S. not?

Joe

[madsenshooter]

Pressure gets distributed evenly in the case, but there is a difference in the thickness of that which is containing the case. The receiver ring adds considerably to the thickness. No rust in this receiver or barrel, I've had them apart, and it is a good tight fit, no screwing it in by hand. There's no bulging where you see that mark, I can lay a good straightedge on the case and can't detect any. Factory loads, you mean the factory still makes some? Just kidding, no I seldom do storebought. But I will try a load with a fresh case and some more case filling powder, gotta work the next 4 days though. I'm gathering that this isn't something you normally see with reduced loads of fast powders.

[Bret4207]

Hi Bob!

The 40,000 you're talking about would be CUP. Johan at Western powders also told me that the US Krag has a max of 47,000PSI in the more modern way of expressing pressures obtained via transducer. I was actually surprised to see someone else using the figure. The guide rib on my Krag also bears on the receiver BTW, someone set it up that way, has an uncut guide rib.

Judging by Bobs past posts, if he wrote "KSI" he probably meant "KSI" and not "CUP".

Could you clear this up Bob?

[atr]

[QUOTE][Quickload estimates your load to a pressure about 35000 psi - well within the 47000 psi max for the Krag. Judging from the picture I would think the chamber needs a bit of polishing. I've seen something similar in guns with rusty and pitted chambers.
/QUOTE]

I like cap,n morgans suggestion....I had a similiar experience and marking on case and cured it by having the chamber polished up....

[madsenshooter]

Got my straight edge in a better light, there is a slight bulge, and I think I know the load that done it! Going back 6 months I'd noticed the fore part of the case looked like this only to lesser degree as I was shooting smaller doses of Blue Dot. Just before I started noticing that, I had made up a load of WC860 52gr I believe with a 3gr kicker of BD, under a 198gr boolit. I shot one of them and made note that it kicked like my 06, 1 was enough. Got around to trying to load that case a couple weeks ago and the primer pocket was enlarged, so it got set aside. Luckily I've stashed away a couple full length barrels, and there is a possibility the CMP is going to have some new ones made. This ol gal ain't done shooting yet. Thanks for all the input, the barrel that's on it may continue to see some low pressure loads with monitoring of the diameter of the bulge. I have another rifle or two to play with also, which may be an even better idea, some things are just so hard to let go of! JUST WHEN EVERYTHING WAS COMING TOGETHER!

[JIMinPHX]

Apparently metallurgy was well understood in Europe, Russia, and Japan.

I'm not sure I agree with that. Look at all the early Mausers that have been rebarreled to high pressure modern rounds and seem to do well like the 93's and 95's. Why would Germany know metallurgy and the U.S. not?

Joe

We were behind the 8-ball on metal knowledge back then. During WWII, carbide was a closely guarded secret in Germany. Krupp was just about the only company that the Nazis chose to trust with it.

[madsenshooter]

This bulge is very small, and I have a new reamer that I think will clean it up. Feel free to comment, of course you realize I'm going to try it, and keep to some more sane loads in the future. If it cleans up I'll be watching closely for the return of the bulge. Now I can see the truth of one gunsmith's comments I found on the web about not chambering an original Krag barrel to the Ackley Improved configuration. Weak enough as is!

[Bret4207]

Considering the age of the rifle, a previous owner could well have bulged the chamber. Beyond that it might be a good idea to stick to mild loads given the problems a Krag can have.

You might also want to get the bolt lug magnafluxed and see if it's okay. A load that would swell a chamber could certainly crack the lug.

[StarMetal]

Well if you remember a while back someone posted a picture of a Weatherby rifle blow up where the owner used a reduced charge of BlueDot and jacketed bullet. To be fair it was surmised it was a double charge. On another note remember some posts about how BD is temper mental? My two cents is use another powder and do something else with the BD with more guaranteed results.

Joe

[madsenshooter]

Well, I ran the reamer, nice old, yet new one I got off Auction Arms. JLLER Tool Co. Judging by where the shavings were on the flutes, I think I got it squared away. It may have opened the neck a little, that's OK as the largest bullet I could use without turning the neck was .311. Doesn't appear to have touched the throat, the reamer looks like it was cut with spire points in mind. It appears to have cut behind where the bulge was and right at the bulge. I stopped as soon as the rim cutting portion made contact with the breechface. It didn't remove much, didn't need to, quite a bit of what the flutes got was dirt, before it actually got down to cutting metal. I discovered my scope mount was loose when I disassembled the rifle, yet another excuse for my poor match results. Found my tube of Lok-Tite, that should take care of that problem. I've not read of Blue Dot being tempermental. I believe its formula is near that of 2400, if I had the $25 to spare I'd get the analysis I just found from my alma mater, Ohio University. Seafire from the Accurate Reloading Forums got me going on it, then Pat McDonald was selling 5lbs at a reasonable price. Nothing left now but cleaning the shavings out and giving it a whirl.

[madsenshooter]

I've cleaned it and test fired it, with a load of 4227 under a 198gr boolit. Case looks normal, the shoulder angle is changed slightly, it was more a reverse radius as it was. The reamer didn't change the throat, the cartridge I used was loaded to engrave the rifling and it still did. The reamer increased the diameter of the body .0015-.002, and the neck the same. I wonder if perhaps all I had was carbon from previous loads that weren't strong enough to make the case seal. Won't know for awhile now, and will be watching for "The Return of The Bulge". That reminds me of an old pal of mine, gone now, a WWII vet who was invited to return to Margraten, in Holland where he served in the 102nd Infantry Division's Cannon Company during the Battle of the Bulge. Said he didn't leave anything there and didn't want to go back, hope mine doesn't come back, whatever it was.

[StarMetal]

Another thing you could have done if you wanted to remove more from the chamber was to put the rifle in the freezer over night and immediately ran the reamer before the barrel warmed up. I think you done good. I'm still going to look at my Krag and see how we can modify it non permanently for you to use pistol primers without piercing them.

Joe

[madsenshooter]

Just modify 1 firing pin, I have several floating around. Or, I'm betting if I made some little gaskets of sheet aluminum with a proper sized hole in the middle, to bring the pistol primers up to rifle primer height, they wouldn't pierce, cause it appears to me that they tear when they expand back to the bolt face from .015 down the primer pocket. Might try that someday, no time now, my NOE 311284 just came in.

[JSH]

I have had no good or even decent results in any case or caliber using BD. Maybe it is just my lot, as a lot of folks harp on it. I finally swapped the last of the stuff i had to a shotgun shooter friend of mine for some more useful powder.
James and I discuss some of the issues that have been around for a long time using fast powders in bottleneck/rifle type calibers, on a regular basis. I use unique in a few, with good to decent results. Makes him cringe. I read of guys using BE in rifles, sorry I will pass, no matter how good they say it works.
jeff

[JIMinPHX]

I've not read of Blue Dot being tempermental. I believe its formula is near that of 2400

I've had some pretty spooky results from Blue Dot when the charge weights were on the low end. I've actually seen the FPS go up as the charge weight went down. Don't ever load Blue Dot below book published recipes. I don't even like loading it below mid range levels. It seems to do best when loaded slightly on the warm side in small capacity straight wall cases. That's warm, as in near max but not over max book published loads.

2400 is not the same as BD. I've had much better results in bottle neck cartridges with 2400.

[madsenshooter]

I have had no good or even decent results in any case or caliber using BD. Maybe it is just my lot, as a lot of folks harp on it. I finally swapped the last of the stuff i had to a shotgun shooter friend of mine for some more useful powder.
James and I discuss some of the issues that have been around for a long time using fast powders in bottleneck/rifle type calibers, on a regular basis. I use unique in a few, with good to decent results. Makes him cringe. I read of guys using BE in rifles, sorry I will pass, no matter how good they say it works.
jeff

Jeff, I just can't argue with the results, as I pictured on this post: http://castboolits.gunloads.com/showthread.php?t=63113 The bottom right pic is a 13 shot group, using two different primers, one load with a Rem 9 1/2M the other with Fed Large Pistol magnum primers. The one out the top I called as I felt my rest slip as the striker fell. BD whipped up on 4895 that day, but admittedly another grain or 2 of 4895 may have given the same results. Gotta remember, this is a 114 year old rifle too! Jim, I'll get that analysis one day, got the page bookmarked, I'll bet the chemical composition is similar but the flake size is different. I know it isn't exactly the same, but close. :Fire: