Reduced loads of slow powders and SEE with cast!

[andym79]

Hi guys, whats the likelihood of experiencing a SEE when using a reduced load of a slow powder and a cast bullet!

It seems from what I have read CB will not get stuck and result in a pressure spike! I am however still uneasy about loading up with a slow power in reduced loads!

Also can a reduced load of H4831 really produce the same velocity in a CB with 12 grains less than it takes to get a jacketed one there?

There really insn't much published data at all for slow powders and CBs!

[GhostHawk]

First off I'd be carefull if you use IMR 4350. I have a couple pounds of it, I think mostly because it is not popular. Full case loads or use another powder is what i've been hearing. I did have some luck using the 4350 with a 40 gr charge with just a tiny piece of poly filler to fill the empty space. Not shoved, tamped, or wadded at all. Just a little piece fluffed up and inserted then seat the bullet above it.

I've had very good luck using IMR 4895 in Mosin 7.62x54r, and 7.62x39 reducing down to 20 grains with no issues, drastically reduced recoil, slightly lowered point of impact at 50. But good punch, fair accuracy, and much more pleasant to shoot.

I'm using mostly a .312185 2r gas check design by lee and I've been very happy with it. I also have the .312155 and it is ok, but my guns seem to like the 185's better.

The IMR 4895 is so much easier to work with, so much more flexible that I've just run with it.

[andym79]

I should outline what I mean by reduced load. The max load for H4350 and H4831 are 44 and 47 respectively! I am looking at loads of 30-33 and 35-38 respectively in the 6.5X55.

[GrizzLeeBear]

SEE events are unpredictable by nature and difficult to repeatably reproduce. They do not necessarily come from a bullet getting stuck in the barrel, which is more correctly a "squib". The one thing that all the research I have read on the subject agrees on is that low case fill with slow powders (like 80% fill or less) produces very unpredictable burning characteristics. In one case a reduced load of slow powder will produce very poor burning and you get a "squib" leaving the bullet stuck in the barrel and becoming an obstruction for the next shot. Another theory is that you can get a "flashover" where the primer flame jumps across the powder (since it is laying in the bottom half of the horizontal case) and the powder burns from both ends simultaneously making it act like a very fast powder. Say, like loading a 30-06 with a half a case of Bullseye, KaBoom!

In any case, trying to use reduced loads with slow powder is EXTREMELY RISKY! You need to fill the case or work with fillers to keep the powder against the primer and take up air space. Otherwise you are much better off sticking with the medium-fast powders that are proven for the caliber you are loading.

Also, 4350 is notorious for producing SEE events with reduced charges.

[tomme boy]

In a jacketed load. The main rifle you have to worry about is a Swedish 6.5mm. Cast, not so much. Wait for Larry on this. I know he has done a bunch of pressure trace loads.

[Ben]

andym79

Quote :

" I am however still uneasy about loading up with a slow power in reduced loads! "


---------------------------

I'm more than " uneasy ", I'm simply not going to do it !
There are too many other safe powders like IMR - 4895 that tolerate reduction in charges. Hodgdon even offers reloading data for reduced charges for IMR-4895.

http://www.imrpowder.com/PDF/Youth%20Loads.pdf

[btroj]

Yeah, I'm listening to Ben.
Ask yourself this- do YOU know more than the experts at the powder company?

I'm not putting my firearms, or myself, in danger because I "just gotta know".

[leadman]

Just so everyone knows, the Hodgdon reduction to 60% of a max listed load in Hodgdon's data is ONLY for H4895, not IMR. I spoke with the ballistics tech at Hodgdon after Dave Scovill seemed to want to ignore this fact in a couple recent issues of Handloader.

I reduce my loads due to a bum neck so do not use slow powders as the extra powder adds to the ejecta and hence recoil.
I have used WC872 in the 6.5X55 with 140gr jacketed bullets and had very good accuracy with only slightly reduced velocities.
The older Accurate manual has loads for their 870 for several cartridges. I use it in my 7mm Rem magnum as does my son. Hardly reduced though at 80 grs.
There are many threads on this and I think one is going right now.

[Yodogsandman]

I tried a load of 34.0gr of Reloader 19 with .5gr Dacron this weekend in my 6.5x55, M38, 22" custom. This was using a 160gr Lyman 266645 boolit "dressed", all lubed up with gas check on. It was too fast! Just too fast for my alloy. One foot or so group at 50 yards. I did have one lucky group that was 6 inches for 5 shots. I had no signs of any excess pressure. I dropped the load down to 31.0gr Realoder 19 with .5gr dacron added and will try them out again the next trip.

Some time ago I cut the dacron sheet into 1/2" squares and they weigh .5gr or so. I pull one out of a coffee can and pull the fibers apart, folding them back into/onto itself until I have a nice fluff ball. I then push it into the case mouth (in this case) with a wooden match stick ( with head removed) so that its just in the case to the powder but, not compressed at all and still fluffy. The fluff filled the case from the top of the powder charge to the base of the boolit. It's time consuming but , not hard at all.

You should be careful with anything you load. You should certainly read the sticky on using fillers. I use dacron fluff as a safety measure to prevent SEE when using reduced loads of slower burning powders. Using a little fluff of dacron filler to keep the powder charge positioned to the rear of the case is just another tool for us to use. It's not that much different than raising the barrel to position the powder rearward and slowly lowering the barrel to shoot. Just a better way of doing it. I've done it for about 20 years, mostly in my FR8, 308 win. (7.62x51) when using surplus powders. Notably, one powder that was close to Accurate Arms 2230. Using dacron tightened my groups and kept the cases from being covered with soot with each shot. I've shot many thousands of boolits with it. Enough to use up a few 8 lb jugs of powder.

[rhead]

The situation is too easy to avoid to take the chance. go to a faster powder if you need a slower velocity.

[andym79]

The situation is too easy to avoid to take the chance. go to a faster powder if you need a slower velocity.

The thing is I do not need or want a slower velocity, I am chasing high velocity in the Swedish Mauser M96 6.5x55! I want an accurate load to a minumum of 2100fps if possible. The load data for cast bullets is limited.

For a 140 grain jacketed projectile the data suggests 39.5-44 grains of H4350 and 42.5-47 grains of H4831.

In order to achieve similar performance with cast bullets Quickload suggests 32-37 and 36-39 grains of each powder respectively. I have seen reference to loads used of both powders lower than those Quickload ranges.

[44man]

The Swede is a big problem with the long leade. Too much room for boolit movement and most times the primer pressure will push out a boolit before ignition, powder then can burn towards the case head.
My friend and I used the same load of 4831, If I remember it was 46 gr with the Hornady 129 gr. Super accurate but we both had SEE events. Neither rifle was damaged but we needed a mallet to open the bolts. Never found the primers. At least the gun is strong.
I worked loads with Varget and 36 gr with a 140 gr bullet gave me a group of .436" at 100. With the 129 I use 37.5 gr. Make sure enough bullet/boolit is in the neck.
I would never download 4831, our SEE events were with good loads. Filler will not save you.
Cast can exit the case from primer pressure easier then jacketed, too much running room to rifling. If a boolit even stutters, pressure will skyrocket.

[andym79]

So small for bore projectiles and H4831 are a big no no!

Can a cast bullet really get stuck in the forcing cone long enough, I guess anything is possible!

[Outpost75]

One of the best references on this subject, from Finland: http://guns.connect.fi/gow/arcane1.html

[44man]

So small for bore projectiles and H4831 are a big no no!

Can a cast bullet really get stuck in the forcing cone long enough, I guess anything is possible!
You need resistance to bullet/boolit movement is all. Against rifling or case tension.
Guys use "M" expanders in revolvers don't know that the gap is saving their guns. easy to pop a boolit into the cone and rifling with a primer before ignition. Some primers have 2000# of force. They talk of air space with H110/296 but then blow out a boolit to increase air space.
I had boolits stick in bores of the .454 without any powder burn by using starting loads of 296. SR primer is just wrong for the case. Lot of pressure with not enough fire for the airspace. The case is large and needs a LP mag primer but the .44 is too small for them. Accuracy goes to pot from different boolit movement from a too high pressure primer. Imagine the powder actually going off with the boolit up the bore. Gas exits the gap to save you and the gun.
Not so in a rifle, move the boolit out and get ignition can be a disaster. It is not bore size and 4831 is safe in small bores with the right load.
The swede is like a revolver without the gap release. A boolit out of brass, in the rifling is just like reducing the charge, air space. Powder is pushed with the boolit and then ignites, pressure is reversed.
The boolit plugs the bore.
If guys knew how many revolver loads are SEE events, saved by the gap, they would think twice.
How do you think I get accuracy? I reduce boolit movement at ignition. NOT with crimp, stupid idea.

[Larry Gibson]

1stof all lets get one thing clear; SEE is caused by a bore obstruction, most often the bullet itself becomes the bore obstruction because it gets stuck in a fouled or eroded throat (or both) and the burning powder builds the psi to a very higher degree before the bullet moves. This most often occurs with jacketed bullets either light for caliber or with long bearing surfaces and reduced loads of slow burning powders. An SEE can also be caused if the bullet is heavy enough that the powder used generates excessive psi before the bullet moves very far. This is most often prevalent with heavier cast bullets for caliber and using some of the slower fast burning powders and the faster medium burning powders.

So how do we know this? The cause of an SEE is now well documented and has been reproduced in labs with pressure measuring equipment and in the field with, if lucky, nothing more than a bolt that needs to be hammered open…..if not lucky then with a destroyed rifle/handgun and hopefully limited injuries. With my ownpressure measuring equipment (Oehler M43) I also have reproduced such events, but knowing what they are and the indicated symptoms, stopped short of the actual event. I have however had to pound open a couple bolts during my learning curve of what the indicators meant. The SEE caused by the know bore obstruction is well known and documented.

The theory of “detonation” of small amounts of fast burning powder in a large volume case is also misunderstood and proven inaccurate. Besides such small amounts of powder nothaving the physical potential to cause the catastrophic event even if they did “detonate”having been proven such has never been reproduced in any test. Detonation of reduced loads of slow burning powders also has not been proven in any test. Both remain unproven theories and have been repeated so often over the last 50 or so years they have become “fact”. Until proven in reproducible testing they remain non facts or myths.

An SEE event should not be confused with an overloaded cartridge or with a defective cartridge case or out of battery firing. While the end results may indeed be the same the actual cause is different. Understanding the root cause of all these catastrophic events helps us prevent them. Ignorance of the actual cause of such an event can lead us down another just as hazardous path to another different such catastrophic event.

In my testing, including pressure testing, of slow burning powders in the 6.5Swede (documented in the thread) powders such as 4350, H4831SC, RL22 and AA3100 were used at less than 50% load density with a filler. There was absolutely no indication of pressures piking and no indicators of an impending SEE were noted. Those powders ignited and burned progressively just as they should have.Understand that when a filler is used correctly, dacron or buffer type, the dace capacity is reduced by the filler. Hence, with a given load with and w/o a filler, the load with the filler will give a higher psi.

AsI have suggested to andym79; when going to a slower powder (such as he is doing going to Varget after 4895) use the max accuracy load of the faster powder as your start load of the slower burning powder. If a filler was used (dacron or buffer) continue to use that filler until load density is over 80 – 85%.

LarryGibson

[44man]

Larry, Varget is faster then 4831. In the area of 4064. Easier to ignite too. 4895 would be a good choice too.
Varget can be used in small cases like the 7BR and 7R, 7 Waters, etc, even though Hodgdon says it is too slow.
You are correct in that an SEE event is a bore obstruction "stuck bullet". A filler will not prevent it if conditions are right. Filler keeps powder closer to primer flame, true but a moved and stuck boolit is still a bore obstruction.

[44man]

What guys do not understand is we shot thousands and thousands of shots with our loads before we got the SEE events. So I can't tell you the book loads listed as the most accurate are safe any longer. It was not the load, it was what the bullet did before ignition. I know very well what happened, we did not seat deep enough. In the Swede, seat to the cannelure. Get brass around the bullet. Lubed, cast can move easier. Retain the bullet first. Just like my revolvers.
just how far can an "M" expander be tossed?

[Larry Gibson]

44man

Understand quite well what burning rate Varget is. The choice was andym79s next move, not mine. If you read the threads I suggested the slower powders; 4350, RL19, H4831SC and RL22 as his next move. He chose to go with Varget.

What guys do not understand is we shot thousands and thousands of shots with our loads before we got the SEE events.

Also understand that quite well which is why I said; the bullet itself becomes the bore obstruction because it gets stuck in a fouled or eroded throat (or both) and the burning powder builds the psi to a very higher degree before the bullet moves."

Your use of "thousands and thousands of shots" obviously led to the "eroded" throat and that combined with fouling induced the SEE. In other words all your shooting ended up creating the conditions necessary for the SEE to occur.

Larry Gibson

[Hamish]

Your use of "thousands and thousands of shots" obviously led to the "eroded" throat and that combined with fouling induced the SEE.
Larry Gibson[/FONT]

Im having trouble figuring out how you "obviously" know that his throat was eroded. I would think that you would have to physically examine and measure it.

[andym79]

So if a SEE is possible when using cast. The best way to avoid it is good neck tension and a firm crimp?

Further still to make this unlikely event, even more unlikely a 160 grainer in the Swede touching the rifle from the start?


How do you think I get accuracy? I reduce boolit movement at ignition. NOT with crimp, stupid idea.

Can you elaborate on this point, especially crimp being a stupid idea!


Retain the bullet first. Just like my revolvers.
just how far can an "M" expander be tossed?

Are you implying that M dies should not be used, as without them neck tension will be higher?

[andym79]

One of the best references on this subject, from Finland: http://guns.connect.fi/gow/arcane1.html

Good article but its about subsonic loads, thats what I use Trailboss for. I am looking for an accurate high velocity load. The idea behind asking about slower powders was to give the bullet a more gentle push upto speed!

[Yodogsandman]

I had the same idea for the Reloader 19 loads, a more gentle push rather than a shove out the gate.. I just miscalculated the startig load a bit. The load was too fast but, not dangerous sitting behind the butt plate. I hope to bring my chrony next trip and we'll see whats going on. I do like velocity but I'm not looking for that, yet. I'm just looking for an accurate load. I'm also using up some boolits I cast back in 1998!

[enfield]

I assume SEE stands for something that all you posters *** u me the rest of us know.

[Larry Gibson]

Im having trouble figuring out how you "obviously" know that his throat was eroded. I would think that you would have to physically examine and measure it.

Because "thousands and thousands of shots" with "the same load of 4831, If I remember it was 46 gr with the Hornady 129 gr" will cause erosion of the throat. A study of throat erosion, it's causes and how it happens in rifles will show you that. Having studied throat erosion gives me the knowledge that there had to have been throat erosion in 44man's 6.5 barrel when the event occurred. Also having shot out numerous rifle barrels myself, including two 6.5s (one of them with a lot of rounds of 4831 behind a 129 gr Hornady bullet) gives me the practical experience to "obviously" know there was throat erosion.

Thus a supposition of "obvious" can be made based on 44man's description of what led occurred with the rifle prior to the event. That is unless you want to take 44man at less than his word that he shot "thousands and thousands of shots" of that load before the SEE?

Larry Gibson

[Larry Gibson]

So if a SEE is possible when using cast. The best way to avoid it is good neck tension and a firm crimp?

Further still to make this unlikely event, even more unlikely a 160 grainer in the Swede touching the rifle from the start?

No, the best way to avoid an SEE is to use a proper powder with the bullet used. You are fine with Varget and with the slower burning powders mentioned by me, especially if you use a Dacron or buffer filler when load density is less than 80 - 85 %.

Can you elaborate on this point, especially crimp being a stupid idea!

A crimp is not needed with your rifle loads if loaded as mentioned.

Are you implying that M dies should not be used, as without them neck tension will be higher?

I've no idea what 44man is "implying" but with cast bullets the M-die is essential. You should have .003+ neck tension using a standard Lyman 6.5 M-die with .266+ sized cast bullets. That is quite sufficient. Not using the M-die with cast bullets will simply result in damaged bullets and loss of accuracy.

Larry Gibson

[Larry Gibson]

I assume SEE stands for something that all you posters *** u me the rest of us know.

SEE stands for Secondary Explosive Effect.

Larry Gibson

[303Guy]

I wasn't going to say anything but since it already been said, I have used H4350 at quite low load densities but under a heavy boolit. I did use a filler (Dacron mostly) and I found it to work as well as Varget (which works quite well at low load densities). I don't remember how low I went but it was enough to burn cleanly. I'm not sure I want to push my luck though but basically I was looking for a low pressure load that still reasonably filled the case and would not over pressure with a full case. But that is not in a Swede so my mileage will be different anyway.

[andym79]

I wasn't going to say anything but since it already been said, I have used H4350 at quite low load densities but under a heavy boolit. I did use a filler (Dacron mostly) and I found it to work as well as Varget (which works quite well at low load densities). I don't remember how low I went but it was enough to burn cleanly. I'm not sure I want to push my luck though but basically I was looking for a low pressure load that still reasonably filled the case and would not over pressure with a full case. But that is not in a Swede so my mileage will be different anyway.

What weight bullet? Was it in a 6.5mm CARCANO?

[andym79]

On a slightly off topic Lees manual lists a lot of reduced loads for the 30-06 whilst not similar in its over bore characteristic of the 6.5x55 is serves to demonstrate that loading down even of slow powder can be done, depending on the projectile weight to bore ratio!

For example Lee lists reduced loads of Varget down to as low as 26 grains in the small for bore 130GN projectile. (For jacketed its 49+)

H4350 is first listed for the medium to bore projectile of 165GN and goes as low as 29 grains. (For jacketed its 51.8+)

H4831 is first mentioned at the medium-heavy for bore 180GN projectile, but it does go down as low as 29 grains and list a low 15000psi. (For jacketed its 51.8+)

The super slow H1000 is first mentioned at a heavy for bore 200GN projectile and goes down as low as 39 grains. (For jacketed its not listed)

On that principle then in the 6.5x55, Varget is suitable for all but the smallest projectiles. H4350 should be suitable from 129 grains upward, H4831 for 140 grains upward and H1000 only for the biggest projectiles 160GN +.

Lee suggests
"The slowest burning powder should not be reduced more than
20%. Each preceding powder may be reduced 1% more.
Example: 20%, 21%, 22%, 23%, 24%, etc."

If I apply this principle to the 6.5x55, and only to Hodgdon (ADI) powders due to availability.

For a 139-144GN projectile.
H870 - 20% (53x.8=42.4)
H1000 - 21%(50x.79=39.5)
H4831 - 22% (47x.78=36.7)
H4350 - 23% (44x.77=33.9)
Varget - 26% (36x.74=26.6)
H4895 - 27% (35.8x.73=26)

These figures of course would relate to a hypothetical load without a filler and in theory with a filler to reduce case capacity could probably be a bit lower.

[44man]

Throats are not eroded worth doing anything. The problem is the deep chambering made for very long bullets. There is no resistance at the bullet.
The Swede might get the most SEE events then any other rifle.
Guns to watch powder charges with are the Weatherby mags and any with a lot of free bore. Long free bores reduce chamber pressures. But important to retain a bullet until powder burn keeps pushing.
Eroded throats only increase free bore, they do not "catch bullets". Usually reduces accuracy but our Swedes can take .410 shells off the 100 yard rail all day.111594This was full military garb, made a higher front sight and kept filing and adjusting until centered. Last 3 shots at 100 with open sights is in .432". I shot the can twice at 100 off hand. I don't see how you can say I have eroded throats.

[1Shirt]

When it comes to the issue of reduced slow powder charges and SEE, the old saying: "If you don't play with fire you won't get burned" applies!
1Shirt!

[BruceB]

My ex-wife's Browning bolt-action 7 Mag was completely destroyed by this phenomenon, giving her some pretty serious injuries in the bargain.

It DOES exist, it DOES happen, and it's a very good idea to be aware of the potential..... and to do everything possible to avoid creating the conditions that MIGHT lead to the event.

[44man]

So if a SEE is possible when using cast. The best way to avoid it is good neck tension and a firm crimp?

Further still to make this unlikely event, even more unlikely a 160 grainer in the Swede touching the rifle from the start?



Can you elaborate on this point, especially crimp being a stupid idea!



Are you implying that M dies should not be used, as without them neck tension will be higher?

Crimp is just an aid to case tension, in and of itself a loose bullet can pull it. Over crimping can reduce case tension, it does almost nothing to aid powder burn.
"M" dies do reduce tension, use came about for soft lead. probably works best with BP.

[44man]

My ex-wife's Browning bolt-action 7 Mag was completely destroyed by this phenomenon, giving her some pretty serious injuries in the bargain.

It DOES exist, it DOES happen, and it's a very good idea to be aware of the potential..... and to do everything possible to avoid creating the conditions that MIGHT lead to the event.
This is the answer, you might get away with it for a long time and tell everyone reducing is no problem. I am not going to be the one to recommend it.
Seat bullets where they need to be without trying to get close to rifling with a free bore. That was our mistake.

[Larry Gibson]

Andym79

You might keep in mind that all of Lee's data is copied from else where. Lee does not develop or test the loads listed. As to the 1% reduction it is a decent theory. But if you are using a Dacron or buffer filler you are reducing case capacity. Thus the theory does not apply.

Larry Gibson

[Larry Gibson]

If 44man did indeed shoot "thousands upon thousands" of that load in his 6.5 Swede then the throat will be eroded whether he thinks so or not. That makes it rough and with fouling added it can really lock a bullet there. Any rifle of any cartridge fired with "thousands and thousands" of such loads with have throat erosion. That is a proven fact. Do a search and read the Handloader article I've posted numerous times. It is also about the 6.5 Swede and SEE.

Yes the longer throat is also a contributor. That is why the SEE phenomenon first came to notice many years ago. Back then the big contributor was the 25-06. Numerous SEEs occurred with that cartridge. The thing most often in common was a light weight bullet with a reduced load of surplus 4831. The light weight bullet didn't reach to leade and created some freebore so the bullet could be pushed out. Most of the rifles and been used quite a bit with hot loads using 4831 and also had eroded throats. The SEEs most often occurred after several shots had been fired. The reduced load allowed the bullet to jump to the fouled and eroded throat and stick before the reduced powder charge began burning efficiently. When the powder di burn the bullet could not get moving fast enough and pressures reached catastrophic proportions and the SEE event occurred.

Eroded (as in rough if you ever looked at one closely) throats that are fouled by incomplete burning of powders (that frequently happens with reduced loads of slower burning powders) do indeed "catch" bullets. This can be further exasperated with really reduced loads by the glass and/or granular particles from the primer residue if it is not blown out. All this is a fact, proven over and over again.

Larry Gibson

[tomme boy]

Most people don't realize the throats are pitted and cracked and eroded because they have never looked at them through a bore scope.

[303Guy]

What weight bullet? Was it in a 6.5mm CARCANO?

No, I wish! It was in a 303 Brit. A very short barrelled one too (15 ½ inches). I used 208gr down to 194gr boolits. The lighter boolits were to control overall length with the boolit base flush with the base of the neck. The boolits engaged the rifling leade on chambering but not too tight that the loaded cartridge would leave a boolit behind if unloaded or the boolit get pushed back into the case. Also, these were paper patched boolits which were held quite firmly in the neck under friction. So, a very different ball game and I would suggest cannot be applied to the Swede with plain cast.

[44man]

The Swede is a pretty low intensity round and not over bore. Not subject to what a mag case or calibers like the .220 or Cheetah do to the leade and rifling.
303 has a handle on it and many do not know how important resistance to boolit movement is.
Eroded free bore gets LARGER and reduces keeping the boolit straight to the rifling reducing accuracy.
Larry can not explain my accuracy if my leade is ruined. Since my load of 4831 burned so clean brass did not get dirty, grasping at straws to prove something like fouling does not hold water.
Since high intensity cartridges eat out steel making the start of rifling larger, how can that stop a bullet?
Most Swedes have been through the wars with corrosive primers yet still out shoot most modern rifles.

[Larry Gibson]

So what's your heartburn 44man? Many rifles will shoot quite accurately with eroded throats. Although at a certain point benchresters and match rifle shooters will rebarrel because accuracy does degrade. BTW; "eroded throat" just means the throat is getting eroded. It does not mean the throat is eroded away or "ruined". You made the claim of having an SEE with your 6.5 swede after "thousands upon thousands" of the load you mentioned. There will be throat erosion if that is true......are you now saying your claim is not true? What does the accuracy of the rifle have to do with a bullet getting stuck (or the reasons why) in the throat.....absolutely none.

Now you make claims about my loading abilities (the primer thread) w/o seeing any of my loads or knowing how I load. Thus don't come back here and say I can't make a judgment on what occurred with your own claimed SEE given the claimed facts as you stated them. You can't have it both ways. The throat on your rifle had some erosion (if what you claim as to the number of shots with that load was in fact put through it) and it may have contributed to the bullet getting stuck. That's all I said. I did not say at all your "leade was ruined", just eroded is all. Your wild speculation and assumptions as to what I said are incorrect.

BTW; I've got to ask why you were using the m-die with that jacketed 6.5 load anyway? “In the Swede, seat to the cannelure. Get brass around the bullet. Lubed, cast can move easier. Retain the bullet first. Just like my revolvers.
just how far can an "M" expander be tossed?” Are you saying there you were using the M-die? And now you say not to use the m-die, even with cast bullets? Sure appears that way.

Larry Gibson

You might Google 6.5 Swede throat erosion. You will find lots of examples and explanations of the topic.

[Deep Six]

This was an interesting read. I actually just built a Czech ’98 into a 6.5x55 sporter. Barrel was a short chambered ER Shaw 1:8 that I finished at home by hand. I recently started doing load development and settled on IMR 4831. I am using the Berger 140 VLD over 45.5 gr and seated at 3.100” with a medium crimp from a Lee FCD and using a WLR primer. This load is shooting about 0.400” at 100 yards for 5 shots so it’s definitely a keeper. But after reading all this, I’m now a bit concerned. Do I have anything to worry about? Are there any precautions I should take?

[44man]

This was an interesting read. I actually just built a Czech ’98 into a 6.5x55 sporter. Barrel was a short chambered ER Shaw 1:8 that I finished at home by hand. I recently started doing load development and settled on IMR 4831. I am using the Berger 140 VLD over 45.5 gr and seated at 3.100” with a medium crimp from a Lee FCD and using a WLR primer. This load is shooting about 0.400” at 100 yards for 5 shots so it’s definitely a keeper. But after reading all this, I’m now a bit concerned. Do I have anything to worry about? Are there any precautions I should take?
NO, with less free bore so you are close to rifling. Or seat deep enough for case tension.

[44man]

So what's your heartburn 44man? Many rifles will shoot quite accurately with eroded throats. Although at a certain point benchresters and match rifle shooters will rebarrel because accuracy does degrade. BTW; "eroded throat" just means the throat is getting eroded. It does not mean the throat is eroded away or "ruined". You made the claim of having an SEE with your 6.5 swede after "thousands upon thousands" of the load you mentioned. There will be throat erosion if that is true......are you now saying your claim is not true? What does the accuracy of the rifle have to do with a bullet getting stuck (or the reasons why) in the throat.....absolutely none.

Now you make claims about my loading abilities (the primer thread) w/o seeing any of my loads or knowing how I load. Thus don't come back here and say I can't make a judgment on what occurred with your own claimed SEE given the claimed facts as you stated them. You can't have it both ways. The throat on your rifle had some erosion (if what you claim as to the number of shots with that load was in fact put through it) and it may have contributed to the bullet getting stuck. That's all I said. I did not say at all your "leade was ruined", just eroded is all. Your wild speculation and assumptions as to what I said are incorrect.

BTW; I've got to ask why you were using the m-die with that jacketed 6.5 load anyway? “In the Swede, seat to the cannelure. Get brass around the bullet. Lubed, cast can move easier. Retain the bullet first. Just like my revolvers.
just how far can an "M" expander be tossed?” Are you saying there you were using the M-die? And now you say not to use the m-die, even with cast bullets? Sure appears that way.

Larry Gibson
You have a hard head, I have no erosion to speak of. You also say I was using the "M" die, just where did you get that after I said it is bad. Never a thought so those that use it need strong arms. *** in any gun!
You are 100% incorrect in almost every post. I know about the "M" die without ever going near it.
I know about BR and even a jointed aluminum rod run down a bore is cause to change the barrel.
Your understanding of eroded bores is so sad. I do not need to try stuff like the "M" die to understand.
But you buck facts. you show no proof at all, just blather. I am correct with primers.
You get other things wrong too, More then one shooter for all the shots, more then one gun.
since the 6.5 is good for several hundred years where do you say "TOO MUCH?" What makes you an authority?

[andym79]

How well do H4350 and H4831 burn under low pressure?

Apparently Varget doesn't burn efficiently in lower pressure conditions!

[Larry Gibson]

Andym79

Both burn well with medium heavy and heavy for caliber cast bullets with load density over 80%. If less than 80% load density use a filler.

Larry Gibson

44man

What ever you think.

[44man]

Sorry about it Larry but you can't change what I say to fit. I admitted the SEE was my fault by not seating deep enough, was not the charge I used.
Since I use a fairly light bullet, going to faster Varget and learning from a mistake lets me shoot the old gun with confidence now.
I feel I offered a good assessment of what can cause SEE.
It has nothing to do with how many times a gun is shot, If you get any erosion and chase the rifling by seating out farther you might get brown shorts.
I mentioned the amount of shooting from both of our rifles to show you can only get away with stuff for so long and I do not like to hear someone say "I do it all the time!"
I will not be the one to suggest reducing slow powders. You have to stop telling others that I said such and such. It gives me the feeling you do not read well or understand.
Too many have picked out one sentence and started an agenda without taking the whole thing in context.
I do not pick your posts apart to add to them.
What caused my SEE and also my friends? Darn right, WE DID so I have the right to tell others what to stay away from. Some will thank me yet there is always someone ready to bash.
How about a truce?

[grouch]

Anodym79: I don't want into the heated discussion. Maybe you could try CBE's 266132 mold, which should get you contact with rifling and 1 - 2 lubrication grooves still covered by the case neck. That should solve most of the problem. If high velocity is your goal, maybe a conversation with Veral Smith at LBT would be a good start, as that's a focus of his.
In either case, I think you'd be likely twice struck by lightning before you'd experience SEE - as long as there's not some other undetected goof!
Grouch

[Larry Gibson]

There is entirely too much "concern" over a potential SEE with cast bullets in rifle cartridges using slow burning powders. It is a very, very remote possibility and you'd really have to be out in left field with the components. The cast bullets and slow burning powders under discussion are entirely safe to use with "reduced" loads, especially if a Dacron or buffer filler is used. Stop worrying about it and load some up and see (pun) how they shoot. You might be surprised at how well.

Larry Gibson

[M-Tecs]

Fire checking and erosion starts when you pull the trigger the first time but it really doesn't matter until accuracy degrades to an unacceptable level.

With the long range guns (600 to 1,000 yard) they tend to group OK but you start to see unexplained elevation issues. With a 308 match rifle this is normally 3,000 to 4,000 rounds but some will go 6,000 or 7,000 before they will not hold X-ring. With a 6.5 x 284 you are lucky if you get 1,200 to 1,400 rounds.

Some pictures of what shooting does to bores. Never thought about erosion and SEE.

https://www.youtube.com/watch?v=pwEZgOruBpk

http://www.6mmbr.com/hawkeyeborescope.html (http://www.6mmbr.com/hawkeyeborescope.html)

http://www.rifleshootermag.com/2010/09/23/gunsmithing_bore_061405/ (http://www.rifleshootermag.com/2010/09/23/gunsmithing_bore_061405/)

http://www.gradientlens.com/Applications/PrecisionShooting.aspx (http://www.gradientlens.com/Applications/PrecisionShooting.aspx)

http://forum.gon.com/showthread.php?t=449357 (http://forum.gon.com/showthread.php?t=449357)

http://www.6mmbr.citymaker.com/f/Lil...eScope_VID.wmv (http://www.6mmbr.citymaker.com/f/Lil...eScope_VID.wmv)

http://www.exteriorballistics.com/reference/rifleinout.cfm (http://www.exteriorballistics.com/reference/rifleinout.cfm)

http://www.fulton-armory.com/%5Cfaqs%5CM14-FAQs%5CTEGauge.htm (http://www.fulton-armory.com/%5Cfaqs%5CM14-FAQs%5CTEGauge.htm)

http://www.riflebarrels.com/articles/barrel_life3.pdf (http://www.riflebarrels.com/articles/barrel_life3.pdf)

http://benchrest.com/showthread.php?65581-Rimfire-Bore-Erosion (http://benchrest.com/showthread.php?65581-Rimfire-Bore-Erosion)

[Larry Gibson]

M-Tecs

Thanks for the references. The rest of the world understands but after "thousands and thousands" of rounds and after which "I have no erosion to speak of" I guess it's me that "does not read well or understand", eh? But it does not matter, 44man and his buddy had SEE's and they learned something. BTW his 47 gr of 4831 under a 140 gr Sierra or better yet, the Hornady 140 SP is an excellent load. I find 49 gr even better but that's with jacketed bullets. Varget and RL 19 are my powders of choice for use with jacketed 120 - 129 gr 6.5 bullets in the Swede.

For cast bullets of 129 - 145 gr it's awfully hard to beat AA4350, RL19 or H4831SC with a Dacron or buffer filler.

Larry Gibson

[M-Tecs]

One more that I find very informative.

http://www.shootersforum.com/rifles-rifle-cartridges/68744-bore-life-centerfire-rifles.html

[shooter93]

Merrill Martin once ran a test on throat erosion and fire checking. Actually he did many and Merrill is a very hard man to dispute as he does/did very extensive testing under controlled circumstances and very good equipment. The particular test I'm referring to had to do with indexing cases. In very few rounds he could see and measure erosion greater on one side as opposed to the indexed side or vice versa....each round was indexed the same every time. A lot of this was attributed to powder grains striking the bore. That particular type of erosion was virtually stopped when shoulder angle was increased to a point where the turbulence point was inside the neck. That may very well be the biggest advantage to an Ackley improved chamber. It has made a visible change in my 220 Swift Ackley. I chose that caliber just to sort of substantiate Merrill's tests but I was certain he was correct. Erosion starts with the first round ever fired. At some point accuracy becomes unacceptable to the owner of that firearm.

[Michael J. Spangler]

Shooter93
Do you have any links to those tests? That's a pretty cool subject. I would love to read about.
Does p.o. Ackley have any info about throat erosion with his improved cartridges?

[shooter93]

Ackley didn't do much with erosion. Martin was published a lot in Precision Shooting which is no longer in business. I may have kept that article but finding it may be a problem...lol. I don't know if a Google search would bring anything or not. There were several articles on turbulence point in the magazine which again I should have. It's a good idea I think for fast moving rounds you intend to shoot a lot. I'll see what I can find.

[andym79]

I am not saying a SEE can/cannot or will/will not occur with these powders and cast, but humour me for a minute. Suppose that it can and does, how do/would you reduce the risk?

I can think of this as a list:

1. Use large bullets for bore (140-160 grains)
2. Load the bullet, if long enough so that it starts in the rifling (a long or wide one)
3. Ensure that there is as much neck tension as possible.
4. Add a firm crimp.
5. DO NOT USE magnum primers.
6. Fillers should be useful, if not keep ammunition with projectile up until firing, and perhaps lift the muzzle skyward immediately before firing.
7. Check that the throat is in good condition (I am not sure how to do this without a bore scope).

Any opinions, or additions to this list?

At the moment I am thinking along the lines that I am close to where I want to be with H4895 and Varget.

So there is no point in me starting with loads of H4350 that will get me 1900-2000fps! If they have already been previously achieved using a faster powder.

Again Quickload is not a replacement for field experimentation or proven loads, but it indicates that starting a load below 34 grains of H4350 would be pointless if I am trying to better my H4895 and Varget results.

Has anyone used less than 34 grains of H4350 and got 2200fps without a shotgun buffer type filler?

[303Guy]

In my experiments I have basically done what you are proposing. My neck tension came purely from paper friction and I used either a powder positioner (Dacron) or a filler (compressed wheat germ, compressed wheat bran or corn grits). My lowest loading with H4350 was around 60% or more.