7.92x57 Experiment

[offshore44]

I really like these Yugo Mausers as well. I agree that they are very underrated by most folks. The M48 is a Mitchel's Mauser that my wife got me "off the rack" several years ago for Christmas. It, apparently, had been shot with the then available corrosive surplus ammo and not cleaned correctly. The damage to the bore was very minor and is cleaning up nicely as I shoot it more. The 24/47 was on the rack at different gun shop. Very ugly with all of the cosmoline and dirt, & etc still on it. The wife found that one as well. When I cleaned it up it was in near pristine condition with an almost perfect bore. Even the rare, early stock cartouches were in good condition. The 24/47 shoots gas checked 190grn cast great! The action does need to be polished out though, it is just a bit gritty when you cycle it. Both are stock with no modifications other than a little judicious polishing here and there.

Anyway... I completed the push through sizer yesterday, and the results are kinda ugly but really produce a nice looking boolit. The booits come out very uniform end for end and in diameter. The most challenging part was coming up with the plunger to push the boolit through the die. Lots of ugliness there on the way to success. Good thing cast boolits can be remelted! The end result look a whole lot like the Lyman 314299 mold that izzyjoe mentioned. The sizer makes a very uniform 0.3125" diameter boolit in one pass. I can push that into the bore of the M48 with my thumb and get very slight engraving from all four rifle lands. I would have to hammer it into the barrel of the 24/47, albeit it would hammer gently.

Now for the paper... How "hard" do you think the paper should be? I have two kinds that give me a final, un-sized diameter of 0.323" +/- a very slim hair. The velum does that because of the stretch when I wrap it on, and it is some very tough stuff. The cash register tape is much more fragile when damp with spit. I seem to end up with fuzz and minor lumps on about half of the patched boolits with that. It does dry on nicely though if you ignore the fuzz.

Patch size... I changed the dimensions of the patch some. The length is the same, because that is two full wraps without any overlap and a just discernible gap. The width covers the start of the ogive as much as paper shrinkage allows. Any longer and it would gap out. The base is 100% covered with a folded tail that looks like a shotgun shell crimp. I have a horrible time with twisting tails. I put both patches on with a lick spit dampening and let them shrink and dry. I will also tumble lube with Lee Alox and then run into the 0.314" lubrisizer die to make sure the bases are nice and flat and crimped.

Powder... So bpc477, to much of a good thing with 44 grains of Varget? I'm betting you are correct. I'll back it off per your guidance and see what develops. I was hoping that Varget would work, because I've got eight pounds of it and haven't used it for reloading anything yet.

Thanks, once again, for all of your help! I'll keep you posted...

[Moonie]

Where do I get one of these wives that finds guns for me...

[offshore44]

Where do I get one of these wives that finds guns for me...

I found mine at a Blue Grass Festival 30 years ago...she wasn't a shooter then. She sure is now though. I have no idea where you would find one, but they are out there.

You should see the guns she has found for herself...I think that is why she finds these for me.

[303Guy]

If I didn't have H4350 (AR2209) I would use Varget (AR2208). (I don't because they look identical).

You could try dry wrapping the cash register tape then dampening the tail after folding (or before). Give the dry patch a few twists with finger and thumb and it tightens up well and takes on the boolit shape.

[offshore44]

If I didn't have H4350 (AR2209) I would use Varget (AR2208). (I don't because they look identical).

You could try dry wrapping the cash register tape then dampening the tail after folding (or before). Give the dry patch a few twists with finger and thumb and it tightens up well and takes on the boolit shape.

Thanks 303guy, I'll give that a try! Don't you put a dab of stick glue on the tail when you dry wrap? I thought that I read that here someplace...

I don't have any H4350...but I do have a boat load o' Varget that needs to be burned productively!

[303Guy]

Not stick glue, just school paper glue with some water added. Maybe the stick glue would be easier to use .... Mmmm .... ?

[offshore44]

Not stick glue, just school paper glue with some water added. Maybe the stick glue would be easier to use .... Mmmm .... ?

The light bulb just went on! Trade name in the States is Elmer's Glue! Duh... I must have eaten a ton of that stuff when I was in grade school. (When I wasn't making boogers out of rubber cement.) Hmmm...I wonder if paste glue thinned out would work?

I did some experimenting with some stick glue and dry patching. I would start the wrap and get one full wrap plus a little, smear the trailing edge of the patch with a small bit of stick glue and finish the wrap. Worked with fingers and with a cigarette roller. The cigarette roller put the patch on nice and tight, and really stuck the edge down on the 405 grn 458's. I have been experimenting with just a small dab from the end of a flat tooth pick where the trailing edge crosses the boolit base lately. That seems to work pretty well so far. Doing the whole edge seems to get glue everywhere, even though it doesn't seem to effect shooting any.

[offshore44]

[snip]

"44.0 grains of Varget"........ that'd likely be the reason for the severe leading in your barrel, IMO. I think that load is simply too hot for your bullets. I know that you said that your bullets are of a very hard alloy, but contrary to the assertions of some, it is NOT always possible to get to J-word velocities with PP, in these rifles. With my M48, for instance, if I push much past 2300 fps.....I get leading and no accuracy....no matter what combination I've tried. Different powders, harder bullet alloy, etc., have made no difference. I don't know why, perhaps it has something to do with the relatively fast twist rate of these barrels (1 in 9.45")....vs. a more relaxed twist in a "modern" 30/06 or .308. That's only a guess. But, I have never been able to get to the kind of velocities some here claim for their PP rifles. I'd suggest dropping your charge weight a good deal. If you still have a full length barrel, as opposed to the shorty my rifle wears, then Varget should be a fine choice....but something more like 36 grains. Minimum safe charge weight for Varget, in the 7.92 x 57 case, is about 33 grains (65 % of full case volume)........ so 35 or 36 grains would not require filler. You could try a bit less, say 32 grains......but then add a tuft of cotton or dacron wool on top of the powder charge. This would make the load safe. My best PP load is 32.5 grains, albeit with Hodgdon Benchmark (which is almost identical to IMR 3031).....faster than Varget.....due to my shorty barrel. I use cotton or dacron wool, even though the powder charge is borderline safe....because I have gotten an accuracy improvement with it. But, fillers are a controversial area, which many wish to avoid. In any case, I bet a good deal lighter charge will give better results.

Next question. 36.0 grns of Varget is a full 4.5 grns under the closest Hodgdon published load data for Varget and my boolit weight in the 8mm Mauser. My boolits weigh right at 190 grns patched and ready to go into the case. I was using data for a 200 grn j-word bullet with a starting load of 40.5 grns and a max of 47.5 grns. I thought that 44 grns would be a pretty good starting point. Where did your Varget data come from? Just asking. 8mm Mauser data is pretty scarce it seems, and I try to be as safe as I can.

[303Guy]

I've used 30gr Varget (AR2208) under a 200gr boolit with cotton filler in the Brit. The case is considerably smaller though. I've also used 30gr H4350 (AR2209) under a 141gr boolit in the Brit. But I used wheat bran filler to make it burn. I wouldn't dare use such a low charge of that powder without a substantial filler for fear of SEE. 30gr is 65% load density.

[offshore44]

I've used 30gr Varget (AR2208) under a 200gr boolit with cotton filler in the Brit. The case is considerably smaller though. I've also used 30gr H4350 (AR2209) under a 141gr boolit in the Brit. But I used wheat bran filler to make it burn. I wouldn't dare use such a low charge of that powder without a substantial filler for fear of SEE. 30gr is 65% load density.

Yup, that is kinda what I was thinking... Click...boom...CR*P!!!

Fillers make me nervous as well. Never used them.

Well, there's always H4895 and 5744.

I may just load up these last bunch of PPCB's with H4895 and mess around with different powders later. I've been saving my 4895 for the PP in the 458 Win Mag though. Hmmm... A little faster powder in the big bore and use the 4895 in the 8.

[bcp477]

I did not use published data - such data has no bearing on this particular issue. I have data, in my reloading books, as to the volume of Varget per grain.....I simply calculated the minimum safe charge weight by taking 65% of a full case, by VOLUME. This calculation has nothing to do with charge tables. Obviously, one would never load a 100% charge of such a powder.....that would be WAY WAY over pressure. The danger of double ignition with rifle powders is due to excessive empty case VOLUME. The 65 % rule (some people use 70 %) is designed to ensure that one does not load such a small charge that this could occur. But, it has nothing to do with loading table data.

The minimum safe charge weight with Varget, for the 7.92 x 57 case, using the 65 % volume rule, is just under 33 grains (I rounded up to 33 grains in my previous post). So, just to be safe, I suggested 35 - 36 grains. This definitely WOULD be safe. I have done similar loads in the 7.92 x 57 for many years. With filler, as I alluded to in my previous post, you could go below 33 grains, with perfect safety - but ONLY with filler added. You will not find loads of 35 - 36 grains of Varget, let alone 33, on ANY loading table....because such tables are developed almost always using jacketed bullets....and with accuracy in the test rifle being the major consideration, as well as safety. This is a special circumstance.

As I stated before, my best PP load, for my M48, is 32.5 grains of the powder I use (Benchmark), which is only a little above the minimum safe charge weight. Nevertheless, I add filler just as a precaution....and because I have found an accuracy improvement with it, in this load. The filler bumps the pressure of the load a small amount, tricking the load to higher velocity than it would produce otherwise, but yet without the other effects of a commensurately larger powder charge. There is some evidence that the fibre filler also gives a bit of a "gas check" effect....and protects the bullet.

Anyway, fear not. The info I gave you IS SAFE. I would NEVER publish any such info unless I was ABSOLUTELY certain of it. As I have years of experience in working with the 7.92 x 57 cartridge and old rifles that shoot it - almost exclusively - I have REAMS of data to rely on.

[offshore44]

I did not use published data - such data has no bearing on this particular issue. I have data, in my reloading books, as to the volume of Varget per grain.....I simply calculated the minimum safe charge weight by taking 65% of a full case, by VOLUME. This calculation has nothing to do with charge tables. Obviously, one would never load a 100% charge of such a powder.....that would be WAY WAY over pressure. The danger of double ignition with rifle powders is due to excessive empty case VOLUME. The 65 % rule (some people use 70 %) is designed to ensure that one does not load such a small charge that this could occur. But, it has nothing to do with loading table data.

The minimum safe charge weight with Varget, for the 7.92 x 57 case, using the 65 % volume rule, is just under 33 grains (I rounded up to 33 grains in my previous post). So, just to be safe, I suggested 35 - 36 grains. This definitely WOULD be safe. I have done similar loads in the 7.92 x 57 for many years. With filler, as I alluded to in my previous post, you could go below 33 grains, with perfect safety - but ONLY with filler added. You will not find loads of 35 - 36 grains of Varget, let alone 33, on ANY loading table....because such tables are developed almost always using jacketed bullets....and with accuracy in the test rifle being the major consideration, as well as safety. This is a special circumstance.

As I stated before, my best PP load, for my M48, is 32.5 grains of the powder I use (Benchmark), which is only a little above the minimum safe charge weight. Nevertheless, I add filler just as a precaution....and because I have found an accuracy improvement with it, in this load. The filler bumps the pressure of the load a small amount, tricking the load to higher velocity than it would produce otherwise, but yet without the other effects of a commensurately larger powder charge. There is some evidence that the fibre filler also gives a bit of a "gas check" effect....and protects the bullet.

Anyway, fear not. The info I gave you IS SAFE. I would NEVER publish any such info unless I was ABSOLUTELY certain of it. As I have years of experience in working with the 7.92 x 57 cartridge and old rifles that shoot it - almost exclusively - I have REAMS of data to rely on.

Please don't mis-understand my statements...I was not trying to impugn your skill or experiences, though it may have sounded that way. I have only been reloading about a year or so, and have no "reality filter" to say one way or another if your statements are true. If I have offended you, I truly apologize and ask that you try to understand where I am coming from on this subject. It is a product of my caution and inexperience.

Anyway...where did the 65% (70%?) minimum load charge volume rule come from? That must be an empirical observation from years of reloading experience shared among the clan, I'm guessing. Does it work for all, most, or some powders?

I agree that published loading data is very sparse for the 8mm Mauser, even for j-word bullets. That is the bane of my existence, because I truly like shooting them. They just work for me, it seems.

I am too new at this to attempt filler at the moment, so I guess that I will take any hit on consistency / accuracy for the time being.

[303Guy]

Thanks for that insight bcp477. Much appreciated!

Have you folks seen Jeff's results with using wheat bran filler in his 310 Cadet? (He lost three cases and it was at my suggestion! Oops. )

[offshore44]

Thanks for that insight bcp477. Much appreciated!

Have you folks seen Jeff's results with using wheat bran filler in his 310 Cadet? (He lost three cases and it was at my suggestion! Oops. )

Ouch! That just doesn't look right...chunks o' brass missing is never good sign.

[bcp477]

Offshore,

No offense taken, not at all. You did nothing to give offense, anyway (you simply asked a pertinent question). If I sounded offended, then it is I who should apologize. I tend to sound very emphatic, because I have a thing for precision (I despise sloppy in-exactitude). I speak the same way - so others tend to think me always angry or something. I certainly don't intend it that way. One of my MANY faults (one of millions, to be sure), no doubt. Sorry for the confusion.


Those photos illustrate exactly why I NEVER use cereal fillers of any kind. This type of material weighs as much or more than the powder, so the weight of it MUST be figured in with the load specs....it increases pressures, though no one knows how much (just as true with all filler materials).....and it is absorbs moisture. The moisture absorption can and often does lead to caking.....which can lead to disaster in bottleneck rifle cases. The filler can be baked, to remove as much moisture as possible, but you still have the other issues to deal with.

These things are not the case with fibre fillers, such as cotton or dacron. Fibre fillers weigh almost nothing, so the exact amount used can be "eye-balled" (no need to weigh it), they are gas- porous, so they cannot form a plug and raise pressures to alarming levels.....and they do exactly what fillers are supposed to do - hold the powder column in place over the touch hole. They are also cheap.....FAR cheaper than shotgun (tiny plastic ball) type fillers. Caveats for use of them are few - the "rules" are very simple.


1) Fillers are only needed...and should ONLY be used.....with charges of relatively slow rifle powders (in rifle cases)..... of less than 65 - 70 % of full volume. They serve the purpose of simply holding the powder column in place, so that it cannot "string out" along the bottom of the case (when the cartridge is horizontal). That configuration of the powder column is what leads to double ignition ("S.E.E.", as it is properly called).


2) NEVER use filler - ANY filler - if the charge being used is more than 80 % or so of a full load, per published load tables. In such circumstances, fillers are not needed, anyway. Any filler will raise pressures, by an unknown amount....so it is tempting fate to use them in loads that don't need them.

3) NEVER use filler with extremely fast pistol or shotgun powders. Again, they are not needed.....and the pressure curve for such powders is steep enough that it would be EASY to get into trouble. Just don't try it.

4) When installing a tuft of fibre filler, use as little as reasonably necessary. NO need to overdo it. You are NOT trying to fill up all of the empty space in the cartridge case - only hold the powder against the touch hole.

5) Do NOT "tamp down" the fibre filler against the powder column. Just lightly push the material into the case, down against the powder. No need to try to create a tight plug - that is NEVER what we want here.

That's about it.


Now, Offshore, I certainly am not trying to talk you into the use of fillers. Let's be clear about that. I only offer it as one possibility (there I go again - I can't stand to leave anything out because of my darned penchant for precision). I rather agree that, at your experience level, it might be best to stay away from fillers now. But, you won't need filler with charge weights of 35 - 36 grains (of Varget) as discussed before.

Oh, as to the "65 - 70 % rule" - I have no idea from whence it came. It seems to be a rule of thumb developed through lots of experience. I'm sure that there are published materials which quote this principle, but I do not know what they are. I've heard it as long as I've been hand loading - and I've always stuck to it, out of simple prudence. It really applies only to slow to medium- slow rifle powders. Shotgun and pistol powders are too fast for need of this rule - but, then again, they are too fast to produce anything but low velocities in a rifle with large cases and a "normal" length barrel (you can't safely load enough of such powders to overcome this problem - without going WAY over-pressure). With a full length rifle barrel, a proper rifle powder is called for - one can't simply go to a much faster powder and expect suitable performance. I use a fairly fast rifle powder (Hodgdon Benchmark) with my shorty (18") M48 barrel - as it is appropriate for that configuration. With a 23" barrel, Benchmark or something similar, would tend to be too fast to offer good performance. A slower powder, such as Varget, is indicated.....hence the need for the safe minimum charge "rule".

[303Guy]

The filler that caused the destruction of those cases is actually very light and fibrous and very compressable. I wouldn't call it a cereal filler. It does seem to form a wad (which was the idea). The amount I use to fill 25% of case volume is 3gr.

Just mentioning it for the sake of information.

3) NEVER use filler with extremely fast pistol or shotgun powders.

Found that out for myself. Not so much a pressure problem but the filler does not always exit the bore. I found two cases with the filler still inside!

Wheat bran filler prevents the patch from blowing off the boolit base with 'normal' loads.

bcp477, I shall be heeding your advice.

Just a quick reality check, would H4350 (AR2209) be safe in the Brit at 75% load density?

[bcp477]

303Guy,

H4350 is pretty slow....slower than the Varget/ IMR4064/ Reloder15 range of powders. According to the data I have, this powder works out to about 0.07251 cc per grain. With the 303 Brit case having a useful max capacity of around 3.28 cc.....this works out to approx. 45.2 grains or so. 75 % of that would be about 33.9 grains. I have loading table info that shows H4350 in charge weights up to 48.0 grains (compressed) with a 150 grain bullet.......and up to as much as 43 grains with a 215 grain bullet.

33.9 grains (75 %) should certainly be safe, without filler.....with whatever bullet you choose.....but I would NOT go much below that (unless you want to add a little fibre filler). Empty case volume gets to be more and more of an issue, the slower the powder. So, with something like H4350, I should apply a "rule" of a bit more than 70 %, myself (which is exactly what you've done, with consideration of 75 %). But, I do think you will be fine with this.

Note: I have not used H4350, myself. I am ONLY speaking from calculations derived from published sources. "Your mileage may vary", as they say.

[303Guy]

Thank you. Much appreciated.
I am scared of the stuff! (But I'm more scared of getting H4350 confused with or mixed in with Varget so I choose to have only the one. I do think Varget is a great and versatile powder).

[303Guy]

OK so I tried loading without the filler and I found that I could load higher with what appears to be the same pressure. That is, 30gr with fibrous filler shows the same degree of primer flattening as does 38gr without the filler. I estimate an increase in velocity of 160fps. We'll see when I chrono it. (I'll be testing 35grs next which is an 80% load density in my PMP cases but I do like the idea of a little extra velocity).

[303Guy]

Here the pics. Those on the right are 30gr with filler and those on the left from top to bottom are 38gr with filler, 38gr without and 35gr without.

30gr was below the 70% limit and I wanted pressure without too much muzzle blast.