Powder and reloading questions

Shovel said:
One is a Mauser 98 Israeli rebarreld to 308 Nato the other is the Marlin w Belgian FN mauser action. I've read about the extractor mod but haven't checked for it. Ill take a look and also try the taking the bolt out and loading the empty case on the bolt.

from what I understand the chamber size is the same for nato and 308 win. The brass wall thickness is different
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That is my understanding as well. I found various US Army documents that described doing Copper Crusher pressure testing, but then that document reported the results as "PSI", not "CUP". Then some SAAMI and CIP references show piezo test results in "PSI" - the two systems measure pressure at different places. No doubt added to some confusion about whether they were the same pressure or different, since documents exist that show either pressure as "PSI", and then some as "CUP". Is different units, taken from different places in chamber, so not likely easily converted from one unit system to the other - but the pressure generated by the round - that the rifle needs to contain - is likely the same, between 308 Win and 7.62 NATO. Gets even wonkier for some that read about a 7.62 CETME cartridge that the Spanish used after WWII - is exact same external size as a 7.62 NATO, but much lighter bullet and lower breech pressure - was developed to work in their CETME select fire guns that were not working out so well, initially - which were intended to ultimately use full power 7.62 NATO rounds, once they got various "issues" sorted out.

As you will find in many cartridges that get fired in full-auto weapons, is likely the case walls are thicker and the primer is "swaged" into the primer pocket, on 7.62 NATO cases - so it is less likely to back out when fired. That means that there is a bit more commotion to re-size and use mil-surp cases, even though you will use exactly the same re-sizing dies - 308 Win versus 7.62 NATO. Is typical that the same powder load and same bullet seating depth with generate higher breech pressure if you use 7.62 NATO military brass, versus thinner commercial 308 Win brass - but like many things - not always safe to say "always" about that. There may or may not have been slight differences in the way the free-bore and lands were placed - and most definitely got compounded for me with .223 Remington versus 5.56 NATO, which I think is a different discussion.
 
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Shovel said:
From what I've read the way to measure the coal is to...
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Maybe less precise, but much easier: Take a full-length resized case and cut a slit in the neck, just enough that the neck tension is reduced but will still hold a bullet. Slip your chosen projectile in, leaving COAL "long". Hand feed it into the chamber, and slowly close the bolt. This will push the bullet up against the lands, and then back into the case. Carefully open the action and remove the "cartridge". Measure this COAL with calipers.

That will tell you the COAL for that bullet in that barrel, with the bullet just touching the lands. Most would probably recommend setting COAL to .020"-.040" shorter than this, as a starting point.
 
alpining said:
Maybe less precise, but much easier: Take a full-length resized case and cut a slit in the neck, just enough that the neck tension is reduced but will still hold a bullet. Slip your chosen projectile in, leaving COAL "long". Hand feed it into the chamber, and slowly close the bolt. This will push the bullet up against the lands, and then back into the case. Carefully open the action and remove the "cartridge". Measure this COAL with calipers.

That will tell you the COAL for that bullet in that barrel, with the bullet just touching the lands. Most would probably recommend setting COAL to .020"-.040" shorter than this, as a starting point.
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There is a refinement to that method - pretty sure I read it in John Barsness reloading book - so do exactly what you say, but first colour up that bullet with a Jiffy Marker - bullet will stop when it hits the lands, but might "grab on" - so when you extract, that bullet might come out part way - look on the Jiffy Marker on the bullet - the case mouth will scrape it off on the way in - lets you reset to where that bullet was when the bolt closed and bullet was "hard on the lands". As with most things in reloading - do that three or four times to see what you get for variance in your technique or measuring.

I think his technique required a cartridge that had been fired in that chamber - so you could close the bolt. Since it had been fired, the bullet should slide into the case mouth, and should fit into the chamber mouth. He described to pinch or squish that case neck slightly - so that it would hold or scrape on that bullet as it was re-seated into the case. That way, do not care if it falls out or gets stuck to lands upon case extraction - once you get it out can see how far it went into that case. I have done that several times - I prefer the "dowel in back and cleaning rod (with blunt end fitting) down front", but that is just me.
 
Potashminer - That's a good refinement if you want COAL for neck sized brass only, right? For full length sized, you've got to use FL sized brass.

And yes, whatever method you use, repeat it several times to confirm COAL. It's easy enough to do, and if your numbers vary a lot then you know there's something weird happening.

I should note that unless you're measuring with a bullet comparator, bullet tip deformation can be an issue when measuring COAL. For a beginner, I'd just say make sure the bullet you take the COAL measurements with has an undamaged tip (or just not a significantly shorter bullet OAL than "normal". And generally stay away from bleeding-edge-max-pressure loads until you do get a comparator (and a bunch more experience!).

Or just use bullets that aren't really sensitive to this problem. Geez, so many little details... OP, read your manual first!
 
I do the two sticks ,too. I use dowels, a Stanley knife to mark , and calipers to measure . As the barrel dowel gets marked up, it get can get confusing. Coloured felt-tips help.
 
alpining said:
Potashminer - That's a good refinement if you want COAL for neck sized brass only, right? For full length sized, you've got to use FL sized brass.

And yes, whatever method you use, repeat it several times to confirm COAL. It's easy enough to do, and if your numbers vary a lot then you know there's something weird happening.

I should note that unless you're measuring with a bullet comparator, bullet tip deformation can be an issue when measuring COAL. For a beginner, I'd just say make sure the bullet you take the COAL measurements with has an undamaged tip (or just not a significantly shorter bullet OAL than "normal". And generally stay away from bleeding-edge-max-pressure loads until you do get a comparator (and a bunch more experience!).

Or just use bullets that aren't really sensitive to this problem. Geez, so many little details... OP, read your manual first!
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Neck sized?? Not sure - as I read it, Barsness used previously fired, unsized brass for his technique - idea was to establish a distance from closed bolt face to "hard on the lands". What you chose to do with that is up to you? When properly sized, either neck sized or FLS brass is going to be about .002" smaller inside case mouth than the bullet diameter (as per Richard Lee) - so way too tight fit to slip, when the bullet touches the lands.

As far as using a comparator - as you say - for most shooters / reloaders is pretty much keeping the marketers and sales folks happy - not really much for the average shooter. Is typical that a re-loader is going to use a seating stem that does NOT touch at the bullet ogive - so fussing to measure to that, and IF there is significant difference of bullets, one to the next in the box, the reloader ends up with COAL anyways, not the base to tangent length. Is not to worry about, I do not think, unless you are trying to get your 10 shot average from .020" to lower than that, at 100 yards - almost a whole different ball game, than making a round to go "bang".
 
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downwindtracker2 said:
I do the two sticks ,too. I use dowels, a Stanley knife to mark , and calipers to measure . As the barrel dowel gets marked up, it get can get confusing. Coloured felt-tips help.
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For the front - down the muzzle - I filled a Robertson screw head with solder - to make it solid - then chucked it in my lathe to make it dead right angles to the 8-32 thread - and trimmed to make it .295" diameter or so for checking the 30-06. Is others for .264" bullets, for example. That is what gets turned into the cleaning rod that I slide down from the muzzle end. When I find contact, I have some 1/2" or 3/4" wide masking tape - rip a piece about 3" or 4" - hold it horizontal and touching muzzle on each side of the rod and fold it around. I do the bolt face first, then same with the bullet tip. Measure with calipers from leading edge of the two tapes. Then, I can rip them off and repeat. I found I have become way too shaky to accurately draw a line and then measure from line to line. The tape thing seems to work - if I can repeat three times or more and get similar number on caliper, each time, then I think I am close to correct.
 
I just knife the dowels. You can eye ball about as accurate as the calipers.

I also have Stoney Point set up. Mine's made by Hornady. You can buy them at Higginsons. But rather than buy all the specialized cases, I bought the odd ball tap from KBC . You have to open the necks up a 1/2 thou over the bullet diameter. No problem I have a metal lathe and can make the expanders, except I haven't programed the VFD I installed. VFD is variable frequency drive, you can control speed by the frequency input to a 3 phase motor. . VFDs are common in industry and are used in automation. That where the problem comes in, it's an industrial VFD., and I'm an old phart.
 
Good stuff!! Waiting for the caliper and the bullet sizer. Sizer might take a few days. Got the press Thank You bertn. Butter smooth. Lee manual mention they used a CH press in their factory. Going to shelf the shotgun conversion for now and look for a manual. Thanks for the notes! Can't say enough about this site and the members

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FWIW - Your Marlin with Micro-groove rifling likely has an oversize bore diameter - more than the standard oversize typically found on these guns. This will result in a reduction in the depth of the already shallow rifling. Increasing the diameter of the bullet may compensate, and allow the bullet to grip whatever rifling there is. However, the bullet will always take the path of least resistance when entering the rifling - if the path is to deform over the rifling, theres trouble.
Cast allows you to increase the diameter, but introduces another very important variable - hardness. Personally, I wouldnt bother with cast before trying another option. I would take a 303 bullet (0.311 in dia) or a 7.63 x 39 bullet (0.310 in dia hopefully) and see if it fits into the neck of a fired case, If it does, I would load it and fire it. That would offer the best chance for the bullet to grip. If this fails, casting is very likely a dead end.
 
A soft lead slug that is pushed through from your chamber to the muzzle (or other way - but all the way through) will give you the smallest diameter within your bore - chances good that is what the bullet will conform to - the SMALLEST diameter. The positive groove marks on your slug will measure to be the SMALLEST groove diameter within your bore. If you have an inch or two where the grooves are filled with fouling, or perhaps a manufacture oddity - then the rest of the rifling won't do much for that bullet passing through. Is likely that you will feel that as you push that slug through - the tight spots and the loose spots. You might get "eye-opener" by doing that, or about nothing unexpected.

And .001" diameter will make a difference, so want to be fairly fussy with your caliper when you measure that slug - I actually use a Mitutoyo micrometer to do that, not a caliper. Most calipers are accurate plus/minus .001"; most decent micrometers are accurate plus/minus .0001". If you are trying to measure to the .001", that is within the error / accuracy range of most calipers - will say so on the tool or on the box that it came in.

I had read that Marlin Micro-Groove rifling was often made with unusually large groove diameters, but I presumed that the bore diameter was the same - maybe I got that wrong. It is my understanding that the "bore" diameter is the diameter of the hole that got drilled through, before the rifling was cut or swaged - so the grooves are always larger diameter than the "bore" diameter was. And is typical that you want a jacketed bullet size quite close to the groove diameter, not to the "bore" diameter. Is common to want a cast bullet to be .001" or .002" larger diameter than groove size - the lands will swage it down to the snug size that the barrel wants - if you could chamber that round in the first place.

From that article that I linked in Post #140 - near the bottom, that writer wrote "...Microgroove barrels tend to have oversized groove diameters, and as a result, Microgroove barrels early on earned a reputation for not shooting cast bullets well. ..." He has more to say about that, both before and after that passage, how to deal with that.
 
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A machinist will tell you calipers are +/- .005 . Even then they use Mitutoyo electronic calipers bought from a reliable dealer, NOT AMAZON . Chinese fakes abound. I got a deal on mine at $150 . Mostly when reloading I use a $20 Chinese dial calipers I bought 30 years ago . You are only measuring case length and cartridge overall length. A thou here or there is a so what.
 
Shovel said:
Its this caliper. Pretty good reviews https://www.amazon.ca/dp/B00B5XJW7I?psc=1&ref=ppx_yo2ov_dt_b_product_details Still waiting for it. I see there are different mold sizes. . Next step is to push a lead slug or bullet thru. Been suggested a few times in this thread. Wood dowel is probably best?
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You will likely want to read the pamphlet that comes with that one - the specs on that ad say it has .001" accuracy - you will want to find out what they mean by that - exactly - most others that I have seen say words like "within .001" - so if the dial read .645 the "real" dimension could be .644, or .645 or .646 or anywhere in between - all those would be "within" .001" of the dial reading, which is what those other makers say their unit is capable of measuring - assuming no user error at all - squareness, etc. As I have probably posted a couple times - is good idea to take a measurement - record it - close your caliper jaws and see it read "zero" and then re-measure that same thing - repeat three times or so - see if you get three times to zero and then three times same measurement. Sort of a test of your technique and the tool's precision / repeatability.
 
That looks confusing, chuckle. Having both, allows you to chose which system to work in . Sometimes you'll find three places after the the decimal point , when in metric it's a simple 12mm. I like it much better than the electronic ones . I used my Chinese one at work for over 20 years and here at home for 9 years, The Chinese can make decent stuff.

A dial caliper works on a exposed rack and pinon. The rack can collect dust, dirt or chips. Compared to the screw of a micrometer, it's pretty coarse. The head slides on gibs, they can be loose. The measuring area on the outside jaws is a distance away from the head. For all those reasons a machinist will say caliper are only accurate to plus or minus 5 thou.

You need it.
 
Got the caliper looks good. I'll keep it clean. Going to get a wood dowel in the next little while. Guess I got bit. Since I have the presses and only need the dies for 357mg/38sp got them coming. Question can I use small pistol primers or do they have to be magnum?
 
For centre fire rifle loads - you can work up loads with either standard or magnum primers - can not necessarily interchange one primer for other with same powder loading - or pressure can get too high - I presume it is the same with straight wall hand gun cartridges. If you have that Richard Lee book - "Modern Reloading" second edition - page 551 shows they report small pistol primers used in 357 Mag, and page 561 shows that used small pistol primers in 38 Special. I had read in a few places on Internet that the Lee organization does NOT do pressure testing of the loads that they publish - is always copied from some other pressure tested source - but is typical to want to know what primer was used when a load is reported - want to know more than just bullet weight and powder weight. However, a book by John Barsness is on the way where apparently he contradicts that - I have not read it yet - to be seen what he wrote.

By the way - you will likely need more than just the die set - is likely you will also need a shell holder for your press, and you might need shell holders for whatever case length trim system that you use, or pilots for it. As we found out the hard way, a guy showed up here that I was going to help load up some 22 Hornet - I do not own that size, and found out really not much can be done for reloading without a correct size shell holder, although we had bullets, primers, powder, brass and a die set for it.
 
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Thanks! Its the Lee set and comes with the holder. Nice bonus I've noticed. It's for a single action. Should be easier to figure out coal and case length. Time to open up the book. See if the shot and pistol powder I have will be good
 
Shovel - I might have it wrong, but consider what you read in reloading manuals to be "reports" what they got with their stuff at the time - may or may not be what you get using your stuff - I have "worked up" several loads that go past the "book's" Maximum load without any pressure signs that I can see, and at least once I was several increments lower than the book max and I was getting significant (to me) pressure signs. So what you find in a reloading manual maybe should not be considered as "guaranteed" - more like a report of what they got - and they were not using your tools, your components, your rifle when they did their test - but you will be when you do your test - and the extent of your "test" might be the first shot that you fire of your new loading. As was written in a hand loading article by John Barsness, about nobody gets 3000 fps with 165 grain bullets in 30-06 using RL-22 powder, but Nosler reports having done so, in several of their manuals - is not likely that you will get there at 30-06 sane pressure levels, but you might.

Responsible modern reloading data tends to be worked up using pressure testing machines, which most hand loaders do not own or have access to - was much published that was based on various "home grown" type of signs of pressure - I follow many myself - but is still a "make do" kind of thing compared to truly pressure tested testing. I have no doubt that most modern factory ammo is known to be safe pressure for any rifle chambered to that cartridge - SAAMI and CIP publish maximum pressure levels - is no law that factories have to be at MAX - but they will know exactly where their product is, and will be at or less than SAAMI or CIP standards - something most of us can not precisely know about our hand loads.

What you might run into in older data is the difference in names of stuff - I think I have Speer 3 that refers to using 4831 powder - so, today, is that IMR 4831, or H 4831, or AA 4831 powder - are they the same or different to each other - then and now?

At my desk is Modern Reloading, Nosler 9, Speer 14, Hornady 9, Sierra V, Lyman 50th, Woodleigh, Hodgdon's Annual 2013, Western Powder 5.0. Is also boxes of older versions of manuals here - mostly because they still have data for less common rounds that have been dropped from later editions. Some seem to think is enough to find "one" recommendation on a website - but I have written about errors that we found from that - do NOT rely on only one source of information - for no other reason than it is too easy for typo's to occur, or some clerk-typist cut and pasted to/from the wrong place, and so on. It is actually a bit of surprise to find identical results in more than a couple of those books, and for sure, I think, Lee's is not original work - is somebody else's results.
 
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