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8mmFMJ
10-10-2014, 6:39 AM
I pulled about 200 8mm mauser berdan 196 grain 1950s yugo. The original OAL was 3.255 which is extremely long when comparing to any projectile in the 8mm lineup (in my Lyman manual). Max OAL is 3.250 :eek:...They chamber, and I've shot thousands over the years before I got into reloading.

- Can I copy the OAL and set em there, or is it ok to chamber it too long to find out when it hits the lands, then back it off .030 or so and set em there? And can I do this for every rifle/projectile combo I own?


The powder is 1950s surplus nitrocellulose sheet (square flake). Average loads were 41gr per round.

-Should I reduce em to 40? Anyone have a load sheet for the square flake surplus powder so I can load up 150gr with it for plinkers. I want to save the 196 grain pulled projectiles.


Thank you!

sargenv
10-10-2014, 6:55 AM
If you're reducing the weight of the projectile, I'd stick with the same powder charge. You will notice a pretty good reduction in recoil and increased velocity with the 150's. I'd use the same charge since pressure with this powder will already be reduced due to less resistance. If possible, I'd put a generous crimp on the 150's as to increase resistance and ensure ignition.. since the 150's will have less resistance than the 196's.

I might even just replace the unknown propellant with a known one (canister grade) of the proper charge weight for that bullet. I suspect you can find a load for the cartridge with several medium burn rate rifle powders if you were to go to that trouble.

krwada
10-10-2014, 7:25 AM
For the 1st thing ... I think you will find that you will probably NOT be able to get the projectile to seat as the the thing hits the lands. The throat of any milsurp Mauser is going to be very generous at the least ... and will most likely be somewhat eroded in general. Personally, I would stick to the OAL that gives you the best function for your Mauser.

As to reloading for lighter weight projectiles... you will definitely be safe to use the identical charge weight of the existing powder. I do not think it is a good idea to experiment around with the mystery, (pulled) powder... but this is just an OPINION, (I do not wish to get flamed .... ala Calguns style)

I think the better bet is to just dump the powder, and use some readily available medium rifle powder and use the charge weights as recommended by your reloading manual for the 8x57 using the 150 grain projectile and the documented rifle powder.

Mot Mi
10-10-2014, 7:29 AM
That's a big difference in projectile weight. I'd suggest to bump it down by at least 15% 46 grain difference and if you were to use the same charge or even slightly less it may cause a kaboom. I think 36-38 should be fine with the surplus but like sargenv suggested, I'd go with a more known source of powder rather than relying on something made 60 years ago with maybe no known data.

if you were to test it, go with 20% reduced from 196 gr. Which puts you at 32.8. Seems 35-38 sounds about right for that surplus pulled powder and 150 gr projectiles.

sargenv
10-10-2014, 7:52 AM
If he is dropping from a 196 to a 150, there is no need to reduce powder.. If he were going up to 196 from a 150 then ABSOLUTELY there would be a need to decrease powder weight..

Canister/commercial powders for this cartridge are available... and that would be the safest way to go..

8mmFMJ
10-10-2014, 8:11 AM
One would surmise that when I do use the pulled projectiles, that the original load or 1 grain less would be perfectly fine to use. Correct? Don't want to toss what is equivalent to 40$ of powder just because it was old. The powder looks fantastic. It was the primers that kept me from using the ammo.


Thank you all for your fast responses

krwada
10-10-2014, 8:23 AM
One would surmise that when I do use the pulled projectiles, that the original load or 1 grain less would be perfectly fine to use. Correct? Don't want to toss what is equivalent to 40$ of powder just because it was old. The powder looks fantastic. It was the primers that kept me from using the ammo.


Thank you all for your fast responses

Going from 200 grain projectiles down to 150 grain projectiles... you probably can use the same charge weight. I would NOT reduce this. There is a very serious concern here with under-charging your rifle loads. You can get this very nasty effect ... (especially with slower burning powders) called delayed ignition. This generally occurs with using reduced loads with slower burning powders and lighter projectiles.

Using the charge weight that was meant for 200 grain instead for a much much lighter 150 grain projectile ... with a medium or slow burning powder ... puts you squarely in this loading regime.

This is why I said the very safest route would be to dump the original powder and use some known powder and loads as published from a modern loading manual.

I have never personally experienced delayed ignition. yet ... However; it IS discussed in some of the modern reloading manuals. I believe there is a small section that discusses undercharging and related symptoms in the Lyman #49 manual.

Going from 200 grain to 150 grain is effectively a 25% drop in projectile weight... That is a lot!

If you were going from 200 grain down to 180 grain ... then it is probably OK.

So ... why are you going down to 150 grain? It seems to make the most sense to me to just use a different primer and exactly the same projectile and the same powder with the same charge weight. After all ... you already have the projectile, powder and the cases no?

Mot Mi
10-10-2014, 8:29 AM
Oh sorry was early for me and read it wrong. I retract my statement. You're safe using the same charge. I was thinking the wrong way. If the bullet was over 196 than yeah you would have to reduce. Sorry about the confusion.

krawda, its probably safe to assume he has more 150 grs for plinking perhaps and 196 for the heavy duty long range if needed. Regardless, id try some surplus loads with 150gr and see how it fares before producing the rest of it.

OpenSightsOnly
10-10-2014, 11:20 AM
I pulled about 200 8mm mauser berdan 196 grain 1950s yugo. The original OAL was 3.255 which is extremely long when comparing to any projectile in the 8mm lineup (in my Lyman manual). Max OAL is 3.250 :eek:...They chamber, and I've shot thousands over the years before I got into reloading.

- Can I copy the OAL and set em there, or is it ok to chamber it too long to find out when it hits the lands, then back it off .030 or so and set em there? And can I do this for every rifle/projectile combo I own?


The powder is 1950s surplus nitrocellulose sheet (square flake). Average loads were 41gr per round.

-Should I reduce em to 40? Anyone have a load sheet for the square flake surplus powder so I can load up 150gr with it for plinkers. I want to save the 196 grain pulled projectiles.


Thank you!


I used my 8mm milsurp for this exercise.

I loaded Sierra 150 gr SPT, once fired PP cases, used the Sierra manual for IMR 4064 charge weight.

Well, it grouped ok. Then I loaded 200 gr SMK with the Sierra accuracy load, grouped tighter.

What I'm saying is that use the surplus bullet and powder (get the average for the lot) but use a different case and a modern non-corr primer - you'll be GTG.

The 98k loves the heavy 198gr or 200 SMK with the slow burning powder.

BTW - I pulled one of my 1938 Spitzers and compared the powder to the 1949 8mm Yugo, first year of 8mm Yugo production. Both powders are flake type and appear to be the same.

pacrat
10-11-2014, 1:02 AM
One would surmise that when I do use the pulled projectiles, that the original load or 1 grain less would be perfectly fine to use. Correct? Don't want to toss what is equivalent to 40$ of powder just because it was old. The powder looks fantastic. It was the primers that kept me from using the ammo.


Thank you all for your fast responses

Dropping bullet weight with same charge will be OK. NOT the opposite.

Danger with greatly reduced loads of slow powders in large cases is "flashover detonation". aka BIG KABOOM. Slow rifle powders are designed to burn progressively faster as pressure builds. With small charges of slow powders, there is air space over the charge laying in bottom of case. Rather than the primer igniting the rear of the powder column and progressively burning forward in an ever increasing pressure curve. The FLASH of the primer ignites the powder all at once as the primer flame passes over it full lenght in the case. NO pressure curve, just KaBoom. NOt Good. Rare but does happen.

COAL in a bolt gun is whatever the magazine will hold, unless you jam the lands first. With a surplus Mauser, not gonna happen.

If your primer problems are ignition failures. Yugo surplus ammo has notoriously hard to light primers. Sometimes 2 or 3 clicks for each boom unless conditions with the rifle are optimum. This is common with Yugo ammo. FP protrusion for Mausers is .055" to .065". I run mine at .060"

Suggest a thorough cleaning and lubing of bolt interior, lots of 100 yr old crud can hide in there and soften FP strike. If problem persists switch to a Wolfe 22# spring. Both of which are easier and cheaper than pulling down and reloading with new primers and bullets. and usually fixes the click not bang problems with Yugo ammo.

JM2c............enjoy your Mauser