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View Full Version : Lessons learnt reworking 1950's yugoslavian 8mm Ma


Westcliffe01
07-04-2011, 04:04 AM
So this weekend I finally got my reloading bench complete and the press set up.

I got into a bind with Brownells since I ordered 1lb of smokeless powder together with the press "kit" and all the dies. That 1lb of powder held my entire order up for a week because of a BS hazmat issue that prevents Brownells from shipping more than 99lb of powder per day. So remember, if someone in front of you orders a bunch of powder - it could be weeks before you see yours... It was pretty frustrating and the sales staff refused to cancel the order for the powder and didn't offer to ship the other items either. I finally said I was going to call my credit card company to reverse the charges and that that point they started listening....

Anyway, I'm new to reloading so the learning curve has been steep. Lots of checking and rechecking to be sure I am safe... Thank god I went with the Hornady Lock n Load system. It took a while to get each of the dies dialed in, but now I am all set. Twist the die about 30 degrees to get it to release from the press (breech locking system, like an AR bolt). It comes out and your "zero" is preserved for the next time. I can see how one would have to set up a conventional threaded press every time you change a die. I got the following dies: 8x57 full length size and deprime, 8x57 neck resize and 8x57 bullet seater / crimp. In addition, I got the exact same set of 3 dies in 7.62x39, as well as a collet style bullet puller with an 8mm collet.

If you were counting that was 7 different tools. The press comes with 3 "lock n load" bushings and I bought 6 more, leaving 2 spare for the moment.

Anyone who had followed my previous thread on 1950's yugoslavian 8mm mauser ammo would have noted that this surplus stuff is very cheap (less than $200 for 900 rounds delivered) and it has brass casings and a "proper" lead core copper jacketed bullet (200gr FMJBT). My experience with shooting it has shown that accuracy is not very good (4-6moa out of a brand new Remington 700 "classic").

So the first objective with the reloading equipment is to see what is up with the Yugo ammo and whether the powder is metered accurately, bullet weight consistent etc. I thus set aside 50 rounds (matching the cartridge tray provided with the press) and extracted the bullets. Here I made my first mistake: Research on the web indicated that some sort of sealant was used between bullet and case on military ammo and conventional wisdom was to first seat the bullet deeper by 0.016-0.020, then extract it. Seating it deeper would "break the lock" of the sealant. Well, I did that for the first 15 bullets and the first thing I noticed is that the cartridge neck is slightly deformed by the force exerted since the bullet has a cannelure into which the neck is crimped. After the first 15, I tried extracting the remainder without reseating the bullet and it was no more difficult and caused no deformation to the cartridge neck.

My work flow was as follows (after a little initial trial and error):
Load the collet die
Insert a bullet in the press shell holder and raise it up until the neck touches the collet.
Tighten the collet on the bullet, then raise the press lever to pull the case off the bulllet. Set the bullet in the tray.
Release the colllet. This does not yet release the bullet. I place a bolt on top of the shell holder on the ram of the press and raise the ram so that the bolt pushes on the underside of the bullet. The upward movement releases the grip of the collet and this frees the bullet.
Lower the ram and catch the bullet before it falls on the ground. I placed the bullet point first into the cartridge from which it was removed.
Process the entire batch this way.

Then, I dumped the powder from each cartridge on the electronic scale to weight it. Then dumped it onto a small bucket. Then weighed the bullet. The goal was to determine how accurate the original powder was metered and how much variation there was in bullet weight. I would say that the powder charge variation was around +- 1.5gr. The bullets had a max deviation of +-2gr (for a 200 gr bullet). The powder itself was in flake form (neither spherical nor cylindrical). I have not been able to make a determination analytically whether those 2 variations would be responsible for the 4-6moa performance I had achieved with the test rifle. The same unit was down to 1moa using Privy Partisan modern ammo with a similar 196gr FMJBT bullet.

I then did a neck resize on the whole batch of primed shells, to prepare for a new powder charge. I damaged the first shell by leaving out the neck expander, but got it right thereafter. So I had to pull another bullet to get back up to 50. Then did the fiddly job of setting up the powder measure. This is one of those operations which would be a lot easier if one had a video to watch. By process of elimination, I figured it out. Raise the handle, lower the handle, get reliable metered charge... Lower the handle, raise the handle, not so good... And it doesn't like to stay up either (the handle that is). Loaded a charge in each of the cases.

Bullet seating and crimp was pretty easy. I'm shooting a bolt rifle, so I didn't try to put a heavy crimp on the bullet. OAL and straightness were fine.

So, I have to see if the range will be open tomorrow to go and try out the new powder. BTW, I settled on 41.5gr of Hodgsons H4895 for the 200gr bullet. That is about in the middle of the max and low charge levels indicated in the Hodgson datasheet. I don't know whether berdan primers behave like regular or magnum primers, so I certainly didn't want to be near max loads and the charge weight was also very close to the weight of the original powder from 1950.

Wish me luck at the range... Pictures to follow.

Westcliffe01
07-04-2011, 09:33 PM
So... Remember that the first 15 cases were distorted at the neck when I pressed the bullet in to "free" the neck crimp ? Well, almost every one of them would not chamber since it appears that the distortion enlarged the diameter just before the neck started. I suppose I should have checked this after pulling the bullet or after neck sizing, but I didn't.

As for the rest, the grouping was not better than 4moa. I also had 2 misfires, which both fired on the second strike. This has never happened before with this ammo. Was it a fluke ? Or connected to the new powder ? No idea.

Anyway, for the effort and expense involved it appears to offer no substantial advantage. So I will be buying more of the Privi boxer primed FMJBT ammo (it is cheaper than buying just brass) and I have the first 60 cases already deprimed and prepped for running in the tumbler to clean them. So I need to order up some hunting bullets and get set.

Whats that saying about a poker player knowing when to stop ????

Westcliffe01
07-04-2011, 09:40 PM
I also just ordered the last 36 boxes of S&B 7.62x39 soft point hunting ammo for just over $9/box - again basically for the price of the brass. I have to check function in my AR, but I think it will be OK, unless it bends the tip of the bullet... that could be a problem...

Wideners (http://www.wideners.com/itemdetail.cfm?item_id=8506&dir=18%7C830%7C852) has something similar except those have FMJ bullets.

The 70's and 80's yugo ammo shoots very well meanwhile in my 7.62x39 AR, I just don't know how well it will work on hogs and deer without expanding bullets.

Teg
07-05-2011, 04:24 PM
The soft point should be good, I've seen some folks use them for Coyote and they seem to work fairly decent.

grumble
07-05-2011, 05:31 PM
Let me make a couple comments about your two unexplained misfires.

Since I'm not there to look over your shoulder, I'm guessing about what happened.

The Beridan primer system squirts small jets of flame from the primer into the powder area. A Boxer primer squirts one, larger and longer, jet of flame towards the powder. So, for the same amount of flame generated by the primer, the Beridan primer should cause a more even ignition by starting the propellent in two to four places, depending on the number of jet holes in the brass. But, it also shortens the distance the flame travels.

Now, when you use the "stock" flake powder, it is more bulky and takes up most of the space inside the case. The H4895 you used is a more dense powder, and I'll bet the light load you used only filled about 2/3 of the case capacity. So, if for whatever reason, the powder inside the case is mostly on the bullet end of the cartridge, it is very possible that the flame jet didn't reach the powder with enough energy to ignite the powder. If for example, you tipped the muzzle down before firing a shot, or even if you slammed the bolt forward, the powder could be out of reach of the primer jet.

Pull those two bullets if you can and see if the powder is scorched but not ignited. That will tell the whole story.

Two solutions (if this is the problem): (1) Always tip the muzzle skyward before shooting. (2) Use an inert filler, like corn meal, over the powder column to take up space and hold the powder column in place against the primer holes. Another solution might be to increase the amount of powder to fill the case to at least 3/4 of its capacity.

I'm a big advocate of using an inert filler, especially if you should ever use cast bullets. If you try this, even with your reloaded milsurp bullets, I bet you'll see a major increase in accuracy.

Westcliffe01
07-05-2011, 09:06 PM
Grumble, the new powder was only slightly less dense than the original. In both cases the primers didn't fire at all first time and all I did was wait a few seconds, raise the bolt, lower it again (to recock the striker) and shoot again and it did fire. The only ones which weren't fired were those which wouldn't chamber. I went through all of them last night and pulled the bullets and dumped the powder back in the measure again.

I'm not too sure how to dispose of brass with live primers ? Since it is primarily the primers that are corrosive, I am loathe to fire them all in the chamber one after another...

I'll take some pics of my modest setup a bit later tonight...

grumble
07-05-2011, 09:33 PM
Oops. OK, it wasn't the primer jet, then! <GGG> Guess I should have read your earlier posts more closely. I've been down the same path you're traveling now, more for the fun of it than anything. I have almost two pounds of that square flake powder sitting out in my shed. Why? Beats me! Just didn't seem right to just burn it.

I'm in a different situation than you. When I want to dispose of primed brass like that, I just throw it in my burn barrel and listen to it pop, my grandkids think that is a fun project. It's next to impossible to destroy the primers without igniting them, neither oil nor water will make the primer material (fulminate, or whatever it is) inert. If you don't have a way to burn the primed brass, and if making the brass inert is important to you (so just burying it isn't a good option), the next best thing would be to full length resize it, put in a few grains of that commie powder with a scoop of corn meal on top, and go outside and shoot it in the air. It smells like cornbread when you do that. <G> If you want to wait for the next 4th of July, you can top off the blank rounds with wads of rolled newspaper in place of a bullet. Then you get a loud pop AND the smell of cornbread!

Ok, ok, so I'm not helping. But those are the kinds of things I do, since I rarely have any adult supervision.

Westcliffe01
07-05-2011, 10:25 PM
So here is what yesterdays targets looked like with the DPMS in AK47 caliber.

After my initial disappointment with this rifle, I am thinking that it really deserves a decent trigger and the free float handguard. I was trying a different trigger technique yesterday using just the tip of my finger, but the trigger weight is so high that my muscles were cramping before too long... I have heard that buried under some of the crap small parts, the DPMS rifles are generally very accurate. I have just had to dig real deep to expose it..

Guys, this is a 16" barrel, 4-5lb trigger and 1970's Yugoslavian FMJ ammo at 100yds.
http://keithandseija.com/Blog/wp-content/uploads/2011/07/target0002-7-04-2011.jpeg

http://keithandseija.com/Blog/wp-content/uploads/2011/07/target0001-7-4-2011.jpeg

Westcliffe01
07-06-2011, 01:22 AM
Hard to compose shot, since the aisle way is less than 3 ft wide, so sorry about the angles... I also cut off the powder measure on the left hand side. The lower framing is 2x4 and both the backplane (3/4 plywood) and the 2 sides (1/2" plywood) act as braces. So the bench is really solid. Everything is glued with gorilla glue (not furniture grade, I know...). Work surface is 2 layers of 3/4 ply screwed and glued.

I am looking for a shallow cabinet to screw to the left hand side to hold bulk goods (powder, primers, boxed bullets). I can still expand the die storage quite a bit as can be seen. Those blue organizers were I think $18 each.

2 3/8" bolts hold the press down with double washers top and bottom. I still have to run a bead of black silicone caulking around the inside edge of the work surface and screw a 2" aluminum flat bar as an the front edge of the bench to stop things from rolling off onto the floor. The sides need to be cut to a more pleasing profile and then re-stained and sealed. It is serving its purpose already...

http://keithandseija.com/Blog/wp-content/uploads/2011/07/Reloading-bench.jpg

Westcliffe01
07-06-2011, 08:28 PM
I should add that the work surface is the thickest linoleum I could find (about 1/8"). I wanted a surface which would be non marking to blued items like barrels and actions as well as being easy to clean. I had to buy a 12' long strip, but it was 98c/sqft so for about $30 I have enough material to refinish it 3 times over...