7.62x38r MilSurplus Replicated Gas Seal Load with Cast Boolit

[dmmccarter]

I have been working on a gas seal load that would replicate the velocity of a Military Surplus Nagant 7.62x38r round for a couple of months and thought I'd share what I found.

Boolit: Lyman 311008 FN 115GR
Case: PPU 7.62mm Nagant
Powder: Trailboss 5.1gr C
Primer: CCI 550
Dies: Lee M1 Carbine (with custom seating), Lee Universal Decapping, Lee Universal Expander (with custom flare die), custom crimp die.

Data: (taken from 10ft from the muzzel)
Test Round: 113 GR Cast Boolit Gas Seal
Hi Vel: 974
Low Vel: 834
Ave Vel: 907
Ext Spread: 140
Std Dev: 36
+1SD: 944
-1SD: 870


Basline: 108 GR Military Surplus Gas Seal Round
Hi Vel: 937
Low Vel: 846
Ave Vel: 900
Ext Spread: 91
Std Dev: 30
+1SD: 931
-1SD: 870


Chart:
http://i44.tinypic.com/30bea75.png

Let me know if you have any questions, if this is useful for you and if you have any feedback.

[texassako]

I have not tried TB yet, might need to try it out. I have been using a similar PB boolit (I was given a batch) with Graf's FFFg with good results using a .32 ACP die set to basically neck size the brass. I also used the Ranchdog .32 ACP design but it was to light and did not shoot to POA. A modified bolt made a good seating stem to get it flush with the mouth. How full is the case with 5.1gr ?

[dmmccarter]

At 5.1gr of TB it is slightly compressed, and I know that compressing TB is usually avoided, but this load replicates the MilSurplus rounds so well and it is very consistent with CCI 550 primers. (CCI500 primers provide a -3% difference with the same load and boolit).

Saying that, I have also worked up some ~1025 ft/sec rounds with the same boolit and 3 other powders. Two of the loads should that should work well with my suppressor.

I've tried FFFg (Goex) and didn't have good results. The velocity was around 650 to 750. I'll work on it again some other time as I was focusing on 1st, a MilSurp replication round and 2nd a faster subsonic round for use with a suppressor.

[dmmccarter]

Here are photos of the loaded rounds and the boolit...

http://i43.tinypic.com/2rxgw84.jpg

[littlejack]

dmmccarter:
Welcome to the CastBoolits.
Those are some good lookin rounds you loaded there.
I fired my first rounds in one of the Nagant revolvers a couple weeks ago. I was at the gun club, and another fella let me shoot his. At 12.5 yards, I shot the revolver standing w/a two handed hold, single action. The revolver put 7 rounds in a group you could cover with a 50 cent piece. I turned to the fella and said "I am going to get me one of these".
The ammo was military, and looked to be jacketed bullets. Berdan primed. Now for the question.
What dies are you using to reload your cases with?
I picked up all of the Berdan primed brass, but really don't want to get into the berdan primers, and the lengthy depriming process.
Jack

[dmmccarter]

...
What dies are you using to reload your cases with?
...

Thank you for the welcome Jack. I've learned a great deal lurking these pages and am happy to share what I've picked up.



...
Dies: Lee M1 Carbine (with custom seating), Lee Universal Decapping, *Lee Universal Expander (with custom flare die), custom crimp die.*
...


I'll take some photos of the modifications of the Lee M1 Carbine dies and of my custom crimp die later today.

[dmmccarter]

http://i42.tinypic.com/2rpu0ev.jpg

Here are the dies in order of operation...
decapper, expander, <prepared case>, M1 seating die, custom crimper, M1 sizing die.


http://i44.tinypic.com/686lud.jpg

With my lathe I made a custom flare die for the Lee universal expander. The flare of the mouth needs to be very slight as to not over work the brass and avoid annealing.
(I'm gonna make another flare die as soon as I fix a problem with the lathe.)

http://i43.tinypic.com/4grhig.jpg

Not my best work, but this is when I started to detect something going on with the lathe :D

http://i44.tinypic.com/33endxj.jpg

Here is a prepped case.

http://i42.tinypic.com/2zqu4ra.jpg

I modified a bolt to use for the M1 seating die.

http://i39.tinypic.com/2cep2dl.jpg

http://i39.tinypic.com/3508l1g.jpg

This is the custom crimp die. Like the flare, it needs to be slight as to not over work the brass. I tried many tricks but making this die was the only way I could avoid annealing the brass and keep case splitting down to a minimum and extend case life.

http://i39.tinypic.com/awurur.jpg

Not much modification here however I turned the decapping pin upside down to keep the boolit in place should there be any pressure from the final sizing operation.

http://i42.tinypic.com/dpde9s.jpg

Here are three finished rounds and a cast boolit...

[littlejack]

Thank you for your photos. Very well done. Nice pics. I am still looking for one of the revolvers, but there seems to have been quite a run on them. Suppliers are sold out.
Your information will come in handy for my reloading of the beast.
Jack

[Bored1]

Nice work. Thought about fixing your lathe and offering a few of those sets for sale? I know I would be interested in a set!

No lathe here, and no knowledge to use one if I did get one.

[dmmccarter]

Nice work. Thought about fixing your lathe and offering a few of those sets for sale? I know I would be interested in a set!

...

Thank you.

Yes, I hope to have it running again next week and will be making some sets.

Basically, to make the system I have work, one should have LEE Universal Decapper, LEE Universal Expander, and a LEE M1 Carbine Die set.

I am making the custom parts for the Expander, M1 Bullet Seater, and Crimp Die and figure about $55 should cover it.

[leadman]

I also have one of these revolvers. Mine has a slightly larger bore on the end of the barrel than the chambers in the cylinder so gas seal cartridges take a pretty good push on the rod to get them out of the cylinder after firing.

I found that by cutting off the brass flush with the end of the cylinder and loading the Lee 93gr RN bullet with 2 lube grooves I lose almost no velocity as the boolit is long enough to seal the gap when fired. Much easier to load also.

I am using Unique and it works well with good accuracy and no leading. I also found my barrel is .3135" so I size the boolits to .314" and cast them soft at 8bhn.

[longusmc]

That's fantastic! I believe this is the best example I have seen yet for reloading this round. I would also be interested in a set of dies!

[390ish]

I always thought it would be fun to rebarrel a lever gun for this round. Refuse to answer any questions about it at the range. Would drive bubba crazy. Make a good squirrel round.

[Artful]

390ish that's just evil [smilie=1:

dmmccarter nice work, what kind of groups are you getting with military vs your cast boolit loads?

[leadman]

I made a tool that fits in the Lee Universal Flaring tool to put a crimp similar to the Russian surplus cartridge when I was experimenting with the gas seal version. Now I just barely crimp over the end of the boolit to ensure it stays in place.

[dmmccarter]

...
dmmccarter nice work, what kind of groups are you getting with military vs your cast boolit loads?

I'll post pics of the groups when I get a chance to get back to the range and shoot for accuracy. The groups were pretty tight even though I was using manual holdovers to get the rounds in the bulls eye.

Lately I've been working on 1050 fps Unique loads and am looking at a way to adjust the front sight for elevation. My pistol shoots high with either load, which is ok for me because I expect with the suppressor I'm ordering I'll need a taller sight.

[Ray1946]

I was just wondering; what was the diameter of the cast bullets you were using? I have been taking some measurements of the groove diameter of my gun. As near as I can figure, the groove diameter is a whopping .3135-.314. The end of the chambers in my gun measure .334-.335. If you allow .002 for expansion, that means the thickness of the brass can't be more .009 if you plan to shoot a .314 boolit.

I haven't tried to measure the rear of the barrel where the case is pushed in to, but if it is smaller than .335, something is going to have to give....

I went out the other day with some of the original ammo that came with the gun. This appears to be a wad-cutter lead bullet seated about .370 below the top of the case. I chonoed 5 rnds. and got 483-572 fps. Pretty anemic by anyones standards................

[dmmccarter]

Hi Ray, sorry, I have been off on other projects... 1964 Sailboat restoration, 1978 GS1000 Wes Cooley Race machine build and sale, deer hunting and now back to reloading. My fiancee' knew what she was getting into with me...

Anyway, I've been using Lyman 311008 mold and sized though a lee die at .314. I'm looking into how to get the boolit down to a consistent .313 or .312.