PDA

View Full Version : A "Duplex" Load Guaranteed to Win Any Bullseye Match!



Andy_P
01-26-2007, 12:48 PM
I scored 32 out of a possible 20 with just a two shot group. See below:

212690

It was a "Duplex" Load, but not what you might have thought. I make up 43 Mauser to shoot in my Mauser 71/84's out of Starline 45/90. I have a pet load with 500gr bullets, and one day I got to thinking that since that long neck gripped the full length of the 500gr bullet, why would it not grip two 250gr bullets lined up end-to-end? Fact is it does:

212689

Just a bit of fun. The two bullets take very different trajectories, ending up 2-4 inches apart at 50 yds. I imagine this is explained by the upset caused as the two bullets start to separate as they leave the bore, plus the effect of the front bullet's shock-wave, "contrails", shielding effect, etc. One of the two bullets actually hit where aimed on both shots, so it appears that at least one bullet goes where aimed, and I have to think it was the front bullet.

I could only do this because of the long (0.800") neck of the 43 Mauser. You might be able to pull this off in the 45/70 and 458 Win Mag as well, but only if the rear bullet is firmly gripped, and that depends on the taper in the case. I chose a powder that had the rear bullet sitting on top of the powder column, which further prevented it from falling into the cartidge, and the same would be advised for other cartridges.

454PB
01-26-2007, 02:47 PM
Without being too critical, your 250 gr. boolits need some work. It looks like your mould or alloy was WAY too cold.

357maximum
01-26-2007, 04:46 PM
Without being too critical, your 250 gr. boolits need some work. It looks like your mould or alloy was WAY too cold.

That was the first thing I thought.....the second was that brass looks like it might be headed towards inseppient head seperation right quick.....cool idea though...I have shot twin 429 balls out of the triple 4 , but never did much formal paper punching though...

9.3X62AL
01-26-2007, 06:13 PM
An evil thought crossed my mind a few weeks ago......I got a Lyman #358101 mold at NCBS a couple years ago, and these can be loaded in the fashion shown above (stacked) to roughly equal the mass of a 38 Special wadcutter. I was going to give 10-12 rounds to Buckshot the other day to "try out my new wadcutter mold design" while he was running his K-38, but thought better of it. After he figured out how 10 bullet strikes occurred when 5 shots were fired, he might throw something heavy at me--like a range stool, maybe. All bad.

357maximum
01-26-2007, 07:13 PM
An evil thought crossed my mind a few weeks ago......I got a Lyman #358101 mold at NCBS a couple years ago, and these can be loaded in the fashion shown above (stacked) to roughly equal the mass of a 38 Special wadcutter. I was going to give 10-12 rounds to Buckshot the other day to "try out my new wadcutter mold design" while he was running his K-38, but thought better of it. After he figured out how 10 bullet strikes occurred when 5 shots were fired, he might throw something heavy at me--like a range stool, maybe. All bad.

You wouldn't want buckshot throwin his stool at ya now[smilie=1:

rvpilot76
01-26-2007, 08:13 PM
You wouldn't want buckshot throwin his stool at ya now[smilie=1:
That happened to my brother when he was in Kenya on his WestPac tour with the Marines. Baboons are nasty little buggers (not saying you're a baboon, Buckshot)!

Kevin

Andy_P
01-26-2007, 08:51 PM
"Without being too critical, your 250 gr. boolits need some work. It looks like your mould or alloy was WAY too cold.

That was the first thing I thought.....the second was that brass looks like it might be headed towards inseppient head seperation right quick"


Real bunch of old biddies here. What do you guys do for fun?

Yea, the mold was too cold - I cast all of four bullets and couldn't care less what they looked like.

Incipient separation? No - that's a piece of thin-wall tubing to build up the casehead diameter so I don't get that.

Safeshot
01-26-2007, 09:56 PM
I have had a "lot better" results with "double bullet" loads loading the bases of the bullets together. First bullet into case - base "up", second bullet into case - base "down". I keep the bases together and seat them together. This allows for more of the neck to grip the bullets and the second bullet out of the bore acts just like a wadcutter. It also prevents the bullet nose from expanding or upsetting. I like to make sure that the neck grips both bullets firmly so that there is no seperation or "air space" between the bullets. Hard cast bullets seem to be better suited for this. Keep loads moderate and watch for signs of high pressure. Have fun, be safe.

357maximum
01-26-2007, 10:20 PM
"Without being too critical, your 250 gr. boolits need some work. It looks like your mould or alloy was WAY too cold.

That was the first thing I thought.....the second was that brass looks like it might be headed towards inseppient head seperation right quick"


Real bunch of old biddies here. What do you guys do for fun?

Yea, the mold was too cold - I cast all of four bullets and couldn't care less what they looked like.

Incipient separation? No - that's a piece of thin-wall tubing to build up the casehead diameter so I don't get that.


Hey buddy....did not know how advanced of a caster you were for one...there are all levels of casters here...from never casted before..all the way up to fellas that casted over dung, as trees had not been invented yet...relax the post was not a flame in any way...

secondly...I did not realize there was tubing there, Just trying to keep your head attached to your shoulders on that one....as there are all levels of handloaders here also....some might not recognize head seperation, just as i did not recognize the shimstock on your casing...nothing was presented in a .."oh look how shi%%y his boolis and brass are manner"..relax

What do I do for fun I cast/load/shoot/shoot the sh!t/ and sometimes I kill..no I do not harvest much..the occassional shroom or berry, but I kill my animals....

Michael

Bret4207
01-27-2007, 09:39 AM
Incipient separation? No - that's a piece of thin-wall tubing to build up the casehead diameter so I don't get that.

Ah, I was wondering what that was. Don't take offense Andy, we just didn't know what was going on. Neat idea. I've heard of it but never saw it done before. What kind of stock do you use and where do you get it?

BTW- I'm just across the big river near Ogdensburg. Howdy neighbor!

PPpastordon
01-27-2007, 09:42 AM
"What do I do for fun I cast/load/shoot/"

Max - shouldn't that next word be repeat?

bruce drake
01-27-2007, 09:46 AM
Wow, THat is a neat trick. shimming the brass for longer life. Did the rest of the 45-90 case expand to the same diameter as the shim the first time you fired?

Andy_P
01-27-2007, 10:17 AM
Incipient separation? No - that's a piece of thin-wall tubing to build up the casehead diameter so I don't get that.

Ah, I was wondering what that was. Don't take offense Andy, we just didn't know what was going on. Neat idea. I've heard of it but never saw it done before. What kind of stock do you use and where do you get it?

BTW- I'm just across the big river near Ogdensburg. Howdy neighbor!

Yea, when the only comment was a criticism, it put me off, but it was just guys trying to be helpful - I should have seen it as that. :oops:

Anyways, I make 43 Mauser from Starline 45/90 brass. It's the ideal stock to use, but it needs some tweaking. The rim needs to be turned down to 0.590" which is easy. The length is about perfect and just needs about 0.025" trimmed off, that's easy too. The tougher part is bolstering the casehead diameter up from 0.500" to the 0.515" range. You can just let it balloon if you want to keep pressures down, but that still greatly increases the likelihood of separation where the bulge begins (I have experienced it). My solution was to secure a 1/2" long piece of 17/32" (0.531") K&S thin-wall brass tubing against the rim and solder it in place. If you work quickly, apply just a small bit of solder and quench immediately, casehead softening will be minimized (again I work with pressures just above Springfield Trapdoor). You then turn the tube down from 0.531" to 0.515", and upon first firing the case swages right up to it, making the seam practically flush as the pictrure shows. A common practice in making obsolete cartridges - I do the same to make 8x52R Siamese from 7.62x54R. The remaining problem is the rim thickness, which is about 0.025" too small in the 45/90. I have sourced some thin brass shim washers that will be affixed beneath the brass tube and soldered in at the same time, and that should complete the process.

A lot of effort, but little expense. Since I expect up to 50 firings from the brass though, it's well worth it.

Buckshot
01-27-2007, 12:23 PM
..................Sometime back one of the guys on the British and Militaria BB hit on the idea of forming 577-450 form 45-90's and nylon :-). The main idea was reduced capacity cases as modern drawn 577-450's will hold dang near 130grs of BP. He'd had a friend with CNC capabilities turn up a case body and then drilled through for the 45-90 case to be stuck in.

The 45-90's rim kept it from moving forward, and when fire formed the exposed case expanded to fill the chamber area. This effectively locked the case to the nylon (or HDPE or whatever it was) body. This was somehting he was thinking of making up and offering for sale. It worked, but I lost track of it and checking back later I guess it didn't meet with wild support.

..............Buckshot

357maximum
01-27-2007, 02:26 PM
"What do I do for fun I cast/load/shoot/"

Max - shouldn't that next word be repeat?

Yep, with a big long infinity....................behind it...you caught me asleepin at the keyboard....

Andy_P
01-27-2007, 02:48 PM
Another neat old trick you can use for these "Double" loads is to make up short wadcutters by putting a gas-check upside down in the grease groove of a long (500gr ish) mold. Stack them end to end for 2-3 nice sharp round holes.

Here I have (L to R) - 145gr, 195gr and 485gr "Triple".

http://www.pridham.ca/45_Cal_Wadcutters.jpg