Singleshot 400-444

[andym79]

Hi I guys, I am thinking of building a single shot rifle for 300-500 yard shooting.

I am thinking a wildcat cartridge a 444 marlin necked down to .400" a 400-444.

This is the bullet I am thinking of using, how can I improve on the design and would a 1:18 twist be the sweet spot?

Thanks197493197495

[15meter]

Ever look at a 450/400 nitro express? Yours looks like a shortened version of that.

[OlDeuce]

Good afternoon AndyM79.................Have you given any thought to a 40-82WCF???? Easy to do ,easy to get Ol Deuce

[andym79]

Ever look at a 450/400 nitro express? Yours looks like a shortened version of that.

Looks similar, but the express is a fair bit more cartridge!

I also think the 450/400 was also a 405 not 400 calibre (not that you said it was 400, but I have a .400/.392 barrel available).

[andym79]

Good afternoon AndyM79.................Have you given any thought to a 40-82WCF???? Easy to do ,easy to get Ol Deuce

Thanks the 40-82 is a fine cartridge, but I have a .400/.392 barrel available to me and the 40-82 is a .408.

I was essentially going for a .400 version of the 40-65 and have a bit of 444 brass but no 40-65 or 45-70 brass laying around.

The 40-65 would be a cheaper option I guess as this wildcat will be a custom bullet mould, dies and a reamer.

[Boz330]

18 twist should stabilize that boolit just fine.

Bob

[Chill Wills]

Sounds fun. Given you have a the barrel and brass in hand, so those are not optional, everything almost designs itself. Is there a plan or print on file with the reamer maker? Measuring the brass wall thickness against the reamer print (and all print diligence) is a good idea.

What action will you be fitting this too?

[15meter]

Looks similar, but the express is a fair bit more cartridge!

I also think the 450/400 was also a 405 not 400 calibre (not that you said it was 400, but I have a .400/.392 barrel available).

I'm using 41 mag cast pistol bullets for plinker loads probably to big for 400/392 barrel....

[EDG]

Since you are in Oz why not use local brass such as .303 Brit or .303 Basic.
For use in the US I would look for a version of the .40-50 Sharps Straight or the 40-70 2.5 SS using Hornady .405 Win brass. On second thought it might be better to use .303 Brit brass in the US for the .40-50 Sharps version too.
You can check out the 40-50 Sharps over at the ASSRA American Single Shot Rifle Association. There are a number of guys that shoot it with both BP and smokeless. The small case seems to be fine for cast bullets with both powder types.

You have to register to post there. They welcome shooters from all over the world.
https://www.assra.com/cgi-bin/yabb/YaBB.pl


The easy to find Lyman 40-70 dies can be cut off to make the shorter version.

In the US I would plan to use a .408 groove diameter barrel since it is pretty much the standard barrel blank groove diameter. There are many existing .408 cast bullet designs by Redding, RCBS, Lyman and others. Normal twist used in the Browning 40-65 BPCR rifles was 18" and they shoot very well with 400 grain bullets.

If you run a .444 Marlin case into a .40-65 FL die it only sizes about the front half of the case. The resulting case looks very much like your proposed case.
Your case requires custom dies and a custom chamber reamer. If you use the .408 bullet diameter you may be able to find existing dies and reamer designs (to cut short chamber) to make your chamber and ammo. I have shot undersize 300 grain bullets meant for the .405 Win (.410) grain bullets in a 40-65 and really gotten excellent results and some very enjoyable shooting.


There are no real technical defects in what you have proposed.
However your design does not use the most commonly available components (in the US) that can cut the lead time and cost of a new barrel, chamber reamer, die set, brass and bullet molds.

[andym79]

Thanks for the replies, its great to get feedback. I have given the custom reamer and dies some thought. My smith has a 7x57 reamer, I think maybe with that and a .400 n&t reamer that the proposed chamber might be able to be cut. As to the dies the same might be possible to open a 7x57 die up in the neck shoulder region so that it sizes to about .424".

Its something that requires further thought, but do you reckon that the 7x57 and n&t reamer might work?

I fully appreciate what you are saying about the 408 bullet though there are many designs similar already out there.


Thanks

[EDG]

I am sure there is some reamer that can be made to work as you describe. All you need to do is determine if the 7X57 is the right size at the shoulder so it will clean up. I would recommend that you test your reamer on several pieces of scrap steel to make sure it is exactly what you want before you commit your barrel blank.

I have kicked around .375 and .408 calibers made by cutting off .375 H&H, .416 Taylor and .416 Rem dies and running the standard reamers in shallow to create a chamber for rounds based on 45-70 brass.

When reaming a large bore barrel for a relatively slender case you are in the area of reaming where a half round D reamer can be made to work.

197768

http://www.homegunsmith.com/archive/T19762.html




Thanks for the replies, its great to get feedback. I have given the custom reamer and dies some thought. My smith has a 7x57 reamer, I think maybe with that and a .400 n&t reamer that the proposed chamber might be able to be cut. As to the dies the same might be possible to open a 7x57 die up in the neck shoulder region so that it sizes to about .424".

Its something that requires further thought, but do you reckon that the 7x57 and n&t reamer might work?

I fully appreciate what you are saying about the 408 bullet though there are many designs similar already out there.


Thanks

[andym79]

Thanks for that constructive input. So hypothetically if I want a .424" neck is a .429" shoulder going to work with that. By that I mean will it clean up well

I have a couple of friends who have made their own D reamers for wildcats. But be worth having a chat with them.