Machinning brass tube to reduce case capacity.

[GARD72977]

I have been thinking of finding some brass tube and machinning it down to fit in a 45/70 case to reduce capacity fot light loads.

Im thinking of chamfering the inner part of the bottom slightly. Using a arbor press to press them in.

Any thoughts on doing this?

[JimB..]

I’d just switch to trail boss.

If the sleeve shifts forward a bit during firing I think you’ll be done for the day. Not likely to happen on the first firing I suppose, but multiple firings and resizing might make it a little loose.

[earlmck]

Many years ago I tried this with a 219 Improved Zipper (for which you start with a 38/55 case made from a 30/30 and put in your filler piece for which I used .223 brass). Worked well, but I concluded it was still much more work than it was worth. But the idea is quite viable.

I'd say "go for it" -- it'd be considerably less work to do on a 45/70 case than my bottleneck case that required blowing out, annealing, making the filler piece to fit nearly perfectly, necking down in 4 stages, neck turning, annealing again...

Yes indeed: go for it!

[Mr_Sheesh]

If you could neck expand the case then install the tube, then size the neck back down to normal size, that might retain the heck out of the tube.

I do remember seeing someone discussing threading the primer flash hole in a 50 BMG case and screwing a tube into that, to pass the flash from the primer to about mid-case, for more consistency of ignition? Sounded a little uh, UNIQUE to me, but maybe it works pretty well.

Could braze the tube in place maybe, to help retain it? Be careful of what's annealed vs not and so on of course. Interesting problem!

[Buckshot]

.............I've got a couple old articles on reducing case capacity by inserting a smaller cartridge case into a larger one, but the larger was always a BN design. Having the insert move forward into the barrel quietly waiting there for the next projectile would provide too much excitement for me. So far as 'Forward Ignition goes' (via a longish flash tube), it's been done. I forget who I'd read about doing that (back in the 60's ?), but I know in the Navy the 3"/50's and the 5"/38's (the only 2 I've witnessed) had tubes extending up 3/4 of the length of the case. Don't recall if there were any holes in the circumference of the tubes, as I didn't look close enough. Just saw them as we heaved them overboard :-)

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

[GARD72977]

If i press it down the case to the same depth as the base of the bullet you would be able to tell if it moved. Im also thinking it will press on low enough to start rounding the bottom a little. This would put pressue back on it during firing.

[JimB..]

I still don”t recommend this, but if I was determined to try it I would do a few things to try to ensure that the bushing stays in the case.

Make the bushing long enough that the bushing bottoms out in the test case and that the seated bullet bottoms out on the bushing.

Cut a couple shallow grooves around the bushing and then, once inserted in the test case, roll the case walls into those grooves.

Be sure to cut the bushing to match the interior profile of the test case, I doubt that it’s a cylinder.

Start with a new test case.

Good luck, and post pictures.

[Gewehr-Guy]

I tried the same concept once for a 577 Snider, but used rolled up heavy paper instead of brass. I rolled a strip tightly around a wood dowel and pushed it into the case. They stayed in the case for several firings, but got charred and you have to remove them to wash the cases. Don't know how they would work in a 45-70, but it would be easier to experiment this way than to make up a bunch of brass sleeves . You would want to look after each firing to make sure the tube didn't lodge in the barrel, didn't in my test but 45-70 might perform differently.

[GARD72977]

There is no way I can machine it to match the interior of the case with manual equipment. If its not too thisk and I anneal the tube it would take the shape of the case as it was pressed in with an arbor press. I have little concern for it being pushed out. It will be almostto thebottom of the case and pressure will expand it to the sides of the case.

[Chill Wills]

How about reducing the case capacity by using 1/2" or 3/8" wads under the bullet? CircleFly shotgun wads and other makers are a source of thick wads in rifle calibers. Maybe safer and for sure, less work.
Just an idea....
Beyond that, make yourself or buy one piece brass from Rocky Mtn Cartridge Co. A few bucks each, not cheap but last forever.

[15meter]

If you could neck expand the case then install the tube, then size the neck back down to normal size, that might retain the heck out of the tube.

I do remember seeing someone discussing threading the primer flash hole in a 50 BMG case and screwing a tube into that, to pass the flash from the primer to about mid-case, for more consistency of ignition? Sounded a little uh, UNIQUE to me, but maybe it works pretty well.

Could braze the tube in place maybe, to help retain it? Be careful of what's annealed vs not and so on of course. Interesting problem!

Seems I read that some cannon shells had an extend primer flash tube to help ignition and that some experimenters took the tube to the top of the powder column, making the powder burn from the front. I don't remember the theories for front ignition.

[Don McDowell]

Call Rocky Mountain Cartridge and order however many reduced capacity cases you want.
http://www.rockymountaincartridge.com

[kokomokid]

I think the army used a cardboard tube to reduce loads to 60 grains for the carbine 45-70.
I picked up some brass from Gaintwist barrel co that is machined to shoot a reduced load of 23 grains 4198 and a 405 bullet.

[GARD72977]

Rocky
Mountian is a little higher than I can afford.

I feel like you need 10 pages of fine print when you post something like this. Internet safety experts wear it out

[Don McDowell]

You could also just load with 1 f and a thick wad stack. Blackpowder cartridges don't really lend themselves to "reduced" loads particularly well.

[country gent]

h The tubing you need may be found at online metals. It can be cut to length and turned to just what you need as to the case taper between centers. I would recommend several things if you do this. Turn a close fit of tube to case taper. Either red or green locktite the tube in or a very good epoxy for the initial installation. Then use a canelure tool and roll a canelure in the case at the end of the tube to mechanically lock it into place in addition to the locktite / epoxy. The other issue you may have here is getting cases with the tubes to expand and seal the chambers like they should. A tube with .015 wall is doubling wall thickness of the case in the head body area.

The wad stack or thick wads would be easier the use of 1/8" or 1/4" wads may accomplish the same thing and be easier to do. Another plus to the wad stacks are cases arnt modified leaving them useable for full power loads if ever desired. You could use a thin wad ( .010-.060) a wax wad (poured to thickness) and another thin wad to fill space. Wax can be melted and poured to desired thickness then wads cut from the sheet for this.

Elmer Keith and a few others worked with primer tubes years ago. The tube was screwed into the flash hole and extended to the front of the powder charge. Benefits were lower extreme spreads and standard deviations due to more complete ignition burning of the powder charge. Some claimed lowered fouling and unburnt powder. Heat was said to stay more localized in the chamber area of the barrel. Drawbacks were the time work installing them. flash holes drilled and tapped, tubes threaded and cut to length. Installed a little long so primer pockets can be uniformed back to truly flat. a slot or means of removing if needed. Tubes either were removed to deprime or a long skinny decapping pin was needed. Cases modified in this manner were good for one basic load as the variances in powder height and bullet depth would affect them. The tube also reduced case capacity making existing data for a given cartridge in useable.

The other issue with the modified cases is if when someone else gets a hold of them and tries standard loads in them.

[beltfed]

Why bother:
Just use Alliant Unique powder and load with the std 45-70 case
and light bullets.
I did this for plinking with my M86 win: 45 colt bullets and about 12 gr Unique
beltfed/arnie

[17nut]

Why?

BP will shoot just fine with a void above, in a cartridge.
Frankford Arsenal knew this 140+ years ago ;-)
Gallery loads you know!

The probelm occurs in frontloaders with a short started bullet when powder has ample time to burn and accelerate up the tube.
Not the small amout of air in a cartridge.
If you really think this is the case then please explain why airspace between powder cernals is no problem but doube that is suddenly a disaster. And please feel free to add documentation for blown rifles and or revolvers due to airspace in the cartridges!

If you are adamant about depleting air then why not use some foam rod insulation: https://www.google.com/search?q=foam+rod+insulation&ie=utf-8&oe=utf-8&client=ubuntu&channel=fs&gws_rd=cr&dcr=0&ei=IExdWpiiD4jE6QSgk7SYAg

[bob208]

the arsenal used cardboard tubes to reduce the .45-70 for carbine loads.

turn the tubes to a .001 press fit in a unsized case. then put the tubes in the freezer over night then drop them in and size the cases.

[Geezer in NH]

I do remember seeing someone discussing threading the primer flash hole in a 50 BMG case and screwing a tube into that, to pass the flash from the primer to about mid-case,
!

Elmer Keith wrote of this in one of his books. "Hell I've Been there " if I remember right.

[country gent]

You can turn the taper with a manual lathe. You need an expanding mandrel dead center and live center. We made the dead center by simply turning a piece or round stock in the chuck or collet to a 60* point. the mandrel sits between the centers with tension to grip the centers ( a small lathe dog can be used to drive but for light turning isn't necessary) and the tailstock is offset to the desired taper. The machine then turns the taper using the carriage and feed. The pain to this is resetting the tail stock back to zero when done.

[bstone5]

Trail Boss loads work well in the 45-70.
Loaded some where the red powder coated cast bullets are visible as they
travel to a 200 yard target.

[Mr_Sheesh]

Yep "Hell I was there" I think, seen it mentioned other places too

[Gamsek]

I use this and they work great in my 7x64 (similar to 280). 212488https://uploads.tapatalk-cdn.com/20180123/35b97a222a93cc9d9a591a50b2dcc075.jpg212489

www.samereier.de
see Reduzierhülsen
They speak English
5€ per case, neck sizing die with long pin is 40€

https://uploads.tapatalk-cdn.com/20180123/a74b85673fed7f97cb950223cacfa4b1.jpg

[Ballistics in Scotland]

Front ignition has been known for a long time, and other things being equal, provides greater efficiency and consistency. (It was in another context that Keith said "The hell with efficiency. What we're after is results.") The trouble is that primer burn is almost inconceivably brief, and what we gain that way, we are likely to lose by its meeting the powder slightly later and cooler.

The need to improve on it is a lot greater in a powder charge one to four feet long, than an inch or two. Increasing the amount of composition (short of so much that you can't use a brass primer cup any more) won't much extend how far the burn goes, among grains which may be very large. In artillery that tube is filled with very easily ignited powder, often black powder long after the black powder age. The tube is usually perforated, suggesting that the benefit was in ignition throughout the charge rather than specifically at the front.

Front ignition might be useful in preventing the supposed log-jam of grains at the shoulder of a bottlenecked and sharp-shouldered case. But then, it is far from certain that there is such a log-jam. It imposes a lot of trouble decapping if the case is to be reused, and there could easily be a danger of a tube being blown out and remaining as a bore obstruction, especially if something as thin as the web around a conventional flash-hole is tapped for it.
I once experimented with copper sheet of about .005in. thickness, in the cylinder gap of a revolver. A small pistol primer, with no powder, would dome and rupture the copper, and a magnum rifle primer is far more powerful.

There might be some point in a .50BMG or .338/.50 military rifle, for anti-materiel use at extreme ranges, or light anti-tank weapons, in which the last fraction of velocity improves armour penetration. We can afford not to reload when we are paying taxes. But in our amateur capacity I think we are better off finding a powder that permit the use of a larger case. Or deciding that our kind of shooting doesn't need the ultimate in results.

[Grapeshot]

Frankfurt Arsenal used to insert a cardboard tube in the case to accept a reduced charge and still be able to seat a 405 grain bullet to the proper depth.

[StrawHat]

Frankfurt Arsenal used to insert a cardboard tube in the case to accept a reduced charge and still be able to seat a 405 grain bullet to the proper depth.

That was the first of three methods used by the Arsenal to reduce the capacity of the casing. The next method employed card wads between the reduced powder charge and the bullet. Both of these methods required additional loading steps but also additional steps manufacturing the case as the head stamp had to include the letter “C” to distinguish these rounds from the rifle (full charge) rounds. The final method required no additional steps as they merely seated the bullet down on the reduced powder charge which created a visual difference between the two loading.

Kevin

[texasmac]

I have been thinking of finding some brass tube and machinning it down to fit in a 45/70 case to reduce capacity fot light loads.
Im thinking of chamfering the inner part of the bottom slightly. Using a arbor press to press them in.
Any thoughts on doing this?

Since vegetable wads are around $18/1000 the easiest method is to insert sufficient number of 0.060" wads. Although it’s a well know and accepted practice to ensure that black powder cartridges are sufficiently filled with powder to eliminate air gaps between the powder column, wad and bullet base, it's not a safety issue if the gap between the wad & bullet base is relatively small. And it’s been proven that leaving an air space when loading with black powder and no wad is a myth. To this day, some black powder shooters that breech seat bullets routinely leave a gap between the over powder wad and bullet base and do not have chamber ringing or high pressure problems. But in most cases the gap is relatively small

The main reason for stacking wads (made from hard material) with reduced loads is to hold the powder against the primer for a reliable burn & consistent ballistics. When using wad material, what you don't want to use is a highly compressible material like polyester pillow stuffing, which will compress into a solid mass. When the solid mass hits the base of the bullet the pressure goes sky high & can ring the chamber or worse. BTW, theoretically the same can potentially happen if using a short wad stack to hold back a small amount of black powder, resulting in a large void between the wad and the base of the bullet.

In other words, if using a wad, any air gap between the wad and bullet base should be held to a minimum. If not using a wad the air gap can be as large as desired, but don’t expect consistent burns and good accuracy.

Wayne