trying breach seating.............

[Catch]

Catch here again…..I want to try some 311299 breach seated in my B78 single shot chambered for 30-06. I want to keep the speed down to 32 40 levels. I would like to use smokeless, perhaps 2400, Unique, or 4227. Never tried this before and hope for some advice. Not using gas checks……Give me some ideas…. Is 21 grs 2400 in such a large case dangerous ? Wad over powder ? Help…..
I don’t want to mess up Thanks guys…………………Getting old, 87 at Xmas, but its still so much fun





God bless all the good cops, and keep them safe...............

[mehavey]

1. See https://castboolits.gunloads.com/sho...-2400-in-30-06 and C.E.Harris / https://castboolits.gunloads.com/sho...Rifles-Article

2. As to "breech" seating, i assume you only mean seating the bullet out long enough to engage the lands -- not seated separately

3. By "wad," what are you thinking about exactly ?

[Wayne Smith]

My understanding of 'breach seating' is to seat the boolit in the lands prior to loading the cartridge. The cartridge is primed, loaded, a wad is used to hold the powder in place, put into the chamber and fired.

[Catch]

I guess I’ll just start over. I plan to take a 311299 sized to .310 and place it in the breach of my B 78 and push it into the lands so that it is 1/16 in front of the case mouth. The primed case will follow containing 18 grains of 2400. Supposedly this powder is not position sensitive but I did not know wheather to use a wad ( usually use dacron) in front of the powder, or a card wad behind the bullet. I thought I understood the breach seating, but maybe I don’t. Some advice would be helpful before I pull the trigger. Thanks again

[mehavey]

Breech seating does not usually (ever?) leave the bullet actually ahead of the case mouth.
To do so would compromise pressure build-up and neck/chamber/wall sealing.

As alternative, I suggest establishing maximum distance to lands....

> Gently push a bare bullet into the chamber and up against the rifling using a wooden dowel. Use another dowel (or flat-faced cleaning rod)
> from the muzzle to slightly push the bullet back & forth on-again/off-gain from the rifling against the dowel. when satisfied that the bullet
> is just barely contacting the rifling, mark the dowel/cleaning rod with a razor blade right at the muzzle. Then remove the bullet, close the
> breech, and push the dowel/rod all the way to the bolt face. Mark it again.

The distance between the marks is your MAX OAL at bullet/lands engagement. Seat the bullet to 1/16 more that than for positive lands jam.

[charlie b]

I was taught that when breech seating the bullet is not touching the case. It is seated well into the rifling. A wad or wads are used between the case and bullet to close the gap. This was for black powder so not sure how it relates to smokeless bottle neck cartridges.

[mehavey]

Reading more (and) remembering my Sharps from 40 years ago, the objective was a fully lands-engaged bullet.
I have to also admit it was with soft bullets, did not need a mechanical-advantage ram, did involve BP, and no mouth gap,

[Catch]

I believe one of the good things about the 311299 bullet is that its long nose is designed to go into the lands while the base is designed to seal the bullet in the bore. I have read that seating above the case mouth (the agreement is usually 1/16 of an inch) eliminates all the case problems that interfere with accuracy.
I realize that this is old knowledge normally concerned with black powder and I don't really want to mess with the mess. Smokeless is different and hearing about ringed chambers and the like, I hoped to contact some folks who are still shooting with this method. I figure I better think about it before I make a mistake. Thanks again for all your help.............

[JSnover]

The only 'true' breech-seating I ever witnessed was done by seating the cast boolit with a seating tool, then inserting a charged case behind it and closing the action.
I assumed the tool set the boolit properly and the unsized case mouth was able to slip over the base of the boolit. This seemed totally logical to me and I never thought to ask about it, never heard of any gap between the boolit base and case mouth.

[JonB_in_Glencoe]

The only 'true' breech-seating I ever witnessed was done by seating the cast boolit with a seating tool, then inserting a charged case behind it and closing the action.
I assumed the tool set the boolit properly and the unsized case mouth was able to slip over the base of the boolit. This seemed totally logical to me and I never thought to ask about it, never heard of any gap between the boolit base and case mouth.

I never witnessed it, but Tim (AKA:Goodsteel, AKA:MBTcustom) posted one of his tests with a breech seating tool he made and the results. It was in a long thread like the link below, I had a quick look but I can't seem to see it in this thread...it may not have been on castboolits, maybe on his own webforum?
https://castboolits.gunloads.com/sho...et-mold-design

It could be in the 30XCB thread, but I don't have the time to skim through it.
https://castboolits.gunloads.com/sho...ighlight=30xcb

Anyway, I'm not sure how you will Breech seat a boolit without a tool? But, Tim would be a good one to contact, if you start thinking you will do this, and need help making a tool.

[Green Frog]

In ASSRA, breech seating in single shot rifles such as Ballards, Winchester High walls, Steven’s 44 1/2S, etc puts the bullet in front of the case mouth by 1/16” or more. There is sometimes a wad placed near the powder (allowing just a little “slump” and sometimes a wad at the case mouth as well to protect the load. The use of fillers such as Dacron or corn meal has become somewhat passé.

All of this is very specialized stuff and deserves much more discussion than I’m willing or able to type here on my iPad. You might wish to seek out the ASSRA.com forum and read some of the extensive discussions on the subject there. In schuetzen we do it all the time.

Froggie

[blackthorn]

If I recall correctly, when Goodsteel left this forum he deleted most (if not all) his posted input. That may be the reason you cannot find a post you are seeking. Pity!

[DonHowe]

Catch here again…..I want to try some 311299 breach seated in my B78 single shot chambered for 30-06. I want to keep the speed down to 32 40 levels. I would like to use smokeless, perhaps 2400, Unique, or 4227. Never tried this before and hope for some advice. Not using gas checks……Give me some ideas…. Is 21 grs 2400 in such a large case dangerous ? Wad over powder ? Help…..
I don’t want to mess up Thanks guys…………………Getting old, 87 at Xmas, but its still so much fun





God bless all the good cops, and keep them safe...............

Based on shooting breechseated .32-40 in matches...
Cast your bullet@ soft,, 30-1 or 25-1. Make em hard and you won't be able to seat em. Seat the bullet into the rifling until .060" ahead of the chambered case. Personally, I would try w/o gas check.
As for the load, powders like 2400, 4227, 4759 are perfect. With plainbase bullets, best accuracy come between 1350-1450 fps. In .32-40 14.5gr 4227 runs 1400-14/0fps depending on barrrl length. In the larger case I might start there and work up. Charge the case and plug the case mouth with a 1/4" thick floral foam wad. Seat a bullet, chamber the case and shoot.
A good bullet in .30 would be the tapered 311467 with gas check shank removed.

Edit: it is beneficial to flar the case mouth until it is snug in the chamber neck. This helps seal the chamber. As for 2400 powder, Lyman give velocity of 16 grains in a loaded cartridge at ~1600fps, a bit fast for plainbase but could be ok with a gas check.

As stated previously, this is based on expetience.

[DonHowe]

if I could figure out how to post pics I could show a couple of types of breechseating tools .one is a push type, pretty easily made. Both types use a modified case which holds and aligns the bullet for insertion into the chamber.

[JSnover]

if I could figure out how to post pics I could show a couple of types of breechseating tools .one is a push type, pretty easily made. Both types use a modified case which holds and aligns the bullet for insertion into the chamber.

That's what I've been experimenting with lately, a drilled case with a screw to adjust for different weight/profile.
The typical breech seating tools are sort of a toggle action type and they're more expensive than they look.

[DonHowe]

What I started out with for my High Wall is a push type seater made up fairly quickly by a friend with a lathe.
This thing is made from a mild steel rod 3/8" diameter about 9" long. It has a section 1 5/8" to 1 3/4" long reduced to .25" diameter. The step down makes a stop. The .25" dia portion is further reduced and threaded to accept a drilled and tapped bullet-diameter length of brass (the bullet pusher). A case is drilled thru the primer pocket to .25" diameter to accept the .25" portion of the rod. The opposite end of the thing has a handle fitted.
The .25" portion is inserted into the case the the brass piece is screwed onto the rod and down into the case protruding 1/16" or so. In use the rod is pulled back into the case, a bullet inserted, the case and bullet inserted into the chamber and the rod pushed forward until I l the step stops against the case. A reasonably soft bullet is critical or the pushing hand will get really sore.
The seater I describe is for .32-40. The length of the reduced diameter portion would vary according to cartridge length.
Alternately a temporary arrangement could consist of, say a .30 caliber case with a length of 5/16" brass rod glued in and cut off ahead off the case. A bullet would have to be pushed into the chamber neck the the plugged case inserted and gently tapped home then removed via the extractor. If you are lucky enough to have a Stevens 44 1/2 or CPA single shot this plugged case is all that is required for breechseayins as those actions will cam the case and bullet into place when the action is closed.

It is my belief that breechseaying or in Popes case a muzzleloaded bulletcame into vogue due to lack of sufficient precision to produce a chamber properly aligned with the bore of a barrel. In other words, simply elimina t ing a variable t he shooter could not control. I believe that today a match-quality chambeting job in a good barrel could deliver equal accuracy with carefully loaded cartridges.
Still,shooting groups with carefully cast and breechseated bullets is a fascinating and enjoyable experience. Many older shooters, weary of the hustle associated with other shooting disciplines have fallen in love with the slower pace of the "arcane" sport of shooting breechseated single shot tigles.