45/70 (no) neck tension question

[guninhand]

I have a mold that gives a bullet with a perfect slip fit in my fired 45/70 cases. Accuracy results have been mixed, and variable fishtailing winds didn't help. My question... is a slip fit always preferable versus some case sizing to get neck tension?

Also, my slip-fitted bullets rounds don't just chamber, the nose is seriously bore riding and the round has to be forced in the last 1/2 inch as the nose gets engraved. I made a little off centered round doo-hickey with a mechanical advantage to do this final chambering.

[JeffinNZ]

I shoot my .38/303 exclusively with zero neck tension. I have no sizing die you see but don't need one. I compress the powder column so that a seated bullet engraves and get fantastic results.

Make sure ALL the cases are the same on inside neck diameter.

[Boz330]

I have a mold that gives a bullet with a perfect slip fit in my fired 45/70 cases. Accuracy results have been mixed, and variable fishtailing winds didn't help. My question... is a slip fit always preferable versus some case sizing to get neck tension?

Also, my slip-fitted bullets rounds don't just chamber, the nose is seriously bore riding and the round has to be forced in the last 1/2 inch as the nose gets engraved. I made a little off centered round doo-hickey with a mechanical advantage to do this final chambering.

The best thing to do is try it both ways and see what works best in that gun. Usually you only need about 1 or 2 thousanths tension. Anything more than that will distort the boolit.
If you are shooting BP with a nose that tight on your boolit, you will eventually run into the fowling hindering your round from chambering. You might also be pushing the boolit back in the case which will change your powder compression from round to round which in turn could affect the group.
Have you tried setting the boolit back in the case till it chambers fairly easily? You might slug your bore and see what the bore is, the nose should be several thousanths smaller. Slipping the nose in the end of the barrel will also be an indicator of the fit. It sounds like you might need a different boolit. I am assuming that the boolit length is a fit for your rifles twist rate. There are a lot of variables that could be a problem. But there is a lot of info here as well in past posts. Good luck.


Bob

[hiram]

You can size the nose only down a little to allow easier chambering. You could use a 44 mag sizing die. Remove the decapping pin, screw the die in the press, place the bullet on the ram, and slide it in to the first band. Take a wooden dowel and push the bullet out. Band diameter stays the same and nose diameter is reduced.

[montana_charlie]

Accuracy results have been mixed,
Sometimes an off centered round doo-hickey can have leverage equal to that of a powder compression die.

What if (in a clean barrel) the off centered round doo-hickey pushes the bullet well up into the bore...but in a slightly fouled chamber, the off centered round doo-hickey simply causes the bullet to seat deeper into the case while further compressing the powder charge?

You could expect a varying situation like that to give mixed accuracy results.

This boils down into the question of how do you know 'what is being forced into where' when you use the off centered round doo-hickey.

If it happens that using the off centered round doo-hickey actually shortens your OAL (sometimes), then something like heavy neck tension might be the answer in preventing that. Of course, that introduces a new variable...and a new set of questions. Do you never anneal a neck? Do you anneal frequently to maintain neck tension at a standard level? Is that after every three firings, or every firing?

I personally like slip-fit bullets in fireformed necks...just as you do. But I am inclined to agree with Boz330 that your bullet is not the best choice for that kind of loading...because it requires the off centered round doo-hickey.

Have you ever considered 'breech seated' ammunition?
CM

[guninhand]

Thanks for the replies.

Results varied from 4 of 7 bullets in one hole at 200 yds in an 8 inch group to 10 rounds giving a well dispersed 5 inch group

Here's a pic of the round being chambered as far as it will go without using the off centered round doo-hickey (OCRDH)
http://i238.photobucket.com/albums/ff170/guninhand_2007/chamber.jpg

And here's a pic of the round after engraving, a distance of about 0.28 inch for this particular round.
http://i238.photobucket.com/albums/ff170/guninhand_2007/engrave.jpg

My main concern is that the force of engraving might be cocking the bullet out of alignment with the bore. I've not annealed as there was no neck tension involved, the bullet can be remove with fingers from the round and gives a nice sucking pop sound when you do.

I'll try the various suggestions posted here and might even try to breech seat so that the inserted case will mate up with the bullet as if an assembled round had been inserted. The bullet os 510 grains and there would be a lot of extra room in the case with the usual breech seating method.

[montana_charlie]

Is that object at the bottom of the second picture your off centered round doo-hickey?
For some reason I thought an OCRDH would look...well...older (or something).
CM

[Jon K]

guninhand,

Get a boolit that fits the gun.
Slug or do a chamber cast......determine specs.
Shop around, research sizes available, get samples, if you can, before buying a mould.

It's not worth the headaches, trying to make something shoot, that doesn't fit properly. Fit and consistancy is a major factor in accuracy.

Jon

[Don McDowell]

Just going by your account of the groups, and the picture of the loaded round. I'ld recommend seating that bullet deeper into the case , until the loaded round will just chamber. Shoot 50 like that for record, then load 50 more same seating depth only this time resize the case and see what the groups look like.

[Boz330]

I don't think you can seat that boolit deep enough to stop the engraving. The reduction in powder capacity would be significant. Try another boolit. If I shot a 45-70 I'd offer to send you some to try, but I shoot a 40-65. You definately need to slug that barrel to see what your dealing with.
From the picture it looks like you have a Hi-wall, what brand is it?

Bob

[jlchucker]

A friend of mine had this problem with his Ruger #1 45-70. When I met him at the range, I happened to have my own 45-70 with me, along with some 385 gr handloads. He tried a group with some of my ammo with better-than good results. The difference--mine had a Lee Factory crimp, because I use a levergun. He started getting outstanding groups once he developed a load with a light crimp.

[montana_charlie]

I don't think you can seat that boolit deep enough to stop the engraving.
I think you're right, Boz. Judging from how close to the case the engraving gets, the chamber has no freebore, at all. The leade starts right at the case mouth.

Would a paper patched bullet, patched to bore diameter, seem like a good choice in that rifle?
CM

[Don McDowell]

Looking at the picture , the two rifling marks showing up aren't equal length. So either the bullet is off centered during chambering, or theres something bad wrong with that chamber.
It won't be that tuff of a deal to seat the bullet deeper and get that nose out of the lands. Cuz it just don't look to be that great of a distance if you go off of the shortest mark on the bullet.:roll:

[Boz330]

AW HA a thought came to me when I looked at that boolit again. There is a ring around the nose. Check the nose of one of your new cast boolits and then check the nose after you size and lube it. If those boolits are soft, and it is going in the lube-sizer hard, you might be swelling that nose. I have seen that done before by one of the guys that I shoot with. If there is any kind of a mistake that can be made he has done it. I'd bore you with the details but I don't have time to write a novel.

Bob

[August]

I have a BPCR just like yours. When the cartridge looks like the one in your picture, it's time for me to clean the fouling from the bore. I use a Paul Mathews' designed, bore riding bullet. It has tapered flats that allow the bullet to TOUCH the lands, but it doesn't get engraved. The bullet you're using obviously needs to be seated a lot deeper in the case to work properly. If you're going to shoot Shutzen style, then you'll need a proper bullet for the job.

With respect to crimping, as opposed to finger seating in loading, I use only enough crimp to take the bell out of the case. So less is better, as you suspected.

What are you doing in the way of powder compression? And, the first thing I should have said, you ARE using black powder -- right?

[martinibelgian]

My guess is the nose it getting bumped up - if you're compressing your powder, are you using the bullet to do so? Or it could also be the lubesizer. Measure the boreriding nose as cast, after lubing and after seating - that should give you a clue... If that's a Lyman 457125, the nose usually is on the small side.

[Dale53]

I have a Star Sizer/luber, an RCBS sizer/luber and a Lyman Sizer/luber. I ended up pan lubing and using a Lee push through sizer (the Star will do this also) to process my bullets. My 40/65 Browning BPCR will shoot under 1" at 100 yards (6" at 500 yards) using this method. I full length size and expand with an expander no more than .001" smaller than my bullet. This gives me about .002" neck tension. I get consistent results.

I use NOTHING but black powder. My powder of choice is Swiss 1½.

Dale53

[guninhand]

There's a lot of points made in those new posts. The gun is a Browning BPCR and the bullet is Buffalo Arms mold product no. 459510C2, which is tapered to the first band. I haven't asked them what's the diff between this version and the other identical mold save that it is not tapered. I bought it figuring it would be likely the bullet could be seated further out before rifling was engaged. The mold looks like a SAECO but has no markings on it at all, none.

I'm sizing it in an RCBS .459 die and it appears to do a perfect job, putting lube in the grooves without touching the bands but also leaving no excess lube on the bands.

With the first alloy I used it cast the easiest and most perfect looking bullets I've ever made.

When I do neck tension with other bullets I use a Redding neck die-series B. This is with a 320 gr RCBS GC bullet I happened to have, and use smokeless with it. I've used only 777ffg with the heavy Buffalo Arms bullet so far.

One thing I've got to try is pure lino as I think the dimensions will shrink enough to avoid the engraving I'm getting now.

[13Echo]

Linotype metal is designed to make the sharpest possible casting for printing and shrinkage is minimal so the bullet is actually likely to be even larger, and, since it is rather hard, you'll have an even harder time chambering the bullets. It would be interesting to know the diameter of the bore riding section of the bullet and the dimensions of your barrel.

Jerry Liles

[montana_charlie]

One thing I've got to try is pure lino as I think the dimensions will shrink enough to avoid the engraving I'm getting now.
Something closer to pure lead (30:1) should give you a smaller diameter...
CM

[EDK]

Try taking micrometer readings of your fired brass and reloads...and compare to a full length sized casing. Do the same with the boolit in a reload and the boolit before assembling a cartridge.

I've been neck-sizing my 50/90s and scraping brass off the base when loading them in my SHILOH SHARPS. I found I wasn't eliminating the bell in the case mouth. Unsized fired brass didn't have the scraping problem. A little bit of crimp might help the accuracy too.

Going to a softer alloy will give you smaller diameter boolits. More of a spitzer type nose might be another answer. (I like the RCBS 320 GC in assorted MARLIN Cowboy rifles too.)

A micrometer is a very useful tool for the reloader. You can get accurate and repeatable readings that may solve your problems. A dial caliper is only good for "quick and dirty" measurements...you need better than that for solving various reloading problems.

Look at Mike Venturino's SHOOTING BUFFALO RIFLES OF THE OLD WEST and see if there's some info there that will help. Maybe post something at shilohrifle.com/forums or one of the other Black Powder Cartridge Rifle web sites.

:cbpour::redneck: