Front drive band too large.

[Ben]

I have a 4 cavity, NOE , 45/70 mould. Two cavities of the mould will cast a nice 350 gr. plain base bullet, the other two cavities produce gas checked bullets.

The bullet is very accurate out of several 45/70's that I've tried it in.
The problem ( at least for me and my rifle ) is the front band ( in front of the crimp ring ) is a full .460 ". That .460 " causes me to have to deep seat the bullet into the case, which I did not like.

Today, I experimented with the idea of reducing the dia. of that front band only and leaving the rest of the bullet at a full .460".

Seems to have been a great success. I'll know more when I fire these 10 rounds , that I loaded today with the new OAL, at the range.

I reduced the front band from .460" down to .456". Made a big difference in the chambering of the round.

Here is the .460" dia. cast bullet prior to any sizing of the front band.

 

[Brad]

Will be interested to see how this works out for you. I have a feeling it will work well.

 

[Ben]

Brad,

It is an awfully small portion of the bullet that has changed dimension. I'm hoping I won't see a big change in performance ?

Ben

 

[Brad]

Being able to seat the bullet longer is good in my opinion. It also looks better.
The small change in that one band won't alter the overall bullet fit. If you could make it so that band was the largest that would fit the throats it would be ideal.

 

[Ben]

I got the idea of the reduced front band dia.,from several of my Lyman 38/357 moulds. The front band on many of them ( directly in front of the crimp ring ) is .003 - .004 smaller than the remainder of the bands on the bullet.

By the way, they shoot just fine.

 

[fiver]

this is the same thing me and Ian [and I, whatever] was talking about in his 45 colt thread.

the 45-70 was specced to have a tight throat right from the get-go, when saami was formed they just used the original drawings.
by the time most mold makers come along the throats on those guns had been pushed forward and they went with what they had on hand.
now we get newer guns [the 45-70 was hanging pretty idle for a long time] they read the saami prints and chamber accordingly, then we have to deal with the mis-match.
anyway, about .005 under groove diameter seems just about right.

 

[Ben]

I'm optimistic that this combination will work out well for me.

Ben

 

[KHornet]

Logic says it will work just fine Ben!

Paul

 

[Ian]

Made it the shape it should have been to begin with. Those old Lyman lube-sizers will never be obsolete.

 

[Rick]

Should be just what your looking for. I did the same thing years ago with the SAECO #264 6.5mm 140 gr, the front band was too big for it to chamber in a custom Shilen match grade chamber. While I size on the Star I used the SAECO in & out Lubrisizer to size nose first, depth set to size just enough of the front band. Worked great. My alternative was to use the RCBS 6.5mm 140 gr, a very similar bullet but with a much shorter front drive band. I liked the longer band of the SAECO. If my experiments are typical Ben should be a happy camper.
.

 

[Ian]

That must have been for the Marlins or something, most of the .45/70s I've seen have very tight, short throats.

 

[Ben]

most of the .45/70s I've seen have very tight, short throats.

As does mine ! !

Ben

 

[Ian]

Good on you, Ben, that ought to take care of it if you don't mind the extra step. The tight throat is actually a good thing for cast bullets, provided you aren't trying to paper patch them....then you have the opposite frustration!

 

[Brad]

My 444 Marlin has a throat like that. Darn near any fully diameter bullet in front of the case mouth makes it a no go. That rifle could use a new throat.

 

[Ben]

Ian,

Ben, that ought to take care of it if you don't mind the extra step.

This extra step = 20 bullets nose 1st into the die, = another 35-40 seconds added to things.

If it works well, I can easily live with that small incumberance.

Ben

 

[Ian]

I bump the front bands on one or two myself as required for a good fit, the results to me are worth it.

 

[Pistolero]

Looks good, I bet it will work. My 86 Win Miroku needs two diameter bullets, literally not throat.
Fortunately, the Rem 405 Jbullet is a two diameter bullet. Have not found a cast that will
work in it properly. This might be the trick.

Bill

 

[JSH]

I have the same issue only in two 41 mags. Make that three, buddy in La. has a Bisley hunter with the same issue.

 

[Ben]

If one doesn't like the idea of bumping the dia. of the front band, Tom at Accurate will make adjustments to any of his moulds to correct that problem for you.

Ben