45-70 Handload Question

[David I.]

I purchased some 405gr hard cast bullets to be shot out of my H&R BC and I know the throat is none too long on this gun, here is what I have run into: I set up my dies and seated a couple bullets to have a COL of 2.540" as specified. When I chamber this round the bullet is engraving the rifling approx. .035". I have heard this can be a good thing for accuracy with hard cast but I'm worried about excessive pressure. Should I be worried regarding engraving the rifling about .035"? I'll be loading using 4198 powder to velocities of approx. 1400-1500fps. Please advise, I'm hoping I don't have to throat my gun and go to all the bother of renting a reamer, but if I have to I will.

[Okie2]

I'd suggest moving this question to the H&R section...more guys will read who know about such things.   I have the same gun & caliber & have learned lots of good stuff over there.   Can't answer your question as I am loading it in the Lyman 357122....330 (actually is 340) hollow point.  I also use the H4198 (35 grains) & had to upgrade to magnum primers as the LR primers wouldn't ignite properly.  I hope you get your question answered as I have a larger mold coming in July.  Scott

[Dances with Geoducks]

I set my 45-70 cast right on the lands.
I use a 400gr RN & 500gr Postel mold
I took a case, belled it, then hand stuff the boolit to 2.90.
Then set it in the chamber, used a wood dowel and pushed it as far in as I could.
Then closed the chamber, and ejected it.
This is the measurement I use.
Some of the mold designs are too short to do this with, and expose the top lube ring.

I read this method in a reprint of how they made rounds in the field in the 1880s.

[Steve P]

I set up my dies and seated a couple bullets to have a COL of 2.540" as specified.

As specified by whom?  Are you crimping the bullets in the crimp groove?  Which 405 bullet?

You seat those bullets per your gun.  Your OAL is per your gun, not per someone elses data.  If you have to seat the bullet a little deeper than the crimp groove, you may have to use a little lighter crimp onto the ogive of the bullet.  You will have to work up to your load until you find the sweet spot for your gun.

I am assuming your 1400-1500 fps is a goal for your load.  If you do have to seat the bullet a little deeper, make sure you start with a little less powder as a bullet deeper in the case will increase pressure and possibly velocity depending on the gun, twist rate, etc etc etc.

Steve

[David I.]

Steve, as specified by the loading data from Hodgdon as COL, most loading tables I've seen state COL of 2.540 for cast 405gr. If the listed COL of 2.540 is a suggestion then I need to know that. Yes, I'm crimping in the crimp groove, but with this bullet and a COL of 2.540 it's crimping towards the bottom area of the groove, I have some room to seat the bullet deeper if I need to. I'm using Gardners Cache hard cast bullets. In the NEF/HR sub forum in the FAQS & HELP section under Cast Bullet Acurracy it states that with hard cast bullets a chambered round should just touch or engrave the rifling. My question is: How much can it engrave the rifling before it's considered too much? It sounds like a little is OK, but how much is a little?...I need an amount. The 1400-1500fps is listed by Hodgdon for a lighter Trapdoor Rifle load with a 24" barrel using this powder and cast 405gr bullet. Gardners Cache told me he sets his at 2.540, but I don't know if he is using a short throated H&R BC.

[quickdtoo]

I agree with Steve, seat them deeper so you're just touching the lands and work your load up again from start, even levergun loads are no problem for the H&R BC, but the problem I see with loading into the lands with the BC is not getting complete and consistent latch engagement which will lead to inaccuracy regardless of the load, there's no leverage like you would have in a different action type to force the bullet into the lands and bring the action into battery and fully locked up. You don't need to crimp your loads for the BC, so that's not an issue. 

Tim

[David I.]

Thanks Tim and Steve, I appreciate the info. I will seat the bullet deeper in order to just touch the rifling with a chambered round. I will be carefull how much powder I use since I'm seating deeper, but as you said the H&R BC is strong enough to handle very strong loads. As an added comment I'd like to say: In my past reloading over the years I have always stuck to the powder manufacturers loading tables and that includes the COL they state for each specific load they referance. I have never had a need to change anything like COL until now.....due to the H&R BC's rather short throat. In the past with different ammo (45LC) I did try different powders and bullets but I always stuck with the loading tables until I found a load from the table my gun liked. I never had to change the listed COL, there was never a need to......until now!