Cast diameter 45-70

[surfanarchist]

What is the maximum and optimum dia. folks with experience are using on their cast 45-70? I'm casting for 355gr GC and 405gr no GC for two Browning 1886 rifles, a SRC and a full size rifle, and a Marlin 1895 LTD V. Here's my question. My mold throws a boolit .462 - .463 and I'm wondering what to size these to. Throat slugs are about .458 + - but I've read that a larger dia. will give better accuracy.

If I size these to .461 am I looking for trouble? Given the measurements I've quoted do folks thing accuracy/performance would be better or worse with 3 1000ths oversize?
I did look through with the search function but didn't really see anything specific to being 3 1000ths oversize. I know shooting will give me the final answer but I need to order a sizing die so I'd like to order only once.

Thanks,

Wayne

[surfanarchist]

Well I did a better search and in fact there is a ton of stuff on 45-70 diameter. Lots of opinions. I think I will be fine at .461 but of course anyone wanting to make me smarter is welcome.

[Wally]

I have a Marlin .45-70. I size bullets to .460" and it is quite accurate. I tried shooting pan lubed, undersized bullets and found they chambered just fine, but offered no better accuracy than sizing to .460". I use the RCBS 2-Cavity Bullet Mold 45-325-FN-U 45 Caliber (458 Diameter) 325 Grain Flat Nose Universal as well as the Lyman 1-Cavity Bullet Mold #457193 45 Caliber (458-459 Diameter) 405 Grain Flat Nose. The lighter bullet is just as accurate out to 250 yards. I have used Unique & Red Dot powder.

[Hickok]

I size my boolits to .460" for my Marlin 1895 Ballard rifling. BUT, at times they can fit snug in the chamber, and I really have to be careful of the crimp, getting it just right so as not to increase the neck diameter.

I test every round as to chambering before going to the range or hunting, as some will be too tight.

I am going to get a .459" sizing die, as the .460" sized boolits are just a smidgen to big, and it is a hassle.

My Marlin barrel slugs at .457" (.4568" to be exact) so a slightly smaller boolit should chamber easier.

[FredBuddy]

.462 fits snugly in unsized brass and chambers easily in my Marlin 1895 CB.

Shoots well, too.

However, I noticed the barrel gets warmer, from the extra friction, I suppose.

So it's back to .460 and minimal sizing.

[John Boy]

Step 1 - slug the bore of your rifle to determine groove diameter
Step 2 - Size the bullets 0.001 to 0.003 over groove diameter
Step 3 - Test the accuracy of each 0.001 - 0.002 - 0.003 to determine which diameter produces the best groups
Why diameters have to be greater than groove diameter? The bullet bases have to be able to obturate in the grooves while traveling down the bore to prevent leading and provide a gas seal for full velocity = accuracy

[Kraschenbirn]

This may not be relevant 'cause I don't shoot a .45-70 levergun but for both my single-shots...a Pedersoli RB and an H&R Trapdoor...I pan-lube and load 'as-cast' which, depending upon which mold, is .461-.462. Neither gun likes anything under .460.

Bill

[pjames32]

My 1895 slugged 0.4575. I size 0.459 with good accuracy an minimal leading. I'm using an NOE 350gr mold that drops 0.461.

[Bird]

What is the maximum and optimum dia. folks with experience are using on their cast 45-70? I'm casting for 355gr GC and 405gr no GC for two Browning 1886 rifles, a SRC and a full size rifle, and a Marlin 1895 LTD V. Here's my question. My mold throws a boolit .462 - .463 and I'm wondering what to size these to. Throat slugs are about .458 + - but I've read that a larger dia. will give better accuracy.

If I size these to .461 am I looking for trouble? Given the measurements I've quoted do folks thing accuracy/performance would be better or worse with 3 1000ths oversize?
I did look through with the search function but didn't really see anything specific to being 3 1000ths oversize. I know shooting will give me the final answer but I need to order a sizing die so I'd like to order only once.

Thanks,

Wayne
If you size to .460 or more you may well have problems with reliable chambering. 1 thou to 1.5 thou over is plenty. I have used 0.5 thou over with no problems with checked bullets.
If you take a fired case and measure the inside mouth diameter, that will be the largest bullet you can load and fit into the chamber if the crimp is applied correctly. That would still give you 1 thou chamber clearance. My brownings chamber and bore specs seem to be spot on, and I use .4585 bullets for the .457 bore. I tried .459 bullets, and got slightly better accuracy, but to the point of splitting hairs. It might have been me, pure luck, or the fact I tried pure lino, and maybe .459 did actually shoot better, that I do not know. I have run loads to the point where recoil has become obtrusive, and have never seen a speck of leading in the barrel using clip on wheelweights and bens red lube and gas checks.
The plain based .405's are commercial cast bullets at just over .458. These go to around 1450fps?, just below the point of leading using 34.5 grains of IMR4198 with excellent accuracy.

[surfanarchist]

Thanks all for the information and your experiences. After reading a lot, measuring, making dummy rounds, etc., for me the answer is.459. .460 will not chamber reliably. .458 on a gas check works well but Im going to .459 for plain base cast. Now i need to make and shoot them.

[murf205]

Yep, works for me too. My Marlin CB slugs .4575 and it loves .459 boolits (405gr Accurate Molds) either GC'd or PB boolits, powder coated or lubed with Carrnuba Red lube.

[surfanarchist]

Yep, works for me too. My Marlin CB slugs .4575 and it loves .459 boolits (405gr Accurate Molds) either GC'd or PB boolits, powder coated or lubed with Carrnuba Red lube.

I 'm using a brand new Accurate 260-405M PB and 460-355N GC combo mold. I've never bought a custom mold before and I'm just flummoxed at the higher quality of the Accurate mold.

[murf205]

Accurate was my first custom mold as well. Tom really makes a work of art. I bought a 4 cavity mold with 2 405A and 2 with 405D, one GC and one PB like you did and my rifle loves either one. I have driven the GC'd boolit to 2k fps with no lead and good accuracy, but it was a brute to shoot. I've since loaded it down to 1400fps and it is MUCH more fun. At the slower speed it will still shoot through a T-Rex!

[JonB_in_Glencoe]

I have a Ruger #3 in 45-70, I assume groove dia is around .457 to .458
I size and Lube a NOE 460-405-RF with a .459 die.
that fits in the chamber nicely.

[murf205]

I have a Ruger #3 in 45-70, I assume groove dia is around .457 to .458
I size and Lube a NOE 460-405-RF with a .459 die.
that fits in the chamber nicely.
JonB, that Ruger #3 really lets you know it when you torch off a 405gr boolit in that little gun, doesn't it. I have a friend with one and I've seen his shoulder turn colors after 20 or so rounds, but he likes 'em pretty warm! That steel butt plate is really special.

[W.R.Buchanan]

My RCBS 45-300FNGC mould drops at 461-2 with WW's and I size to .460. This is a gas check boolit so there is no leading. My load for this is 33 gr of 5744 for about 1550-1600 FPS. It is stout but manageable, and I can shoot 40 in one sitting in my Marlin 1895CB. I started at 25 gr and worked up until I got an acceptable trajectory out to 200 Meters. I stopped at 33 gr when that happened. This load is also suitable for Hunting anything in N/A should that need ever arise.


I also installed a Gra-Coil Recoil Reducer in the buttstock so the gun weighs 8 lbs instead of the rather light 7 lbs it started out as. This gun really needs to weigh 9 lbs to be really comfortable to shoot but it is what it is and it would be hard to add more weight to it. The Gra-Coil weighs 1 lb and it's filled with Mercury. The gun balances right, now, but another pound in the buttstock would make it butt heavy. It also has a 1" thick Pachmayer Recoil Pad.

As soon as all my stock of those is gone, future boolits will be powder coated.

This eliminates leading completely.

My .44's only need one patch ran thru after shooting to remove the powder fouling from the last shot.

PC'ing is definitely the easiest way to eliminate Leading from your life, and the side benefit is if you have a mould that is dropping small you can bump it up .002-.004 just by applying the PC.

I might add that I load these with my Buchanan Precision Machine Hand Press and they are a Piece o Cake.

Video on this coming soon.

Randy

[irishtoo]

i load for 4 .45-70, mine and a friends. noe 397-.460 pb , powder coat and size to .460. fun and accurate. just watch how far out you crimp them. the ones i carry hunting i drop into a h&r handi chamber just in case. irishtoo

[barnabus]

This may not be relevant 'cause I don't shoot a .45-70 levergun but for both my single-shots...a Pedersoli RB and an H&R Trapdoor...I pan-lube and load 'as-cast' which, depending upon which mold, is .461-.462. Neither gun likes anything under .460.

Bill

what mold are u using for ur Pedersoli? i have a Pedersoli Sharps im working with.

[pmer]

Thanks all for the information and your experiences. After reading a lot, measuring, making dummy rounds, etc., for me the answer is.459. .460 will not chamber reliably. .458 on a gas check works well but Im going to .459 for plain base cast. Now i need to make and shoot them.

I've been having this sort of chambering trouble with a rifle too. My bore is .4595. .458 jacketed bullets will chamber but .461 cast boolits won't chamber. IF I size a boolit to fit this chamber it will be too small for the bore and the barrel will lead like crazy. I opted to do a little neck turning and that opens up more options for sizing to the bore.


I just got a 46-305s from Accurate Molds. It's a smooth sided boolit that casts right to my requested diameter of .458 and I have these powder coated to .461 and been starting to shoot them at .460 and unsized. I only tried a couple loads and am getting 2-3'' groups plus flyers. Hopefully it will tighten up.

[Kraschenbirn]

what mold are u using for ur Pedersoli? i have a Pedersoli Sharps im working with.

I've several .45 molds but the two that work best for me are the Lyman 457124 (404 gr. from 25/1) or an old Ohaus 936405 that drops right at 450 gr. from same alloy. Boolits from both, 'as-cast', measure .461 (+/- .0005?) and are seated to barely contact rifling.

Since posting original comment, I've acquired another .45-70; this one an Taylor (Uberti) Highwall and it seems, also, to prefer that old Ohaus boolit but, alas, the mold has been out of production for quite a number of years.

Bill

[Bird]

Measure the inside neck diameter of a fired case. That will give you the largest bullet that you can use, and still allow for a couple of thou case to chamber clearance. My 1886 Miroku is limited to a 0.459'' bullet, a 0.460'' is on the tight side. Accuracy is fine.

[GregLaROCHE]

I think crimping can play a big part. I’m not crazy about the results I often get from a factory roll crimp. I just got a tapered crimp die. Can’t wait to try it.