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Re: 45-70 Marlin mold

Posted: Tue Jun 09, 2015 2:09 pm
by Bangbangman
I can get .458 gators, so that problem is solved. Can they be seated and crimped with standard kit or do they need specialist equipment?

I've been looking for a sizer that could take as-cast .463 bullets down to .462 or .461 but can't find any.

My bore slugged at 0.4545" three inches from the muzzle and 0.4595" on today's chamber impression:

Image

However, it shoots .462 bullets much better than .458

Any suggestions where I could find such a sizer? Or should I go for as-cast .461 and try and find a .460 sizer, hoping the gun likes this diameter?

It's complicated, this business!

Re: 45-70 Marlin mold

Posted: Tue Jun 09, 2015 3:22 pm
by mtngun
Yes, cast bullets are complicated, that is for sure. :lol:

First off, do you have a lubrisizer, or will you be tumble lubing?

I believe that Buffalo Arms makes custom sizer dies for the RCBS/Lyman lubrisizer, however the one that examined lacked a tapered entrance. :(

There may be other people making lubrisizer dies, I don't know. "Buckshot" at Cast Boolits used to make them but I dunno if he is still in business. I sent Buckshot a PM, I will let you know if I hear from him.

Re: 45-70 Marlin mold

Posted: Tue Jun 09, 2015 10:35 pm
by Bangbangman
At the moment I have no casting or sizing equipment.

I'm trying to keep costs down so a new Lyman-RCBS lubrisizer might have to wait. However, I'm prepared to fork out on the things that really make a difference in the long term.

Not sure what my alternatives are, though, if I want to size to an uncommon diameter like .462

I haven't been able to shoot any bullets between .458 and .462 so it's quite possible that .460 would work, for e.g.

Thanks for making enquiries on my behalf, and for your quick and patient responses.

Ben

Re: 45-70 Marlin mold

Posted: Wed Jun 10, 2015 4:55 am
by mtngun
Buckshot is still in business, offering both RCBS/Lyman lubrisizer dies as well as push-thru dies.

Re: 45-70 Marlin mold

Posted: Wed Jun 10, 2015 5:05 am
by Bangbangman
Thanks for that, I'll try and contact him on Castboolits. If he won't ship to UK or can't make what I need, .463 bullets might be a dead-end.

So if I go for an as-cast diameter of .462, these should shoot in my gun unsized, since that's exactly what I'm doing with my current bought cast bullets. I could then size them to .461/.460 later, if I found problems with concentric it's/roundness. Am I completely wrong about this or is it a reasonable work around if sizing dies are a problem?

I assume push-thru sizing and tumble lube will be my cheapest option for now.

Ben

Re: 45-70 Marlin mold

Posted: Wed Jun 10, 2015 5:20 am
by mtngun
Yes, push-thru and tumble lube is the cheapest way to get started.

Most people shoot 0.460" or 0.461" in their Marlins.

IMHO you need to address the barrel's tight spots.

Re: 45-70 Marlin mold

Posted: Wed Jun 10, 2015 1:12 pm
by Bangbangman
Sounds... Involved! Does it mean lapping/fire-lapping?

How do I know my "tight spot" isn't due to my amateurish bore-casting? I guess I could repeat it, trying to hit the same spot as before.

Re: 45-70 Marlin mold

Posted: Wed Jun 10, 2015 1:34 pm
by mtngun
Bangbangman wrote:How do I know my "tight spot" isn't due to my amateurish bore-casting? I guess I could repeat it, trying to hit the same spot as before.
Sure. Yes, firelapping. Some background here.

Re: 45-70 Marlin mold

Posted: Fri Jun 12, 2015 11:18 am
by Bangbangman
I read your guide to making fire-lapping bullets.

What abrasive do you use and do you need to "go through the grits" from coarse to fine?

How do I know how many shots to fire?

I'm instinctively afraid of "grinding-out my throat and rifling!"

Is there any reason I can't get on with ordering a mold as already discussed?

I have PM'd Buckshot on Castboolits about .462 sizing die but no response yet.

Thanks for all your advice.

Ben

Re: 45-70 Marlin mold

Posted: Fri Jun 12, 2015 12:14 pm
by mtngun
Bangbangman wrote:What abrasive do you use and do you need to "go through the grits" from coarse to fine?
I use Clover brand silicon carbide grease, purchased from a machining supplier. I happen to have 150 grit (very coarse), 280 grit, and 500 grit. I don't know if Clover is available in the UK but you should be able to find something equivalent.

Auto parts stores sell valve grinding compound, but often it is coarse, 150 grit or so.

You may be able to find lapping grit on ebay, too. Sometimes it is sold in powder form, and I suppose you could use the powder to make your own grease, just mix the powder with oil.

The 150 is very coarse and I've only used it on very rough barrels. Normally I start with the 280 and then follow with 500, which leaves a mirror finish.

If you only buy one grit, I would suggest 280-ish.

Several shooting outfits sell lapping kits with several different grades of grit, but they're $40 or so.
How do I know how many shots to fire?

When there are no more tight spots in the barrel ? :lol:
I'm instinctively afraid of "grinding-out my throat and rifling!"
I don't blame you. I am not a big fan of lapping myself because it can make long throats longer and big throats bigger. However, since you are starting out with a nearly throatless barrel, that would actually be an improvement.
Is there any reason I can't get on with ordering a mold as already discussed?
No reason, since I don't recommend making the bullet a "glove" fit in the throat, anyway.