reloading .308 cast lead

[Muir]

What I have seen, is inconsistent burns in such loads. So I use case fillers not to reduce empty space, but to hold the charge in a repeatable position against the flash hole.

This. Lyman made a case for KAPOK fillers to hold the powder against the flash hole to avoid this. Unfortunately, cast bullet competition shooters using this found that they would get a ring/bulge in their chamber necks. "Grex" granulated shotgun buffer was used but I never followed the results.

There is a warning to be had about small charges of quick burning shotgun powder such as Red Dot and Green Dot listed in the Lyman manual if you look, they often generate jacketed bullet pressures in the 45K class delivering puny velocities. It's a great illustration as to how pressure and velocity are not in lock step with each other. It is very possible to get high pressure with very low velocity.~Muir

 

[Jon Smith]

The concern with small quantities of fast powder in large cases, seems to centr on, the primer may flash over the whole charge, and the lot goes off. Rather than the flame front burning through the powder at a predictable rate.
Causing a high peak pressure.

Crock - The real concern is the guy pouring powder not paying attention with the fast powders and 'double charging' (even triple charges were no unheard of) like in the ol pistol reloading days - lots of bang bangs destroyed like this. You are confusing yourself small quantities of slow powder in a large case 'Secondary Explosive Event' again little proof of that happening...

 

[devonair]

Muir, dodgyrog, enfieldspares, thanks for your wisdom.
I will slug the barrel + chamber.
Still waiting for the rifle after applying for variation, won the gun at auction weeks ago and feel like a kid at Christmas.
Didn't mean to hijack the thread, apologies zzr600.
Don't think I will mess with fillers or small powder charges, not too keen on that sort of excitement!

 

[dodgyrog]

One final tip - clean ALL the copper fouling from your bore before shooting lead.
C2R or Forest foam does it well.

 

[gonzo]

Muir:
I have a double 450/400 that had that exact problem. A previous owner used a case filler that compacted to form a plug, and caused quite a bad bulge at the neck. It was passed to me as a project though, as the owner wanted to see it recovered.


John Smith:
My posting #20 addresses this.
I will try and find my original texts on the subject and see if it was a warning on fast or slow powders. I'm always happy to be corrected.

zzr600:
Unless I've missed it, you have not indicated what sort of shooting you were looking to get into with cast loads. Long distance, short range plinking?

 

[Muir]

You are confusing yourself small quantities of slow powder in a large case 'Secondary Explosive Event' again little proof of that happening...

In fact, there is almost none. The H.P. White Laboratory (SAAMI) set out to make "detonation" happen and was eventually successful, but it took a lot of engineering to do so. A friend of mine recently loaded 13.5 grains of H335 instead of 23.5 in one of his 17's. I was there while he shot. Sooty cases and the bullets hitting low off the bull. That was about it. Detonation has become such an ingrained urban legend that people are terrified of reducing starting loads by 5% even though many reloading manuals advise it.~Muir

 

[Muir]

Muir:
I have a double 450/400 that had that exact problem. A previous owner used a case filler that compacted to form a plug, and caused quite a bad bulge at the neck. It was passed to me as a project though, as the owner wanted to see it recovered.

I remember that there was a real blow-up in the Cast Bullet Association because one of the top BR shooters on the production class was blaming Accurate Arms 5744 powder for kanking the chamber in his 30-06. I produced two years worth of notes showing that I was shooting the exact same charge sans filler with no ill effects.(I still do!) Old ways are hard to give up. Shooters are better off loading low pressure charges of bulkier powder than to mess with micro charges and a filler.

Are you going to sleeve or rechamber that 450? ~Muir

 

[gonzo]

Urban myth it may well be. But it does get trotted out by the 'you're not shooting that on our range' people.
Double charge is certainly a risk. Have seen so many of those. Mostly people loading pistol cal rounds, where checking should be easy. (Never had an overcharge or empty case myself. Fully progressive presses are the worst for this.
But certainly the burns are erattic with the small charges i use on a pistol/carbine rated range. So I case fill for that reason.

I'm not sure on the cal for the double. It would be nice to keep it in 450/400, and easier on the paperwork.
But that is a long way down the line. Gived the wall thickness at the chamber mouth, i recon I am going to have to sweat the ribs off, chop off the block and thread the barrels back into the block. And all thefun of regulating and putting the ribs back on.
Reaming and sleeving the chambers is not going to be easy on this gun.

 

[Muir]

Urban myth it may well be. But it does get trotted out by the 'you're not shooting that on our range' people.
Double charge is certainly a risk. Have seen so many of those. Mostly people loading pistol cal rounds, where checking should be easy. (Never had an overcharge or empty case myself. Fully progressive presses are the worst for this.
But certainly the burns are erattic with the small charges i use on a pistol/carbine rated range. So I case fill for that reason.

I'm not sure on the cal for the double. It would be nice to keep it in 450/400, and easier on the paperwork.
But that is a long way down the line. Gived the wall thickness at the chamber mouth, i recon I am going to have to sweat the ribs off, chop off the block and thread the barrels back into the block. And all thefun of regulating and putting the ribs back on.
Reaming and sleeving the chambers is not going to be easy on this gun.

Good luck on your decision. I have sleeved and reamed the the chambers on single shots but as you alluded to, a being a double rifle adds a whole new level of work. I worked with a gunsmith who specialized in sleeving the big AYA 12 and 10 gauge shotguns that came into our shop to 45-70, 45-90, and 405 Winchester. He turned the sleeves on a slight eccentric so that he could regulate the barrels before final set into the existing tube, by rotating them and fixing them into place with a grub screw from the underside of the block. He placed them with accraglass. He made his own sights and supplied the 'rifle' regulated to the customer's wants. Sounds kind of strange but they were well regulated and I never heard of one having a problem. All these years later I still know of the whereabouts of one of his 45-90's and the owner won't part with it.

As to the Urban Legends. There are many people who know how to reload but only 2 in 10 have looked beyond assembling ammo. I was on a range one day with a Model 1888 Trapdoor Springfield 45-70. The rifle was pristine and drew a couple of lookers when I uncased it. One fellow asked me what load I was shooting and I told him i was shooting 52 grains of H4831 under a 405 grain cast bullet. The man came unglued. I was going to blow my gun up! Called me an "...f--ing idiot who didn't know s--t about reloading." I shouldered the rifle (as he beat a hasty retreat) and touched off a round. I flipped open the breechblock, caught the case, and tossed it to him. I told him that luckily, what I didn't know about reloading I made up by understanding internal ballistics. He said he didn't understand why the gun didn't blow up. I said, "Exactly."

You're right. I have seen more guns trashed by double charges of fast fuel than by anything else.~Muir

 

[gonzo]

I have a double 45/70 project, on a shotgun action, in progress at the mo.
I had planned on doing exactly as you described. But I couldn't bring myself to ruin a good set of barrels. So have made a complete new monoblock. And it keeps the gun useable as a section 2 firearm, with the SG barrels.
Also, a sleeved and filled 12 bore set of barrels could get a bit front heavy. Unless you reduce the length significantly (after sleeving, unless you are an RFD).

I do have plans to do a 32cal double and a toy 22lr double by sleeving.

 

[Muir]

I have a double 45/70 project, on a shotgun action, in progress at the mo.
I had planned on doing exactly as you described. But I couldn't bring myself to ruin a good set of barrels. So have made a complete new monoblock. And it keeps the gun useable as a section 2 firearm, with the SG barrels.
Also, a sleeved and filled 12 bore set of barrels could get a bit front heavy. Unless you reduce the length significantly (after sleeving, unless you are an RFD).

I do have plans to do a 32cal double and a toy 22lr double by sleeving.

Yes. The finished product was heavy so he usually cut them back to 20-ish (iirc) inches. I have relined many 22LR using commercial liners. I finally got tired of the hit and miss quality and began turning down surplus Model 52 Winchester barrels -that were on the market then- into liners. I actually had an English fellow (last name Rose) who came the the US on some kind of business once a year. He would bring me High Standard Victor pistol barrels to fit with a M52 liner during his stay. I must have done a half dozen of them for him....~Muir

 

[gonzo]

Muir,
You are US based, then?
I envy you when it comes to what you can do legally when home gunsmithing.

The UK laws are a bit odd when it comes to SG to double rifle conversions.
If a shotgun has ever had a rifled barrel fitted of less than 24inch, then it becomes a firearm.
This was intended to stop people taking short rifles etc and converting them to smoothbore. But it also catches double SG/rifle combination guns. Probably unintentionally. As if I take a section 2 shotgun and hook a set of 18inch rifled barrels on, at any point. That gun becomes a section 1 firearm for the rest of its life. Even if sold with only the shotgun barrels.
So I need to keep my barrels to 24inch. Which could make them heavy if they were also full length sleeved.

 

[Muir]

Muir,
You are US based, then?
I envy you when it comes to what you can do legally when home gunsmithing.

The UK laws are a bit odd when it comes to SG to double rifle conversions.
If a shotgun has ever had a rifled barrel fitted of less than 24inch, then it becomes a firearm.
This was intended to stop people taking short rifles etc and converting them to smoothbore. But it also catches double SG/rifle combination guns. Probably unintentionally. As if I take a section 2 shotgun and hook a set of 18inch rifled barrels on, at any point. That gun becomes a section 1 firearm for the rest of its life. Even if sold with only the shotgun barrels.
So I need to keep my barrels to 24inch. Which could make them heavy if they were also full length sleeved.

Yes. I'm in Montana, USA.
While home gunsmithing is legal, I was a professional gunsmith. I grew up in the trade, so to speak. I've been attached to the shooting industry, in some manner or another, since I was 10 years old. When it became evident that CNC machining was allowing gun makers to easily offer options that used to be my bread and butter, I returned to college and retrained for a new profession. I retained ties to the industry working in R&D and consulting. I still have my tools and work on my own rifles but gave up my license years ago. Now I just like to reload and shoot.~Muir

 

[zzr600]

Muir:

zzr600:
Unless I've missed it, you have not indicated what sort of shooting you were looking to get into with cast loads. Long distance, short range plinking?

Most of my shooting is at the 50-100m range, for target practice. I'd like to be able to shoot lower powered and cheaper rounds and save the hight velocity/more expensive for when I go to 200m+ ranges.

 

[enfieldspares]

GM bullets, via Hannam's do hard cast lead .308 bullets. Trail Boss is a problem but if you've no velocity restrictions then you could use those American powders suitable for lead bullets that remain still available post-REACH.

 

[gonzo]

303 or 308 with 185gn cast, and a charge in the range of 10 gn of unique, or similar. Works well in my enfields (no4 and T4) at 50yds.