PRS Big Lube 45-70 worthless in a Browning/Miroku 1886

[OD#3]

BIG disappointment the day before yesterday at the range. I'd spent the better part of two days making a compression plug and then loading 70 grain charges of FF Goex behind the PRS Big Lube .45-70 bullet. Of course, this was after spending hours casting up several hundred projectiles in my new mould from Big Lube. It turns out that my Browning/Miroku '86 SRC, in typical fashion, is nearly throatless. Although it chambers 420 grn. LRNFP's just fine, the stubby Big Lube offering (mine weigh about 375 grains) has an ogive that's just too fat. After several tries, I managed to get one round chambered and fired but decided not to try and bully the mechanism through the remaining rounds. The few aborted attempts had heavy land markings on the bullet ogive. Good thing I only loaded up 20 rounds. Since I don't want to go through the trouble and expense of reaming out the throat, I guess I have to find someone with a more generous leade who wants to shoot up the remaining 19 rounds. Or maybe someone will trade me 19 empty cases for them... Its a shame. That bullet looked so promising for black powder, and it was so much shorter than my 420 grain bullets, I never dreamed it would be incompatible with my 1886.

[Lead pot]

If that rifle is like my friends it will most likely have a .456 groove like his rifle.
I pulled out the Lyman PH 457-121 PH and cast 50 for him and he ordered his own mould.
The Parker Hale mould drops out at .456" . It might be a little heavy for you if your one of those that like to shoot pistol bullets in a .45-70, it drops out at 475 grains but it is a find shooter in his 86.

[Gunlaker]

I've been using the 457193 seated to 2.52" and it seems to work reasonably well.

Chris.

[OD#3]

Guys, I really appreciate your suggestions on which moulds have worked for you in 86's. Thanks. I think, based on pictures of the 457193, that the 420 grainers I've been using with smokeless loads are from that mould. An acquaintance gave me about 100 of them years ago as scrap lead. They were very hard and miked at .458, and as I didn't have a 45-70, I was just adding them to my melt occasionally. They were pre-lubed with some hard blue lube, so I tumble-lubed them for good measure before loading them up. Incidentally, my smokeless loading was a bit hot. They clocked at about 1800 fps, but despite this I didn't really encounter any leading trouble from them. I wish I knew what alloy they were, because they shot really well, and I'd never have thought I could drive a PB that fast without trouble.

[cajun shooter]

The Big Lube bullets have in my testing not had enough bearing surface to make good Long Range bullets. The bearing surface is taken away to make room for the extra large lube grooves. This also leads to a bullet with a very large nose area. You would be better served to try the rifle style of bullet.
The Big lube design on all bullets is made to supply enough BP lube to the barrel to prevent fouling.
This is just a guess but most shooters of the Big Lube style bullets use a 20-1 alloy with a 10 BHN.
That only holds true for shooters using BP charged loads with BP lube.

[Baja_Traveler]

All my Big Lube moulds - the .357, 38-55 and my .45 are intended for shorter range shooting (up to 200 yards) and work great for that. I cast them in 20-1 or a bit harder with great results. My .45 mould doubles as a boolit for my Old Army, and when I cast for that, I cast 30-1 alloy for ease of loading.

[John Boy]

Back in the initial days when I knew spit about BPCR, my first rifle was the H&R BC. My first 45-70 bullet was the Big Lube 500gr, actually 485grs that was designed too long (now discontinued) so that only 52grs of BP could be poured and compressed like a brick. So I loaded 20 with Triple Seven and off to the range for my 1st BPCR shoot with the H&R having a vernier on it - my best friend told me I needed a vernier otherwise it wouldn't group worth a darn

100 yds - shot 15 rounds to get my 100yd base setting on the rifle. Might add, I had previously made a trajectory table with numbers that 'I hoped would be correct'

Had 5 rounds left - Ah, what the heck, might as well expend them on the 600yd range like the real BPCR distance the 'big boy's shoot at.

Flipped to the trajectory page for the BC - yep, 153 MOA on the vernier says I'll shoot center hits every time!

There was a club member next to me shooting high bore with about $10,000 of rifle and equipment. Felt a tad embarrassed with a $300 rifle and not knowing s*** from Shinola. Anyway, with my cheap $8.95 rifle rest and a sandbag, I proceeded to fire the 5 rounds as fast as I could aim and pull the trigger.

Now, that day was in the 90's, bright sun and the mirage was running fast (I had no idea then what the effect of mirage was shooting long distance) and my scope could detect a bullet hole if it had to...

The club member couldn't see his 308 holes either so we decided to drive to the pit along with Dan, a BPCR club member and a good one

When I saw the target, I was in total amazement ... in the 7 ring, the group was about 7" wide and 2 3/4" high ... with 3 holes that could be covered by a silver dollar. The guys were in total amazement too. I tried several times later to replicate the group with the Big Lube bullet & Triple Seven and couldn't even get close

I have subsequently shoot the H&R with a good bullet and BP reload and trust me, the Green Mountain barrel SHOOTS, even out to 1000yds but not with the original '500gr Big Lube' bullet

Then one day, I decided that Big Lube bullets served only 2 purposes: put a large lube smear on the muzzle and their real purpose is for short range shooting. So, I sold everyone that I had purchased and use bullets that have been in existence for decades - for all the calibers that I shoot

[Springfield]

Hmm, JB, sounds like the bullet had potential but you just couldn't fine it's sweet spot again. Not really the bullets fault. And the 45-70 385 grainer(or thereabouts) does have a very fat nose. It works in my Trapdoor and my BC, but not my buddies BC. Too bad it isn't made with a slightly smaller nose, I know a few other guys who could use it then. Every bullet doesn't work in every gun, that's for sure. OD#3, maybe you could crimp the bullet in front of the crimp groove, making it a bit shorter. With soft lead it should stay in place fine. I made a batch for a friend of mine with the same problem, so I just ran the nose into my Lyman sizer and resized just the nose to see if it would work, and it did. A bit more effort though, have to size every one twice.

[OD#3]

You know, I've considered the "size the nose smaller" option. It seemed like it would be a good deal of work, and I'd be out the cost of a smaller sizing die. As for seating them deeper, I could try that too, but I don't want to lose blackpowder capacity. That one round I managed to get chambered clocked only 1194 fps, and that was with 70 grains of FF compressed just far enough to seat the big lube bullet to the crimp grove. Granted, that was just one round, but I've seen plenty of range reports from people quoting a bit faster velocities with even heavier bullets and 63-65 grains of FF. I don't know how they do it.

[cajun shooter]

They do it with the bullets designed for LR. Try the Saeco 745 mould or look at the Sage Outfitters site. The Saeco 645 is another great mould.

[XTR]

You really should look at the thread I started and posted on for about a yr trying to get a Win-Mir 45-70 to shoot cast, though I was using smokeless. I gave up. I'm now pursuing my BP and cast fix with a C Sharps '74.

Yes, your rifle has a SAAMI chamber, yes it has zero throat, all you get in front of the case is the lead angle to the top of the lands, yes the groove dia is probably about .456.

[Just Duke]

BIG disappointment the day before yesterday at the range. I'd spent the better part of two days making a compression plug and then loading 70 grain charges of FF Goex behind the PRS Big Lube .45-70 bullet. Of course, this was after spending hours casting up several hundred projectiles in my new mould from Big Lube. It turns out that my Browning/Miroku '86 SRC, in typical fashion, is nearly throatless. Although it chambers 420 grn. LRNFP's just fine, the stubby Big Lube offering (mine weigh about 375 grains) has an ogive that's just too fat. After several tries, I managed to get one round chambered and fired but decided not to try and bully the mechanism through the remaining rounds. The few aborted attempts had heavy land markings on the bullet ogive. Good thing I only loaded up 20 rounds. Since I don't want to go through the trouble and expense of reaming out the throat, I guess I have to find someone with a more generous leade who wants to shoot up the remaining 19 rounds. Or maybe someone will trade me 19 empty cases for them... Its a shame. That bullet looked so promising for black powder, and it was so much shorter than my 420 grain bullets, I never dreamed it would be incompatible with my 1886.

All I use is SAECO Moulds for my 1886's and will not handle the ogive of most moulds. Here's many many test reports HERE with the SAECO moulds.

[XTR]

This is what your chamber looks like. This picture is from TexasMac, it's a cast of the SAAMI chambers that you get in a WinMir, somewhere he talks about the lead angle on these too and it's pretty steep, but I think if you wanted to try paper patching patched to bore that may work pretty well.

Good luck shooting cast in this rifle, maybe you can get it to work, I couldn't get anything from 340 to 405 to shoot in it so I gave up and ordered 500 jacketed 405 Remington bullets from Midway, they shoot great (as in about 1") over 50gr of 3031 for about 1700FPS.

[Chicken Thief]

You could try to size the boolit in the case until it will chamber and see what that brings you.
It might just be that it works.

Dont fl size the finished cartridge just enough that the top of the case thins enough for the round to chamber.

[rr2241tx]

The key to making those Miroku 45-70 BPCR rifles shoot is to start with a bore riding bullet of 500 grains or better and about 65 gr of powder. The bore is .450, groove normally .456. 20:1 or 30:1 both seem to work equally well. It can be done. My shooting partner uses my mould to cast for his Miroku and gets excellent results. That Paul Jones mould drops 30:1 at 586 grains. His gun also shoots a 500 grain Gov't roundnose very accurately. Texasmac did the trigger for him.

[Just Duke]

SAECO 300 GRAIN @ 100 yards
28 Grain of Hodgden 4198.

[Just Duke]

Here's the SAECO #018, 405 grain cast wheel weight samples.








Winchester 1886 Take Down 45-70.
Bullets sized to .459 and 28 grains of Hodgden 4198
Here is the SAECO 405 grainer at 30 yards shot resting on my elbows.

[NSB]

We need at least one dumb question a day to show what we know. I'll offer one up: What is involved in correcting this by reworking the chamber? What is the actual cost and how difficult is it? Someone must be able to do this at a reasonable cost. You're taking metal out, not adding it on. I have one of these and went to jacketed to make it shoot.

[Just Duke]

We need at least one dumb question a day to show what we know. I'll offer one up: What is involved in correcting this by reworking the chamber? What is the actual cost and how difficult is it? Someone must be able to do this at a reasonable cost. You're taking metal out, not adding it on. I have one of these and went to jacketed to make it shoot.

Fix the bullet not the rifle. PM me and I'll send you both some SAECO's lube and ready to go..

[NSB]

Duke, I really appreciate the offer but I'd still like to know what would be involved in fixing the rifle. Since I bought this gun over a year ago I've read a lot of posts on the problem with the chamber/lead on this gun. It seems that other brands don't have this problem and shoot cast pretty good. What would it take to make the chamber/lead better? I'm sure you're correct, I'd just like to know the cost of the alternative. Thanks.