Hey Guy's - I'm looking really hard at a Siace chambered for 45-70. I've searched around the forum and most have settled on 32,000 for the maximum pressure allowed in most doubles.

I use Garrett ammo loaded to 35,000 in my other 45-70's. This same Siace is chambered for 30-06, which has a standard chamber pressure of 60,000. If my logic holds true, I ought to be able to use ammo in the 35-40,000 range and be safe.

What am I missing? It seems like a no-brainer to me but every bad thing that ever happened to me started with a seemingly simple decision...

I appreciate your thoughts.

JDA

I have a couple of Siace 45-70 doubles and they are very well made. My regulating load for a 405 grain bullet is about 1650 fps and 300 grain bullets at about 1850. These are mild but regulate. I feel like the Siace should handle much hevier loads but regulation is the big factor. These guns are made in 30-06 and 444 Marlin so pressure are higher than 40000 psi in these cartridges. The Siace is a very light framed gun and I wouldn't want to try and make a magnum out of it. If you want a magnum 45-70 get a Ruger No 1. The Siace double in 45-70 with a proper regulating load is a joy to shoot and will kill anything you want within reason.

Sam

Sam - Thanks. I'm not trying to make the gun something it isn't. My opinion is that the 45-70 is a fantastic killer for all of North America. I've used the Garrett ammo in a WWG Guide gun and have never recovered a bullet.

Since I've had such good luck with these loads (and have about 20 boxes), I was hoping to be able to use it in the Siace (assuming it will regulate).

If 40K pressure and above are safe for the 444 and '06, I continue to think I'll be OK using the Garrett ammo in the Siace??

I can't believe you made me do math this early; the 30-06 at 60Kpsi gives a backthrust of 8700 pounds, and a 45-70 at 40Kpsi gives 5800. Assuming an oiled chamber. Which you never do. Think about this; both of those rounds are not far apart in case head diameter (.470 vs .500). So, your conclusion is valid from a mathematic point of view.
And as stated; regulation is more important.

dpcd - Thank you. I'm not smart enough for that kind of math. What weight bullets did you use to get the back thrust (or does it even matter?)? I use the 420's in guide gun.

Reading your post, I'm guessing I'm ok to touch a couple of these off and see what happens?

Appreciate it!!!

Pressure doesn't know bullet weight. It reacts on a square inch basis of the area it has to work against. Yes, the rifle will handle it. A lot of people (not you) mistake recoil for pressure; wow, that 577 NE must create a lot of pressure. No, it doesn't, but it does have a lot of area to work against. That is why we can put a .223 on a Contender pistol at 55000 psi with no problem, but a 444 Marlin at the same pressure will stretch the frame.

So, If I'm understanding correctly, because the base of the 45-70 case is larger in diameter, the 5,800 pounds of back-thrust will be spread out over a larger area on the face of the receiver, thence reduced stress on the frame verses the 8,700 that the 30-06 produces over a smaller area?

I think I understand. In any event, I'm going to give them a try. I have several different loads from Garrett and all are advertised at 35,000CUP.

I also have several boxes of ammo from Grizzly cartridge, but i'm not sure what pressure they are loaded to, so I won't try them.

Really appreciate your help!

I'm not trying to be a smartazz but do you understand what we mean by 'regulation'?

Yup, I understand regulation of the barrels (you won't offend me and that's was a fair question).

I have/had several other DR's that I shoot, but this is the first one I've had in 45-70 where I'll shoot ammo that is outside the traditional spec (in terms of pressure).

Maybe I've been lucky, but I've never had trouble finding ammo that would regulate in any of my Doubles. I had a Merkel O/U 9.3x74r that would shoot anything I crammed into it to the sights (got rid of it because of a questionable single trigger that I didn't trust). I had a Beretta 30-06 689 that would do the same (Got rid of it because it was so awfully ugly). I just picked up a Merkel 140e-1 6.5x55 that shoots the couple of different boxes of ammo I bought for it perfectly (under an inch at 50yds).

I guess I'm just lucky and I hope that carries forward with this new Siace. Since I'm not a reloader, I'm going to try several different Garrett's and see what works. The reality is that I only need to be "Pie-Plate" accurate at the ranges I'll be using this at.

It'll be fun!

JDA

If you are after pie plate regulation then that explains why you aren't worried about it. Anyway, the axial thrust of cartridges fired in chambers is given in pounds that is pushing against your frame; hence 5800 is less than 8700. The area available to push against was allowed for in the formula.
You are going to have to start reloading; really. It will be more fun.

I understand that some of those hot 45-70 loads use a special thicker case ?? You don't want the case to split driving hot ones.
The 45-70 performs well, don't try to make a magnum out of it !! Too bad the PMC 350 @ 2150 [?] is no longer made, that should take anything in north America.

Never heard of a thicker 45-70 case; the standard ones are thick enough to handle 55K psi with no problem; Ruger and Siamese Mauser loads are way above 35000 psi that Garret uses.

quote:

Originally posted by mete:
I understand that some of those hot 45-70 loads use a special thicker case ?? You don't want the case to split driving hot ones.
The 45-70 performs well, don't try to make a magnum out of it !! Too bad the PMC 350 @ 2150 [?] is no longer made, that should take anything in north America.

I actually have a couple boxes of these. Great round - Not sure why it is not currently manufactured?

Those don't have thicker brass than standard Rem or Win or Starline (which is thicker in the necks; good brass).

Thanks for your help above…

So I got a really good deal on this Siace - But there are some changes that I'd like to make - I'd like to have the forearm reshaped and both stocks re-checkered.

I'd also like to have claw mounts installed.

How much am I looking at spending and who should I have do the work?

It sounds like this 'really good deal' is going to get expensive quickly..

Yeah - I'm guessing 12-1500, but that's why I'm asking

The 12-1500 will be just for the claw mounts. (reference NECG)
Add another 12 for stock re-shaping and re-checkering.
Personally, (I have no money), I would install Kimber dovetail rings and leave the stock alone.

Kimber dovetail rings? Can you post a pic?

Why not just drill and tap the rib for a flat based scope mount.

I just kinda want it to look "right". I guess I could have some Talley's machined to fit over the rib. That might work.

Searcy will build a optional rib that will hold Talley rings on his rifles. If you live in CO and are close you are welcome to see what it looks like.
Pretty bullet proof design and you can't even tell the rib is there if no scope is on the rifle.

Snowwolfe - I would love to see that. Peyton is about 7 miles from Meadow Lake airport - If I flew in there, would you be able to drive over?

It would give me an excuse to fly and I'd buy you lunch!

Yes, I can drive over. Airport should be easy to find.
Send me a PM to work out the details as I have two trips planned in the near future and will be out of state.

quote:

Originally posted by srose:
Why not just drill and tap the rib for a flat based scope mount.

Sam, I've done this but most ribs are not exactly level on top. One that I did, once the rings were installed on the bases the rings were not in line with each other. the front one leaned to the right slightly and the back one leaned to the opposite side slightly. Most ribs need to be milled to level the area where the bases are to be mounted. Kimber makes a gun smith's flat bottomed base about six inches long with multiple screw holes and three different recoil stops. this allows you to attach the rings to the base in two or three different ways and clamp it to the top of the rib to see if everything lines up, and to get the eye relief right before drilling the mounting screw holes. That smith's scope base is exactly the width of the rib on my 140E-1 Merkel 9,3X74R double rifle and if the rib is milled perfectly flat it only has to be milled about 1/16th inch deep and when the base is mounted looks like it is part of the rib. Makes a very clean mod!

I have one and if I can find it in my vault I will post the part number here later.

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