Excessive pressure

[cannonball1]

I have made a 1 in 24" twist barrel muzzleloader, 1" accross the flats, 45 Caliber. I am shooting paper patch bullets and want to shoot a 450 to 500 grain bullet with 90 grains of Goex black powder.

Will that create to much pressure??

 

[BrownBear]

I'd sure ask the barrel manufacturer for starters.

 

[fleener]

You said that you made the barrel? what kind of steel did you use?

Breach plug, did you make that as well, or did you buy one?

In the right setup you are not unsafe.

Fleener

 

[FishDFly]

In the right setup you are not unsafe.

Or in the wrong, not safe.

 

[old gunsmith]

There are so many variables to consider, for instance, are there barrel keys dovetailed into the barreled if so, what's the residual wall thickness at that point? Same thing for a rear sight dovetail. How many threads of contact in the bolster? Is this a name brand American made barrel or a Spanish import? Perhaps the best thing to do would be to take the rifle to a gunsmith who understands muzzleloaders to get an opinion. OG

 

[Col. Batguano]

You are essentially recreating the 45-90 Winchester factory load. What to the loading charts tell you the pressure is in that cartridge?

 

[fleener]

I have 7 ML rifles that are made to shoot .45 cal conical bullets. I shoot both grease groove and paper patch bullets. The bullets are around 520 to 540 grains. I shoot 86 grains of 2F swiss in these rifles. The barrels are made for shooting the higher pressures associated with this type of setup. The rate of twist is 1 in 18 for 6 of the rifles and 1 in 20 for the other. With the exception of my original Rigby made in 1864 the barrels are all either Badger or Green Mountain and are made of steel that is suitable to shoot smokeless loads.

So, you can easily shoot heavy loads, you just need to have the right setup.

Fleener

 

[curator]

90 grains of "black powder" (you don't mention the granulation, Fg, FFg, FFFG?) With a 450-500 grain bullet should generate about 28,000 to 30,000 PSI. This would be fine with a patent breech and a platinum lined nipple, but could be unsafe with a drum and nipple type breech. Certainly the Whitworth, or Parker Hale "Volunteer rifle" can handle these kind of loads.The CVA/Traditions breech "may" be able to handle these pressures, but simple drum and nipple cannot handle them for very long inviting a catastrophe.

 

[Zonie]

According to the Lyman Black Powder Handbook & Loading Manual , curator is about right. He might be a bit under the actual pressure for those 450 and 500 grain bullets because the Lyman book shows pressures like those for a 245-325 grain slug.

One thing it does show it, they don't list any 3Fg powder. The test powder was either 2Fg or one of the Pyrodex rifle powders like RS.

3Fg powders burn fast and make a lot of breech pressure so I suggest they be avoided in your bullet loads.

I also suggest using a lighter weight bullet and smaller powder loads.
Your shoulder will thank me.

 

[fleener]

I have a few friends that shoot 3f swiss in their long range ML.

Platinum lined nipples are used by most shooters. Ordinary nipples will erode quickly due to the pressure. Platinum nipples will erode with enough shots. I just had 4 nipples relined with platinum.

Again, if you have the right setup it is not dangerous.

Fleener

 

[cannonball1]

Thanks for the information. Here's what I may have left out. It is a side-hammer. I am using 90 grains of 2F Goex powder. I just got back from shooting the 450 grain bullet and it will not group, so I am going to shoot a 400 grain paper-patch .441 buffalo arms bullet. Right now I am using a t/c regular nipple. I need the lower nipple for alignment. This is a .45 caliber Oregon barrel with a hawken type hooked breech.

Where and what is the best way to go on a nipple. Any other suggestions would be appreciated.

 

[BrownBear]

...Oregon barrel....

Great barrels. I have a couple of them, and once I hit on the right load combo they give stellar accuracy.

Keep on working on your loads, and I bet you have a winner there.

 

[Many Klatch]

Try it with 70 grains of 2F and a 500 grain bullet. The faster twists work better the bigger bullets.

 

[fleener]

1 in 24 twist is not a fast twist for shooting big heavy conical bullets. 1 in 18 would be very much the norm and the trend is starting to go towards 1 in 16.

For a rifle like this I like the bullet to be close to bore dia. It should not start hard, and should go down the bore with just a little more than the weight of the ram rod.

You did not mention the use of a wad. Try a card wad, or wool felt wad, or a combination of both.

You are using a lighter bullet, with a slower twist barrel. I would drop the powder charge.

You did not mention what you intend to do with this rifle or what ranges you are wanting to shoot.

I would drop the charge down to 70 grains, use a wad with a properly sized bullets and see what you can do. I am assuming that you are not going to shoot it past 500 yards. 70 grains is plenty of powder.

Your paper on the bullets can make a difference in your groups. I do not lube mine and I tried 5 or 6 different kinds of paper before I found one that grouped well. The paper I settled on is air mail paper that is really old, bought it on ebay.

I do not have any idea on what type of steel that Oregon uses for their barrels or if it is safe for what you are trying to do.

Rick Weber in TN is a buddy of mine, he makes the platinum nipples. Not sure what he is charging but they will be around $45 each. [email protected]

What are you using for sights? peeps, scope or open?

Fleener

 

[azmntman]

H e said $50.00 when I ordered one for my .31 1849. EXCELLENT work, nice guy. Getcha one (or 3) :thumbsup:

Mine had a very odd thread and he had to fabricate it. Still turn around time was excellent!

 

[cannonball1]

I am using a veg. fiber wad. The last time I shot this 400 grain bullet it gave me a 1" - 5 shot - 100 yard group with the 90 grains of BP and with the Malcolm 32" scope. For one that is use to 1 in 60" twist. 1 in 24" is fast. I am now using butcher wrapping paper for the paper patch. The Greenhill Ballistic formula suggests a 380 grain for this particular 45 cal. I might try some of them. Right now I have decreased my pre-measured charges to 80 grains. That should be a safe charge?? I would like to shoot to 400-500 yards with some sort of a group.

 

[fleener]

I would still go down to 70 grains and see what you can do for a group.

A couple of years ago I was shooting my Rigby .45 cal with a 530 grain bullet with 70 grains of 2F swiss. I used this load in several matches including the 2015 World Long Range match. I used this load for out to 600 yards and won plenty with it. For 900 and 1,000 yards I was using 75 grains of powder and set a new world record at 900 yards.

The point is you dont have to have a heavy charge to shoot well.

I did have issues at the World match with 1,000 yards. I think my bullets with 75 grains were just to marginal and the conditions were causing me trouble.

I now shoot 86 grains of 2 f in this rifle and all of my LRML. I shoot the same powder charge in 8 different rifles, keeps it simple for me. I weight my powder to the 10th of grain and can simply grab a bag of powder vials and know they are the right ones.

With my current comb I am right at 1,300 fps, which is where I need to be for 1,000 yards.

If you are only shooting out to 500 yards, if your able to get an accurate load 70 grains is plenty.

I cant post pictures from Photobuck anymore but I could show you a half inch, 3 shot group at 200 yards with a scope. 1.75" groups at 200 yards with peep sight. I am not happy with my groups unless I can get them to 1" or less at 100 yards with peep sights.

1" group at 100 yards, 5 shots is certainly not bad, I do think you might be able to shrink it.

keep us posted.

fleener

 

[cannonball1]

Thanks for the information I will try it. I have already done so though and could not get a group, but afterwords I found the scope was just a little loose and that could have been my problem. I have had real good luck with single wrap square cut butcher paper,but as of yet cannot get a decent group with double wrap onion skin paper. That could have even been my problem. Some of the bullets seemed to be going in sideways at 30 yards. The wrap may not be coming off well. I am a real novice at this paper-wrap.

 

[coloradoclyde]

Wher's Idaho Ron?....We need his input on this topic.

 

[rodwha]

"Help me Obi-Ron. You're my only hope."