Cup pressure question

[rikstar65]

First, for a given bullet load, how can I find the cup pressure (c.u.p)? I have found powder data that listed c.u.p for a given bullet but it was for only one charge , not all the different possible charges. It does not seem very useful if it's not reported for every given charge. Also , how does one know what c.u.p a firearm will handle. I have been told to make sure my firearm can handle a given pressure , but I cannot find the answer. Specifically , I would like to know if a new Winchester 1892 45 colt (miroku) can handle this load: sierra 240 gr JHC with 22.3 grains of H110. Any ideas about how I may find this answer. I called Sierra and Winchester and they danced around the question like politicians.

[Larry L]

Went down this trail with my brothers arm load of 45 Colt rifles. The accepted pressure for the 45 Colt per SAAMI is 14,000 CUPs. The caveat to this is if you are shooting the ammo in a RUGER or TC ONLY. Then the pressure is 25,000CUPs per SAAMI. But the lever action Winchester rifles, either original or replicas, don't possess the strength to stand up to a steady diet of Ruger loads. It may not stand up to one round of it. You'll use normal pistol loads in that rifle or expect issues. Like you, I thought H110 would make a dandy powder for the round. I found no loading data for it and would expect it to be a bad choice now. H110 works best at higher pressures than the H110 would achieve in the rifle. You'll end up with erratic pressures at best and maybe even one of those unexplained Kabooms. Like I heard it once said- you can't make a hot rod out of a bicycle. YMMV.

[rikstar65]

Thanks. That makes sense. It makes me wonder why Sierra has the set "rifle data" for the Winchester 94. I think I will call them back and specifically ask what the c.u.p is for the load I am interested in.

[Savage]

According to Speer data that I have:
250 grain Gold Dot HP
Test firearm: Ruger Blackhawk 7 1/2" barrel
Case: Starline Primer: CCI 300/350 (magnum 350 primer for H110 loads)
start load for H110: 19.0 grains for 1091 fps
Max load for H110: 21.0 grains for 1200 fps

Based on the above, it sounds like your load may already be at max allowable pressure or above. Be sure you have load data from a reliable source, not something posted on the net or from a gun shop commando.  H 110 may not be the best powder for loads in the acceptable pressure range for your Winchester.
Stay safe,
Savage

[Larry L]

I doubt Sierra has the CUPs on it with any of their new data. They've pretty much gone to the Piezo equipment and gotten rid of the copper crusher units. Most everything they'll have in the way of recent data is going to come at you at PSI, not CUPs. There is no conversion between the two. Finding rifle data is not a problem, finding any that seems to have an advantage over pistol loads wasn't out there when I was working on bros loads. Yeah, you can pick up some velocity just from the longer barrel but to actually be able to find a powder that makes the round come alive wasn't there.
I'd like to know what Sierra has for you in your conversation with them.

[rikstar65]

Today I spoke to very helpful Sierra technical representative. He basically said the sierra 45 colt load that I quoted above (240 gr JHC with 22.3 gr of H110 - this is straight from the Sierra manual) would be fine in my 92 based on the fact that the test rifle for the data was a Winchester 94AE. I have confirmed through multiple sources that a new Winchester 92 ( made by Miroku) should easily handle anything the 94 can. THAT'S really what I have been trying to confirm and I am now satisfied with that conclusion. I think I will start with 21.5 grains to be safe and the work up. This load also requires a crimp with the Lee factory crimp die just in case someone else is planning to use this load.

[Richard P]

All the above reiterates the need to do lots of research ----especially when dealing with cartridges that transitioned into the smokeless powder era.  Owners of original black powder arms should be doubly aware to ensure no ammo intended for modern steel arms will find its way into the cherished oldies.
It pays to consult multiple sources and even go as far as contacting a powder or bullet maker for advice. Additionally, researching the characteristics of powders pays dividends. You need to know that H110/ W296 are not powders of choice for low pressure loads. 
Years ago Handloader Magazine (Wolfe Publishing) printed a several topic series entitled ''Pressure Factors''. It may be available as a reprint or on a disc.

[stimpylu32]

First, for a given bullet load, how can I find the cup pressure (c.u.p)? I have found powder data that listed c.u.p for a given bullet but it was for only one charge , not all the different possible charges. It does not seem very useful if it's not reported for every given charge. Also , how does one know what c.u.p a firearm will handle. I have been told to make sure my firearm can handle a given pressure , but I cannot find the answer. Specifically , I would like to know if a new Winchester 1892 45 colt (miroku) can handle this load: sierra 240 gr JHC with 22.3 grains of H110. Any ideas about how I may find this answer. I called Sierra and Winchester and they danced around the question like politicians.

If you have not checked yet , Hodgdons lists a load for the 45 colt with H110 in their Ruger & TC section using the 240g Sierra 240g JHC . Their load lists at 27.2g to 28.0 and a CUP of 27,900 to 30,000 , this is right at the VERY TOP end of the 45 colt CUP scale , so please be careful . 
 
stimpy

[Larry L]

Here's another issue which is why I decided H110 is not a good choice, if you read the introduction to the Hodgdon reloading page, it specifically states not to reduce any H110 load data more than 3%. Doesn't sound like a good choice but that's me. I would like to know how this turns out though.


Reduce H110 and Winchester 296 loads 3% and work up from there. H110 and Winchester 296 if reduced too much will cause inconsistent ignition. In some cases it will lodge a bullet in the barrel, causing a hazardous situation (Barrel Obstruction). This may cause severe personal injury or death to users or bystanders. DO NOT REDUCE H110 LOADS BY MORE THAN 3%.

[stimpylu32]

Larry
 
I agree that H110 is not the best choice here , it runs at much too high of a pressure range for my taste , yet were does one start with that 3% ?
 
Hodgdon lists the load starting @ 27.2g for a 240g JHC , while Sierra lists their starting load @ 22.3g and Speer 's @ 19.0g . Now thats a hell of a differnce in loads , and these are the experts ! 
 
stimpy

[Larry L]

Glad you made my point. As you might know, H110 is a military powder, made by Primex out of Florida, designed for one cartridge only. H110 is  just a draw down from it and is not exactly variable or user friendly. You can get in trouble with this stuff quick. I use a lot of it but also recognize it's probably the most dangerous powder in the storage box. Doesn't mean you can't use it safely, just the data seems to be WAY too far apart for my reloading practices.

[rikstar65]

Wow. Thanks all the good info. Kinda scary. The sierra manual listed the H110 as an optimal " accuracy " load and I know a hunting guide in  Canada that uses the 240 gr JHC with 22.3 H110 load with a 94 model and thinks its a great load. I'm sure he has  a lot more experience reloading than I do, as do all of you. Perhaps H110 should be left to experienced reloaders. Does anybody have advice on a safer powder I could  use with the 240 gr Sierra bullet for hunting?

[stimpylu32]

Wow. Thanks all the good info. Kinda scary. The sierra manual listed the H110 as an optimal " accuracy " load and I know a hunting guide in  Canada that uses the 240 gr JHC with 22.3 H110 load with a 94 model and thinks its a great load. I'm sure he has  a lot more experience reloading than I do, as do all of you. Perhaps H110 should be left to experienced reloaders. Does anybody have advice on a safer powder I could  use with the 240 gr Sierra bullet for hunting?

Alot depends on how hard you want to push the 240's , the H110 load will put you in the 1300 to 1450 fps range and thats fast for the old 45 colt cartridge . If your willing to step it down a notch look at either 800X or Win 231 , both will put you in the 1000 fps range .
 
stimpy

[rikstar65]

I've been reading over previous posts. One thing that is confusing is that the hodgdon data says that for ruger / TC only,  the starting load for the 240 gr Sierra is 27.2 at 27900 cup. They also warn to not reduce the load by more than 3%. However the Sierra manual lists 45colt RIFLE data specifically using the Winchester 94 rifle and the starting load is 20.7 for the same bullet and max load of 23.2gr.  No cup is noted but intuitively it must be well below 27900, which seems like a safe Pressure to me. They do specify using a firm crimp and federal 155 primers- i believe this helps keep pressures consistent. Sierra specifically recommends the H110 at 22.3 gr for the best rifle accuracy. Hodgdon does not even acknowledge the 45 colt rifle in their data ( that is disturbing!). So is it safe to assume that Sierra knows something that Hodgdon does not know about their own powder? After speaking to the Sierra rep, i think I will try the h110 and start with the 21.5 gr load which Is one step above the start load. Any thoughts on this logic? Sorry to beat a dead horse, but I believe the disconnect is that most people and powder/ bullet manufacturers think in terms of 45 colt revolvers (SAA loads vs Ruger/TC loads) and Totally ignore the rifles. That is why I ended up with the Sierra 240 gr bullet... They actually have the rifle data.

[rikstar65]

Stimpy, I really appreciate the input. I didn't see 800x or win 231 in the Sierra data. Which manual was that load data in? I may need to get another couple of manuals. Thanks again.

[stimpylu32]

Your right , most times they tend to think of the 45 Colt in Revolver loads , as for the difference between Hodgdon and Sierra , thats an easy one , Hodgdon's tests for general use while Sierra tests for their products . They were also using different batch's of powder which in itself will give different results .
 
As for the 800X and win 231 , those came from Hodgdon's web site under 45 Colt standard with a 250g bullet , not TC loads . For what its worth , I shoot a ton of 45 LC in Handgun and have found that a heavier bullet going slower does a better job for what I'm doing - your mileage may very . 
 
Lyman's 49th
Pistol data
240 grain JHC
unique 8.0g to 8.8g = 827 to 917 fps
2400  15.0g to17.0g =765 to 997 fps
Power Pistol 8.2g to 9.2g = 861 to 957 fps
N340 8.8g to 9.8g = 870 to 982 fps
Rifle data
unique 7.5g to 9.5g = 952 to 1176 fps
2400 15.0g to 18.5g = 973 to 1321 fps
 
Here you can see that while the load does not change much on the lower end the top end does along with the fps .
 
stimpy
 

[rikstar65]

Thanks Stimpy. Looks like I need a Lyman manual!!   

[Larry L]

And now I'll really screw yer mind up. Try to remember that the bullet you have chosen is for a pistol, not a rifle. It's meant to run at about 900-1100'ps tops. Start pushing it more than that and the bullet comes apart on impact. That makes a lousy hunting bullet. Here's an article for you to consider:
http://www.gunsandammo.com/2011/07/07/hunting-bullets-for-the-fast-45s/


Remember, if this was easy, anybody could do it.


From The Sierra PC Program, your bullet and various better powders yet still getting into the same velocity:
Blue Dot powder
Start 14.5 grs= 1300'ps
Max 16.4 grs = 1500'ps


AA7
Start 16.8grs= 1400'ps
Max 18.2grs= 1500'ps


Unique
Start 11.1 grs= 1300'ps
Max 12.1grs =1400'ps


Hope this helps with the project.


FWIW, I settled on a 250gr Speer bullet in bros 45 rifles using HS6 powder. They are running out of his many rifles at about 900'ps. He's decked some pretty big hogs with them, upward to 400lbs. In my opinion, he's a little light on weaponry with that big of an animal but he's the professional hunter in the family.

[stimpylu32]

rik
 
Never thought it could lead to this did you ?    For what its worth , I have 12 different manuals on my bench and another 10 web sites that I get and compare data from . I didn't even realy think about till Larry said something , he's right , the bullet you have was designed more as a Personal Defence bullet than a hunting bullet , so you'll have to slow it down some to use it for say Deer hunting or other thin skinned game .
 
stimpy

[rikstar65]

Excellent article , Larry, and yes, Stimpy, this is getting complicated. Again, I appreciate all the input even if it does make my brain hurt ! Is your brothers 250 gr speer bullet a hollow point (JHP)? I could slow my 240 gr Sierra to 900 to 1000 by using the Sierra ruger / TC data. I already have unique powder that I use for my SAA ( new vaguero) revolver.  it's frustrating that they publish high velocity loads for that bullet if it really can't stand up to them.
Rick

[srussell]

Larry
 
I agree that H110 is not the best choice here , it runs at much too high of a pressure range for my taste , yet were does one start with that 3% ?
 
Hodgdon lists the load starting @ 27.2g for a 240g JHC , while Sierra lists their starting load @ 22.3g and Speer 's @ 19.0g . Now thats a hell of a differnce in loads , and these are the experts ! 
 
stimpy

give new meaning to not reduce it buy 3%