Recreating 45 ACP performance in BP

Discussion in 'Blackpowder' started by SPJackson, May 12, 2021.

  1. Dave T

    Dave T Member

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    This link - https://goexpowder.com/wp-content/uploads/2018/06/cartridge-pistol-revolvers.pdf - from GOEX says in the 45 Colt a 255g bullet loaded with 40g FFg gives 770 fps. That is so far off of reality (both published results and my own experience chronographing that load) it brings into question the entire GOEX data and link.

    Guess this is an example of even the factory or manufacturer getting it wrong.

    Dave
     
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  2. DocRock

    DocRock member

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    You need @rodwha in this thread. As I recall, he has quite a bit of chronograph data for a range of loads.
     
  3. rodwha

    rodwha Member

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    I’ve wondered if they’ve just refined their powder to improve it some. It seems older data for Goex tended to show even poorer velocities compared to what tends to be similar powders in the last decade and some.
     
  4. rodwha

    rodwha Member

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    Well, none of it is mine. But when I first got my ROA I looked at it and thought the cylinder sure seemed close to the size of modern cylinders and figured standard .45 Colt loads (400-450 ft/lbs) should be achievable. But when I asked around, mostly on traditional forums, I kept getting the answers of it being woefully inadequate and barely able to achieve .38 Spl performance levels (200-250 ft/lbs). And so I kept looking and eventually found that this was true if one used the standard powders. Using an energetic powder one can achieve much more, and what I was looking for as I needed my sidearm to be effective and humane.

    From the chronographed results I’ve seen my NMA using a bullet and a 30 grn charge of 3F Olde E or Triple 7, which weighs 33 grns, I can achieve roughly standard .45 ACP performance (350-425 ft/lbs). To me a bullet achieving at least 300 ft/lbs (.44 Spl performance) is doable and humane. And it’s not really the foot pound numbers, but the velocity with the mass I’m looking for. Foot pounds of energy is just a convenient and easy way to look at it. Really I feel the Taylor Knockout is a much better means of figuring effectiveness.
     
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  5. SPJackson

    SPJackson Member

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    Thank you, I assume they are using the 142 grain .454 Hornady balls I can easily find online. Based on these results I guess I should look into using Swiss or Eynsford
    3Fg.

    You reminded me that "grain" can be a unit of volume and weight. I've meant 30 grains by volume all this time though, so I doubt I created any confusion. If I did I'm sorry.

    Thank you. That is very reassuring to learn. Can I ask what mass of bullet you used? Was it 230 grains or more?
     
  6. Malachi Leviticus Blue

    Malachi Leviticus Blue Member

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    That is an often misunderstood and repeated notion.
    Grain is a unit of measure of weight not volume.
    References to measuring grains by volume for BP mostly come from 2 similar directions.
    one relatively straightforward one being that first the Black Powder was weighed by weight and a volume of that weight was determined. An example would be where folks make a powder measure from spent brass casings. If they want a 25 grain measure they figure out how much volume of the case is filled by 25 grains of Black Powder and trim the case to that size. Now that case can be used to measure 25 grains of Black Powder by volume. The unit of measure is still weight, but it is being measured with a volume measurement device because the weight per volume is reasonably consistent if you use the same powder. So you can literally measure weight by volume. This is essentially the same thing most smokeless cartridge re-loaders do. Weigh a charge, measure its volume, then measure by volume from that point forward with the same powder because it's much easier.

    The other direction referencing measuring grains by volume for BP is where the confusion mostly comes from. It is when using BP substitutes that have significant weight differences by volume from Black Powder. Pyrodex for example was designed to give similar performance at the same volume as Black Powder, however it actually weighs much less. So the intent was for Black Powder shooters to take the convenient volume measurers they had been using for real Black Powder and use the same measurers for Pyrodex. The shooters were calling it a 25 grain load when it was BP and Pyrodex called it a 25 grain load by volume, really just meaning it was supposed to be equivalent in performance and volume to Real BP. I believe safety and convenience were the key factors.
     
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  7. Ugly Sauce

    Ugly Sauce Member

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    What he said. For your purposes, and experimentation, you will want to measure your charges by weight.
     
  8. rodwha

    rodwha Member

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    Actually grains is just a measure of weight. It fills a certain volume but that volume is different as powders all weigh a bit differently with more energetic powders tending to weigh more. Each powder measure measures differently as well. I only know the weight of my powder charge because I sent bullets to a fellow in Alaska to replicate my loads and run them across his chronograph.

    For balls I use .457”. I need them for my ROA and it would be too difficult juggling other .45 cal balls. I like simplicity. But there’s also data that supports that the extra bearing surface provides better results, and many match shooters prefer them as well. This makes sense to me especially if the chambers are undersized. This is dramatically proven in the Rem.31 pocket.

    When I ordered my Pietta NMA I assumed it would have the slow 1:30” twist rate they used to come with. This is often why we read that these guns can’t shoot a conical well at all. So I created a 195 grn bullet that’s just .460” long. This was partly inspired by a fellow who had loaded Lee’s 160 grn bullet in a repro and his mentioning the short length. So I also created a 170 grn version that I figured would get a high enough velocity to reliably expand. However I prefer to squeeze the most out of the accuracy and will be creating a final universal bullet filling the excess space with lead working from their more accurate powder charges. I have a better powder measure where I can work in 2.5 grn increments, but with what I have now and the measurements I’ve taken my new design will weigh about 220 grns +/- 10 grns.

    http://accuratemolds.com/bullet_detail.php?bullet=45-170C

    http://accuratemolds.com/bullet_detail.php?bullet=45-195C

    Here’s what I’ve worked up so far with my current data for my universal bullet. This 245 grn bullet was my hot bullet that I didn’t create as I thought I’d be moving to VA and hunting bears and so wanted a heavier bullet and so I went with the 285 grn version instead.

    E4-EB531-B-908-D-4-A70-B8-B7-29-B0-FDFE060-F.jpg


    I forgot to mention that my NMA has been reamed to .449” and chamfered. I’m contemplating using a hand reamer to take it out further as my bore is .4525”. The walls look mighty thin as is but I’ve been told that it can be safely done while using energetic powders with stout charges and bullets. I’m still a bit intimidated though.
     
    Last edited: May 15, 2021
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  9. rodwha

    rodwha Member

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    Here’s a pic of my loaded NMA using 30 grns and my 195 grn bullet. Plenty of room to elongate the projectile. I guess I really anticipate my new design to weigh something more like 215-235 grns. Hard to say as I shaved a bit from here and there and shortened it too.

    5-CD6-E335-0-FCF-49-A0-B849-D9068-C37-FB1-E.jpg

    And to give a clue as to how much mass can be squeezed into a small space here’s my 285 next Kaido’s modified Lee 255 and his 240 grn version as well, next to my 195, a .451” ball, and my 170 grn bullet.

    E7522-E12-CA4-A-4-F10-8039-3843-D79116-C5.jpg
     
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  10. Onty

    Onty Member

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    Picture of your revolver is not very clear, but those chambers look like that they are chamfered. If so, how chamfering affect affects ramming force when bullet is seated in chamber?
     
  11. rodwha

    rodwha Member

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    They indeed are chamfered, as well as reamed to .449”. I use .457” balls and my bullets are supposed to drop at .456” but I think they come closer to .455”. They all seat easily is enough, no need to put a lot of force.

    I recommend the chamfer as it gets rid of those pesky rings of lead. I need to do it to my ROA as well.
     
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  12. Onty

    Onty Member

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    Also, I might be wrong, but those chamfers look different than 45° (per side), more like 30°!?
     
    Last edited: May 15, 2021
  13. Onty

    Onty Member

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    I must admit that your post is one of those I copy and keep as a reference. Also, the same with some posts from TheOutlawKid, rodwha, arcticap and others. In addition, I appreciate links for some earlier posts/topics with valuable info and details. There is always "New Kid in Town", and for somebody who just started here, would be very hard to find all that.

    Thanks and keep it this way!!!
     
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  14. Jackrabbit1957

    Jackrabbit1957 Member

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    I offer a 5 degree chamfer on my tuning jobs, its done with a tapered reamer. Stops those pesky lead rings, have never had a chain fire from one of my revolvers since doing this. Also seems the ball is a bit easier to start into the chamber. Have never had one creep forward either.
     
  15. Blackpowderwarrior

    Blackpowderwarrior Member

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    What size hand reamer do you have brother? Im thinking deeply on buying one for my pietta 1860 army. Im very impressed with the groupings I've seen once the cylinders are reamed and the forcing cone angle cut anew. The groupings ive seen out of these revolvers put all modern pistols to shame.
     
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  16. Jackrabbit1957

    Jackrabbit1957 Member

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    The chamfer reamer is a small tapered pipe reamer, I measured the angle and its 5 degrees, I hand turn it until I get about .250 depth. I also have a .453 chucking reamer for opening up the chambers. A word of caution, if your drill press has any runout don't ream under power, learned the hard way to stick hand turning only.
     
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  17. woodnbow
    • Contributing Member

    woodnbow Contributing Member

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    I was too chicken to hit the switch so I chucked the reamer in the drill press and hand turned it on the two cylinders I have done myself. I had good results but since then I have hired Charlie Hahn to do them for me.
     
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  18. Onty

    Onty Member

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    My guess that standard 11° barrel forcing cone reamer will do the same. Here is one from Brownells, works from .38 to .45: Yeah, some kind of handle, better yet, arbor for a drill press or mill is required.

    p_080486200_2.jpg

    Also, others should have something similar, 11° barrel forcing cone is some sort of standard for majority of revolvers' manufacturers and custom smiths. If I am not mistaken, on some new revolvers even Ruger vent from 5° to 11°.
     
    Last edited: May 17, 2021
  19. Onty

    Onty Member

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    Good point. That is the reason for any precise work, I like to use mill. And collets if there is right size.
     
  20. SPJackson

    SPJackson Member

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  21. Onty

    Onty Member

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    I agree that something is wrong with above chart. Take a look at 45 S&W and 45 Scofield (assuming Schofield, BTW, as far as I know, 45 S&W and 45 Schofield are the same). Any idea why they are listed separately, and charges and velocities are so different?

    45 S&W, bullet 250 gr, powder FFF, charge 28 gr, velocity 710 fps
    45 Schofield, bullet 250 gr, powder FFF, charge 34 gr, velocity 660 fps
    455 Webley, bullet 265 gr, powder FFF, charge 18 gr, velocity 710 fps


    Interesting data regarding 455 Webley cartridge (and revolver), assuming data are correct. Using undersized cylinder chamber exit dia to squeeze the bullet, pressure was raised and result is higher velocity with less powder.

    Here is article from G&A about 45 Colt, https://www.gunsandammo.com/editorial/45-colt-load-data/370003 :

    45 Colt, bullet 255 gr, powder Goex FFFg, charge 35 gr, velocity 920 fps

    Considerable difference from data on Goex chart.
     
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  22. GeoDudeFlorida

    GeoDudeFlorida Member

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    Mike Venturino did an article on this subject back in April, 2020, for Handloader Magazine. Some of what he wrote has been myth-busted here but, the article still contains some good info. I think that article, and Mr. Venturino's sources, are where the myth about .45Schofield rims not fitting SAA cylinders came from.
    https://www.handloadermagazine.com/all-american-45s - if you have an account with Handloader Magazine
    https://www.magzter.com/stories/Mens-Interest/Handloader/All-American-45s - if you don't
     
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