IMR4064 load

[KenH]

Hello all - My buddy and I loaded some 45-70 rounds using IMR4064 power - both loads were a tad less than 1,000 fps, his with 28 grains of 4064 with a Lee .457-340 (weighted about 345 grains) bullet while I used 30 grains of 4064 with a Lee .457-405 that cast around 415 grains a tad over 1,000 fps on chrono. He shot his from a H&R with 22" barrel, while I used an old Springfield trapdoor with a 22" barrel (been cut down before I got rifle).

He reported his powder didn't burn clean at all - said after firing he would even pour a few grains from fired brass. I didn't see anything to make me think my rounds were not burning clean - I didn't really check, but nothing flagged attention. He was with his Dad shooting at home while I was here at my home shooting.

Now, my question - could the unburned powder be caused due to lower chamber pressure? Per QuickLoad the 345 grain bullet with 28 grain of 4064 power has about 6050 PSI of chamber pressure while the 415 grain bullet should have around 7850 psi. After all, 4064 is a fairly slow burning power - perhaps 3031 would be a better choice for lighter loads? Too bad there is no longer much data for the IMR 4759 powder, I've got 3 lb of it :) I'd LOVE to find a QuickLoad powder file that had IMR 4759 powder.

Thanks to all for any info.

Ken H>

[BwBrown]

4064 is my goto powder in the '06. Never noticed that much (or any, really) unburnt powder.
But I have found 4831 to be very forgiving (accurate at nearly any speed) in my 450 Marlin - a ballistic twin to the 45-70.

I have no experience with your 4769. But since you have a supply of it, work up loads carefully, and then just dance with what ya brung.

[KenH]

Thanks for the input - but how light where your loads in the 'o6? Note I said no problem with the slightly heavier load, but with the 6kpsi chamber pressure is where the unburnt powder seems to be.

Always careful when working up a load, but in this 45-70 there will be NO heavy loads - the old shoulder doesn't want the pounding any more.

Ken H>

[RobS]

Way to light of a load for 4064. Switch to a more appropriate powder for lighter loads.

[KenH]

Rob - you are confirming the low chamber pressure prevents cleaning burning of 4064? Is there any reason the light low with 417 grain that produced a calculated 7860 psi chamber pressure that did burn clean is ok with 4064? OR - is there some reason that is still too light a load for 4064?

Thank you for your input.

Ken H>

[tdoor4570]

I use IMR 3031 in one 45-70 and black powder in the other 4064 didn't work for me at all

[RobS]

Rob - you are confirming the low chamber pressure prevents cleaning burning of 4064? Is there any reason the light low with 417 grain that produced a calculated 7860 psi chamber pressure that did burn clean is ok with 4064? OR - is there some reason that is still too light a load for 4064?

Thank you for your input.

Ken H>

Yes, chamber pressure. There is a reason why reloading manuals do not have that light of a load for 4064. There is a needed pressure to burn efficiently. Velocity spreads can increase as well with poor ignition of the powder etc.

[KenH]

Thanks Rob - you have confirmed what I was thinking from what I saw - it takes at least 8,000 psi chamber pressure to burn 4064, and I'd expect even better to have 18K for a really clean burn. This is what I needed confirmation on due to working with QuickLoad data on the two different loads we tested.

That QL program is really nice - one of the best things I've spent money on.

Ken H>

[aspangler]

Try 22-24 gr 2400 under 405 Lee. 1000-1400 fps. NO FILLER. Try the load of 13 gr Red Dot under the 350-450 gr cast. Should be gentle on the shoulder. YMMV For the lawyers out there, use this at your own risk.

[Larry Gibson]

Put a 1 - 1.5 gr Dacron filler over those 4064 loads. That will help some with ignition consistency and accuracy. Both loads are really to light for enough psi for the 4064 to burn efficiently otherwise. However, yours appeared to burn cleaner because the heavier bullet you used increased the psi which increased the burning efficiency.

If you use 36 - 38 gr of 4064 with the Dacron filler under the 405 +/- Lee bullet you will push 1300 - 1350 fps +/- at 22,000 psi +/- and have very good accuracy. The psi was measured by me via an Oehler M43 and is still considerably less than the SAAMI MAP of 28,000 psi for the 45-70.

Larry Gibson

[KenH]

gentle on the shoulder
Now THAT I do like:) I only have perhaps 1/2 lb of Unique and a couple lb of Green Dot - what do you think of those for "gentle on the shoulder" loads?

Larry, Remember, this is for an old Trapdoor - think 22,000 psi is suitable for an OLD trapdoor in good condition? I'd sorta been holding it to below 18K chamber pressures. I've shot compressed loads (65+ gn) of FFg with 345 grain bullet and the kick wasn't too bad, not at all.

Larry - don't you have one of those neat PressureTrace system for testing chamber pressure? Have you tested black powder to see actual chamber pressure of different loads? That would be GREAT to have. I'd drooled over that equip.

Ken H>

[Larry Gibson]

Yes I have a M43 PBL made by Oehler to measure pressures and several other things.

The old 18

"18K" psi was for L.U.P. method of measurement and does not compare to modern transducer and strain gauge measurements. The SAAMI MAP of 28,000 psi for the 45-70 is for "trapdoor" loads. I shoot the above mentioned loads all the time in my own 3 "trapdoors". I also shoot quite a few loads that are close to the SAAMI MAP. Many "recommended loads with 2400, 4759 and 4198 have higher psi than the 4064 loads under discussion. I have indeed pressure tested BP loads. With the 405 gr Lee HB bullet 70 gr of GOEX Cartridge runs 1310 fps out of my TD rifle at 20,300 psi(M43). The Rapine 500 gr 460500 over the same charge runs 1245 fps at 22,300 psi(M43).

In case you now wonder how SAAMI came up with 28,000 psi as the MAP for TD loads it is because that is what the MAP runs with the 500 gr gvm't bullet over 3031 which was the highest psi load that was approved for used in the M1873/84s.

Larry Gibson

[KenH]

OK Larry - THANK YOU!!! for this clarification on the chamber pressure rating of the TrapDoor rifle. I'v been very confused because in one place I'd read 18K psi max for sure, other places would say 28K. I read Goex Cartridge is a discontinued black powder grade that reportedly had a burn rate between 2 and 3F - does this sound right? If so, the FFg would (should?) give slightly less pressure/velocity since it's a tad coarser?

I had asked a question on a different thread about rebarreling a BP Rolling Block action with a modern E.R. Shaw barrel in 45-70 trying to determine safe loading range for it. It sounds like the standard 45-70 ammo purchased at sporting stores should be ok as long as it doesn't say P+ ammo - comment?

Ken H>

[Edward]

2400 is my favorite powder in my 45/70 but also include 1/2 gr dacron (filler),also great in 30-30/35 rem

[KenH]

I've read a lot about how popular 2400 is for light loads, but never used it myself. For some reason, back in the '70's I wound up using IMR's PB powder for pistol and light loads. I don't see much about PB powder these days - anyone use it for light loads in 30-30 or 45-70?

Ken H>

[Larry Gibson]

OK Larry - THANK YOU!!! for this clarification on the chamber pressure rating of the TrapDoor rifle. I'v been very confused because in one place I'd read 18K psi max for sure, other places would say 28K. I read Goex Cartridge is a discontinued black powder grade that reportedly had a burn rate between 2 and 3F - does this sound right? If so, the FFg would (should?) give slightly less pressure/velocity since it's a tad coarser?

I had asked a question on a different thread about rebarreling a BP Rolling Block action with a modern E.R. Shaw barrel in 45-70 trying to determine safe loading range for it. It sounds like the standard 45-70 ammo purchased at sporting stores should be ok as long as it doesn't say P+ ammo - comment?

Ken H>

That is correct about GOEX Cartridge being between 2 and 3f BP. I've found it closer to 3F though and use 3F also.

As to the Shaw barrel on the RB action; it's not the strength of the barrel that determines the level of 45-70 loads that should be used. It is the strength of the action. The BP RB action should still be held to "trapdoor" psi's regardless of the modern Shaw steel barrel. Modern factory 45-70 ammunition will be safe in the RB as long as it says something like "Safe for use in trapdoors" or "safe for use in all rifles" If it is not safe for use in trapdoor level rifles it will say for "modern rifles only" or even specify the types of rifles.

I tested some Remington 405 gr JFP factory ammunition. Under the jacketed bullet was 33.1 gr of an extruded powder. It produced 1105 fps out of the 24" test barrel and no pressure reading was recorded during the 10 shot test string. That means the psi was less than 9 - 11,000 psi which is the minimal psi needed to put a measureable strain on the gauge.

Larry Gibson

[KenH]

Larry, thank you so nicely for sharing your info from personal testing. Your advice on the E.R. Shaw barrel is very helpful. I'm not so concerned about loads for myself, but concerned about folks who might acquire the rifle after I'm no longer around. I doubt seriously it will EVER see anything but handloads while I'm around.

Since getting the QuickLoad program I've been amazed at how much info can be had. Even with chrono testing loads and being impressed with how close the chrono'd loads are to the QL calculated fps, I do have questions on on the recoil calculator (and other questions,but they are for later as I learn more).

I "think" I understand the why, but calculating with Unique powder, H4227, and IMR3031 for fps of 1,100 fps, the calculated recoil is much less for Unique while a good bit higher pressure in a 45-70 with a Lee .457-405-F bullet.

Unique: 11.42 grain, 15723 psi; recoil = 5.62 lb/ft/s
H4227: 21.62 grain, 8838 psi; recoil = 10.6 lb/ft/s
IMR3031: 30.7 grain, 8346 psi; recoil = 15.1 lb/ft/s

Note the high pressure of Unique but very low recoil level compared to the other two powders. From what I've read, it seems the H4227 at 10.6 is about the same level of recoil as a 30-30 factory load while using 3031 for the same 1,100 fps you've a good bit more recoil.

Can anyone explain this please?

Ken H>

[Larry Gibson]

Ken

I've not done the math so I'll just assume the figures are correct. In your calculations you should have had to ad the weight of the powder to the bullet(?). Thus the weight of the "ejecta" (bullet + powder) is larger for each increase in powder charge. That increases the recoil.

Larry Gibson

[rking22]

I don't have quick load,or I would check for myself, anyway a question. I believe quick load gives muzzle pressure, if so is the muzzle pressure of the 3031 load approx 3x higher(or notably higher) than the unique load? Thinking the additional gas generated by the additional powder is giving the increased recoil due to the hi pressure gas venting behind the bullet. Something I have always thought but did not have data to explore in detail. Think of an air hose with 30 PSI vs 90 PSI, and the force generated, like a jet engine. Any way thanks

[RobS]

Recoil is not necessarily a pressure only comparison. A person needs to consider the caliber, the weight of the boolit, peak pressure and the velocity associated as well.

[rking22]

Understood, the above loads used the same boolit, gun and cartridge with only the powder changed yielding the same velocity. Looking for thoughts as to what my be the greatest contributior to the approx 3X increase in recoil between 3031 and unique. Especially since the unique has a higher peek pressure. The work generated is near the same due to the same velocity of the same projectile(other than the additional 5% powder weight). So I assume the lower peak pressure is extended in time, toward the muzzle. More solid propelent then more gas to "exhaust". The math makes my head hurt, so thought QL could do the number crunchin :)
Besides just a point of curiousity anyway, except when we want to gently coax a softish boolit along at a good clip :)

[KenH]

rking22: you have understood my question perfectly. Using Unique powder, H4227, and IMR3031 for fps of 1,100 fps with a Lee .457-405-F bullet. Here is the info about muzzle pressure per QL:

Unique: 11.42 grain, 15723 psi;recoil = 5.62 lb/ft/s; Muzzle psi = 937
H4227: 21.62 grain, 8838 psi;recoil = 10.6 lb/ft/s; Muzzle psi = 1550
IMR3031: 30.7 grain, 8346 psi; recoil = 15.1 lb/ft/s; Muzzle psi = 1741

As you can see the muzzle pressure is greater with the slower powder, which is to be expected (I think) because it burns slower giving more powder burning late into muzzle. The Unique being a lot faster burning gives a quick high peak pressure rapidly dropping off well before end of barrel which is why it takes so much more chamber pressure to generate the same fps for bullet. The higher the muzzle psi, the greater the muzzle blast.

Larry: I understand what you're saying, the weight of powder is added to bullet weight in recoil calculations (I'm sure QL does this in recoil calculations), but there's only 20 grain difference from lightest powder charge to most powder charge. Doesn't seem like <5% difference in mass (power+bullet weight) would account for 300% difference (5.6 to 15.1) in calculated recoil?

The only thing I can figure is the high pressure happens so quickly (almost 2ms) there is little time to overcome the mass of rifle to get it moving, hence lower recoil, while the slower powder while generating a lower pressure is spread over a longer time (almost 2.8ms). While .8ms doesn't sound like a long time...... time is relative?

Thanks to all for comments and ideas - this is how I'm learning MUCH more about internal ballistics than I ever imagined I'd get involved in. This QL is worth every penny it costs. Seems to replace all my reloading manuals I've got!

Ken H>

[rking22]

Ken, thanks for the numbers. The peak pressure ,I would think, has little to do with recoil since it is applied to the area of the bullet base and the the area of the case head equally. Also the time to reach peak pressure being extended with slower powder should act to reduce felt recoil due to the longer acceleration time, not sre about "calculated recoil". The same reason that slower powders let us get better results when near the limits of the alloy, at least thats my thought and experience. The bullet is not going as fast (relatively speaking) when it is engaging the rifling and overcoming inertia for rotation. Like accelerating from a stop on a wet road, gentle with the right foot yields better traction.
I need to review my gas pressure math,but looks to me that we have 2x the gas pressure at the muzzle and 3x the amount of gas (30 gr load vs 11 gr load, if gas generated is directly proportional to charge wt across powder types????) that acts to accelerate the gun as the bullet leaves the muzzle. Or maybe the increased pressure is the direct result of the 3x more gas in the same volume, discounting burn rate??? Thats the reason muzzle brakes work, the higher the muzzle pressure the better they work, and the louder they are :)
I had, for a short time, a 30-06 with a 16.02 inch barrel INCLUDING a muzzle break. It was the loudest thing I ever fired with ball ammo, but recoil was very light! I'm talking less than an equal weight 243 light, and 13 gr Redot with a 170 cast felt the same as the ball did,recoil wise.
Looking forwarn to more info and discussion around this, thanks for bringing it up.

[KenH]

Yea, I don't know about this calculated recoil myself - just for FYI, I read somewhere a 30-06 with factory load of 150/170/180 (I don't remember the exact bullet weight) was "20 ft/lb/s" range while a 30-30 with factory load of 150/170 grain (again don't remember exact weight) was in the "10ft/lb/s" range. This is also what I get from QL recoil calculations. I don't understand the QL recoil calculations. i.e. Take an 18" barrel 30-30 with 168 gn Serria BTHP loaded with 27 grain 3031 to give 2006 fps with 10.56 ft/ls/s recoil. Now, leave everything same, except change barrel to 30" and you get 2220 fps with 10.03 ft/lb/s calculated recoil. I realize there's not much difference, but I did sorta expect recoil to go up with higher fps and longer barrel. Remember, the rifle weight did NOT change with increased barrel length.

Ken H>

[Larry Gibson]

The difference is the exit psi which effects the gas velocity which affects the calculated "recoil". The longer barrel with the given load had a reduced exit psi even with the higher velocity.

Larry Gibson

[KenH]

Thanks for the info Larry - the higher the exit psi, the more recoil - and muzzle blast..... makes sense.... I guess :)

As I said before, this QL program has given me more hours of "what if" than I ever expected - which leads to learning more.

Ken H>

[badgeredd]

Here is a useful recoil calculator. Note PSI is NOT any part of the calculation!

http://www.shooterscalculator.com/recoil-calculator.php

Edd

[badgeredd]

Here is another recoil calculator that apparent has left out a pressure figure.

http://www.huntamerica.com/recoil_calculator/

[KenH]

I've been out of town, and out of touch - just checked those links and they are interesting in they give a good bit different results for a 170 grain bullet with 40 grain powder, and a 9 lb rifle. One is 8 ft/lb while other is 10.28 ft/lb - BUT - that does still give a decent indication how much recoil a load would give. Thanks for the links.

Ken H>

[leadman]

Sorry for the thread hi-jack but have some comments on the Rolling blocks. Always worries me when someone wants to load to higher pressures in these guns.
I shoot 3 rolling blocks, 2 are originals, one a Pedersoli.
Take a good look at the chamber area and try to imagine what would happen to you when the breech let go. Dutchman posted some pictures here of different RBs that let go. In most cases the shooter has died due to pieces of the breech entering their skull.

Make sure the pins, hammer, and breech block are in good shape and ammo loaded to lower pressures. There is much discussion in quite a few threads here. Stay safe.

[KenH]

I don't think anyone in this thread has mentioned anything about loading to higher pressure in a Rolling Block.... Have they? All the loads talked about here are well under "trapdoor" loads - do you not consider "trapdoor" loads safe in rolling block that's in good condition? OR - do you consider the trapdoor action strong than a rolling block design - both are BP actions.

Per Larry Gibson earlier in this thread:
"18K" psi was for L.U.P. method of measurement and does not compare to modern transducer and strain gauge measurements. The SAAMI MAP of 28,000 psi for the 45-70 is for "trapdoor" loads.

Shouldn't a case full of FFg black powder be safe in a good rolling block? Larry mentions testing BP loads:
I have indeed pressure tested BP loads. With the 405 gr Lee HB bullet 70 gr of GOEX Cartridge runs 1310 fps out of my TD rifle at 20,300 psi(M43). The Rapine 500 gr 460500 over the same charge runs 1245 fps at 22,300 psi(M43)

I have discussed what should be possible max loads in a rolling block action with a modern E.R. Shaw 45-70 barrel installed. After much discussion I've reached the conclusion the breech block is the possible weak point. Where a new breech block and new pins made from modern material, I do think the action would handle a good bit of chamber pressure.

I'm always looking for new info and different viewpoints - and wanting to learn.

Ken H>

[FergusonTO35]

Save the 4064 for your .30 WCF and .257 Roberts, two cartridges where it really excels. Heck I'm thinking about going to 4064 for all my higher pressure rifle loads. It's always available here!

[KenH]

Oh, the only reason I loaded a few 4064 was because I was testing a few cast bullets, and I only had 1/3 of a can and was using it up just to get rid of it. I've always used 3031 for the 30-30 in years gone by. The only other rifles I'm loading for at this time is the 45-70 and 50-70 ammo.

Ken H>

[35remington]

However those recoil calculations were done is in error. Identical muzzle velocities with identical bullets in the same gun will not see a 3 fold increase in recoil just changing the powder charge needed to obtain said velocity, nor a two fold. Perhaps a better source is needed as that one is wrong, whatever it is.

Keep in mind the major component of recoil is bullet weight and velocity. The other factor of powder charge weight is relatively minor and cannot account for the differences claimed....because the claimed differences do not exist.

[35remington]

The tough part to figure in the recoil equation is the velocity of the propelling gasses, as they likely vary. A long time ago (see Lyman's 45th) the velocity of the propelling gasses was claimed as 4700 fps, but that was likely a full power load of high pressure running a slow, high muzzle pressure propellant. Gas velocity for a cast bullet load is likely considerably lower, but how much? Let's make the point that it can't be as great a difference in recoil as stated earlier, with a 405 grain bullet at 1100 fps, just by changing powder.

Remember the major component of recoil is bullet weight and velocity. Using the erroneous figure of 4700 just to make a point, and an 8 pound gun, I get:

With 11.4 grains powder (Unique actually needs more than that to get 1100 fps by a few grains) 9.9 ft/lbs
With 34 grains (I think 34 was used) 14.4 ft/lbs

The error, is, of course, the gas velocity. It is very doubtful it is this high at muzzle exit with either powder, thus artificially inflating the effect of the powder's contribution to recoil. With Unique the gas volume is low as is muzzle pressure. It's probably low with 3031 as well, because the pressure never got very high in the first place. Actual measurement would place the likely recoil figure as lower than that calculated here.

The nettlesome thing is agreeing on just what the exit velocity of the gasses are.

[35remington]

Velocity of the bullet times its mass in grains plus (+) the 4700 (erroneous) times the weight of the powder charge. Divide this figure by the gun's weight in grains and square the result. Remember to multiply before you add.

Then, take the weight of the gun in pounds divided by 32.16 (that number should be familiar) and multiply by 0.5. Take this figure and multiply by the first, and you have recoil in ft/lbs. Inflated a bit high due to the gas velocity figure.

Further, shoot a load like that described....you'll realize recoil is not anywhere near tripled, confirming the validity of the equation in terms of which one is "righter."

[KenH]

Thank you so much for the additional info you've provided - and I do agree with your comment there is no way the recoil could be 3 times as much at same velocity. Perhaps it's all in my mind, but it does seem like the recoil is different between a fast vs slow vs BP at around the same velocity/bullet. Perhaps that's only in my perception due to difference in muzzle blast.

Thank you again for your comments.

Ken H>