I've been having some problems with my 45-70 loads

[WoodenFrog]

Every now and then I get one that seems to have quite a bit less velocity than the rest.  I'm using 28 grains of XMP 5744, pushing a 330 grain cast bullet.  I'm using it for shooting in CAS side matches at 200 yards.

I'm using a RCBS powder measure, and it seems like I'm cutting some of that stick powder in two pieces when I'm dispensing it sometimes.  I'm wondering if I might be throwing erratic charges.

Or could it be that the 28 grains of powder just isn't igniting properly in that large case?

Would you recommend a different powder?  Or have any other suggestions?

[quickdtoo]

My experience with 39-43grs of XMP5744 in a 45-120 which has a considerably bigger case than a 45-70, shows it's not position sensative at all, shoots 1½" groups at 100yds w/iron sights regardless of whether the powder is all the way forward or anywhere else. Accurate does recommend CCI 250 magnum primers for the 45-120, though.

http://www.accuratepowder.com/loaddata_caliber_rifle_standard_458cal.htm

Tim

[Lone Star]

How much lower is the velocity for the errant shots?  Degrading a propellant like 5744 in a powder measure should not effect the charge much if at all, and the difference in charge weight shouldn't be that much either - try weighing ten throws and see what the spread actually is.  

Perhaps it is the powder's position in the case.  If every now and then the charge is, say, at the front of the case then the velocity may be somewhat different than it is when the charge is centered or at the back of the case.

5744 is not noted as being very position-sensitive, but the charge weight you list produces relatively low pressures - under 14,000 psi.  Do you note a difference in the amount of unburned powder in the barrel after the slow shot?

What primer are you using?  Pistol primers are often used for CB loads, but they may not be hot enough for this load; Accurate recommends rifle primers only.   Is it possible that the bullet lube you are using is contaminating a few powder charges?  The above are a fw of the posibilities.

[quickdtoo]

Perhaps it is the powder's position in the case.  If every now and then the charge is, say, at the front of the case then the velocity may be somewhat different than it is when the charge is centered or at the back of the case.

5744 is not noted as being very position-sensitive

As a matter of fact, it's designed to not be position sensitive...
http://www.accuratepowder.com/data/5744.htm

5744 has some very specific design criteria. First, it is double base with a high percentage of Nitroglycerin. This gives the propellant a high energy content. It also promotes consistent ignition even with low volume powder charges in the large capacity "old timers' such as the 50 Sharps. In fact, the 50 Sharps was used in some of the development work for this propellant. Nitroglycerin contributes to excellent shelf life and reduces the effects of humidity and temperature.
Second, 5744's short length provides uniform metering so you can spend more time shooting and less weighing charges.
Third, 5744 has a relatively low bulk density. This contributes to its ease of ignition. In fact, ease of ignition and consistent velocity, regardless of powder position in the case, are the two main criteria we set in manufacturing new 5744.

[WoodenFrog]

The lubricant I'm using is Lee Alox, but it's well dried before I load the bullets.  I wonder if the Hornaday spray case lube could cause degradation of the powder?  I'm using Winchester rifle primers.

[Larry Gibson]

"WoodenFrog"]Every now and then I get one that seems to have quite a bit less velocity than the rest.  I'm using 28 grains of XMP 5744, pushing a 330 grain cast bullet."  

My experience chronographing numerous loads with numerous bullets (275 gr- 510 gr) in the 45-70 using XMP5744 shows distinct velocitiy variation with bullets under 400 gr with charges less than 30 gr.  I did not get consistant velocity (5 shot strings with an extreme spread of 50 fps or less) with 28 gr unless a 385 gr or heavier bullet was used. It took 25 to 26 gr with a 405 gr bullet to get consistant velocity but I found 28 gr to be the right load for that weight bullet.

Basically I found XMP to be a poor powder in the 45-70 with lighter bullets unless you wanted to get up into 1800 fps or so. I did not so I don't use XMP574 any more. I use Bullseye with 275 gr bullets at 1050 fps. that load is very accurate out to a considerable distance. I most often use Unique with 300-340 gr bullets at around 1300 fps if I want "medium range power" in my TDs.

Larry Gibson

[Lone Star]

5744 has some very specific design criteria.....In fact, ease of ignition and consistent velocity, regardless of powder position in the case, are the two main criteria we set in manufacturing new 5744.

Yep, that's exactly what the advertising copy states.  Those of us who have actually used 5744 however find it a good power for some uses, but it is still somewhat position sensitive at low charge levels.  But would this cause such a noticeable difference?  Probably not.

Whatever the reason, something is causing the occasional extreme(?) velocity variation.  Lee Alox worked for me fine years ago, and the OneShot case lube has never caused me identifiable problems either.  Winchester rifle primers are among the hottest available.  Perhaps the bullets should be seated tighter in the case (larger bullet diameter or smaller sizing die) or be crimped.  Otherwise that leaves the powder as the most likely culprit - the wrong choice for the desired bullet/charge level.  Hey, if every recommended load worked great, handloaders wouldn't neet to experiment.  

[WoodenFrog]

Yes, something is causing it, and I can't figure out what it is (obviously).

I'm quite familiar with reloading, and have done it for over 35 years.  And, I'm not reloading in my Dillon 550 either.  I'm using a Lyman single stage press, and using Hornaday dies and  lee crip die for extra tight seal.

What seems to be the most popular powder for cast bullets around 330 grain for 45-70?  What 45-70 smokeless power do you guys use.  I think I'll go with the most favored by you guys, and see if I can figure out my problem.

Thanks.

[WoodenFrog]

5744 is not noted as being very position-sensitive, but the charge weight you list produces relatively low pressures - under 14,000 psi.  Do you note a difference in the amount of unburned powder in the barrel after the slow shot?

I have noted sometimes there are several grains of unburned powder in the barrel after firing it.

[quickdtoo]

I've used some light 2400 loads with the 350gr Hornady with great results in my 45-70 Handi, it's a real popular mild load used by the NEF/H&R forum members in their Handis. Alliant also has some Rl 7 loads, but I've not use that powder yet.

http://recipes.alliantpowder.com/

Tim

[Lone Star]

For relatively mild cast bullet loads (1100-1300 fps) I've had excellent results with IMR4227.

[WoodenFrog]

Which powders would be better considering I've got a 34" barrel?

[Lone Star]

My Pedersoli rollingblock has a heavy 28" long octagonal barrel and it thrives on 23-26 grains of IMR4227 and 400-grain cast bullets.

[zrifleman]

For consistent partial case loads try SR 4759 in the 26-27 gr range. It burns much cleaner and more evenly than other powders mentioned. It needs no case filler and not likely to ring a chamber. I used MP 5744 when it was a repackaged  military powder and thought it was the best thing since sliced bread. Not so the new stuff--it leaves too much unburned powder in the barrrel and accuracy is just so so. Good old 4759 is hard to improve on.

[Lawful Larry]

What 45-70 smokeless power do you guys use.  I think I'll go with the most favored by you guys, and see if I can figure out my problem.

Thanks.

Don't know what you are loading for, as far as gun, but when loading for my original '84 Trapdoor I use 3031.  I load a 405 gr. RNFP hard cast bullet over 35 grs.  I find this to be a pleasant round to fire in my old trapdoor.  I don't go over 38 grs though, cause of the gun's age.

For hunting loads I load 50 grs. of 3031 under a 405 JSP for my Winchester 1886.  I am still working this load up and do not have all the data on it yet.

I think anytime you go below the published load recommendations of the powder company, you will be in unchartered territory and should use caution.  But I am sure you know this if you have been reloading for over 35 years.   :wink:

[rllepsy]

Everyone seems to have covered all the base but I'm with the IMR4227 recommendations and the SR4759. 4759 has worked consistently well for me in a number of bullet style/weight combinations. Though they no longer recommend it Lyman has called for use of poly fiber wads at 1/4" x 5/8" @ !/2 gr. each. I've noticed significant improvement using wads with the recommended recipes in standard deviation and group accuracy. This has been the case for Marlin, Ruger and a 73' springfield. If you can refer to Lyman's 47th reloading manual for more info. You may want to verify the OAL of your cases especially is your crimping the bullets. Sometimes crimping can improve the consistency of you loads in shot to shot performance but not always. Good luck. I'd appreciate it if you publish the resolution to your problem!

[jd45]

I've got a can of XMP-5744 on which it gives load data for 45-70. It reads 27.5grs under a 405gr lead bullet. Maybe the bullet weight (330gr) is the problem? Tech service ph # is 800-416-3006, jd45

[ButlerFord45]

35 grains of IMR 3031 will give you a mild, consistant load.  It has become a sort of "standard" amongst many shooters of older 45-70's.  IMR 4064 is also an excellent powder for the 45-70.  My experiences with XMP 5744 left a lot to be desired.

[ajj]

Mr. Gibson summarized 5744 usage in this caliber very well.
Try 4759.
It is an almost universal misconception that barrel length is an important variable in choosing the speed of a rifle powder. Not so.
Good luck and good shooting.

[McLernon]

My .223 "drops' a shot every once in a while too(like 6 inches low). It does it more often with my reloads so I don't reload for it anymore. I purchase Winchester White Box ammo.  I suggest you check some recent threads under McLernon regarding ignition problems caused by the transfer bar and hammer extension. I still haven't pinned the problem down completely but I got much better results without the hammer extension on. If you haven't been using a hammer extension maybe your(and mine) hammer spring is too weak and needs replacing with a stronger spring to reduce lock time and ensure proper impact of the transfer bar and firing pin. I am told by NEF that this can result in significant muzzle velocity drops.

McL

[jh45gun]

I also use 3031 for my 45/70 loadings. You can use up to 38.5 grains for the weaker actions and more for the lever guns. My Remington Roller is a bit stronger I feel than a Trapdoor since it was made for smokeless loads ( Model 1902 number 5 action) so I shoot around 40 grains of 3031 in my gun. Jim

[willysjeep134]

My dad reloads for his 45-70 with 3031. He wasn't crimping very tight and he would get some flat out misfires, but that doesn't sound like your problem.

He now uses a Unique load that produces the same velocity. He loads 300 grain JHPs. All of his loads are much slower than factory loads, but he hunts whitetails and doesn't need all that velocity. He also crimps a lot tighter now, and gets a lot more reliable loads.