4759 plastic jug-4759 metal jug

[kennacl55]

How much difference is there in 4759 in the metal can as to compared to 4759 in the plastic can?

[Deleted]

IMO the only true way to find out for sure would be to run known safe and proven loads thru your gun and the chrony and compare the speed difference as well as where they impact the target. That should give you a good feel for the comparison on the two. Someone else more knowledgeable may chime in with a better solution, that's just what I'd do.

[jims]

I have not shot 4759 out of the can for some time, plastic now when I can find it but as I recall there was not significant difference between the two for me. Slight variation as I recall but small. I actually had forgotten about the difference as again I no longer find the metal cans here.

[ET]

From my past experience the metal can of 4759 produced about 100 fps more with muzzle velocity. The peak pressure with the metal can of 4759 also produced about 5K higher peak pressure. Adjust the 4759 from the plastic bottle by an additional 3-4grains you would regain the velocity originally lost from the metal can 4759.

This is with a 50Cal load.


Ed

[herman]

My thoughts are that the old lot numbers with 4759 in the metal 8oz cans was the best powder you could get for the 50 cal savage.The velocity drops actually started with the later lot numbers in the metal cans.Not saying that the plastic can lots aren't good they are but with a lot of speed drop.
I remember making a post way back that I counted up how much 4749 that I had shot and it was 15 + lbs and made the statement that if the powder stayed the same that it would be the only load I would shoot in my 50 cal.
But since the speed dropped so much I usually shoot other loads in my 50.
N120 was another top notch powder for the 50 cal but like the 4759 its not available any more.
I found 2 comparsion pics on photo bucket that I will post below.It was comparing loads with 2 guns,bullets and even chronys.
For years now if someone wanted me to set up a 50 for them I would use 4759,with the plastic jugs the velocity
isn't there but the accurate ness is.Several years a gun shop owner asked me to check out a 50 cal for him.He said it had been sent back to savage twice and they said it was ok but the owner of the rifle still complained that it wouldn't shoot so he gave him his money back.He was getting ready to send it back for the 3rd time is the reason he asked me to give it a try.
Took 2 shots to get on paper and the next 3 went in about an inch.just to show the plastic jugs are accurate but slower speed.
Using my favorite load of 4759 (in certain lot numbers that I don't remember now)I always got 2450 fps with a 250 sst.
I have shot up to 50 grs with the plastic jug and couldn't reach my fps as I did with 47.5 grs of the old lot.
If you notice in the data 48 grs starts getting slower that usually means you have reached the max grs for that load.



Pic the rifle sent back twice.

My favorite load of 4759 old lot.

[TGinPA]

FWIW, this was posted in 2011 on the old board.

Pressure Traces: pn45: SR4759 Loads with New Plastic v Old Metal Canisters
I am running out of my old lot of SR4759 in a metal canister. The new lots which come in plastic containers are said to be different, requiring more powder to obtain the same velocities as from the old lot. From what I have seen quoted, 2-3 more grains are needed to equal what the old lots provided. To see what changes regarding pressures might occur, I traced old and new lots of SR4759 using a resized 300gr Rem jhp loaded sabotless.
Gage and Module Manufacturer = RSI USB model
Trigger Sensitivity = 0, Strain Gage Voltage =4.9 Gage Factor =2.1 PSI Correction Factor: 0
Barrel Temp = 72-76 degrees F. measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled
Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (13 fps. added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06in. Barrel ID = .452in.
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .032 in. Sensor dist fm BP=1.1in. Bullet Diam.= .458 resized to .448in.Type = 300 Rem jhp Bullet weight = 300gr. unknurled. Sabot: none Wads:Lubed wool over .462x.060 lubed fiber.
Powder: Panel 1: SR4759 metal canister 43gr 3shots.
Panel2: SR4759 Plastic container 46gr. 3 shots.
Panel 3: SR4759 Plastic container 50gr. 1 shot.
Primer :Fed 209A
Shot fm. dirty barrel. These load seemed safe in my barrel under the test conditions but may not be so in other conditions.

Of interest is the small extreme spread for both 3 shot traces, to be expected with relatively fast powders and relatively heavy bullets. Under the test conditions, the burn characteristics of the new SR4759 powder lot in plastic containers seem significantly slower than the older lot in metal canisters.. With the bullet tested, to obtain equal velocities required about 3gr. more of the new powder lot compared to the old lot, in agreement with previous observations. However, to obtain equal peak pressures in the 40kpsi range requires about 6gr. more of the new powder compared to the old lot. At these pressure levels with a 300rem jhp bullet, when powder loads are set so that peak pressures are matched, velocity is about 100fps higher with the new powder.
TG



Using a 300gr Rem jhp, to match the velocity of the older powder lot with the new plastic container powder lot required about 3grains of more of the new powder. This is in agreement with previous statements on this board. But it is also of interest that this matching of velocity was accomplished with about 3kpsi less peak pressure being generated by the new powder. Under testing conditions, to match peak pressures required about 6 gr. more of the newer lot. If powder loads between old and new lots were matched so that peak pressures were the same, the new powder lot generated about 100fps more velocity with this bullet than seen with the older lot at the same peak pressure.
TG

[jims]

Good information