I have the opportunity to pick up so SR 4756 powder at a reasonable price. I have never reloaded with this powder before. Is it good for .357 magnum/38 special and 45 auto? How does it meter?

Thanks for any information.

It is a very fine powder that meters very well.

It does well in the 38 special with lead and Jacket bullets from a snub nose to a six inch tube, in my loadings.

It will give you a factory 125gr Jhp load in a 6" magnum at 1448fps and also a Fac Dup. load with the 158 xtp .

This powder can be touchy with maximum loads so be sure to work up on all maximum loads and I got best results with "Standard" primers. A cci500 and a f100 are NOT interchangeable in my test and chrony readings.

Better than Unique and burns clean.

4756 is a controversial powder. Some swear by it, some swear at it.
Often used to hotrod the 38spl and 357 mag but at the cost of higher
pressure than expected or desired. It is the only powder that has ever
given me any problems with loads right out of a loading manual. The
older Speer manuals listed loads that some handloaders have found
to be excessive. It doesn't perform well in lighter loads at standard
pressure giving large extreme spreads and position sensitivity, at
least in my loads. I will never buy another can of it.

If at all possible I would try and get my data from a Lyman load data manual, since I have found this data to be close to the actual fps and pressures, as per my loads and test, in my guns.

Hodgdon and Speer are a little too off in their figures for my taste...........but some use them.
I just found that Hodgdon starting loads too low and I was getting high ES in the 150's or more and the cases needed to be at least 50% full of powder with the bullet intact for this powder to start working for good readings and better accuracy.
Since I do not have a N frame I opt. not to try Speers maximum loads.

I have only tried it with 148gr wadcutters. I wasn't impressed with the accuracy, possibly due to the position sensitivity. It does meter well, but there are better choices.

SR4756 is an excellent propellant for standard revolver cartridges. Most of the published data in nearly any manual can be depended on. One manual to stay away from though is the Speer #8, at least for .38 Special. Some of the .38 data is downright dangerous!

One load from the Speer #8, supposedly a standard pressure load, showed from 10.0-12.0 gr in .38 Special with a 125 gr. JHP. While this is purportedly a standard pressure load I have chronographed the startingload of 10.0 gr, and it gave a velocity of 1389 FPS!!!! That is a full blown .357 Magnum load. It gave higher pressure signs than any .357 load I have ever shot. This was in a 6" Highway Patrolman. There was severe primer cratering and sticky extraction, can you imagine what would have happened with 12.0 gr! The DuPont manual gave a maximum load for this bullet of something like 4.5 gr, and that was a +P load as I recall.

I would bet that the data awslate said he had problems with came from the Speer#8, I am not surprised!

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Gunsmithing since 1961

I have used it with good results in 9mm, .38 Special, and .357 magnum.
I stay well within the recommended charge range, but I do that with all of 'em, really.

Yeah the good old Speer #8 which I still have but don't consult very
often these days. Early 70s, SR4756 and Speer 140 gr JHPs in my 6"
Highway Patrolman. Sticky extraction and primer flow so severe that
I had to pound on the cyl with the heel of my hand to get the gun
open. There are better powders around for my money than 4756.

I tested SR4756 in my 686 6" back in 2011 and had some eye opener results with my chrony on how touchy this powder is.
These few test were with 38 special brass:

110 win. sjhp med. crimp
f100 6.2..... 869... 817 to961 ES 144
f100 6.5..... 973... 875 to 1135 ES 260
cci500 7.3... 990... 868 to 1050 ES 182
f100 7.5..... 1020... 970 to 1056 ES 86
cci500 7.5... 1078... 996 to 1129 ES 133

158 L
cci500 4.8... 682... 629 to 800 ES 171
f100 4.8..... 728... 650 to 831 ES 180
f100 5.7..... 855... 832 to 885 ES 52
cci500 5.8... 890... 845 to 926 ES 82
cci550 5.8... 916... 898 to 951 ES 53

This powder in my test did not do well with starting loads.....
Over all it did best with a standard primer than a cci550, mostly in my later .357 testing.

4756 is a great powder for 357 IMO.
meters well, clean, accurate.
6.5 grains under any 158 grain bullet is a winner - lead, jacketed or plated.
I like magnum primers with 4756 in the 357.

The problem wasn't with 4756, it was the erroneous data published by Speer in the #8. If you compare the Speer data with the contemporary IMR data you will find that most of the Speer loads were 250% of what IMR recommended as maximum. Give it try with just about anyone else's data and I think you will like it.

The Speer #8 manual, at least some of the .38 Special and .357 Magnum data, gives the lie to the common assumption that any data published in a loading manual must be safe!

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Gunsmithing since 1961

I starting using SR4756 for my .357 magnum loads in the early '70s. The reloading manual available to me at that time was Speer Manual Number 8. On page 370 of that manual the SR4756 loads listed for the 158 gr. Speer SWC or RN bullets were 10.0 and 11.0 (Vel 1305, 1406). I used both loads. With 11.0 gr., the primers blew back into the firing pin hole and left a tit on the fired primer instead of a depression. It didn't take me more than 2 or 3 shots to stop using those loads and experiment with lighter loadings. The Speer SR4756 loads for 158 gr. 38 specials was listed as 8.0 and 9.0 (Vel 1140, 1250). It was lucky for me that I was using a Colt Python for shooting the SR4756 .38 specials because a .38 special revolver might have had problem. It turned out that 8.0 gr. makes a peppy, accurate .357 magnum load.
The reason that I chose SR4756 for my 38/357 loads was because I already had the powder for my .222 Remington loads.

Mark

250%????? I haven't heard THAT! Fortunately I started with the #9 manual.

I was using the ole stand by Lyman #8 and 4756 sure looked like the right medicine for the 357. I noticed that later manuals, including Lyman, had cut back drastically on the loads. Now I know why.


Charlie

In my "L" frame 686 6" revolver "X" grs of sr 4756 gave me 1250 fps in a 38 special case, which should not be used in a J frame.

When I dropped all the way down to 6.0grs in the 38 case I still got a +P speed of 990 +/- in my L frame.
5.7grs spit out 855 fps and should be a nice load for those that have a 4 inch barrel J frame......... I will be testing 5.5grs
to see if there might be an improvement on accuracy but this is almost the minimum for this powder for accuracy in my revolvers with this powder, with lead bullets with a standard primer.

I use SR4756 for 9mm,38sp,357m,40S&W,10mm,44sp, & 44m. The only exceptions are SR7625 for light targets loads in 38sp & 44 sp.

4756 has always been a favorite of mine for 38/357 loads with the 158 gr SWC. It's been hard to find around here lately, even before the ammo shortage.

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Support your Police, & NRA

I just found and bought 8 lbs of 4756. I love the stuff for 38/44 and 38 Supers. It is a great powder just work up your loads over a chrono to your desired velocity or the velocity that matches the book loads.

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SWCA 1646

I suppose y'all know there are 2 editions of Speer #8? There is very little change in the data, but that data was built around 45,000-46,000 cup SAAMI pressures. They still say the cup pressures are in their specs, but I haven't seen any in a long time.

My first handgun deer was a lot of SR 4756 with a Sierra 125 gr JHC in 1972. I liked the idea of 1600+ fps and after I got a chronograph i learned I was actually 25 fps short of 1600 fps using the same M28-2. It'll shoot faster with a Golden Saber and will clock close to 2200 fps out of a rifle.

Most people only go by the old wives tales and have never stopped to recognize that Speer had been checking pressure since Speer #5. There's a picture of the specially produced cylinder with the piezo element sticking out the side. That means every .38 Special/.357 Mag load in Speer #8 was checked for pressure with the latest equipment that we still use.

The only load I've ever had from Speer that was a little hot was from Speer #10 with 14.5 gr of Blue Dot with a 125 gr Golden Saber. That one gave me sticky extraction and I never get that with SR4756.I have checked DuPont SR4756 vs IMR SR4756 and got just about 10 fps difference between the two. One was bought in the 1980s and the other in 2004.

There was a long running thread on "The Load" with 8.0 gr of 4756 with a 158 gr LSWC in .38 Special. I have 10.0 gr with a 125 Golden Saber loaded in .38 Specials in my M66-2 in the bedroom right now. I think it clocks at 1250 fps.

Yes I have both editions.

I have loaded up to Speer 8 max but I recognize that 4756 seems to have more lot to lot variations than most. This is why I wanted a 8 lb jug so I can optimize my loads over the chrono and make a bunch of them.

I was shooting 7 grns with a 158 yesterday and the cases popped out of the 38/44's with the lightest of touches. Obviously a mild load but they hit the velocity I was aiming for (1175 out of the OD's) so I shot them up.

4756 is a good powder. You just have to treat it with more respect than say longshot.

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SWCA 1646

Many of us do not know that back in 1970 the Speer #8 data was based on the magnum with.................

45 to 46,000 CUP

I believe the pressure was "Adjusted" in 1972 to 42,000........
do to the difference in pressures from lot to lot of the powders that was passed to the public.

The company also went on a mission to make its powder more stabile and keep the pressures more in line and safer for the public.

It is "Safe" in all modern data that we have today............
one reason many post that there are "BETTER" powders out there, after being watered down so much.

Actually, Speer #10 says the pressure was changed to 35,000 psi, which is now the SAAMI spec. I had an engineer at Starline try to tell me there isn't any difference between 35000 psi and 46,000 cup and I laughed at him.



The SR4756 cans have been the same color since it was introduced. There's a big can of IMR on the top shelf and 5 of the 8 ounce cans on the third shelf down. I have been using SR 4756 since 1972 and I have never seen any differences in the different lots. If there was too much variation, it wouldn't be SR 4756 in the can!

Some years ago there was an article in Handloader magazine regarding
lot to lot variation of 4756. After tests the author concluded that 4756
did indeed show noticeable variation between different lots. Does it
still today? Who knows?

I wish the powder shelves at my LGS looked like that!!!

Yes, 4756 does vary from lot to lot, but (pardon the pun) not a lot.

I work up my 38 super reloads over a chrono and I see several tenths variation from lot to lot to achieve my target velocity of 1300 fps with a 135 grn lRN. I see the same thing with my 158 grn LSWC 1150 FPS 38/44 loads for the 5" heavy duty.

Since I don't normally check every lot of other powders (maybe I should?) I don't know if this is normal or excessive. I would say the variation is about +/- 7% when I look at my notes.

Side comment. Nice collection of powder and supplies. I am quite envious. I really appreciate the order to it. Someday for me. Someday.

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SWCA 1646

Some thing to think about.................

when the Speer #8 was printed..................

and how long it took to do all the testing. 1972 could have been three years after the testing. Plenty of time to fix the problem with the powder. Just saying.

Even if they did fix the problem, in my test, last year, I was getting large ES spreads in my 38 spl. cases loaded in my L frame 686. If the power was "Improved" it was minimal, I would think. Very "Touchy" in some of my loadings but it was at the top of its game when near or at a maximum factory loading with certain loads.
I was happy that I could test the 38 data in my 357 and do agree that the "Newer Data" is what should be used in K frames to keep the wear down.
Notice that there is NO "J" in the last sentence !!

I know Hodgdon has data for the 357 and SR4756 with a 7.7" barrel ...............
but I sure would like to see their data, pressures and ES spreads on their 110 xtp test !!
Their starting load is 6.5grs of SR4756 at 1292 fps and I don't get 1300fps in my 6" 686 until I am way over their highest loading.
Their high fps was 1574 and mine in the 6" was 1500 with a low of 1470 and high of 1529 before I cut off the powder.
They must have had a "Fast" can of powder ?

PS:
I did get ES of 40 in some 38 loads and 29fps in the 357 loads... not saying it is not a good powder but it could also be my cheap chrony readings. I did notice that is was better as the bullet weights INCREASED.

I have never used it, but I've seen posts in the past reporting results using loads from Speer #8. They reported getting single digit ES. Unfortunately, those threads seem to have disappeared. I'm not suggesting anything though.

Regarding Hogden's data, you won't get anything close to their results in a real gun. I consider them near the bottom of my data sources, just (barely) above Lee.

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Common sense isn't so common.

I know when I chrono 4756 with hot 38/44's I tend to get SD's in the 10 to 15 fps on 20 shot strings. I consider that reasonable.

__________________
SWCA 1646

I've been working SR4756 in 38 Spl. lately and I have been reloading since 1973. To date I find that 6.7 grains of SR4756 and a hard cast 158grain SWC and a standard CCI primer produces some of the tightest groups I've ever fired from a 38. I don't recommend this load to anyone, but in slowly working up this load in a K frame it extracts easily, the primers are still rounded and smooth with a normal firing pin indentation. The report of the weapon and the recoil impulse are uniform and appear consistent with standard pressure loads in a 38 Spl. Next move is to put them over a Chrono my test gun has a 3" bbl. Would be interested in reading Chrono data from anyone who has used a similar load a 3" firearm.

In a 4" 6.5 grns with your set up does 1030 FPS on a 20 shot string. I would expect that the extra 0.2 grns and the 3" barrel would cross out and you are right around 1000 FPS.

I think of that as a good velocity to aim for.

__________________
SWCA 1646

I've used it for loading .44 Spl with lead boolits.

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What would Jim Cirillo do?

On page 364 of Speer #10 published 1979,

I've been using 4756 since the 1970s. Have always found it is a great powder to get the most out of standard cartridges but never has done well trying to get the most out of Magnums...

Don't have my loading data availalble right now as I am out of state but in 9mm, .38 Super, .38 Special, .44 Special, .45 AR and .45 Colt could always get more velocity with less pressure signs than any other powder.

From what I read a long time ago the burning rate of 4756 was changed back in the early 1980s. It used to be about like Blue Dot but the "changed" powder is more like Unique. The article also stated "canister" 4756 was the powder that Remington used in a lot of its factory produced centerfire pistol ammo.

My advise to anyone who reloads is to invest in a good chronograph. Every gun is a law unto itself and I've seen loads that were perfectly fine in one gun have to be tapped out of another. Use loading manuals as a "guide" rather than "The Bible"...

Bob

I have been loading .38 Specials with SR 4756 for 40+ years. My favorite load is 9 grains pushing a Speer or Sierra 140 grain JHP. I could not tell you how many of these I have loaded and fired, but it's a substantial amount.
When I learned that IMR was not going to make this powder any more, I started squirreling away several cans.

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Nemo Me Impune Lacesset

I bought two pounds of 4756 the first I loaded 9 and 40 caliber rounds at starting loads and they wouldn't cycle in my two handguns, went to max still intermittent problems I had to go over max to function properly. I contacted IMR/ Hodgdon and they asked me to send a few rounds to them for examination , I didn't follow through just used the first pound up, the second pound worked flawlessly at starting loads in both calibers, they had different production codes

Are the "SR" powders supposed to be DISCONTINUED at the end of 2014?

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NRA Pistol/Rifle Inst. RSO

Hodgdon's told me that they are discontinuing several powders for 2015 - most of which are already out of production, SR4756 among them.

It seems that there is new methodology for making powder and the ones being dropped cannot be made using it. The older method requires three times the man hours but none of those powders were selling well so Hodgdon's absorbed the loss for several years. But the end is here.

Other companies are no doubt looking at the same situation and we might loose some of our other favorites. And if those powders are popular, there is even more motivation for the companies to stop making them as they are seeing a loss on a lot more sales.

Ed

I saw two 8lb jugs at the gunshow today. It was dated Aug 2014, I believe.


Charlie

I just tested a 4" 9mm with a 124gr plated bullet and.........

SR 4756 kicked Unique's butt in the fps contest with a maximum data loading.

1255 to 1207

Grab some if you find any.

SR4756 is a WHOLE lot cleaner, too.

Ed