Load Testing: IMR 7625 powder

[Wobbly]

I've been reading about this powder on Benos and other shooting forums and got interested. Just found my first can in an LGS last week, and decided to try it on 9mm. So I thought we'd have a thread on this to assemble all the data from all who want to comment.

First of all, this is a very fine grain ball powder. It looks exactly like Accurate No5. So if your powder measure leaks the numbered series, then don't bother trying this powder. 

The Accurate Burn Rate Chart places 7625 as an equal to Unique and Universal. That means in 9x19 it would be good in SD loads for mid-weight bullets, or nice for general use heavy weight bullets. I also see lots of use for it in loads for 38 Super, 38 Spcl, 357 Mag, and 40.

I found the best load data on the Hodgdon web site and a 2006 IMR load booklet. Otherwise, being in the crowded field it is, it's listed inconsistently throughout most common manuals.

My tests loads are ready. More when it stops raining !

[ReloaderFred]

I've been using it for 9x19 loads for about 5 or 6 years now and really like it.  It burns clean and gives good velocity for the charge weight.  I use it almost exclusively with 115 gr. bullets, since that's what I load the most of in 9x19.  The paper targets don't seem to mind being hit by the lighter bullet, and they're cheaper.

Hope this helps.

Fred

[Cesar]

I've been reading about this powder on Benos and other shooting forums and got interested. Just found my first can in an LGS last week, and decided to try it on 9mm. So I thought we'd have a thread on this to assemble all the data from all who want to comment.

First of all, this is a very fine grain ball powder. It looks exactly like Accurate No5. So if your powder measure leaks the numbered series, then don't bother trying this powder. 

The Accurate Burn Rate Chart places 7625 as an equal to Unique and Universal. That means in 9x19 it would be good in SD loads for mid-weight bullets, or nice for general use heavy weight bullets. I also see lots of use for it in loads for 38 Super, 38 Spcl, 357 Mag, and 40.

I found the best load data on the Hodgdon web site and a 2006 IMR load booklet. Otherwise, being in the crowded field it is, it's listed inconsistently throughout most common manuals.

My tests loads are ready. More when it stops raining !

Like N. 5 or N. 2?
N. 5 is fairly slow burning powder. It'd not be very suitable for lighter (124gr or so) bullets or most common HG barrel lengths.

[jameslovesjammie]

IMR SR7625 is one of the most underrated powders of all time.  I've burned through roughly 15 pounds of it, 18.4 grains at a time in my 20 gauge.  It's clean burning, consistent, and produces high velocity with comparatively low pressures in shotgun rounds.  What more could you ask for?

When I bought my MEC 600 JR at an auction about 15 years or so ago, included in the box was an unopened 8 lb jug of SR7625.  I figured since I had the powder, I might as well use it. To this day, it is still my go-to powder for 7/8 oz 20 gauge target loads.  Our local Scheels was closing out old 8 oz metal cans when they were switching over to the 1 lb plastic cans.  I bought somewhere around 10 cans for something like $5 a can.

The Lyman 49th lists it in .32 acp, .32 s&w long, .32 H&R, .32-20, .380, 9mm, .38 super, .38 s&w, .38 special, .357, .44 special, .45 acp/ar, and .45 colt.  It is quite a versatile powder.  Also a good powder for Cast, since the burn rate is close to Unique. 

[SMSgt]

My tests loads are ready. More when it stops raining !

Who do you think you are, the Wicked Witch of the West? Get out there and get wet and stop keeping us in suspense.

[jameslovesjammie]

My tests loads are ready. More when it stops raining !

Who do you think you are, the Wicked Witch of the West? Get out there and get wet and stop keeping us in suspense.

I agree!  Just move your targets back a bit.  Vapor trails are super easy to see in the rain!

[Wobbly]

Who do you think you are, the Wicked Witch of the West? Get out there and get wet....

That's it! I'm sending the flying monkeys tonight. 

[SMSgt]

I read Wicked. Ain't skeered of no flyin' monkey. Clowns are another story.

[1SOW]

I shot in the rain today.
Ditto IDescribe.

[Wobbly]

Honey do's, my youth program, and if you can believe.... even MORE rain.

The good news is, the back yard is now holding during the down pours.
The bad news is that the front yard just washed away for the third time. 

[Wobbly]

The Loads
Fans and detractors alike can finally rest.    I got a chance today to shoot the 7625 test loads, while dodging more rain drops and lightning bolts.

Powder:       IMR 7625
Primers:      Federal #100
Bullets:       124gr Zero HP
Brass:         All were Winchester ex-white box marked "Win"

Load data taken from a 2006 IMR pamphlet stating: 4.4gr to 4.9gr for 124gr FMJ at 1.110" OAL

Since my SP-01 has a 13# spring, I elected to start lower. All shot groups were 5 rounds at 35 feet. Shooting was mid-afternoon, humid, 85F. Groups weren't measured, but all results were acceptable. The results recorded by a Chrony were as follows:

4.1gr     921 fps avg
4.2gr     933 fps avg
4.3gr     959 fps avg
4.4gr     988 fps avg
4.5gr    1002 fps avg
4.6gr    1018 fps avg

SDs were low. All rounds ejected properly, with brass landing from 3 to 6 feet away.

The Powder
SR-7625 from research is a single-based powder. It's finely ground to about the same size as common black pepper. That makes it meter very well, and drops are consistent. Like other single-based powders it burns very cleanly, leaving only a layer of soot inside the gun. There are no residual unburned particles or ash, even at very low loads of 4.1gr.

Density is such that even at 4.1gr, a double load would fill a 9x19 case making loading errors easy to detect. 7625 burn rate varies from chart to chart, but on the whole is generally considered equivalent to Unique. 7625 would be an outstanding replacement for Unique, or an inexpensive replacement for N330.

Some rumors persist about 7625 varying more than necessary from lot to lot (which may account for the Burn Rate chart discrepancies). If buying multiple cans, I suggest purchasing them from the same store and checking lot numbers. I paid $25 for a new 1 pound can from a store that also carried Red Dot and Blue Dot for $18.

 

[1SOW]

Thanks Wobbly for the good info on your 7625 work-up.
Looks like it's fairly slow burning and would do well from mid to high range loads.
The fact that it burns clean as a single-base powder and should meter well is a plus over Unique.

Your test loads were pretty light, but how did the groups look above 1000 FPS?

P.S.  Your components for the work-up could have come from my supplies and the data would be verbatum the same except for the bullet weight.
I borrowed a copy if that's ok with you.

[Wobbly]

Thanks, Wobbly. Quick question -- you said the IMR stated an OAL of 1.110. Is that what you went with?

I usually load Zero 124gr HP at 1.110", so I was delighted to see load data with that exact OAL. Like I said, it was a 2006 IMR booklet, now out of publication.

Also, I don't see much point in a separate 7625 thread. If it is all the same to you, I'll add my data to this thread when I have it.

Be my guest.

 

[Wobbly]

More 7625 testing today. This time with a 10mm and 170gr lead.

Not much data on this, but I was really interested in working this through using lead bullets. I actually hit the middle of the load range with my first loads, then worked to the top and bottom ends. (There is obviously more room left on each end of the load spectrum.) Each load group consisted of 4 rounds. Gun used stock springs and all loads ejected perfectly. No FTFs. As expected, each load shot cleanly. No accuracy data, but the center of the target was gone when I finished.

Caliber:   10mmAuto
OAL:        1.260"
Primer:    Winchester Large Pistol
Powder:   IMR 7625
Brass:     Starline
Bullet:     Missouri Bullet "#2", 170gr Lead FP
Gun:       5" barrel Dan Wesson 10mm Pointman

5.1gr       923 fps
5.3gr       957
5.5gr       972
5.7gr       992
5.9gr      1019
6.1gr      1067

 

[SMSgt]

"No accuracy data, but the center of the target was gone when I finished."

Definitely need to do something about those target rats.