Winchester 572 and 38 Supercomp

[CzechShooter]

It is my understanding that Winchester 572 is the equivalent (replacement) to the old IMR 4756.  Does anyone have any major load data using 572 in a 38 supercomp race gun; compensated no barrel popple holes. Currently loading 124 gr. jacketed RN VVN105, and sometimes VV3N38.  I welcome all thoughts on this powder, thinking about purchasing a pound to try out.  Thanks.

 

[tomjerry1]

I don't know about the Winchester powder, but for what you are asking, Accurate #7 is what I use. No popples, 125 gr HAP, 10.2 gr, 1.230 aol. 

[CzechShooter]

Thank you.  I assume you're making major power factor?  

[Powder Finger]

I can look tomorrow its basically hs7

[CzechShooter]

Looking at a burn rate chart, 572 appears to be a slower than hs-6.  I don't know anything about hs-7, but if both powders are comparable that would interesting to know.  Thank you.

[Powder Finger]

Sorry I thought it was 571 don’t know anything about 572

[CzechShooter]

No worries

[tomjerry1]

Power factor is not a problem, 10.1 approx 170 and 10.2 approx 173 pf, of course this is my pistol. The HAP 125 gr is .356 dia, shoots straight. I won some Montana Gold 124 gr, measures .355 dia, loaded up 20 to take to the range for chrono? I expect good results.

[CzechShooter]

Great information.  I'm going to try and find some Accurate #7 to try as well.  Looking at the burn rate chart, it's slower burning than Winchester 572. 

[tomjerry1]

AA7 has been an open powder for many years, I started using it because it was easier to find, that was awhile ago. Keep your eyes open tho, it is not the go to open powder these days, so when it shows up, you shouldn't have to worry that it will disappear instantly. Look around online, usually you can get it, pay the cost plus hazmat and shipping, and still get it cheaper than local. Shooters World is also pretty good, I believe it is Major Pistol, but don't hold me to it, look it up, it's very close to AA7.

[AverageJoeShooting]

i use AA7 in 38sc 

major PF, 1.235 oal, 9.4 grains, 3 poppels and a BE 3 port comp

 

works perfectly

 

shooters world major pistol is exactly the same powder just made in a different factory. 

[pbairborne]

I've run W-572 in 9 major, so take this for what it's worth. For me it behaved a lot like Autocomp or CFE Pistol. I'm running a 5 in barrel with no holes. I load to 1.175 in and used Tula SR primers using Montana Gold 121 IFP's. 6.6 gr of 572 gave a PF of 153.9. 6.9 gr gave 161.0. 7.2 gr gave 165 and with 7.2 grains I got a power factor of 168.3.

I didn't see signs of pressure. On the other hand, I didn't see an advantage over AC or the HS-6 that I normally use. But given the availability of powder, it may be an alternative if you can't find other powders.