7mm SAUM in S/A best expected velocities

[JERRYHM]

Some information on the 7SAUM,

The Berger 180 Hybrid at 2970 fps will have the exact same wind drift as the Sierra 175 at 3100 fps.

My accuracy node with the 180 Hybrid is at 2985 fps. Maybe longer barrel life, using much less powder.

Remember one thing: "There are no awards for high MV".

Accuracy will win.

 

[GLC]

Thanks to All for responses

Bill & Jerry your saum's obviously work very well with the recents wins (congrats) I am actually loading at the moment for a 7Saum in F class config so i have a lot more free bore to play with, 30" 1:9 Bartlein with BAT 8.5 action, I also have a decent quantity of the Hybrids,if I can get it to bug hole at anything south of 2950 then I am happy, I can also verify your findings Jerry with the 175 Sierra agains the 180 berger vld, with my 7mm/270 wsm at the same velocity the Berger prints much higher on the target.
(almost over the top)

I am looking at around 57-59 grains of H4831sc and 64-65 of Retumbo and H1000?

With regards
Gary

 

[o2fish]

Hello Gary
A little off the topic, but what was your best load with the 7mm300WSM and the 180s
Sorry 7mm270WSM
Regards
Scott

 

[wooger]

R17 didn't work out for me but 4831 got me to 2990 with a 27" barrel. The most accurate (and my current match load for the 180's) is with 4831sc at 2890 fps.

 

[TonyR]

I've had some good results with IMR7828SSC out of a 28 inch 1:9 Broughton 5C. It seemed to like something around 2950 with the 180VLDs. I got higher velocities with MRP and good ES/SD but I've not done a lot of testing with it. I've heard people are getting great results with H4350 but I haven't tried it myself but plan to.

 

[AusFclass]

ive been doing some more testing across the chronograph and looking for the practical max.

i loaded the SAME virgin rem case over and over agin at 66gr of H1000 and found the primer loosend up at 8 firings. 67gr loaded cases last about 3 firings. it does depend a bit on your throat depth.

i was happy with 8 firings so i started working back from that and found that 65.5gr of H1000 gave 2995fps easy and an ES 9 and SD 4. the conditions wernt the best but i held .25moa vertical at 200yds so i think its a very good start.

 

[GLC]

Interesting

Imam still "messing" with my f class saum, it has been shooting very well with a selection of powders, I shot the first comp with it with r17 and 180 hybrid, did ok but too much vertical, however after the comp I did some more work and the barrel had sped up 100fps !with the same load 20 rnds prior, so from 79 rnds to 100 rnds 100 fps difference amazing! all my new development has gone out the window so will have to start again!
R25, 4350, n560 & r22 look good however I am tempted with h1000 but even with my long free bore I am not sure if I can get even 64-65 grains in the case?

 

[pmarauder]

I am tempted with h1000 but even with my long free bore I am not sure if I can get even 64-65 grains in the case?

Do you happen to know your free bore is? I wonder how much a drop tube would help in that type of situation.

 

[GLC]

Pretty sure it's 200 thou of free bore so the bullet is a fair way our of the case, I will check.

I did consider a drop tube but figured maybe a faster powder would be easier!

 

[AusFclass]

im only running .188 FB with .015 jam and you can get 67gr in no probs as long as you dont just dump it all in the funnel at once. drop tube would work fine aswell.

yes its slightly compressed but with BR2 primers its ideal. a full case and top velocity at mild pressure isnt that what chosing the correct powder is all about ;D

i cant get that interview with danny biggs to load but i dont know how he does it with h4350! obviously it works well and its a great powder but the load density must be very low.

the slower the powder the cooler it burns so it has to be a good thing rite?? haha

 

[TheBlueEyedBear]

In the interview he stated that he is using 57.5gr of H4350 for his load. My gun (when I get it) will have a .220FB and should work well with the 180s and this load of H4350. Should have no problem with a COAL of over 3.0.

 

[Steve Blair]

My .284 reamer has a .220 freebore. It lets the 180 Hybrid touch at 3.275 OAL, .204 shank in the case. That should result in a 3.130 OAL in 7 RSAUM.

 

[GLC]

Update:

Tried 3 new powders in the 7 saum f class config (tactical is not finished yet)
(all with Berger 180 hybrid)
Aus Fclass was right 65 Gr h1000 seemed to hit the mark well, group was acceptable but spreads were superb, group could be me so I will load some more and try in a tunnel range I use.
Best accuracy was N560 closely followed by R17 and H4350 so will load up h1000 (I have lots of this) and n560 (I also have lots of this) both powders gave me 3000+ fps N560 near 3050.

 

[Laurie]

Looks good Gary! Are you coming up to Diggle for GB-FCA Round 1 and if so will it be the SAUM that comes with you? Tried the new ICFRA 3/5/600 yard target with only quarter-MOA rings once you get outside of the bull and V-Bull last Sunday. A problem (ring sizes aside) is that PSSA's patches won't stick to it! Every time a bullet hit, some of the patches fell off the older shot holes.

If you're coming up, look forward to seeing you in what (?) three weeks or so.

 

[pmarauder]

Lots of good info on this thread.... Well, I have 61 rounds down the tube on my 7saum and finished fire forming. The shoulders bumped out .006, which gave me a bit more capacity and slightly more velocity with that same load of the H-1000 at 65 and 65.3 grains. Very consistant speed @ 3020 for the 65g and 3040 with the 65.3 fps with very low SD of 3 to 4. This is with the 180 Hybrid at .015 jump. My question is, What have you found the Hybrid likes as far as a seating depth? This is what i have to test on my next range session.
Thanks for all the info guys.
Derek

 

[TonyR]

Lots of good info on this thread.... Well, I have 61 rounds down the tube on my 7saum and finished fire forming. The shoulders bumped out .006, which gave me a bit more capacity and slightly more velocity with that same load of the H-1000 at 65 and 65.3 grains. Very consistant speed @ 3020 for the 65g and 3040 with the 65.3 fps with very low SD of 3 to 4. This is with the 180 Hybrid at .015 jump. My question is, What have you found the Hybrid likes as far as a seating depth? This is what i have to test on my next range session.
Thanks for all the info guys.
Derek

Derek
I've done all of my load development with the Hybrid for my 284 Shehane at 0.010 off the lands and the vertical has been as good as anything I ever saw consistently with the 180VLDs. I plan to do some round robin testing with the Hybrids at some other depths, probably 5, 15 and 20 off. It will be interesting to see if they are as insensitive to seating depth as claimed. I have seen big changes in vertical with 5 to 10 thousandths changes with the 180VLDs.

 

[TheBlueEyedBear]

Derek,
How was the accuracy with the H1000? Is it good enough to stick with or will you be trying H4350 or H4831ssc?
Tony.
What powder are you using with the Hybrids?
Hopefully I will get my rifle before summer ends, but who knows!!

Barry

 

[TonyR]

Derek,
How was the accuracy with the H1000? Is it good enough to stick with or will you be trying H4350 or H4831ssc?
Tony.
What powder are you using with the Hybrids?
Hopefully I will get my rifle before summer ends, but who knows!!

Barry

Barry.
So far, just with H4350 in the Shehane. It is a lttle short on velocity but it seesm to be very stable in long strings and seems to settle in faster than IMR7828SSC on a cold barrel. I also like how much less powder it needs to get to a comparable velocity in the same case but with the 180VLD bullet. I'm using 51.5 to get the Hybrids to 2850 fps out of a 30 inch barrel with the Shehane while it would take about 56+ grains of IMR7828SSC to get the same speed with a 180 VLD. How much of the difference is powder or bullet remains to be seen but it is interesting stuff. I had used it in my 6.5X284 barrel with the 139 Scenars but always thought it would be too fast for the heavy 7mm bullets. I guess not.

 

[pmarauder]

Derek,
How was the accuracy with the H1000? Is it good enough to stick with or will you be trying H4350 or H4831ssc?

Accuracy it OK out of the gate, but i think once i tune the seating depth, it will come together. My barrel was throated for the shorter bearing surface of the hybrid and the 175 XLD. Freebore is .101. My groups are around .5 to .8 at 200 yards right now but with only .1 or so of vertical. And it has been fairly windy everytime i have shot. I am getting very consistant velocity and almost no vertical @ 64.7 to 65.3 of the H-1000. I will let you know what happens with the seating depth.

Derek

 

[TheBlueEyedBear]

Thanks guys! Great info here. Although the guns are not identical we have some great info for narrowing down the possibilities. I have narrowed my powder selection down to the three I mentioned previously, H4350, H4831ssc and H1000. I do have N560, RL17, RL22, and RL25 in case these don't give the expected results. If QuickLoad is correct and I have entered all the proper data, these powders should bring me to the high 29's for velocity, then I can go to work on accuracy. I am with Tony: Anxious to see if the claimed bullet performance is true as far as seating depth.
Thanks to Gary for starting this thread. I am chomping at the bit waiting to be able to contribute.
Thanks again.

Barry