300 wsm - 212 or 241 seneca

[NamibHunter]

Results with 212 Seneca and 4000MR in a 28” 7 twist 300 WSM (not the ideal powder, good speed, similar to RL-26, but a little temp sensitive):

Hard bolt lift at 2910 fps. Brass had an ejector mark and primer pocket opened up 1.0 thou.

Higher node at 2870 fps. Mid sixties powder charge. Node was 1.0 wide. Brass is ok but expected life would be below 10 reloads.

Lower node at 2750 fps. Lower sixties in terms of powder charge. Node was also about 1.0 gn wide. Long brass life, but giving up some performance.

Next time i will probably build a 300 PRC.

Btw the recently released ADG brass is way way better than Norma. Case head hardness on par with Lapua, and a narrow weight range of 2.5 gn. Got an extra 100+ fps from it for lead core bullets.

Will retest the 212 Seneca soon (mine weighs 210.6 gn on average), and try to get to the higher node. With the ADG brass, speed should be closer to 2900 fps.

 

[Steel head]

Btw the recently released ADG brass is way way better than Norma. Case head hardness on par with Lapua, and a narrow weight range of 2.5 gn. Got an extra 100+ fps from it for lead core bullets.

Will retest 2120 Seneca soon (mine weighs 210.6 gn).

I was shooting 7 saum ADG brass with 20 loads on it today
Excellent brass.

 

[NamibHunter]

Phenomenal quality brass. Changing to ADG brass almost feels like a caliber upgrade, like going from 300 WSM to 300 Winmag.

Puts new life into the WSM and it has already turbocharged the 300 PRC.

What a difference good brass makes!

 

[NamibHunter]

300 PRC question: Has anybody managed to chamber a short action rifle in 300 PRC??

I realize the loaded round will be super long with a 241 Seneca bullet, but if i removed the ejector pin, and removed the bolt every time to load a new round, what would stop that from working reliably?

Yes not very practical, but just curious if that can be made to work! It is a short action switch lug rifle.

 

[Schw15]

300 PRC question: Has anybody managed to chamber a short action rifle in 300 PRC??

I realize the loaded round will be super long with a 241 Seneca bullet, but if i removed the ejector pin, and removed the bolt every time to load a new round, what would stop that from working reliably?

Yes not very practical, but just curious if that can be made to work! It is a short action switch lug rifle.

Yes you can do that I don't see anything bad about it. But why? What are your velocities with the 300 wsm?

 

[Steel head]

300 PRC question: Has anybody managed to chamber a short action rifle in 300 PRC??

I realize the loaded round will be super long with a 241 Seneca bullet, but if i removed the ejector pin, and removed the bolt every time to load a new round, what would stop that from working reliably?

Yes not very practical, but just curious if that can be made to work! It is a short action switch lug rifle.

I load in 4.28 long 338 edge in a short action Nuke
I just single feed it like normal
Drop the mag and push it out of the bolt head if need to unload a chambered round.

 

[Two36]

I was shooting 7 saum ADG brass with 20 loads on it today
Excellent brass.

All your 7saum posts have made me realize, I need to build one..

 

[NamibHunter]

Yes you can do that I don't see anything bad about it. But why? What are your velocities with the 300 wsm?

With the 212 Seneca i previously loaded at 2750 fps (28” barrel), to preserve case life as the Norma brass had a softer than desired head. That was the “second” or lower node and shot 0.2” groups. Could get to 2850 fps (28” barrel) before hard bolt lift kicked in, but brass life would have been unacceptable. Will try again with the ADG brass to reach the higher node.

Reason for looking at the 300 PRC is that I am more interested in driving the 241 Seneca around 200-250 fps faster. It was running quite slow before, around 2600 fps.

 

[Steel head]

With the 212 Seneca i previously loaded at 2750 fps (28” barrel), to preserve case life as the Norma brass had a softer than desired head. That was the “second” or lower node and shot 0.2” groups. Could get to 2850 fps (28” barrel) before hard bolt lift kicked in, but brass life would have been unacceptable. Will try again with the ADG brass to reach the higher node.

I am mostly interested in driving the 241 Seneca around 250 fps faster. It was running quite slow before, around 2600 fps.

I’d still run a moderate load first in that ADG brass before you step on it.

 

[Schw15]

With the 212 Seneca i previously loaded at 2750 fps (28” barrel), to preserve case life as the Norma brass had a softer than desired head. That was the “second” or lower node and shot 0.2” groups. Could get to 2850 fps (28” barrel) before hard bolt lift kicked in, but brass life would have been unacceptable. Will try again with the ADG brass to reach the higher node.

I am mostly interested in driving the 241 Seneca around 250 fps faster. It was running quite slow before, around 2600 fps.

2850 isn't bad at all with that crazy high bc even 2750 is good. But yeah if you could get that bullet doing 2900. Have you looked into a 30 nosler? I'm getting a barrel for one and love the case design

 

[NamibHunter]

Agreed.

Have set aside 10 cases to “step on” and found that ADG brass did remarkably well with stiff loads. Probably close to another 100 fps from simply switching brass manufacturer.

See last few posts.

Brass life: How to determine max charge so primer pockets survive a sufficient nr of reloads (at least 10)?

I realize that new brass benefits from fireforming to your chamber, using a medium load that does not blow out the primer pocket on the first firing. The first firing hardens the case head and buys you longer brass life. My question is how do you decide on the powder load for fire forming: Two...

www.snipershide.com

 

[NamibHunter]

2850 isn't bad at all with that crazy high bc even 2750 is good. But yeah if you could get that bullet doing 2900. Have you looked into a 30 nosler? I'm getting a barrel for one and love the case design

Some of the benchrest folks got the 215 Berger to 2900 to 2950 fps in the 300 WSM, using Norma brass, but they all use 32” to 34” barrels. I “only” have a 28” barrel in 7 twist. We shall see what we get from the ADG brass.

Have 10 cases set aside for various cruel experiments, the other 90 are weight sorted and serialized cases that i baby as best i can. I really don’t intend to trash all the brass, way too hard to find! Hoping for more than 15 reloads, which is quite possible with ADG. Could possibly even reach 20.

 

[Steel head]

Some of the benchrest folks got the 215 Berger to 2900 to 2950 fps in the 300 WSM, using Norma brass, but they all use 32” to 34” barrels. I “only” have a 28” barrel in 7 twist. We shall see what we get from the ADG brass.

Have 10 cases for various cruel experiments, the other 90 weight sorted and serialized cases i baby as best i can. I really don’t intend to trash all the brass, too too hard to find! Hoping for more than 15 reloads, which is quite possible with ADG.

Solids make pressure differently than cup/core and your don’t always match the speeds.

 

[NamibHunter]

Got the opportunity to shoot the 212 Seneca / Norma / 4000MR load at 1000 yards in the mountains of West Texas. Great fun and accurate at 500, and we destroyed quite a few rocks. BC held up well, but my Labradar quite on me, so not in a position to do any truing yet.

It was a hot day (80 F) and the load was developed when ambient was between 40 and 60 F, and 4000MR is perhaps a little too temp sensitive, but it produces a lot of speed, similar to RL-26.

What temp stabilized powders work best in a 300 Winmag? Should work ok in a 300 WSM as well. I hope!

 

[Steel head]

In the 4000MR burn range are two excellent powders you should try
H3831sc and R23
N560 as well

 

[Dogtown]

N560 for sure!

 

[jasent]

H4831sc is probably the least temp stable powder I’ve used. H1000 is my favorite tho

 

[Steel head]

H4831sc is probably the least temp stable powder I’ve used. H1000 is my favorite tho

Really?

I haven’t seen that.

 

[jasent]

Really?

I haven’t seen that.

From my personal testing. H4831 sc is .08fps per degree
H1000 .21 FPS per degree
H4350 .16 FPS per degree
H4831 .36fps per degree

 

[Steel head]

From my personal testing. H4831 sc is .08fps per degree
H1000 .21 FPS per degree
H4350 .16 FPS per degree
H4831 .36fps per degree

.08 per degree seems pretty good

Different cartridges and pressure levels change things as well.
In my 260 and 7 saum with H4831SC I could basically ignore temps

 

[jasent]

.08 per degree seems pretty good

Different cartridges and pressure levels change things as well.
In my 260 and 7 saum with H4831SC I could basically ignore temps

This testing was done in 300 wm and 338/375 ruger and 243 win
Test temps were 30f, 60f, and 96f
5 shot strings at each temp
Shot at home so I could keep temps of ammo consistent. Measured with temp gun

 

[NamibHunter]

Has anybody confirmed the BC of the Super Bulldozer 300 cal bullets via long range drop data?

Shot the 212 Seneca out to 1000 yards this past weekend in the Texas Hill Country (mostly limestone rocks). Actual weight range is 210.6 +- 0.3 gn. That stratospheric 0.95 G1 BC seems to hold up: Rezeroed at 100, then shot at rock faces on the mountain at 355, 507 and 998 yards. All high angle shots. Distances were ranged with the Sig Kilo 2400. It shot a little high at 500 (0.5 MOA), and maybe one MOA low at 1000.

But sadly i could not measure speed, as my Labradar has a problem due to a flaky female power socket. So not enough data to do any truing, but based on speed from a week ago (when it was 15 degrees cooler), it seems the published BC is pretty close. [Btw: I used the G7 BC to calculate the scope adjustment, as it is more accurate.]

My forced choice of powder (4000MR) is problematic, too temp sensitive, and it is probably pushing me out of the node when it gets hot outside. [Might have to do a winter and summer load.]

Accuracy was OK at 350 and 500, but not great at 1000. I suspect the ES went way up when the speed moved up (and got outside the node/speed flat spot).

I did not see a repeat of the 0.2 MOA groups posted above at 100, more like 0.8 MOA, another sign that ambient temp pushed me out of that beautiful node.

Now busy trying out plain long kernel H4831 (not the SC version) with the ADG brass. Max speed is slower than 4000MR, probably by 80-90 fps, but the new ADG brass is very resilient (and case capacity is higher), and should help me recover much of that speed loss. H1000 would likely do better, but just cannot find it.

Will know more after the weekend. Fun experiment!

 

[mojavejim]

PVA recommends starting @ .020 jump for the 212. how far has anyone jumped them with good accuracy ?
Looking to mag feed, not interested in single feeding.

 

[Dogtown]

I've got a normal 0.250" freebore on my current .300NM barrel, so I'm jumping them 0.1", which seems nuts, but they're grouping very nicely as long as I load them with tight necks.

 

[mojavejim]

Getting ready to test some in my 300NM, but in my AXMC w/AI barrel it's closer to .160 jump. They are so pointy I need to make a special adapter to measure to the ogive. Hopefully they shoot well, will be amazing around 3200 fps.

 

[Dogtown]

They’re consistent enough that you can just measure COAL instead of base to ogive. They’re so slender and pointy that they can handle shorter freebore than jacketed bullets.

 

[jasent]

They’re consistent enough that you can just measure COAL instead of base to ogive. They’re so slender and pointy that they can handle shorter freebore than jacketed bullets.

This would be true if they were shipped in better packing. The ones I’ve used ranged .005” because the tips get beat up so bad. Shipping in a plastic bag that gets tossed around by usps like a hacky sack.

They are very pointy and those tips are fragile. Mail your self a bag and see for your self.

Only complaint I have

 

[Dogtown]

They are very pointy and those tips are fragile. Mail your self a bag and see for your self.

I’m still working through my stash of 212s and have the 241s if my 7-twist barrel ever shows up. I haven’t seen the the length variation you’re seeing, but I do find the tips more consistent than jacketed OTMs when measuring COAL. But yeah, Warner’s packaging does a better job protecting the tips.

 

[jasent]

I don’t think they need to go to the extent Warner does but a little more protection would be nice.

 

[mojavejim]

Ended up jumping about .200 to fit in my mag. They didn't like that at all, about an moa was best group with N570 from 2960-3175fps. Don't really like to single feed but might try them @ .020 for local 1000yd f class like comp just to use them up. Got about 80 left.

 

[NamibHunter]

My data is probably not much use to you, but here it is:

I got best results with the 212 Seneca around a 12 thou jump in a standard SAAMI 300 WSM chamber. Freebore is only 0.165”, cut for the 241 Seneca. Have to single feed them (short action Curtis Axiom). Seating dept “node” was 6 thou wide. Outside the node the group opened up to 1.5 MOA (not thou!).

Maybe get the Cortina barrel tuner/brake combo, if you have to run with massive jump?

 

[NamibHunter]

Managed today to get the 212 Seneca to 2960 fps in my 7 twist 28” barrel using H4831. Still not hitting max pressure, but have run out of case capacity. Heavy crunch. The H4831 kernels are quite long and packing density is not as good as a ball powder. But temp sensitivity is way better than 4000MR. Btw: Have to settle the powder with an ultrasonic toothbrush. Fiddly!

H4350 is a little too fast on burn rate and hits pressure at 2900 fps. For the sake of extending case life, it would not be practical to run faster than 2850 fps, which is probably giving up 150 fps. Will try IMR4350 next.

Really want to get my hands on H1000 or Hybrid-100, but no luck so far.

 

[brianf]

Managed today to get the 212 Seneca to 2960 fps in my 7 twist 28” barrel using H4831. Still not hitting max pressure, but have run out of case capacity. Heavy crunch. The H4831 kernels are quite long and packing density is not as good as a ball powder. But temp sensitivity is way better than 4000MR. Btw: Have to settle the powder with an ultrasonic toothbrush. Fiddly!

H4350 is a little too fast on burn rate and hits pressure at 2900 fps. For the sake of extending case life, it would not be practical to run faster than 2850 fps, which is probably giving up 150 fps. Will try IMR4350 next.

Really want to get my hands on H1000 or Hybrid-100, but no luck so far.

How’s accuracy
Still Hovering around .8 on average

Thanks

 

[Schw15]

Managed today to get the 212 Seneca to 2960 fps in my 7 twist 28” barrel using H4831. Still not hitting max pressure, but have run out of case capacity. Heavy crunch. The H4831 kernels are quite long and packing density is not as good as a ball powder. But temp sensitivity is way better than 4000MR. Btw: Have to settle the powder with an ultrasonic toothbrush. Fiddly!

H4350 is a little too fast on burn rate and hits pressure at 2900 fps. For the sake of extending case life, it would not be practical to run faster than 2850 fps, which is probably giving up 150 fps. Will try IMR4350 next.

Really want to get my hands on H1000 or Hybrid-100, but no luck so far.

Try h4831sc or rl23 and possibly Imr 7828ssc as well but hear different on being temp stable.

 

[NamibHunter]

How’s accuracy
Still Hovering around .8 on average

Thanks

Load development of the 212 Seneca has been going slow recently, after giving up on 4000MR.

Still busy with pressure test of various powders with the ADG brass: Got to 2900 fps with H4831, but was hoping for more from the 28” barrel. Trying to get hold of H1000 or Hybrid-100. So have not looked for a node or optimized searing depth yet. Will report back when i have a good load.

 

[NamibHunter]

Load development of the 212 Seneca has been going slow recently, after giving up on 4000MR.

Still busy with pressure test of various powders with the ADG brass: Got to 2900 fps with H4831, but was hoping for more from the 28” barrel. Trying to get hold of H1000 or Hybrid-100. So have not looked for a node or optimized searing depth yet. Will report back when i have a good load.

Got the 212 Seneca to 2950 fps in my 28” 7 twist 300 WSM barrel using a fairly compressed load of H4831. Did not reach the pressure maximum, just ran out of case capacity (ADG brass). Good enough, actually. If there is a good flat spot between 2900 and 2960, i will take it.

Will also try H4831SC and see if the smaller grain size allows for an extra grain or two to be packed in there.

H4350 did not get past 2900 fps, it hit max pressure with lots of spare case capacity. Workable, but the powder is probably slightly fast for this bullet.

IMR4350 got to 2935 fps, and the first pressure signs (hard bolt lift) appeared at 2960. Almost the same speed as H4831. About 5 grains of spare case capacity there, so 93% fill rate. Workable - and a very easy powder to find. But not perfect in terms of temp stability…

Have some Retumbo, but so far only tried it with 225 ELDMs in the 30” 8 twist barrel, and got 2750 fps, which is around 100 fps slower than H4831. Once again, ran out of case capacity. Don’t think it will do all that well with the 212 mono, probably too slow burning. Will try it anyway.

Cannot find H1000 yet…

At this point avoiding double base powders and ball powders - due to temp stability concerns.

 

[NamibHunter]

Btw the reloading books are of limited use with these bore rider monos….

Powder recommendations are not exactly perfect either, and max predicted speed is off by about 100 fps, after compensating for barrel length (30 fps/inch).

The 212 Seneca behaves more like a 190 grain lead core bullet. That front pressure ring is quite thin (0.3025”), and will easily go deep into the lands with only primer pressure, so i think the bullet comes to a standstill only when the full 0.3080” diameter shank imbeds into the grooves…. When a full 1.3” of bullet is sitting inside the grooves. Leaving a lot more “combustion volume” compared to a lead core bullet…. Seems to be a trick to buy more case volume - without enlarging the case. [Or at least that is my current theory!]

Use a good micrometer and measure diameters along the length of the bullet, and you will see what i mean.