Pressure Trace: N120/H322 Duplex 200SST

[TGinPA]

Pressure Trace: N120/H322 Duplex 200SST
At Savage Shooter’s request, I tested a series of duplex loads using H322 as the main and N120 as the booster with 200grain bullets. Because he provided all of the reasoning behind this test, I am sure he will chime in. IMO, if this load is shown to be accurate, with relatively low pressures, velocities exceeding 2900fps with sabotted 200grain bullets, this is a goal well worth achieving. It also may further demonstrate the value of looking at other powders such as N120 as boosters in duplex loads.
TG
Gage and Module Manufacturer = RSI USB model
Trigger Sensitivity = 2, Strain Gage Voltage =4.9 Gage Factor =2.1 PSI Correction Factor: 0
Barrel Temp = 64-66 degrees F. measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled
Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (13 fps added to all recorded velocities to correct for distance of chrony from muzzle.)
Barrel Type: PacNor .45 Cal Muzzleloader Barrel OD = 1.06 in Barrel ID = .452
Breech Plug:Savage Std. (screw-in ventliner) ventliner orifice .032 in. Sensor dist fm BP=1.1 in. Bullet Diam.= .458 in. Bullet Type = Hornady 200 SST. Bullet weight = 200gr. ,lightly knurled. Sabot: Harvester Smooth Blue
Powder: T1,T2= N120/H322 14/56gr., T3,T4=N120/H322 14/58gr., T5= N120/H322 14/61gr.
Primer :Fed 209
Shot fm dirty barrel. This load seemed safe in my barrel under the test conditions but may not be so in other conditions.

[Savage Shooter]

After seeing this traces it seems that pressures can be further reduced with less booster. I think that 10grs of booster will be enough to work well with this load. I am planning on test shooting this combo using N120 as booster and H322 as main starting at 10/60 keeping booster constant at 10gr and going up a grain at a time attempting to reach 10/63 with complete sabot integrity. IF 10/63 can be reached I would expect speeds to bump 2900fps.

At 10/62 I would predict this load to go over 2850fps with pressure between 32.5K and 33K. IF this is correct it should shoot very well, we'll see. The big difference in the boosters here is that this type load with n110 as booster is that N110 with 200gr bullets is making nearly 800psi per grain where N120 is making 540psi per grain.

H322 does good "after" boosting if it makes 440 psi per grain.

As far as speed with 200gr bullets:
N110 is averaging nearly 57fps per grain.
N120 is making about 46fps per grain.
H322 is making about 39fps per grain.

Thanks
TG

[Savage Shooter]

This afternoon shot 2 of these loads with N120/H322, 10/62 and 10/63.

Shot 5 shot groups at 200yds and believe pressure is just a touch high for sabot stability due to group sizes. I have had this same type random groups with N120 and H4198 both as a single when you get a grain too high. I see the same thing from my gun at 61gr of N120 and 63gr of H4198 which makes me think this is going to shoot good but at a lower charge weight. Both were shot with 195bx in Harvestor blue sabot.

10/62 5 shot group was 3.5" random round groups.

10/63 5 shot group was 4" random round groups.

Came big rain on targets this afternoon so no pic's, sorry.

Next loads will be 12/58, 11/59, 10/60, 10/61. Will post results. Speed range of these loads will be about 2800fps @ pressures about 32.5k.

[deadeye]

ss-look forward to your next results-keep up the good work!

[ET]

Savage Shooter

I seem to be full of questions lately and in this instance have to wonder what affect the secondary spike might be having on the sabot that’s already been stressed by the first peak pressure. The second pressure rise is faster than the primary pressure spike and adding that additional whack to the load near the end of the bore can’t be helping the situation.

Curious as to what your thoughts are of the possible affect on the sabot from the secondary spike?


Ed

[Savage Shooter]

Mar 31, 2011 21:13:56 GMT -5 ET said:

Savage Shooter

Curious as to what your thoughts are of the possible affect on the sabot from the secondary spike?

Ed

I seriously doubt that accuracy is being affected much by this type 2nd spike unless as you said the sabot is already at about max and getting hit by this 2nd spike is enough to push it over its ability.

Now I am not seeing this on target, note that with both H4198 and N120 Traces used as singles, which are both super accurate, show this anomaly also. I see it this on the N110/H322 at 15/55 traces too.

I am not discounting this type of 2nd spike in any way but just don't know yet what if anything it means to accuracy or consistency.

The one common continually occurring instance I keep seeing affect little bitty groups is "Pressure" period. I firmly believe that (according to TG's PT data) that pressures 33K or over are softening sabots enough to allow lean in the bore and groups open up.

Think about how many say that they are getting super accuracy with H4198 at 60-62 grains but accuracy starts to leave at loads above this...........H4198 is making 525psi per grain, so a 2 grain increase is only 1K but it is affecting accuracy for some reason......I see this at 64gr H4198, groups double..........


Same occurence with N120, accuracy loads reported at 59-60grs, that is where my gun shoots moa groups also........N120 is making about 550psi per grain at 60gr but then is making nearly 570psi per grain at 65gr, hence going up a grain again opens groups by nearly double.

While we do not know the accuracy of TG's pressure numbers since we to not have a test load to compare, however it does not really matter if we are testing loads in the same barrel with the same equipment to establish baselines for comparison to each other.

i.e. we may not know if a pressure that TG reports at 35k is or is not actually exactly 35K but we know it is more than a load reading 33K in the same barrel and same PT equipment.

If you review the 60gr N120 trace (TG's) you will see that peak pressure is 32,412 psi.

Then review 62gr H4198 trace (Edge's) and note that peak pressure was 32,471 psi.

Now is it a coincedence that the accuracy load that most report with both N120 and H4198 are within 59 psi of each other, I seriously doubt it!!!!

I have started using the 32.5K baseline for load development for sabot use applications to see if super accuracy can be kept at higher speeds if pressures are kept in this range.

The 10/62 and 10/63 groups I shot last evening showed the exact same shapes and sizes that both N120 and H4198 show as singles when you step over that same threshold. Both of the loads are at about 33.5K also (same point we see groups open with single) however were at 2900fps.

I think we can come down to 32.4K load at 2825fps consistently and accurately when we find the right powder combo/ratio.

I know SW is using like 12/57 of 5744 or N110 under 2015 and use a WW for his accuracy load. This load will be close to this same pressure.

Summarize:

H4198 is super accurate at 60-62grs but delivers speeds in the low to mid 2700's, shoots cold barrel close to same poi as "shot barrel"
Makes 525 psi per grain at 60 gr and ONLY 530 psi at 64 grains so is not "pressure sensitive".

N120 is super accurate at 59-60grs and delivers good speed of mid to upper 2700's, makes 540psi per gr at 60grs BUT 570psi at 65grs so gains psi rapidly with pressure increase.

Note that my first cold barrel shot with N120 always goes 3" higher at 200yds than any other shot fired during session, even with 20 minute at 43 degree waits,,,,,,,now that is due to pressure sensitivity (barrel tight on first load).

I am attempting to build a duplex that is not pressure sensitive that will behave like H4198 but with 2800fps speeds.

Note that on the traces above the total charge volume was changed 5gr over the 5 traces but pressure change ES was 1592psi total. That can be huge to us hunters for creating a load that shoots the same in about any conditions. This will also stop loads that load a bit tighter or looser from showing such big speed swings. A load like this is relying more on projectile weight for building pressure than load friction as is H4198 as a single.

Now we have to keep it from being temp sensitive, hence, booster.

Hope not to bore, but just to give explanation of what and why my goals are.

[GMB54-120]

Savage Shooter

How does Relaoder7 compare at fps per grain?

And it is possible for it to fit into the equation as a booster or main. I would love to see a bit less secondary spike but the initial spike and curve look very promising IMO.

[Savage Shooter]

Apr 1, 2011 8:58:17 GMT -5 GMB54-120 said:

Savage Shooter

How does Relaoder7 compare at fps per grain?

And it is possible for it to fit into the equation as a booster or main. I would love to see a bit less secondary spike but the initial spike and curve look very promising IMO.

Funny you mention that, I have always considered R7 a relative equal to N120 and H4198 but have recently found out (due to some unposted trace results we are still working on) that R7 may very well be the best single powder for the 200gr bullet class.

TG is still working this one out and more will follow but the short of it is that 65gr of Reloader 7 with 200gr bullet only reached 28K @ 2620fps, but had 40K 2nd spike. TG actually ran it twice to make sure there was not more going on.

Now compare that to N120 making 37K @ 65gr with speed over 2950fps and H4198 at making 34K @ 65gr with speeds about 2850fps. We have seen accuracy decrease with both these loads.

Both traces confirmed that in our applications that Reloader 7 is not equal to N120 or H4198.

Reloader 7 seems to be producing about 430psi per grain and about 40.3fps per grain. This will put slight faster than H322 which is producing about 425psi per grain and about 39.3 fps per grain.

IF and big IF the traces continue as anticipated one could predict Reloader 7 to reach our end goal of 32.5K (mimic H4198 and N120 accuracy pressures) it would take about 70-73gr. This would have to be worked up to for confirmation but at 75 gr (if attainable and IF enough barrel length to burn it could reach over 2900fps.

Keep in mind that as far as we are from optimum powder weight on the traces so far that any powder is capable of hitting a "come alive" as you increase volume and jump pressures up more than exponentially predicted. You can tell this by watching the chrono and expect to see the 40fps increase per grain, it is not fool proof but is a method of watching for over pressures.

If this all holds true with testing it puts Reloader 7 about smack in between H4198 and H322 on burn rates but leaning toward H322 properties per tracing which is what we NEED for more speed.

So short answer is R7 has great potential as either or single and duplex application.

Look at # 146 on this chart::::::: www.reloadersnest.com/burnrates.asp

[GMB54-120]

Thank you for the quick response. Im beginning to really like Re7 but burn charts are not consistent from one source to another. It sure appears to be easy to ignite and has a low deviation, which IMO is worth a little less fps if its more consistent.

Im very curious how well it would work as the booster or main in a duplex for the 45s.

[edge]

Sorry, I don't find that burn rate list as very accurate, not that many really are !

For instance I find 10x much faster than h322.

N110 faster than Lil'Gun, I don't think so!

RL-7 is not 2 spots from IMR3031 and there are just too many deviations from the norm for me... at least from my results.

Perhaps they adjust for volume vs weight, or some other matrix!!

edge.

[Savage Shooter]

Apr 1, 2011 9:59:19 GMT -5 edge said:

Sorry, I don't find that burn rate list as very accurate, not that many really are !

For instance I find 10x much faster than h322.

N110 faster than Lil'Gun, I don't think so!

RL-7 is not 2 spots from IMR3031 and there are just too many deviations from the norm for me... at least from my results.

Perhaps they adjust for volume vs weight, or some other matrix!!

edge.

OK I agree, as it is just a chart, but never use them for more than a starting point anyway and look at several different charts before starting any new to me load......... ONLY Actual shooting will bear this out. What does QL suggest as pressure and speed of R7 with 200gr bullet @ 65, 70 and 75gr?

Trace indicates about 28K at 2620fps with 40K 2nd spike suggesting much more powder needed.

[Savage Shooter]

Apr 1, 2011 9:59:13 GMT -5 GMB54-120 said:

Thank you for the quick response. Im beginning to really like Re7 but burn charts are not consistent from one source to another. It sure appears to be easy to ignite and has a low deviation, which IMO is worth a little less fps if its more consistent.

Im very curious how well it would work as the booster or main in a duplex for the 45s.

I am sure we will have more trace data soon........

[edge]

"What does QL suggest as pressure and speed of R7 with 200gr bullet @ 65, 70 and 75gr?"

65 gr. 2825 fps @ 38kpsi and 91% burnt

70 gr. 2950 fps @ 41kpsi and 94% burnt

75 gr. 3060 fps @ 44.4kpsi and 96% burnt

edge.

[Savage Shooter]

Apr 1, 2011 12:35:16 GMT -5 edge said:

"What does QL suggest as pressure and speed of R7 with 200gr bullet @ 65, 70 and 75gr?"

65 gr. 2825 fps @ 38kpsi and 91% burnt

70 gr. 2950 fps @ 41kpsi and 94% burnt

75 gr. 3060 fps @ 44.4kpsi and 96% burnt

edge.

Thanks this will give us some comparison.

[edge]

I personally like 4759 as a booster because it is so bulky.

As a comparison between the normal booster powders, If I use 15 grains of 5744 it takes up the space of about 17 1/2 grains of H2O or about 0.425 inches in a .458 barrel;

N110 takes up about 19.2 gr of H2O or .468 in.;

but 4759 takes up about 23 gr. of H2) or 0.560 inches.

Since it takes up more room it reduces the expansion ration with the same total weight load.

It also has the advantage of size in relation to your vent liner hole for those that use a cartridge primer. You can use a larger hole for better ignition.

edge.

FYI that 15 grain load in Lil'Gun takes up 15 1/2 grains of H2O or .382inches of barrel.

[Dave W]

Apr 1, 2011 12:53:43 GMT -5 edge said:

I personally like 4759 as a booster because it is so bulky.

As a comparison between the normal booster powders, If I use 15 grains of 5744 it takes up the space of about 17 1/2 grains of H2O or about 0.425 inches in a .458 barrel;

N110 takes up about 19.2 gr of H2O or .468 in.;

but 4759 takes up about 23 gr. of H2) or 0.560 inches.

Since it takes up more room it reduces the expansion ration with the same total weight load.

It also has the advantage of size in relation to your vent liner hole for those that use a cartridge primer. You can use a larger hole for better ignition.

edge.

FYI that 15 grain load in Lil'Gun takes up 15 1/2 grains of H2O or .382inches of barrel.

I would like to see what 4759 does as the booster also.
Bulkier like Edge said and it takes more of it to equal speeds that N110 achieves as a booster or single. IME

[ET]

Savage Shooter

That was a lot more of an answer than expected but gladly accept the additional info it provides to use for evaluating my own studies.

Definitely not boring and hope you attain your desired goal.


Ed

[deadeye]

i am getting an education here also & trying to store as much as possible. with these great minds here i know they will figure out how to reduce the second spike even though i think it is acceptable(this trace). i'm sure some more probing around & you fellas will solve this. keep up the good work!

[ET]

Deadeye

If reducing the secondary was my goal I would try increasing the booster to 20 and decrease the primary to 50. But it may come at a cost of less FPS.
I don’t see a threatening issue with the current secondary either.



Ed

[GMB54-120]

Interesting.. 4759 as a booster for Re7?

Hmmm...i thought i saw that duplex in 50cal on one of the links.