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Post by TGinPA on Mar 3, 2011 14:26:22 GMT -5
Pressure Trace:PN45 N120/H4198 10/50gr duplex 200sst Savage Shooter suggested using a booster powder slower burning than N110 in a duplex load as a way to maintain velocity while keeping pressures below sabot disrupting levels. Troubles with PT module connections limited my test to one usable trace. 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 degrees F. measured at the sensor (IR). Rifle Stand: Caldwell Lead Sled Altitude: 450 ft Chronograph: Chrony Alpha Model 8 ft from muzzle. (8 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 .033 in. Sensor dist fm BP=1.1 in. Bullet Diam.= .458 in. Bullet Type = Hornady 200gr sst. Bullet weight = 200gr. ,unknurled. Sabot: Harvester Smooth Blue Powder: N120/H4198 10/50gr. 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.  |
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Post by edge on Mar 3, 2011 14:34:56 GMT -5
I would think that N120 and IMR4198 are nearly interchangeable.
N120 does generally burn more completely than the other powders that can be substituted.
Rel-7
H4198
I4198
Norma 200
VV N120
edge.
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Post by Savage Shooter on Mar 3, 2011 14:45:40 GMT -5
I would think that N120 and IMR4198 are nearly interchangeable. edge. Edge I thought so too until I really did some burn rate reading and comparing pressure curves. The only 2 charts I have found that list N120 as equal to H4198 are Hodgdons and Vihtavouri's. Look at any 10 other charts produced by shooters like us and you will find N120 at least 10 slots higher in relative quickness. |
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Post by TGinPA on Mar 3, 2011 15:08:04 GMT -5
Compare pressures from a trace I recorded on 3-1-2011 shown in the post below. 65gr of N120 with a 200gr bullet gave peak pressures close to 5k psi higher than todays load of H4198 which was 1 gr. greater. IMO, that might suggest that N120 is significantly faster burning than H4198, at least under the conditions of my testing. Granted that different bullets were used in each test but IMO, that is unlikely to account for a 5k psi difference. dougsmessageboards.proboards.com/index.cgi?board=smokeless&action=display&thread=7818 |
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Post by shooter on Mar 3, 2011 15:15:16 GMT -5
Here what i shot today.15/gr n120 and 50 gr h-4198 the 5 shot ave was 2804 fps. shot with 195 barnes. wind today was 15 mph  |
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Post by Savage Shooter on Mar 3, 2011 15:21:38 GMT -5
Compare pressures from a trace I recorded on 3-1-2011 shown in the post below. 65gr of N120 with a 200gr bullet gave peak pressures close to 5k psi higher than todays load of IMR4198 which was 1 gr. greater. IMO, that might suggest that N120 is significantly faster burning than N120, at least under the conditions of my testing. Granted that different bullets were used in each test but IMO, that is unlikely to account for a 5k psi difference. dougsmessageboards.proboards.com/index.cgi?board=smokeless&action=display&thread=7819Not only higher pressure but much steeper also with less area under curve indicating considerable faster relative quickness. H4198 curves are all much lazier when shot as singles. Our goal is to get to 2850 or so and keep pressures under 36K. Should be a bit softer on sabots while still faster. May not get there but it is a new look. I like that this curves shape under time is "in between" what we are seeing with either powder as a single. |
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Post by edge on Mar 3, 2011 15:32:21 GMT -5
FYI all else being equal, 60 grains of powder:
Approximate estimates.
H4198 2659 fps @ 38 kpsi and 84% burnt;
I4198 2691 fps @ 34 kpsi and 90% burnt;
Norma 200 2624 fps @ 32 kpsi and 87.5% burnt;
Rel-7 2683 fps @ 35.5 kpsi and 90% burnt;
VV N120 2704 fps @ 33 kpsi and 95% burnt.
edge.
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Post by edge on Mar 3, 2011 15:44:32 GMT -5
PS That 65 grain load on 3/1 should be higher than 60 grains ;D
The estimate for 65 grains of N120 is :
2831 fps @ 36,365 and 97.6% burnt.
edge.
I am NOT saying you are wrong at all, just that I would suspect them to be reasonably close to each other...that is all. This is all new ground and your experimenting is much more valuable the the estimates!
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Post by Savage Shooter on Mar 3, 2011 16:18:23 GMT -5
PS That 65 grain load on 3/1 should be higher than 60 grains ;D The estimate for 65 grains of N120 is : 2831 fps @ 36,365 and 97.6% burnt. edge. There lies the problem testing twice now 65gr speeds exceed 2950 in cold temps. 4.1% increase in speed above estimated speed,,,,,what should that do to estimated peak pressure. I am seeing sabots blow at 65gr. and unpredictable as to when they let go so it appears to be on the bubble. I see all the .45 loads tend to blow sabots at pressures above 37.5k when comparing it to the PT's. Everyone I have talked to tells me that at 65gr N120 will blow a sabot at some time or another. |
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Post by ET on Mar 3, 2011 17:04:24 GMT -5
Savage Shooter
I too like the longer time under curve of primary pressure.
Here it appears by reducing the initial peak pressure the bullet load racing a head is reduced extending the time under curve affect. This definitely has a reduction affect on the secondary spike.
TGinPA
Your really putting a lot of effort into this with the different traces you’re providing for the benefit for others to expand their knowledge. Noted Thanks almost seems to be insufficient.
Ed
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Post by dave d. on Mar 3, 2011 18:27:35 GMT -5
I would think that N120 and IMR4198 are nearly interchangeable. N120 does generally burn more completely than the other powders that can be substituted. Rel-7 H4198 I4198 Norma 200 VV N120 edge. :)i was thinking the same thing.all these powders are close enough in burn in our rifles i just dont see the use of duplexing them.i just had this discussion with marty today and im not saying to not experiment i just think you need to go with powders alittle further apart.thanks tg for all your great info and efforts. |
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Post by Savage Shooter on Mar 3, 2011 21:26:02 GMT -5
Anybody got any idea as to which of these 2 powders has the highest relative quickness?
N130 or H4198?
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Post by Dave W on Mar 3, 2011 22:28:44 GMT -5
Anybody got any idea as to which of these 2 powders has the highest relative quickness? N130 or H4198? Based on what little I have shot N130 I would say H4198 is faster burning. 62gr of N130 is in the 2300's sabotless with a 300gr bullet. I haven't shot that high of a charge with H4198 but 60gr is in the mid 2500's with a tight loading 300 SST. N130 is pretty comparable to H322 when duplexed with a 250 SST in both the .45 and .50 with similar ratios. |
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Post by dave d. on Mar 4, 2011 6:51:59 GMT -5
:)Dave w is correct h4198 is a faster powder then 130.
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Post by edge on Mar 4, 2011 7:01:23 GMT -5
If I used 60 grains of each powder for this load, QL would estimate:
60 H4198 at 2800 @ 42 kpsi and 87% burnt with a volume of 75 grains of H2O;
60 N130 at 2620 fps @ 31 kpsi and 87% burnt with a volume of 75.3 grains of H2O .
edge.
PS to get to 2800 fps with N130 QL would estimate 73 grains @ 35 Kpsi and 91.6% burnt.
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Post by TGinPA on Mar 4, 2011 11:18:52 GMT -5
Pressure Trace:PN45 120/4198 12/53gr 200sst. Equipment: Same as 3/3/2011, Barrel temp= 62 degrees F. Bullet Diam.= .458 in. Bullet Type = Hornady 40 cal 200SST Bullet weight = 200gr. ,unknurled. Sabot: Harvester Smooth Blue (9gr) Powder:N120/H4198 12/53gr. 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. Tweaking yesterday’s load resulted in the following pressure trace:  |
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Post by edge on Mar 4, 2011 12:03:45 GMT -5
How about reversing that load?
edge.
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Post by Savage Shooter on Mar 4, 2011 12:19:17 GMT -5
How about reversing that load? edge. I have given that a lot of thought too, a couple of reasons behind trying it this way first were: 1. N120 at 60gr makes more fps/gr than H4198. 2. N120 at 60gr the % of burn is 10% more burnt than H4198. 3. Looking at shooters burn rates (not powder maker's) N120 is always 10-11 slots higher on quickness. This certainly does not make it right, just how I thought thru. I for sure like the trace and shape of curve. Also really like breaking 2900fps at less than 36K. With tweaking of ratios or going up a grain on front or back of load we should be able to get the ES down some. |
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Post by TGinPA on Mar 4, 2011 13:01:05 GMT -5
I'm thinking that before anymore PT data, maybe a few shots at a target might be useful to assess sabot integrity/accuracy at this level?
TG
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Post by shooter on Mar 4, 2011 13:20:35 GMT -5
This is Very Interesting.  |
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Post by edge on Mar 4, 2011 13:33:35 GMT -5
I have become very suspect of burn rate charts for the very reason you mention I think that looking at reloading manuals for actual loads is probably a better way. Quickload is no substitute either and can only give an estimate. Once again how full the case is when comparing powders is very important...IMO edge. |
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Post by edge on Mar 4, 2011 13:51:22 GMT -5
Here is an example of what I mean:
Hodgdon reloading center shows a 458 win mag as does the VV reloading manual
They only have one load to compare.
VV website shows N120 with a 350 grain bullet max load is 69.9 grains and yields 2454 fps ( that equals 83.03 grains of H2O )
Hodgdon website shows 72 grains of H4198 to be max and yields 2548 fps ( this equals 83.17 grains of H2O )
Volume for volume it appears that in a large bore rifle the H4198 is more energetic than N120.....at least in this situation.
Just to compare QL
I plug in 69.9 grains of N120 and reduce the case to 91.5% full and I yield 2460 fps @ 52 kpsi
I then plug in 72 grains of H4198 and QL estimates 2521 fps @ 54.6 kpsi.
Again these sources seem to correlate Relative velocity and relative pressure with these two powders.
edge.
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Post by shooter on Mar 5, 2011 14:28:07 GMT -5
Mark,I Was setting around doing some figuring.I think I could get up to almost 3060 fps second with 10gr n120 and 57 gr h-4198 total charge of 67 gr if my math came out right.I don't no what the pressure would be.
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Post by Savage Shooter on Mar 6, 2011 7:27:55 GMT -5
Mark,I Was setting around doing some figuring.I think I could get up to almost 3060 fps second with 10gr n120 and 57 gr h-4198 total charge of 67 gr if my math came out right.I don't no what the pressure would be. Probably getting to where sabots will stress as predicted pressure would be just over 38K. |
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Post by TGinPA on Mar 7, 2011 14:16:55 GMT -5
Pressure Trace: N120/H4198 13/53gr 200SST Equipment: Same as 3/3/2011, Barrel temp= 60 degrees F. Bullet Diam.= .458 in. Bullet Type = Hornady 40 cal 200SST Bullet weight = 200gr. ,unknurled. Sabot: Harvester Smooth Blue (9gr) Powder:N120/H4198 13/53gr. 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. Another small change with significant results. TG  |
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Post by Savage Shooter on Mar 7, 2011 14:36:19 GMT -5
Thanks TG. Looks to me like we are definitely getting there.
2900fps with good burn rates and softer curves for sabot integrity, peak pressure @ 35K.
Big improvement on 2nd spike.
Good results.
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Post by shooter on Mar 7, 2011 15:26:07 GMT -5
That Looking ;D good........... ;DI think this will be a very accurate load.Good work TG and Mark. |
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Post by rangeball on Mar 7, 2011 15:28:18 GMT -5
Only problem I see is the difficulty in finding 120 on the shelves. I wonder if there is a more readily available sub for it that would work as well?
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Post by deadeye on Mar 7, 2011 15:34:14 GMT -5
excellent work & not losing patience,working up slowly,true "professionals" to all- btw/shooter-great team & shooting!
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Post by Savage Shooter on Mar 7, 2011 15:41:05 GMT -5
Only problem I see is the difficulty in finding 120 on the shelves. I wonder if there is a more readily available sub for it that would work as well? I know I am probably going to regret posting this as I have not tested to verify. But in our applications I think reducing 5744 a bit would be very similar to N120. It has been proven that about any duplex using 5744 as a booster you can change to N110 and get 150-200fps more velocity. 50gr of 4759 makes the same velocity as 60gr of N120. I would think you can reduce booster amounts a bit work up to see how it shoots. This is one of the big reasons I wanted to go down this path with N120. I see N120 and 4759 producing nearly exact same traces as single and on MANY burn rate charts developed by experinced shooters 4759 and N120 are side by side. As a matter of fact 5744 is listed as SLOWER than N120 on most shooters charts. See here at what you cipher out of all this. The burn rate chart I put the most stock when looking for powder switch outs: www.reloadersnest.com/burnrates.asp |
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