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Has anyone played with these?
Savage 10 ML-II and I use smokeless so experience with this specific setup would be helpful.
I will be throwing 200 grain bullets and I am thinking I may have to go higher than normal charge wise to get good stabilization.
I read about the 'duplex' sabots many years ago and was confused so passed up on the idea of giving them a try. Your thread got me to go back and reread about them again this morning and am still a little confused as to the 'why' reasoning behind it all.
I have shot the .40/.50 dead centers, in fact still have 3 packages sitting here. I know the .40/.50 dead centres are deadly accurate out to 150 yds, I trialed them a few year back and was super impressed. The idea that the .357 bullet is that much better than a .40, to the point of having to develop the special 'duplex' sabot system to shoot them still has me scratching my head. But Cecil swears by it and his performance results show them to work.
Have to let me know what you find. I don't shot MLs out to the distance that these are designed for (200+) so I have little interest in spending the time and money to trial them myself.
Big Jack
Best of luck with your new project of duplexing sabots.
I tried my own mixture of sabots to get the 200SST .400” to fly but when I exceeded 2000fps they sprayed like wild fire.
For single sabot load using 200gr bullet I tried 460S&W 200XPB (.451). Here to I started to get wild groups after a certain velocity.
Never tried PR’s setup so I can’t say how they work.
Your 10ML-II has a 1-24 twist so higher velocity than 2000fps shouldn’t be required for sufficient gyroscopic stabilization (RPM) for say the 200SST.
Another bullet I haven’t worked with is the 200FTX .452”.
http://www.hornady.com/store/searchammo.php?mode=search&main_cat=250&categoryid[]=260&categoryid[]=429&categoryid[]=&x=42&y=5
I do know the 225FTX shoots as good as the 250FTX.
A possible problem with lighter copper clad or copper bullets may be insufficient obturation. This may not be so with all lead bullets.
Definitely let us know how you make out.
Ed
I run the 260 gn dead centres with excellent results to 200 yard. Velocity is about 2300 fps Mark. Reasonably heavy recoil. Going with a 200 grain pill with better bc I think I will have to up my charge simply because it should yield higher velocity and stay within safe pressure. Higher velocity is the goal with increased range.
Problem I see is with the powder I typically use being sr4759. It is relatively quick so I think I will need to look at some of the other suitable powders I have.
I use 4759 in reduced recoil loads for many Cals and it tends to produce close to maximum pressures but of course lower velocities. There may be a better powder out there for lighter pills in this ML.
Big Jack
Not sure where your reasoning is originating from for lighter bullets that normally have a lower BC. In order to produce the same drop at a given distance you need higher velocity with a lighter bullet.
For the responsiveness of 4759 there is a big difference from the old 1/2lb can and the now 1lb plastic container. For the standard recommended 4759 load for the 10ml-II there is about 5k/psi difference in pressure and about 100fps difference for a 250gr bullet.
Anyway enough said for now and will look forward to hearing about your results when you put your testing in gear. My main curiosity will be your choice of powder and how responsive it is to temperature change with a lighter bullet.
For what it’s worth a load of 55gr - 4759 (1lb container) and 200grain bullet generated around 30k/psi with a resulting velocity of around 2450fps.
Ed
Thanks Ed.
My thinking is this;
In rifle reloading as your bullet weight goes down, your charge weight increases which brings you back to max pressure again. Often powder type may have to change as well. I know it isn't the same thing as you are not forcing a metal bullet up through riffling but hopefully you can see my thinking.
Greater velocity coupled with a bullet that flies better should give you greater range and better trajectory.
These 10ml's have load data set for 4759 at 43 grains and that combo works well with a 260 to 330 grain bullet. The original 10 Ml's were designed using 300 grain bullets. In my mind when you drop bullet weight down by such a huge amount, 4759 may no longer be the right powder.
Did iyou see incomplete powder burn with the 200 grain set up?
Was pressure comparable to one of your 260 or 300 grain loads?
This just may be a wild goose chase. Temperature stability is definitely a concern.
Here are some powders I am looking at. I have used 5744 with ok results.
H4227 is n extreme powder so temp sensitivity should be ok and I have that one.
AR2205 (ADI)
4227 (IMR)
H4227 (Hodgdon)
5744 XMR (Accurate)
N130 (Vihtavuori)
680 (Winchester)
Has anyone played with these?
Big Jack
Load experimenting is never a wild goose chase but a learning experience for me.
Okay I see your reasoning just not how you define max pressure.
To answer your second question I saw no evidence of an incomplete burn using 4759 with a 200gr bullet.
Here’s an experiment you may want to try to compare lighter bullet to a heavier bullet.
Same zero (height) at 100yds for 200gr and 250gr bullet. Without further adjusting anything move to 200yds and see where the POI is for both bullets.
Sorry I don’t use 300gr bullets as I never saw a need to with what the 250gr provided.
I did do a test for another individual using a 325gr bullet with 4198 that registered 38K/psi. Now that would have rattled my back teeth if I wasn’t wearing a shoulder pad, chuckle.
IMO 4759 is a tad slow but usable with a 200gr bullet. At 1-time Alliant 2400 was a recommended powder that used less grains per recommended 250-loads. This will be a powder I eventually want to try with 200gr bullets.
Ed
I see your point with regard to max pressure.
2400 is something I will order. I also have 5744 which I have had some success with.
Thanks Ed
I don't know if you guys have seen the load/pressure tables included in this article by Randy Wakeman for the 10ML...some interesting info;
http://www.chuckhawks.com/savage_accuracy_loads.htm
Yes some good info there.
Big Jack
I limit the pressure of my loads to 40K/psi to keep a safe margin for error.
The 10ML-II barrel has a rated yield strength over 80K/psi and about 118K/psi for tensile (rupture) strength.
My goal for a 200gr bullet is more for varmint shooting as there are very few bullets in this weight category that will not seriously fragment at close range if your pushing them say at 2500fps. The 200gr XPB (all copper) will handle that velocity but trying to get an accurate load is really challenging.
My original goal was first getting the 200gr bullet up to 2500fps with respectable accuracy. Second stage then with the aid of duplexing powder was to see if the load could be safely taken to 2650-2700fps for 300yd capabilities. I know there is a rule about using multiple powders but they can be safely used if you know what you are doing and have a good understanding of internal ballistics mostly powder burn rate characteristics. I’m not promoting using a duplex but have no reservations for my application with the knowledge I now have.
2013 & 2014 have been bad years for me and hope 2015 will allow me to continue my own load developments again.
Picture below are about the 3-candidates for 200gr bullet testing. For choice of sabot/s I had to knurl them for best load resistance.
Attachment 27656Attachment 27657
And I have a selection waiting to be tested. :)
Again good luck with your endeavor
Ed
Thanks Ed
For me I am looking for a good 300 yard deer load.
i think I found a pound of 2400 and a pound of Viht N110. I already have N120 but use it in my 17fb and that stuff is impossible to find!
Duplexing is something I have been thinking about as well. There are some sources for good load data on that. What is interesting is if done correctly, pressure can be lower than with a single type charge.
If you try this please let me know your results.
Big Jack
You are absolutely right about what a duplex can do for lowering peak pressure and increasing velocity.
The key is having the right amount of booster powder (primary ignition) to generate a sufficient burn for the main slower powder charge to carry a good burn. In essence you are holding a higher trailing pressure curve (below peak pressure) that supports a higher bullet acceleration rate until the bullet reaches the muzzle.
Some individuals have been using duplex for years and swear by it.
I have been reluctant to duplex as long as my load requirements were met by a single powder. Well now that I’m coming to a road block for more velocity than what a single powder can safely provide duplexing is the next obvious step.
Even though not a true duplex I’ve read that some individuals will incorporate about 4-5grns of a faster powder to ensure ignition of the main charge in extreme cold weather.
When I can get back in the groove hopefully in 2015 I will gladly share my results.
Hey if you want to experiment with duplexing starting with a 250gr bullet you can play with these loads that are listed on another board. N110 can be substituted with 4759 for close related results.
Attachment 27661
Ed
I've always been leery of duplex loads in the MLII. Also, 4227 was mentioned as a possible powder. From experience, I can assure you 4227 can be a horrible powder in the MLII. It will not reliably ignite in cold or damp weather. That is why Savage quite recommending it.
Ok good to know thanks.
Tactical870
No disagreement about 4227 if using a standard breech plug in the 10ML-II.
In my case I now use a modified breech plug that produces a higher thermal energy output from the primer and will revisit 4227.
Also by drilling my own vents using a harder screw (Grade 12) my vent orifice starts at .032” again allowing more thermal energy transfer to the powder than a new standard supplied vent.
If Savage would have built a BP with a shorter primer flame channel to vent then they would have produced a top notch ignition system IMO.
Ed
ED
Did you take a look at PR's large rifle primer conversion kit?
I think it will completely change ignition characteristics.
I am seriously looking at this for one of my savage mz's.
If I go that route I will need to start from scratch again.
I wonder if the higher energy produced from say a magnum primer is enough to get say H322 or 4227 going....
I'm still toying with the idea of running 2400. I know some guys like it in the Savage's....
Big Jack
Really can’t say anything about a kit that utilizes large rifle primers as I have no experience with them.
Utilizing the large rifle primer kit I wonder how long those modules last.
Then there’s always the priming and de-priming modules as an extra step.
Preferring a simple setup of placing a 209 into the carrier on the bolt head and seating it into the BP is more to my liking.
The best improvement I got with consistent ignition was recessing the vent into the BP about 5/8” also creating a smaller diameter powder chamber. The only extra machining I need to do with the vent is reducing the head diameter to 5/16” to match the recess diameter.
Also my head spacing is adjust for a good close fit so no blow back or primer bulging.
Have played with H322 before BP modification but always found unburned powder at muzzle. This is using a 250gr bullet because I’m not a fan of 300gr bullet.
A suggested load for REL-7 and 250gr bullet using 63-69grns is another load I want to eventually try instead of H322. 69gns of REL-7 should put you at about 2450fps plus.
As many years I’ve owned a 10ml-II and even with the amount I’ve learned there is still more yet to learn even for me. Just finding the range time and access is the awkward part.
Definitely a lot of fun experimenting and learning with a Smokeless Muzzle Loader.
Ed
While going through my 10ML-II files I reviewed my original notes on duplex sabot experimenting to refresh my memory. Here is a picture of my setup with sabots.
Attachment 27723
In order to get a proper fit with the inner sabot I machined the cup off for a good contact seating using a chuck I made.
Attachment 27724
Up to roughly 2000fps I got a so so response for accuracy. After that it was like a shotgun pattern. Also after 2000fps I could only locate the outer sabot and not the inner sabot. It was as if the inner sabot did not release from the bullet. I momentarily stopped here experimenting and began at looking how to bond the 2-sabots to release as one. Surprisingly there is no glue that will properly bond this type of plastic and fusion with heat is the only way.
Note: Some might ask why not use the 40/50 sabot available. It is not a high pressure formulation and again when you reach around 2000fps they begin to fail. If they ever come out with a high pressure formulation then I wouldn’t waste my time with sabot duplexing.
During this time I noticed that Hornady came out with the 200FTX-.452” diameter and momentarily switched gears for my quest of a high velocity 200gr bullet. Here I hope to push the velocity with the 200gr FTX accurately before returning to sabot duplexing. The .400” 200SST should hold up better to fragmentation than a .452” bullet.
Anyway this is just a brief history of trying to get a 200gr bullet to perform in a 50Cal 10ML-II. For the moment it is on the back burner because of other priorities to deal with. Somewhere down the road it will again appear on the main menu.
By that time I should have also replaced some of my hair follicles that I ripped out with this experimentation.
As for how PR manages a duplex sabot load I haven't got a clue.
Ed
First off, Ed and Jack, thanks for all the info on this thread I do appreciate the read.Quote:
Originally Posted by ET1
But, Yes, I'm one of the ones that has to ask...
Trying not to get too convoluted and using rough numbers to illustrate the point, my confusion lies in the ‘why’ because it seems that there are easier ways to achieve the same end result, at least in terms of accuracy.
Using a standard .40/.50 sabot combination , with a 200 gr Dead Center, with 110 gr T7 it will give me 1550 ft/s at 250 yds with a drop of -6.7 (zeroed at 200)
Using a duplex sabot with a .357 195 gr Dead Centre with 120 gr of T7 will give be 1776 ft/sec and a drop of -5.2 (zeroed at 200)
So roughly, using a smaller bullet and a duplex sabot, I will gain in terms of accuracy, about 1.5” trajectory.
Would it not be simpler to adjust the elevation 'clicks' on the reticle to raise the trajectory of the 200 gr bullet to match the trajectory of the .357 bullet. ?
MikePal
Nothing wrong in asking questions or expanding discussions.
Now I have to ask, where did you get these figures?
Do you have any muzzle velocity figures to share?
Have you actually shot any distances to verify or proof these figures?
For these mentioned bullets would you have any BC ratings so that a base line velocity can be calculated to match that bullet drop?
Ed
MikePal
I’ve answered my own questions by paying a visit to PR site.
http://www.prbullet.com/bal.htm
Read down this page and see how they determine BC for their bullets by using the highest calculated BC. If real time shows less they won’t publish this BC. I call that misleading BS.
http://bulletin.accurateshooter.com/...tics-software/
I use the above program to verify actual BC from range results and review characteristics of loads before testing sometime.
I find it to be a simple handy tool to have.
Ed
The question still remains....wouldn't it be simpler to adjust the reticle to compensate for a heavier slower bullet to achieve the same accuracy (point of aim) as a faster lighter bullet. ie; if one has a drop 1.5 " greater than the other, why not just adjust the elevation (trajectory) ?
MikePal
In this case I can’t give you a definitive answer because it depends upon the shooter how he adjusts to his particular bullet drop for his load.
That first involves where he wants his zero point for what he considers his best MPBR which is what I do. After that I make no further scope adjustments even to compensate any difference at a further specific range because my shooting doesn’t involve a fixed range area.
Ed
I am chasing as fast and flat a round as possible.
When I look at duplex loads and Duplex sabots, I hope to be pushing around the 2600 -2900 fps range with a 200 grainier.
There are existing loads to 2600 fps using a 250 grain bullet.
The goal is having a useable range of 0 to 300 yards.
Keep in mind I am already driving a 260 grain bullet right around the 2300 fps mark and am not satisfied that it will carry to 300 with a good enough/useable trajectory.
I see deer at 300 plus yards where I hunt so hopefully you can understand my goal.
Thanks for this info Ed!Quote:
Originally Posted by ET1
Big Jack
I can appreciate your goal but consider this chart.
Attachment 27729
A 250gr SST using a BC of .18 (value my testing revealed) doing 2600fps still has slightly over 1000ft/lbs at 300yds which is more than enough to take down a deer. If 150yd zero is used you have about 20” drop at 300yds.
Again something to consider.
Ed
Hmmm,? where are you guys getting these velocity figures from that you are quoting, are they just from the charts, or do you actually have chronographs to verifie these velocity figures.
I have and use an Oehler chrono. and I know what I actually get for velocity from my Savage mdle. 10 ML-11 .
I use the Chrony Beta model with cabled satellite screen to view results at the range table.Quote:
Originally Posted by jaycee
Attachment 27735
Ed
I have the identical setup except I have a lighting kit.
I use it on all of my rifles and it works quite well.
I have to ask what you are getting?Quote:
Originally Posted by jaycee
My load shows up at 2380, my buddies is 2465 with the exact same rifle , ??? who knows.Quote:
Originally Posted by Big Jack
Not surprised. Probably has to do with bore diameter or for example if you use different primers or if you are using charges from two separate powder lots. Not uncommon to see this with cf rifles.
I am well aware of that fact , have been reloading various calibers for 55 years , both for myself and commercially for about 10 years, and have been shooting ML's for close to 40 years .Quote:
Originally Posted by Big Jack