N-110/I-4198 Duplex for Scout?

[miked]

45/70 H.I.S. converted Scout. Iv searched both boards and haven't found quite the info I am looking for.

I have 8lbs of IMR-4198 already and 8lbs of N-110 on the way. 8lbs because thats what was available so I snatched it up!

Currently I have been shooting 65 grains of I4198 with excellent accuracy and speed from 3 different monos from 240 to 250 grains with a poly wad. The problem is they are a bit loose on the powder to hunt with in my opinion. I was nervous about that even before I started reading about the 4198 low temp performance issues.

I am going to try going with sabots instead for this hunting season if possible for a good seal and and snug fit, temp insensitivity and positive ignition in the cold. I have two ML seasons. One at the end of October/beginning of November where temps could be as high as 75+ sometimes and then basically all of December where it can be single digits. I had a Blackhorn misfire (first ever) this year on a large doe I was to donate to a needy family a half hour after I shot a coyote and then reloaded. I wasn't too happy!

Right now I have 195 Lehighs and the newer style 240 grain CEB Maximus. Backup if those don't work well will be 225 or 250 grain Fury or Pittman 228 or 250. If I get to choose, I prefer to go with the 240 Maximus.

Id like to know of the Duplex combo's that are safe to try with these two powders and the above mentioned bullet weights with sabot. I am open to trying poly and wool wads behind them if needed as well. Is there any rule of thumb to extrapolate the combination of each powder up and down?

Iv seen some people using low to mid 30 grains of straight N-110 and then a combination of 5-12 grains of N-110 under a larger load of 4198. I haven't seen anything like 20-25 grains of N-110 under a smaller amount of 4198. I am curious what that would do if anyone knows?

Thank you for any information anyone can share!

[billc]

There are many duplex loads in the hyperlinked pressure trace folder that list what you are looking for. However, remember that those files were generated with 209 ignitions your module system will generate more pressure more velocity. I would start with the lower volume loads and work up. I've never shot duplex or with a module so I have no suggestions how much to reduce for starting loads.

[miked]

May 24, 2022 16:19:12 GMT -5 billc said:

There are many duplex loads in the hyperlinked pressure trace folder that list what you are looking for. However, remember that those files were generated with 209 ignitions your module system will generate more pressure more velocity. I would start with the lower volume loads and work up. I've never shot duplex or with a module so I have no suggestions how much to reduce for starting loads.

I did look through them all and saved the couple that pertained but most did not specifically fall into my mix of combinations. Seemed like most were all heavier bullets with my powder combos and other powders with the lighter bullets. I can make educated guesses with the straight 4198 by knowing the recommended max powder/bullet weight but introducing the N110 throws more of a wrench into things where I need to have more closer references.

[ET]

Miked

A rule of thumb introduced by RB (RIP) for duplex was that for every grain of booster you reduce the main powder load by 2-grains. Example, if you use 5-grns of booster you reduce the main powder by 10-grns.
I haven’t gotten into duplex loads yet as I don’t need them for my hunting application. I’m a sabot fan (Harvester) because a sabot seals a bore quicker resulting in a better powder burn IMO. A key element is a good snug fit that serves 3-purposes.
1)A better burn start as the skirt flares faster to seal the bore for pressure build up.
2)A tighter fit supports the bullet in a concentric (centered) position.
3)A tighter fit grips the bullet better to impart a proper rotational spin.

One suggestion I have is work with one bullet weight at a time. One thing I noticed is that lighter bullets like faster powder so as you increase bullet weight a slower powder may provide better performance. The key here is getting a good burn start (ignition) for pressure build up.

[miked]

May 24, 2022 20:02:43 GMT -5 ET said:

Miked

A rule of thumb introduced by RB (RIP) for duplex was that for every grain of booster you reduce the main powder load by 2-grains. Example, if you use 5-grns of booster you reduce the main powder by 10-grns.
I haven’t gotten into duplex loads yet as I don’t need them for my hunting application. I’m a sabot fan (Harvester) because a sabot seals a bore quicker resulting in a better powder burn IMO. A key element is a good snug fit that serves 3-purposes.
1)A better burn start as the skirt flares faster to seal the bore for pressure build up.
2)A tighter fit supports the bullet in a concentric (centered) position.
3)A tighter fit grips the bullet better to impart a proper rotational spin.

One suggestion I have is work with one bullet weight at a time. One thing I noticed is that lighter bullets like faster powder so as you increase bullet weight a slower powder may provide better performance. The key here is getting a good burn start (ignition) for pressure build up.

Perfect thank you! I agree with the sabot sealing. My best bullet to bore groups have came from a poly wad instead of a wool wad abd the fps increase was significant as well.

[Deleted]

I use 60 grains of H4198 with hlbs and a 200 grain sst bullet and get great velocity and groups.One extra thing I do since I use a sabot is to knurl my bullets in order to get a better grip on the bullet so in case the bullet spins in the sabot.

[miked]

May 25, 2022 10:26:35 GMT -5 @brownisdown said:

I use 60 grains of H4198 with hlbs and a 200 grain sst bullet and get great velocity and groups.One extra thing I do since I use a sabot is to knurl my bullets in order to get a better grip on the bullet so in case the bullet spins in the sabot.

Yup Iv shot the 225 grain Furys factory knurled with 55-65 grains of 4198 up to 2625fps with decent groups. Looking to use the N110 as a Duplex for cold weather ignition/pressure and more temp stable with lighter bullets.

[Deleted]

With the combo I stated for my sml I have never once had a misfire in my gun.I do use fed209 primers to ignite my powder.I may swithc to IMR4188 because I am low on my h4198.I hear it is almost equal.

[miked]

May 26, 2022 13:53:20 GMT -5 @brownisdown said:

With the combo I stated for my sml I have never once had a misfire in my gun.I do use fed209 primers to ignite my powder.I may swithc to IMR4188 because I am low on my h4198.I hear it is almost equal.

Good to hear, what kind of temps down to? I am using large rifle magnum primers.

[Deleted]

Here in Indiana our muzzleloader season is in the middle of Dec. for 14 days.It gets from 0-better than -15 degrees without the wind chill factor.But i have built 2 ground blinds that look luke out door toilets that I hunt out of in our muzzleloader season over a 300 yard cut corn field.Nailed a great 12 pt buck aty 246 yds.Dropped drt in 12 inches of snow.

[miked]

May 26, 2022 17:17:17 GMT -5 @brownisdown said:

Here in Indiana our muzzleloader season is in the middle of Dec. for 14 days.It gets from 0-better than -15 degrees without the wind chill factor.But i have built 2 ground blinds that look luke out door toilets that I hunt out of in our muzzleloader season over a 300 yard cut corn field.Nailed a great 12 pt buck aty 246 yds.Dropped drt in 12 inches of snow.

Nice!