New smokeless build

[Ninering62]

The 40 has always been my absolute favorite followed closely by my 358

Greg

I've only learned of their existence in the last 2 yrs or so. Thats right up my ally, & I have my 1st .40 bein built now. Getting the powders to try is going to be a big issue. It IS a big issue right now.

 

[mcdowshr]

Are you smooth-sizing the 40 bullets?

I tried to smooth form a 350 gr Pittman. It absolutely would not obturate. That particular bullet is much too long with a very thick jacket.
I know a couple guys that have had good success full forming them.

 

[ENCORE50A]

I tried to smooth form a 350 gr Pittman. It absolutely would not obturate. That particular bullet is much too long with a very thick jacket.
I know a couple guys that have had good success full forming them.

Aeromax hard core?

 

[Pathfinder60]

Well, this can be a topic that may require more explaining than I have time or room to type but I’ll try to condense it to where it’s understandable.
When most of us began building smokeless mzls we built 45’s because of the bullet & barrel choices that were available. Years of trial and error have all but perfected those 45 caliber guns. It’s relatively easy to build a gun , buy components and get a load recipe from a buddy that shoots remarkably well ( less than half a moa ) out to 500yds.

Then came the 40 cal. There are now great barrels and bullet choices available. So what’s the difference u ask ?

In smokeless mzls most guys smooth form their bullets. These rifles are land riders. That means ( for anyone that isn’t familiar with the term ) the bullet is pushed down the bore only touching the lands. When the powder ignites, the bullet must swell or obturate to cut the grooves in the bullet. After the bullet exits the barrel there is powder fouling left behind inside the bore. The next bullet that is pushed down the bore can be difficult to load because of the powder fouling.

The secret to any good shooting smokeless mzl is finding the right powder that gives the velocity and accuracy without making too much pressure plus burns clean enough so that it’s easy to reload multiple times without the bullet getting tight during loading or stuck in the barrel.

Many including myself are working on the 40 caliber but it is a completely different animal than a 45.
Sorry for the long winded post. I hope it clears things up a little.

I really appreciate the time you took to post your reply. I shoot smooth sized bore riders in both my muzzleloaders I have now so I'm familiar with that process. I see you have made no mention of any kind of over powder wad...be it poly or veggie or whatever. I'd assume that smokeless would require a tightly sealed powder column to ignite consistently, much like BH 209 does...am I off the mark here?
TBH the main reason I thought a .40 might trump a .45 is I'm remembering those long, VLD bullets in 6mm and 6.5mm from my 1000 yard bench rest days and I thought a .40 at 250gr or 275gr driven to the 2700 - 3000fps range would perform really well. Admittedly I have a great deal to learn about the differences between the cartridge gun of my past and this platform that we're discussing. I'm eager to explore this further. Thanks again to all who have taken the time to contribute here...it seems this is a quite popular subject!

 

[mcdowshr]

Aeromax hard core?

The bullets i shot were areomaxs but that was before Kyle added the hardcores to his line of bullets.
After several attempts with several different powders to get them to group i abandoned the project.
The copper fouling was terrible which led me to believe the bullets were just sliding down the lands and the groups were never better than a minute and a half @ 100 yds. I plan on resuming the project after turkey season

 

[mcdowshr]

I really appreciate the time you took to post your reply. I shoot smooth sized bore riders in both my muzzleloaders I have now so I'm familiar with that process. I see you have made no mention of any kind of over powder wad...be it poly or veggie or whatever. I'd assume that smokeless would require a tightly sealed powder column to ignite consistently, much like BH 209 does...am I off the mark here?
TBH the main reason I thought a .40 might trump a .45 is I'm remembering those long, VLD bullets in 6mm and 6.5mm from my 1000 yard bench rest days and I thought a .40 at 250gr or 275gr driven to the 2700 - 3000fps range would perform really well. Admittedly I have a great deal to learn about the differences between the cartridge gun of my past and this platform that we're discussing. I'm eager to explore this further. Thanks again to all who have taken the time to contribute here...it seems this is a quite popular subject!

U are correct about the wads.
I use a wool wad between the bullet and powder. I know some that do not and their guns shoot great as well. One just has to determine what each particular bbl likes.
Some like wool , veggie , poly others like nothing at all.
Ur also correct about the 40 cal bc.
A 45 cannot compare to the 40.
Long heavy skinny bullets have a definite advantage over short fat heavy bullets.

 

[ENCORE50A]

The bullets i shot were areomaxs but that was before Kyle added the hardcores to his line of bullets.
After several attempts with several different powders to get them to group i abandoned the project.
The copper fouling was terrible which led me to believe the bullets were just sliding down the lands and the groups were never better than a minute and a half @ 100 yds. I plan on resuming the project after turkey season

I can't seem to get the Accumax to group to my satisfaction either. I've got a couple hundred each of the 275's and 300's that I just don't shoot.

 

[Wildrangeringreen]

Don't discount cast/swaged bullets as well. They can be Affordable and effective, and can be driven just as hard as metal-jacketed bullets (patching), without the obturation issues copper brings (plus, you can be a little undersized and it'll upset fine = less loading problems from fouling). GRT can be your friend when it comes to SML's and coming up with initial estimations for loadings. Goal should always be 98%+ burn on your powder before the bullet leaves the barrel. This minimizes the fouling (means you are running at an optimum pressure for the formulation). Some powders just don't work well with reasonable weight SML's and certain bore sizes/ projectiles.

for target shooting, .30, .32, .338, .358, .375, or .40 are good options

for hunting at realistic ranges, the .45 or even .50 will be plenty (tiny amount of drop difference from the .40 at realistic hunting ranges, but bigger diameter). If you can't get within a quarter-mile of your prey to take your shot... there are other things you need to work on than LR shooting lol.

For multiuse - the .40 or .45 will work fine.

Far as barrels, any reputable MFG will be good. I'm partial to Lothar-Walther (fully custom contours for only a little upcharge), but I am currently using 3 Shilen no5 (.30,.30,.45) and 1 Douglas no5 (.45) 27.75" barrels for a project I'm currently working on (at the time, they were on sale/available at Brownells). I don't know if it means anything but I like the Shilen Barrels better, the material seemed more resistant to breeching operations.

 

[D55]

I shoot the 275's with 75gr H4198 from a 25" + brake Brux barrel with 1 finger loading pressure at below 1/2"@ 100yds. no wad HIS. 2900+ fps mv. 45cal. Slower powders and/or lighter bullets have a harder time obturating. JME

 

[d414hiker]

I recently inherited a Remington 700 in .223. Matte black finish receiver and barrel, synthetic stock. I'm considering having it become the basis for a .40 cal smokeless muzzleloader with the Fury 250gr or 275gr .402 Star Tip 2P bullets in mind...but not limited to them. I'd like recommendations on barrel make, length and twist rate as well as builders. This is my first foray into smokeless muzzleloaders but not muzzleloaders as I own a CVA Accura V2 Plains Rifle and a CVA Paramount as well.
I appreciate any help the group might offer.

What is the total length of the paramount so I know what case it will fit into?