Custom 50cal smokeless muzzleloader - Canada - "Accuracy Development Solutions" - Ken Thiessen

[quaid]

I purchased the firearm from the OP of another thread on this forum.

Here is the store listing for the custom smokeless build, with specs:

Custom Built Complete Rifle, Includes the below items assembled and ready to shoot!

• Remington 700 Short Action w/ Remington Factory Trigger
• IBI 416 Stainless Steel Smokeless Barrel, Remington Light Varmint profile, 26", 1:15 twist rate, 7R, 50 caliber
• Tundra Strike Chassis (Colour: Stealth Shadow Vortex)
• Comes with 20, unprimed, Arrowhead Gen2 LRMP Modules for use with large rifle primers
• Arrowhead Rifles 3-piece Ramrod w/ Sheath & Bore Guide
• Arrowhead Rifles Spin Jag

With the evolution of firearms, some things are built out of necessity and this is no different in the muzzleloader world. The Massive locking lugs on the front of the bolt makes the 700 Remington rifle action the perfect choice for a muzzleloader.
The smokeless muzzleloader design is not new but we have perfected it in this custom build configuration to provide better performance and accuracy to make ethical shots out past 300 yards.
With the unique ignition system designed by Arrowhead Rifles along with the use of smokeless propellants, this muzzleloader is one of minimal maintenance and pure performance.
This configuration features a full free floating barrel and thus the ramrod is not attached to the firearm to compromise accuracy. This rifle is designed to operate within the published smokeless muzzleloader load data for the Savage 10ML smokeless muzzleloader.

In addition to the content from the store listing, I have learned that Ken Thiessen built this smokeless muzzleloader while he was working for Bullseye. Ken no longer works for Bullseye, and now works for Vortex Canada in addition to his own company, "Accuracy Development Solutions". I understand from one of his appearances on a podcast that Ken has a hobby shooting smokeless muzzleloaders at long distances. That piqued my interest about this custom build.

I've contacted Ken once to ask about this particular smokeless muzzleloader, and he suggested I should expect great results with the standard 10ML loads. Keen-eyed forum members have already taken note of the 1:15 twist rate. I didn't deep dive into twist rate theory with Ken, but he did suggest that he tested this twist rate extensively with successful results. I have conjectured that it might help maintain stabilized flight at extreme distances. Wishful thinking?

It has taken me a while to acquire the rest of this setup, but I'm nearly ready to take it out to the range.
I've JB-bedded a 20MOA rail and mounted a Vortex Diamondback Tactical 4-16x44 FFP. I'm waffling over which scope I want on this muzzleloader long term, but this will do the job while I experiment with loads.

I'm going to start with duplicate 10 round ladders of RL7 and 250gr Hornady SST.
I'll post my range observations in this thread.

 

[GM54-120]

So he uses a Remage barrel. That is around the same size as a small shank Savage.

Be prepared to warranty that Vortex. Many of the Vipers dont handle recoil all that well and your DB HP FFP was made in China. A good solid scope for load work is the SWFA SS Classic fixed power with a Mil-quad reticle. Only $300. They offer a 10x42, 12x42, 16x42 and a 20x42 but the 10 and 16 are about the most popular. All made in Japan by Kenko. Same company that makes and owns Sightron.

If long range is the goal, you are barking up the wrong tree with Re7 and a 250gr SST. The real world BC is only around .200 and i doubt you will ever break 2500fps with Re7. LRMP may gain you some but thats a ton of powder you gotta burn to get there.

 

[quaid]

Noted that I should keep an eye on the scope (pun intended). I have not had any problems with other vortex db and viper scopes, ...yet.

RL7 and 250gr SST are not my end-game, just an available starting point for 10ML loads. I will be elated if I can stretch this out accurately to 250-300 yards before the first week of November (my deer season). Assuming I find success out to 300 this year, I'll work on stretching out to 500-900 next year.

The SST's are readily available, while more exotic projectiles are challenging to find in Canada. Currently I've also got 300gr SST kits, prbullet 45 dynamo (MMP HPH 24 .504"), and 180gr 10mm XTP in prbullet 40x50 blue sabots.

 

[GM54-120]

Highly unlikely you will get the 50x40 sabot to hold together. The PR bullet with a Harvester Red Crushrib will handle anything you can throw at it. Might be too tight for your barrel though.

I still cant imagine what a 1-15 twist is going to do anything other than create more sabot stress. A 1-24 will stabilize a 400gr bullet past 200 yards and any common 300gr bullet. Gunwerks didnt even spin them that fast. I think they were 1-20 and shooting long Parker bullets with ease.

The long range game is not the 50s best application. Too many weak links to deal with.

 

[quaid]

Understood RE 50x40 unlikely to perform well. I bought a few hundred of these in my naive enthusiasm to acquire whatever components were locally available

Noted RE Harvester Red Crushrib. I will look into local availability and/or shipping to Canada for this sabot.

Agreed that this is a strange 50 cal. If it turns out to be a bust and just won't perform for me, then I'll re-barrel into 45cal and start over.

I'm searching from some locally available VV N110, which should be a better powder for the 250gr SST's.

 

[GM54-120]

Here is what happens when you over stabilize a bullet. The nose rises. 1-15 twist is more like a 50BMG barrel to stabilize 600gr+ bullets.
https://www.lothar-walther.com/gun-barrel-blanks/rifle-barrels/50bmg-target-barrels/

 

[GM54-120]

I'm searching from some locally available VV N110, which should be a better powder for the 250gr SST's.

N110 is a great powder for a 250gr bullet as long as you dont go crazy with it. Old Savage data went a little far and gained very little speed over 41gr. About 41-42gr will get you about 2300fps and its rock solid dependable in any temp.

This is one of the weak links im talking about. The slow powders are not efficient with a 250gr bullet in a 50cal. They are even a tad slow in a 45cal with a 250gr. So you got to burn a ton of it and thats assuming you can find a good 250gr bullet to use for long range. They are however pretty good for a 300-325gr bullet in rifles like a MLII. N120 for example is excellent with a 300gr. Really good speed (2300fps+) and you only need 60gr to get it. 63gr will get a 275gr moving about 2400fps reliably. Swap to a 250gr with N120 and you may get 2500fps with 65gr but wait till temps drop. It will lose its temp stability. Possibly losing 100s of fps.

BTW McGowan used to sell prefits aka Remage/Savage nut barrels for SML. They were around $415 or so in SS. They offer a 50cal 8 land 1-24 which is pretty much ideal for a 50cal SML with 300gr sabot loads. They offer it in a 1-20 also if you had the need to shoot longer 300gr bullets.

 

[quaid]

I'm in luck.
It seems that there is local supply of the harvester crush rib red sabot, as well as additional 300gr bullet options.

 

[GM54-120]

Just remember the Red Crush Ribs will be TIGHT. The regular Black EZ-Load work fine in my NULA with a .500 land barrel. Ive used hot N110 and upto 58gr of N120 with a 275gr Parker using that cheaper EZ-Load sabot.

 

[quaid]

First range report:
I set myself up for failure (wrong sabots)
I loaded up 3 ladders of VV110 for use with Hornady 250gr SST's. I used Hornady's included red sabots, and I think this was my mistake. I suspect they do not hold up to the pressures from the VV110, or other smokeless powders. My velocities (and group sizes) were erratic. This was a bit embarrassing, and I probably should have known better.

Velocity (fps)	ladder
Charge (gr VVN110)	1	2	3	Count	ES
<redacted>	2072	1957	2003	3	115
<redacted>	2089	2063	1974	3	115
<redacted>	2036	1929	2088	3	159
<redacted>	1967	2127	2031	3	160
<redacted>	1979	2031		2	52
<redacted>	2129	2231		2	102
<redacted>	2210	2241	2129	3	112
<redacted>	2311	2188		2	123
<redacted>	2252	2067	2222	3	185
<redacted>	2271			1	0
<redacted>	2279			1	0

 

[quaid]

Recovered Hornady red sabots


LRMP Gen2 pressure signs?


All ladders (26 shots), 50 yards.
I did not make an effort to separate their groups as I was mostly concerned with getting velocity measurements. I'll separate the groups next time, and move out to 100 yards.

 

[quaid]

Harverset Crush Rib Red sabots with Hornady SST 250gr

Charge (gr VV N110)	1	2	3	4	Count	ES
38	2327	2303	2286	NA	3	41
42	2342	2433	2436	2429	4	94

 

[quaid]

I also shot some 310gr PR 45 Dynamo with MMP HPH 24
I quit after 6 because it was highly abnormal

 

[Mnt monkey]

Just looking at some of your sabots,, understand you have the stress of a faster twist barrel which I like , I don't know about that fast but I like fast twist barrels, have you sized a 50 cal bullet and run it down that barrel and feel or felt how even your bore is I believe you've got an uneven bore myself probably got a choke at the bottom or the top potentially, when you're loading a sabot load does it feel really even all the way to the bottom seating it? I just had to send the barrel back to a builder his machining work was perfect some of the best I've ever seen but he didn't build muzzleloaders a lot and he really had no idea what the bore was like on the barrel that he used on the gun build it was shredding sabots,,, choked at the bottom where the shank was. So bad I could not size bullets for the barrel. Just seating a sabot load in it it almost would have been hard to notice.

 

[quaid]

have you sized a 50 cal bullet and run it down that barrel and feel or felt how even your bore is

Negative, I have not. I do not have any full-bore lead or copper bullets. The most accessible might be full-bore lead ball, but it's not something I've looked into.

when you're loading a sabot load does it feel really even all the way to the bottom seating it?

To my (admittedly inexperienced) hands, the sabots feel consistent all the way down.
I can pull the breach plug and try a few sabots, paying special attention for changes in tightness (necessary pressure).
I might also be able to find pin gauges for the lands at the bottom and again from the top, to see if they are the same / if they traverse the barrel without obstruction. I'm not sure if my pin gauge set has these diameters, but I will certainly have a look.

 

[Mnt monkey]

It would be worth your effort again it just helps you know your barrel better.

 

[ronlaughlin]

Pin gauge steel is probably harder than barrel steel. Is it wise to put a pin gauge down the barrel?

 

[Mnt monkey]

Since you have such a fast twist anyway have you considered shooting the heavier 50 cal bullets from fury that you can size for that bore,, and get you a sizing die from Hankins.

 

[quaid]

Pin gauge steel is probably harder than barrel steel. Is it wise to put a pin gauge down the barrel?

That's a good thought. In either case, my pin gauge set doesn't have pins large enough for this task.

 

[quaid]

Since you have such a fast twist anyway have you considered shooting the heavier 50 cal bullets from fury that you can size for that bore,, and get you a sizing die from Hankins.

The thought has crossed my mind but I haven't found Fury bullets in Canada, and they do not ship internationally.