NW MRX Load Development

[Ty208]

I’ve searched all the muzzy threads here at RS and several other Forums looking for load development leads on a Accura MRX NW I recently picked up. I’ve found a million threads on 209 loads but not a whole lot for musket loads.

Powder wise, I’ll be using T7 FFFG as BH209 is a unicorn and not recommended w/ musket caps ( I almost missed that). I was able to score RWS 4 prong 1081’s on gunbroker at a very reasonable price fyi. Bullet wise, I snagged the ELDX 340’s and ELR 330’s to start my development and see which one wants to play.

I’m looking into T7’s load specs and will chase the node, just curious where some of you landed and how field results were with your particular concoction ( expansion, penetration, retention, grouping etc). Once I get goin, I’ll post up my results for anyone else goin down this rabbit hole. Thanks.

 

[TNKnoxville]

I started out with Blackhorn in my Accura MRX for my CO hunt. Ran out working up a load! So went to Triple 7. So far 100 and 120 grain/V are working great with my open sights at 50 and 100 yards. I've used the Triple 7 primers and Federal 2029A (got them for the Blackhorn). Really haven't seen much difference in accuracy or crud ring. I'm going to shoot the ELDX 340's. I tried the Thor and had great groups at 50 but horrible at 100 yards. I also have now had 5 of the Thor bullets not be to size and get stuck in the barrel about an inch in. Had to hammer them out!!!

In know there are negative thoughts on the ELDX for elk but they shoot great and I'm only a month away from my hunt and have limited time to play!

 

[ElDiablito]

There really isn’t much rocket sciencery here. The differences (realized in group size) between 209s, musket caps and #11s are fairly small. Id start with ~110 gr volume and shoot a five shot group. If you’re not happy, move up 5 gr and try again. Nearly every rifle will shoot an an acceptable group with 100-130 or so grV of 777. Swabbing between shots with 777 is nearly always a good idea to maintain consistency in bore fouling. Good luck!

 

[Ty208]

There really isn’t much rocket sciencery here. The differences (realized in group size) between 209s, musket caps and #11s are fairly small. Id start with ~110 gr volume and shoot a five shot group. If you’re not happy, move up 5 gr and try again. Nearly every rifle will shoot an an acceptable group with 100-130 or so grV of 777. Swabbing between shots with 777 is nearly always a good idea to maintain consistency in bore fouling. Good luck!

I guess part of my quest specifically is primer intel. My understanding of open breech primer per Idaho FG is that running a 209 primer system would not be an “open” system. I looked at the BH209 breech plug and it was not an “open” system.

Point being, just curious what has worked for others under the NorthWest ML Requirements with musket caps being the big question. I’m a total greenhorn in regards to ML development. Been reloading center fire for years but, not finding many specifics on primer options for NW ML
Didn’t know the 209 would even work on this particular model. Appreciate the feedback.

 

[ElDiablito]

Yes, you’re correct that (generally) you can’t use Bh209 in a non-sealed breech rifle. And you need (generally) a hot 209 to reliably ignite Bh209.

Idaho specifically prohibits 209 ignition. So your options are musket caps and #11 percussion caps. Sounds like you’re all set with the musket caps. They’ll work fine. So will #11s (my preference). I don’t like the flanged musket caps because I feel like there’re a little more cumbersome to work with.

Use what you’ve got and get to shooting! Good luck.

 

[Ty208]

So! Got two packs of ELDR’s and ELDX’s, T7 FFFG and a brick of CWR 1075+ (#11) primers. Got out with my son to get the ML dialed in and #11 style caps don’t fit the breech plug nipple Good thing I brought the long gun.

All my research NEVER revealed any difference in musket vs percussion cap nipple size FML.

In case any other newbie to the ML world is out there trying to figure out the primer / cap game for idaho hunting, musket caps and #11’s are NOT the same size….

 

[ElDiablito]

In case any other newbie to the ML world is out there trying to figure out the primer / cap game for idaho hunting, musket caps and #11’s are NOT the same size….