338 Mega

Don't know all the specifications of your build, but If you can keep your bullets seated out pretty long then I would give Reloder 26 a try. It seems to be the fastest powder option for either of the 338 Mega's I've worked with as long as you seat the bullets out far enough that you can squeeze enough of it in the case. With 250 Bergers you could probably run them up as high as 74-77 grains with a long seated 250 Berger, just an educated guess.
I have been on the hunt for R26 for over 2 years.. wanted to try it in my 338 SS originally but haven't had luck using ammoseek as a notifier.
 
Have my final load for the Bergara 338 Mega build now: 185 Barnes TTSX, 71.8 grains of RL-17, CBTO 2.288" COAL 3.010" (.064" off the lands) Muzzle Velocity 3,140 FPS. Consistently making ragged hole groups. Picture below is one such 3 shot group that I shot with it today at 100 yards. Should be a whitetail deer thumper round without a doubt and will still have enough velocity to expand and enough energy for elk out to about 750 yards at the altitude I hunt. I also had a pretty good load going using 66-67 grains of N550 with the 210 TTSX's at a velocity of 2,880 FPS. They are a good looking round when loaded with the Barnes TTSX's.
 

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Hey guys, quick couple of questions as my build continues. As you saw PBB has got my barrel in production and they are ready to rent the reamer and chamber the barrel. They reached out today and asked if I wanted to use the medium or long reamer. I am pretty sure I want the long, but I wanted to confirm with those of you who have more experience with this than I do. My build is a hunting rig, first and foremost. I plan on using bullets in the 225-250 grain range. I am building on a Tikka action with a long-action bolt stop and long-action MT magazine, but I have a short action bolt stop and a short-action MT mag available to me, so I can seat out to 3.1" with those. Ultimately, my question is that if I go with the long reamer, will I be accepting "too much" jump with the 225-250 bullet class?

My other question is in regards to a muzzle brake. I am really not a fan of them, but my build is going to be semi-lightweight. I have a suppressor coming for it, which will be used once it arrives, but that is going to be 6 months from now. I want to get this up and running before that. So, what are some recommendations on brakes? For information, the barrel profile is a PBB Light Palma finished at 21.5 inches, so I expect muzzle diameter to be very close to 0.800".

Thanks!
 
Hey guys, quick couple of questions as my build continues. As you saw PBB has got my barrel in production and they are ready to rent the reamer and chamber the barrel. They reached out today and asked if I wanted to use the medium or long reamer. I am pretty sure I want the long, but I wanted to confirm with those of you who have more experience with this than I do. My build is a hunting rig, first and foremost. I plan on using bullets in the 225-250 grain range. I am building on a Tikka action with a long-action bolt stop and long-action MT magazine, but I have a short action bolt stop and a short-action MT mag available to me, so I can seat out to 3.1" with those. Ultimately, my question is that if I go with the long reamer, will I be accepting "too much" jump with the 225-250 bullet class?

My other question is in regards to a muzzle brake. I am really not a fan of them, but my build is going to be semi-lightweight. I have a suppressor coming for it, which will be used once it arrives, but that is going to be 6 months from now. I want to get this up and running before that. So, what are some recommendations on brakes? For information, the barrel profile is a PBB Light Palma finished at 21.5 inches, so I expect muzzle diameter to be very close to 0.800".

Thanks!
The 250 BERGER doesn't need much FB so the LA reamer would be excessive for that bullet. The 338 is a round that has a BUNCH of bullet options that are totally different. The use of monos may require a lot more FB as do the high b c 285 and 300 grain cup and core bullets.
Sometimes, you can use the MA reamer and add some FB but there is definitely no one size fits all in the 338 world,
My MA reamer is .046" and the LA is .270, to show you the difference.
You kind of need to focus on a select group of bullets. Your Tikka will accommodate either FB with the right magazine.
 
The 250 BERGER doesn't need much FB so the LA reamer would be excessive for that bullet. The 338 is a round that has a BUNCH of bullet options that are totally different. The use of monos may require a lot more FB as do the high b c 285 and 300 grain cup and core bullets.
Sometimes, you can use the MA reamer and add some FB but there is definitely no one size fits all in the 338 world,
My MA reamer is .046" and the LA is .270, to show you the difference.
You kind of need to focus on a select group of bullets. Your Tikka will accommodate either FB with the right magazine.

Thank you, Rich!

So, if I were planning on using the following bullets, what would you recommend?

225 and 250 grain Nosler ABs
250 grain Lapua Scenars
225 Grain Hornady SSTs and CX
230 grain Hornady ELDX
250 grain Berger Hunters
Possibly 200-225 grain Barnes or HH bullets
 
Thank you, Rich!

So, if I were planning on using the following bullets, what would you recommend?

225 and 250 grain Nosler ABs
250 grain Lapua Scenars
225 Grain Hornady SSTs and CX
230 grain Hornady ELDX
250 grain Berger Hunters
Possibly 200-225 grain Barnes or HH bullets
probably the MA with some FB added based on what your smith thinks. Thats a lot of variety though!
 
probably the MA with some FB added based on what your smith thinks. Thats a lot of variety though!

Thank you, again!

Once I find one that works, that is what it will get, but the ones I have listed are the ones that I will probably start messing with. For now, it is most likely going to just be the Scenars, and the Hornady bullets due to availability.
 
Hey guys, quick couple of questions as my build continues. As you saw PBB has got my barrel in production and they are ready to rent the reamer and chamber the barrel. They reached out today and asked if I wanted to use the medium or long reamer. I am pretty sure I want the long, but I wanted to confirm with those of you who have more experience with this than I do. My build is a hunting rig, first and foremost. I plan on using bullets in the 225-250 grain range. I am building on a Tikka action with a long-action bolt stop and long-action MT magazine, but I have a short action bolt stop and a short-action MT mag available to me, so I can seat out to 3.1" with those. Ultimately, my question is that if I go with the long reamer, will I be accepting "too much" jump with the 225-250 bullet class?

My other question is in regards to a muzzle brake. I am really not a fan of them, but my build is going to be semi-lightweight. I have a suppressor coming for it, which will be used once it arrives, but that is going to be 6 months from now. I want to get this up and running before that. So, what are some recommendations on brakes? For information, the barrel profile is a PBB Light Palma finished at 21.5 inches, so I expect muzzle diameter to be very close to 0.800".

Thanks!
I built mine off of a Tikka action and did the long action. I'm shooting the 250 Bergers and am loading them out to 3.3". Being able to stuff more powder in the case is never a bad thing, just more velocity. But if you're only doing planning on shooting 225s mostly, it may not matter 🤷🏽‍♂️
 
Hey guys, quick couple of questions as my build continues. As you saw PBB has got my barrel in production and they are ready to rent the reamer and chamber the barrel. They reached out today and asked if I wanted to use the medium or long reamer. I am pretty sure I want the long, but I wanted to confirm with those of you who have more experience with this than I do. My build is a hunting rig, first and foremost. I plan on using bullets in the 225-250 grain range. I am building on a Tikka action with a long-action bolt stop and long-action MT magazine, but I have a short action bolt stop and a short-action MT mag available to me, so I can seat out to 3.1" with those. Ultimately, my question is that if I go with the long reamer, will I be accepting "too much" jump with the 225-250 bullet class?

My other question is in regards to a muzzle brake. I am really not a fan of them, but my build is going to be semi-lightweight. I have a suppressor coming for it, which will be used once it arrives, but that is going to be 6 months from now. I want to get this up and running before that. So, what are some recommendations on brakes? For information, the barrel profile is a PBB Light Palma finished at 21.5 inches, so I expect muzzle diameter to be very close to 0.800".

Thanks!
My experience after building 2 338 Mega's using the medium length reamer is that you should always try to use the long action reamer unless you're gonna be shooting 225's or lighter bullet weights. If you're planning on shooting the 250's on up or even the 210, 225 solid coppers like the Barnes TTSX for example I would highly recommend the long throated reamer. Even if your only gonna have a max overall length of 3.100" the extra freebore will help your pressures not spike so fast and sort of spread out the initial pressure curve more or less; just look at Weatherby calibers for a perfect example. Their calibers have extremely long freebore allowing the bullets to jump several hundreds of thousands of inches before contact with the rifle in most cases. Also to note, my Bergara build has a maximum cartridge overall length of 3.100" as well and up to about the Barnes 210 grain TTSX or 200 grain Accubonds are ideal. Anything heavier than the 225-230 Hornady's and the bullets perteude too far down into the case stealing case capacity. The 250 Bergers look strange seated as deep as they have to be to fit inside a 3.100" magazine. I'm thinking about building another 338 Mega on a Defiance XM 3.200" action but if I do then I will definitely be requesting the long throated reamer the next time around no matter what. Some bullet jump of a couple hundred thousands minimizing that initial pressure spike is always a good thing for the 338 Mega I have learned after building 2 of them so far, just my opinion from my experiences with the medium length reamer used on the first 2 rifles.
 
I have been on the hunt for R26 for over 2 years.. wanted to try it in my 338 SS originally but haven't had luck using ammoseek as a notifier.
I tried for 3-4 years and I finally broke down and got a jug of it the hard way, which I said I will not do but I did. I went to GunBroker for it and needless to say I paid well above what it's worth. I'm convinced it never even hits retail sales. I think you've gotta know somebody to get your hands on it. 🤷‍♂️ never in nearly 4 years did I get an in stock notification on it from anywhere and I had notifications set up everywhere, and none of them will let a guy like me back order it. Good luck!
 
Well, my build is mostly done. I say mostly because I currently have it in a B&C stock while I wait for the Manners EH1TK stock that I ordered 4 months ago. Still a bit of a wait, I suppose.

Here are the specs:
Tikka T3 donor action. Was a 270WSM.
Original bolt fluted and coated by boltfluter
Mountain Tactical outdoorsman bolt handle
Oregon Mountain bolt shroud
Oregon Mountain long action bolt stop
Mountain Tactical bottom metal
Mountain Tactical LA mag
Bell and Carlson M24 stock (will be replaced by said Manners EH1TK some day)
M-Carbo trigger spring in the original trigger
Preferred Barrel Blank 1-9" twist, Light Palma contour, finished at 21.5", spiral fluted, and muzzle threaded 5/8-24
Salmon River Solutions SS-Pro 4 brake (will be removed when my suppressor for this rifle gets out of jail)
Mountain Tactical Raptor mount (0 MOA, medium)
Tract Toric UHD 2.5-15X44 FFP mrad/mrad scope (non-illuminated)

I have 50 rounds loaded up for fireforming (68.3 grains of Vectan Tubal 7000 with a Speer 200 grain SP bullet and Wolf LRM primers). Now I just need to find time to go shoot that so I can begin load development. Probably won't get it in before my moose hunt on the 25th, but we will see.
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