300 Norma Mag Won’t shoot Berger 230 or 215s

I had a custom made 300 Norma Mag made by Elk Meadows in Utah. I wanted the rifle to shoot 230 gr Berger bullets at long range. This is a pure target rifle and it is beautiful. I do load my own Ammo and planned on working with specifically with the Berger 230s. To get started I ordered 100 rounds of Loaded ABM 230s and 215s figuring it would be a good start in breaking in the barrel, sighting in the rifle and give me some brass to work with. I know that these are hot loads and probably get velocity at the high end. I was able to chrono a few shots and shot a slightly higher velocity than Lits put on the box. I also loaded up some 198 Flatlines to play with at longer range. Right when the rifle was delivered, Napa had their terrible fires and my shooting range was destroyed. Needless to say my skills have lost some polish and I struggled to develope my loads and sight in the rifle. Also, I am still without a range to do proper load development.

My groups have absolutely sucked with this rifle shooting the ABM loaded Ammo. I have shot 100 rounds with the rifle exhausting the ABM loaded ammo. The Best group is about 1.5” at 100 yards. I went on vacation and shot to last couple of boxes of ABM Ammo with the group about the same 1.5” figuring it was my degraded skills. I tried some of the Flatlines I had loaded up and shot an unbelievable group if 1/2 inch. I thought the problem was me but after shooting a great group with the Flatlines I am questioning the tooling or maybe the ABM loaded Ammo. I expected the ABM Ammo to shoot really well. When I ordered the rifle I had the reamer made to chamber for the 230s. I actually gave 5 rounds of the 230 gr ABM cartridges for the reamer to be bases on. I’m very frustrated and think the reamer was not cut for the job. Attached is the specs. It shows 130 freebore.

Any help you smart Smith’s can give me would be appreciated. Also, any suggested solutions would be appreciated. I bought 1000 230s to load for this rifle and now I’m at a dead end. Is the ABM 230 Berger Ammo not compatible with my rifle? Will my reloading skills be able to improve on what Litz was able to make for me developing a load as I normally do. Is the chamber not cut properly for the 230s? Why would the Flatlines shoot well and the 230s and 215s not? Is the ABM Ammo experience like most factory Ammo and not as good as I expecteded it to be?

I really need some help, direction, and confidence and hope someone here will be able to point me in the right direction.

Here is the link to the ABM loads. http://www.bergerbullets.com/abm-now-producing-300-norma-mission-ready-ammunition/



Oct 19, 2009
Aloha state HI
Steve reamer has but too short freebore. When he chambered mine i had to probide my own reamer with 256 freebore..for 230s your fb should works with 210 and the 198 warner
Heres what steve put together for me
Likes: Wyldeman
Jun 17, 2009
Houston, TX
That freebore is very short. Reamers for the 230 Berger's usually seem to be around ~0.230-0.240".

Unfortunately, freebore's designed for the 230 Berger's don't seem to work well with the 198 flatlines (too much jump), and vice versa. Seems like you need to have a dedicated barrel for each projectile, to make the most out of each projectile.

You may be stuck with the 198 flatlines, which wouldn't be the worst thing in the world.
This is what i was thinking as well. Shooting the Flatline was a surprise, maybe a good surprise but I wanted a gun to shoot the 230s. Granted, I want to shoot LONG RANGE and the Flatlines should accomplish this well. Maybe I should just accept this, sell the 1000 230s and buy Flatlines, but I have to hand feed them as they are to long for the Magazine he chose for me. I could also have him recharger the barrel and all is good?

Thanks for your feedback. It is very helpful and is what I was thinking.


I agree that the CF and the McMillan colors do look amazing. Steve built a solid gun and my only disappointment is that it won’t shoot the 230s despite me paying for the reamer and specing the 230 gr Berger. I didn’t know better and him order it but I paid for it. It is the prettiest rifle that I own. Best part, the rifle only weighs 13.1 lbs including Kahles 624 with sling. I was worried about recoil but I had Steve use one of his Titanium muzzle breaks, and a limbsaver recoil pad, and I kicks like my 308. I could literally shoot it all day and no soreness. I am a real pussy when it comes to hard recoiling Rifles but this is a pleasure to shoot.

I have Spartan rebarreling my 308 now and will probably have him adjust the freebore but it is just another thing on my todo list. Any other suggestions as to what Freebore to use or is there any reference material I could look up? What are others using for their 300 NMs?

Thanks for all the help and comments.
As a follow up, I was playing with a dummy rounds and sure enough the the ogive was hitting the lands with the ABM factory loads. The ABM 230 were loaded to 3.568 COL. A COL of 3.54 hits the lands. To get a .015 jump, I can reduce the COL to 3.525. I am going to give this a try instead of having the chamber throat recut. With some throat erosion, this problem should go away in time. Anyone see a problem with this thought process?
Jun 17, 2009
Houston, TX
Some barrels just don't like some loads is how I would look at it. Some of my 6.5s will shot 1 moa and others less then half with the same ammo.
The .300NM is an incredibly easy cartridge to tune by all reports, and the 230 Berger is a known performer. The OP just needs a gunsmith to take a throating reamer to get the desired freebore and he will start seeing results with the 230's.
Feb 13, 2017
The .300NM is an incredibly easy cartridge to tune by all reports, and the 230 Berger is a known performer. The OP just needs a gunsmith to take a throating reamer to get the desired freebore and he will start seeing results with the 230's.
Interesting, I hope so for my sake. I have 300NM getting chambered now.