105 AMAX Moly wont shoot in my 243...

[joebino55]

I normally shoot 105 AMAX bullets in my 243 and it has shot under .4 MOA at 100 yards once I found a good load. I recently bought 800 moly coated 105 AMAX bullets not knowing they were moly coated. Well I decided to keep them and give them a try rather than send them back. The load I shoot with non moly 105 AMAX is 45.5 grains of Vihtavuori N160, Remington brass, CCI BR2 primers. I seat them .010" off the lands.

With the moly bullets I started at 45.2 gr and worked up to 46.7 gr (in .3gr increments) where I started seeing pressure. I tried seating them .010", .020" and even stuck them into the lands. Nothing I have tried has yielded anything better than 1 MOA groups at 100 yards.

Everything I have read or been told is that moly bullets reduce pressure so you will have to increase your powder charge to make up for it. At least that's what I gathered. Does anyone think it would be any use trying to work down to see if accuracy improves? Or try a different powder? I'm all out of ideas and this is my first experience with moly coated bullets.

The rifle is a Remington 700, trued action, 243Win match chamber, 26" Krieger gain twist barrel from 1:8.75 to 8.3. I mainly use it to shoot F class. I know the barrel isn't shot out because I shot my non moly load today and it shot sub half minute groups.

Thanks in advance for any and all replies.

 

[Nomad47]

FIrst I think you need to 'season' the barrel with 20 to 25 moly rounds. Then start increasing from your original load in .1 grain increments (same seating depth) and I think you will find your load. Good luck and keep us posted.

 

[Dgd6mm]

Don't know much about moly, but you do have to season the barrel. +1 on what Nomad47 said.

 

[joebino55]

I have just over 100 moly rounds through the barrel without cleaning now so it should be seasoned. I wonder if one of the first loads I tried might have shot good had the barrel been 'seasoned'? I guess Ill start back over. Thanks fellas.

 

[Nomad47]

That is what I was getting at, but I guess I wasn't very clear.

I've got to tell on myself. One time I tried to take a short cut to do the 'seasoning' by running a mop coated in moly up and down the barrel after doing a thorough cleaning. But I failed to run a clean patch thru afterward. Well, I went out to shoot some test loads over a chrony and got some really wacky chrony readings. Turned out I blew moly powder all over the sensors. After cleaning everything on the chrony everything was back to normal.

BTW, I've shot 150 rounds between cleanings with moly without a noticeable drop in accuracy. But you do get a moly buildup after that many rounds.

 

[xdeano]

I don't use moly any more, but when i did, i'd mop my bore with liquid moly, let it dry and run a dry patch through to pick up anything. Then i'd shoot, but i'd noticed that my barrel didn't settle down tell i had about 75 or so rounds through the barrel. I'd run it for about 200 rounds and redo the entire thing. The barrel i was shooting was a 22-250, but it seemed to the same thing with a 243 that i was running at the time. My groups would start off in the 1 MOA range and shrink to about .4 or so then open back up after about 200 rounds. Strangest thing i'd ever seen. So i decided i'd stop using it and I cleaned my barrel out really well and shot naked bullets and from the get go i would shoot .4 and stay that way for around 100 rounds before it started to open up.

I also got away from the mess. Gave the rest of my moly to a friend and it was behind me.

xdeano

 

[Nomad47]

I hear ya. I still have 50 or 60 moly coated loads to shoot in my 22-250 before switching to hBN. And I'm already shooting hBN bullets in my 243 WSSM.

 

[WyleWD]

Based on my experiences with moly coated bullets it could be that your rifle just may not (ever) shoot them as well as the naked bullets.

My 6xc bench rifle is set up exactly like 5 others that I know of. They all shoot 95gr Moly coated Bergers extremely well. They all use approx. 36.5gr of R-15 for a powder charge. Mine didn't like that load from the start and after a couple hundred rounds of trying to make it work, I just gave up on the Moly coated bullets. My rifle likes approx. 40-41gr of either R-17, N550, or 4350 (all are slower burning than the R-15)with the 95gr naked bullets.

So it could be that a little faster powder along with seasoning the barrel as described above might(?) bring it all together for ya too. Good luck and good shooting. WD

 

[joebino55]

Well I gave up on the moly bullets after it was suggested by someone that I just remove the moly by throwing them in the vibratory tumbler.

 

[PREMOD70]

Did you notice any difference in the neck seal? My guess is there was more powder residue with the moly bullets which sometimes can be overcome with Reloader powders, JMHO.