Factory Loads Too Hot?
Took my new Christensen Arms Extreme II 300 RUM to the range for the first time last week. I have not learned how to hand load yet so I went out with two different factory loads. Barnes VOR-TX in 180 Gr. Tipped TSX and Nosler Custom in 180 gr. Accubond. I chose to start with the Barnes as I have had great luck with 180 gr. MRX in my 300 WSM. The first shot was on paper at 100 yards, a quick adjustment of the scope and the second shot hit dead center. Both rounds were a little hard to extract after firing. I was not sure if there was an issue with the gun being new or the ammunition. As per the gun manufacturers recommendation I was cleaning the bore after each shot. I ensured the gun was not overly hot and was alternating with my 300 WSM. As I continued to shoot the Barnes bullets to adjust the scope to the proper elevation at 100yds, rounds were hard to eject to the point that the bolt would not eject a spent cartridge and I had to remove it with the rod. I inspected the gun and could not see any damage. I opted to try the Nosler Ammo. I fired several rounds and they all ejected normally with no issue. Talking with a friend that hand loads and an e-mail response from Christensen Arms both indicate that the Barnes loads may be too hot. Has anybody else had this issue? I did e-mail Barnes, however they have not answered.
On another note, I went back out with the gun a few days later and had the chance to shoot at a Coyote on a ranch where I sight my guns in. This gun is the first gun I have ever owned with a muzzle break. I learned a very tough lesson. Never shoot this gun without hearing protection or the replacing muzzle break! I will never own another gun with a muzzle break and may sell this one.
Hard extraction is a big red flag for excessive chamber pressure. Do NOT use that ammo. It may just be that particular lot of ammo, as even factory loaded ammo can be loaded incorrectly.
I do not like muzzle brakes myself, but it is a preference thing for sure.
Does the brake screw on? If it does, take it off when you are hunting. I have a screw on MB on my .300 Wby that is great for bench work at the range. But when I am hunting, I take it off because of the excessive noise.
Have you looked at the fired cases? Usually if the pressure is up, the primer will show signs of pressure in addition to the sticking cases. Cratering in the primer should be there too. The high pressure will cause the primer metal to extrude around the firing pin and make a ridge you can see and feel. It is possible that the rifle has a tight chamber which can cause higher pressures. I really have a problem with an ammo manufacturer producing ammo that is too "hot". Sure it's possible but they are really sticking their neck out.
I guess it's possible to get a gun with a chamber that has minimum headspace and ammo that is at the max and get this problem, but I sure would have the headspace checked by a Smith and really would be interested in what Barnes has to say.
Just my take....
I would say the Barnes ammo is too hot for your gun, I would not shoot any more of it. It could be that the throat of your rifle is a little short for that particular ammo and the bullet is into or touching the lands causing an over pressure situation.
Take this as advice from someone who has lost nearly all the hearing in one ear, you should never fire any gun without hearing protection, period. The majority of my hearing loss was caused by a .22 rimfire in my ignorant youth. Hearing loss caused by gun fire is cumulative and irreversible, hearing aids won't fix it. Take time to use hearing protection, even when hunting! A muzzle brake can be a tremendous asset to good shooting, even on the light kickers.
Originally Posted by chiefgobbler
Thank goodness I do have a screw in MB and it is off now unless at the range.
The primers do indicate an issue. There was was visible mark on the area where the lettering is near the primers on all of the Barnes spent cases. This mark is not on the primers of unfired rounds or the spent Nosler cases. There is a very slight ridge on the Barnes primers themselves but not much different from the Noslers. I will have a gunsmith check the chamber to be sure that is ok. Still waiting to hear from Barnes.
Yep...classic signs of too much pressure.
That name cracks me up .
One thing I was wondering. When you are chambering the unfired round, does it seem a little hard to close the bolt ?
Like BobT said, the bullet may be seated out too far and touching the rifling. You can also see if the rifling is making marks on the bullet. A case that is too long will cause problems also. Another sign of pressure besides the primer is the shiney spots on the face of the case from pressure against the bolt face. When your bolt is hard to lift, you will see it. Sounds scarey enought to me, I wouldn't shoot another round of that ammo.
Can't agree with you more. I use hearing protection hunting ducks, doves, varmits, etc.. I haven't for Big Game but will now. Looking for something that allows me to hear nature and blocks shots and other loud noises.
Yep 30+ years in the Fire Service and a Wild Turkey World Slam led to a hunting buddy giving me this code name.
No problem loading or extracting the unfired rounds and no marks or other indication that they are seated out too far. Small circle marks on the face of the case are there on the Barnes spent cases, not the Noslers.
Good advice by all and especially BobT. I too have a hearing loss caused by shooting a 44 mag without hearing protection. I am a fan of muzzle breaks but when hunting I usually use a screw on CR.