New Accuracy International AXMC 300 Norma high pressure problems

[Stevo3556]

Thanks for taking the time to read this and possibly figure out why I'm having increased high pressure issues.
I am condensing the details.

I purchased this AXMC new and loaded 50 rounds that others have used,
Peterson brass
92.6gr RL33
225 Gr Hornady Match
Fed match mag primers

I loaded a few with a few tenths less and more powder and no high pressure issues. Very slight cratering on primer.

Came home from range and cleaned, loaded 50 more all the same with above listed load. No issues and shot great!

Repeated above. Slightly higher pressure signs, little heavier createring of the primer and a few rounds with slightly shinny spot on head stamp.

Repeated above with NEW brass, same lot as first 50. Now holes in primers and bright spots on head stamp.
Pulled out FACTORY loaded Hornady match ammo, hole in primer and bright spot on headstamp.

I ran a new LabRadar on most of the shots and the speeds have increased from around 3000fps to 3040fps.
I understand the bbl is new and expect the speeds to increase.
Pulled a few of my reloads to ensure I didn't accidentally increase the powder charge, didn't. Measured with second scale, confirmed the first scale is accurate or their both off, my luck...

I realize I my need to bush the bolt, however, I didn't 150 rounds ago.

No carbon ring, even bore scoped, all looks clean.

I understand the bbl will speed up, but this mean an increase in pressures to this degree?
Should a factory round show signs of high pressure?
What is changing?

I have been calling the headquarters in VA since Last Saturday, rolls to voice mail.
Called the distributor yesterday, will get back to me.

I would like to know how to start solving this issue. It has been almost a week and would like to continue shooting my new rifle while not voiding my warranty or damaging anything.

Has anyone with a new AI possibly even with the 300 Norma round had this issue?

Thank you for your time,
Steve

 

[Barney88PDC]

Any chance you cleaned the rifle and left some product (oil / cleaner) in the chamber?

 

[Stevo3556]

Thanks Barney.

Sure there is a trace of shooters choice, however, I cleaned the chamber with a clean mop with a dry patch a couple times. Also the pressures have been building each time I shoot, which is 50 rounds between cleaning and don't go back to "normal" as I shoot. The last time I only shot a couple rounds including the factory load aft seeing the high pressure signs.

Are you thinking there might have been some oil left in the chamber not allowing it to seal? I'm not sure how much would be needed but don't think that would be enough, but I'm not sure how much it takes. I didn't rinse the chamber with brake cleaner to leave it perfectly dry, so again whatever a dry patch around a mop bigger than the chamber twisted around in the chamber leaves is what was remaining. IF that was enough, would you think that after a few shots it would be gone?

Thank you,
Steve

 

[Barney88PDC]

Man I know water on cases from rain can have a huge impact on pressure and cause issues exactly like you described. To me you are describing a carbon ring or a dirty / residue filled chamber. Clean the hall out of the entire barrel, chamber and all. Then make sure to get everything out and go shoot again. I'd think your problem would be solved.

 

[Stevo3556]

Thanks Barney,
It does sounds like something building, carbon ring certainly. I used a bore scope and looked in the chamber and throat and didn't see anything. I have never seen a carbon ring. Should it be appearant? I thought I knew how to clean a rifle, maybe I don't and I don't mind being corrected.

I believe I took some pics, if I still have them I will post them and see what you think.

Thank you,
Steve

 

[Stevo3556]

OK here's some pics I took last week of the chamber of my AI. The borescope I used is used for inspecting the cylinders and valves of aircraft so the focal length is a little too far for seeing close. Pics are great, but hopefully they can rule out carbon ring or other problem with bbl.

Thanks for the help.

 

[NGCSUGrad09]

Are you shooting with a can?

 

[Precision Underground]

Have you stripped the copper out of the barrel? Completely? A lot of copper can increase pressure. I know my 300 copper fouled really badly at first. I have never had to "break in" a barrel because I always used really good blanks. This was a Rock Creek cut so I assumed it would be the same. I called the smith about the fouling and he said tooling marks from chambering can cause a lot of fouling if not broken in properly. I used boretech eliminator(easiest and fastest way I have removed copper) and nylon brushes, wet, scrub, soak for 10, scrub, wipe out, repeat until zero copper fouling could be seen from muzzle with no device on it. It was globbed with copper. Then I did the old shoot 1 and strip back to metal for about 8 shots until the copper got noticeably less after 1 shot. Then went to 3 and clean, then 5, etc until fouling got much less. It took most of a range day but it worked. It does not foul nearly as bad now. I think the 300 is prone to fouling just because of the long bearing surface and the speeds it produces. So add some tooling marks on top of that and it could be dragging a ton of copper in your bore and upping the pressure.

 

[Stevo3556]

Are you shooting with a can?

No sir, not yet.

Thank you.

 

[Stevo3556]

Have you stripped the copper out of the barrel? Completely? A lot of copper can increase pressure. I know my 300 copper fouled really badly at first. I have never had to "break in" a barrel because I always used really good blanks. This was a Rock Creek cut so I assumed it would be the same. I called the smith about the fouling and he said tooling marks from chambering can cause a lot of fouling if not broken in properly. I used boretech eliminator(easiest and fastest way I have removed copper) and nylon brushes, wet, scrub, soak for 10, scrub, wipe out, repeat until zero copper fouling could be seen from muzzle with no device on it. It was globbed with copper. Then I did the old shoot 1 and strip back to metal for about 8 shots until the copper got noticeably less after 1 shot. Then went to 3 and clean, then 5, etc until fouling got much less. It took most of a range day but it worked. It does not foul nearly as bad now. I think the 300 is prone to fouling just because of the long bearing surface and the speeds it produces. So add some tooling marks on top of that and it could be dragging a ton of copper in your bore and upping the pressure.

That is my normal break in procedure. Was told it would not be necessary with the AI bbl. so I did clean after each fifty. Used Sweets 762 for copper cleaning. I saw slight blue after the first cleaning and less each time. Way less than any rifle before, but this is my first new high end rifle.

I am going to clean again this afternoon and load for a day out tomorrow.

I know it's had to actually see the bore, not the right bore scope, but does it look like there is a carbon ring? I have never heard or seen one until I read about it here. Should it be a ring that is on the lands, or just in the grooves? Just in front of the beginning of the lands and grooves?

Thanks,
Steve

 

[Barney88PDC]

Sweets strips copper but I dont think it removes carbon. I use Boretech Eliminator. It strips both. Get a carbon remover and clean it well. Pic 3 shows the place a carbon ring would be the best and it looks black to me.

 

[Precision Underground]

That is my normal break in procedure. Was told it would not be necessary with the AI bbl. so I did clean after each fifty. Used Sweets 762 for copper cleaning. I saw slight blue after the first cleaning and less each time. Way less than any rifle before, but this is my first new high end rifle.

I am going to clean again this afternoon and load for a day out tomorrow.

I know it's had to actually see the bore, not the right bore scope, but does it look like there is a carbon ring? I have never heard or seen one until I read about it here. Should it be a ring that is on the lands, or just in the grooves? Just in front of the beginning of the lands and grooves?

Thanks,
Steve

Get some boretech and a few nylon brushes and go to town. Some people say that's bad but there is no way nylon is going to hurt steel. I have always scrubbed my barrels with nylon brushes and as long as you make sure only nylon is touching the bore you are fine. And boretech will not hurt your barrel no matter how long you leave it in. I would suggest taking off your muzzle device so you can look at the bore and see if there is still copper. Looking for blue does not work at all in my experience. I guarantee you will see a ton of copper at the muzzle. Whether or not that is the issue, I am not sure. The series of events would suggest that it is. But unless you took a good bit of time with copper remover and a brush, it is still there. When I first started getting it out of mine after 100 rounds and a soft cleaning looking for blue, it took another hour of the process I posted above before no copper was visible from the muzzle end. It all started when my first 60 shots from it were very good and then it started shooting bad. Once I got the copper out everything returned to normal. I haven't had it long enough to know how often I will have to totally strip it but I am hoping now that it is broken in good it will be like my other rifles, about every 300-400 rounds.

BTW boretech will turn patches blue instantly on a brass jag. After a while you will start to see the difference between the light blue from that and the dark blue from copper. Still though, I have cleaned mine many times with no clear blue indication but still copper visible from the muzzle end. I have never worried much about copper until my 300 norma. As I said I think just the physics of such a long bullet in a small bore at high speeds makes it more prone to copper fouling. That's just my assessment though, no science to back it up.

 

[Stevo3556]

Sweets strips copper but I dont think it removes carbon. I use Boretech Eliminator. It strips both. Get a carbon remover and clean it well. Pic 3 shows the place a carbon ring would be the best and it looks black to me.

Yes Sir, I used Sweets for the copper cleaning. Shooters choice for the carbon.

I'll have a look at #3 and clean extra today. Thank you.

 

[Stevo3556]

Cleaned with Boretech carbon then copper cleaner. I don't feel like I removed more carbon than normal but I sure removed A LOT of copper. Took almost an hour before I quit getting blue out of the bbl. You two may have figured it out. I hope you are right. I will load tomorrow morning and go give it a try.

Thank you all very much for the help!

All the best in the New Year!

Steve

 

[Stevo3556]

Barney,

My copper cleaner obviously is too old or for some reason isn't working well enough.

You said you were using Boretech Eliminator. Do you think it is as good as cleaning with a carbon then a copper remover in a situation where there apparently is a lot of carbon and copper that needs to be removed on a regular basis rather than more of a maintenance cleaning?

Thanks,
Steve

 

[Stevo3556]

PU,

What load are you using?

After you realized the copper was causing an issue, what is your cleaning regiment now? How often?

I read before I purchased my 300 Norma that some people with double based powders were experiencing the carbon issues. I use don't want to spend an hour cleaning after every 50 shots. If it is necessary would like to find a different cleaner. I have seen some people use the foam cleaner that you let sit in your bbl for a prescribed about of time and then remove. Anyone have experience with these?

Thanks,
Steve

 

[Precision Underground]

Barney,

My copper cleaner obviously is too old or for some reason isn't working well enough.

You said you were using Boretech Eliminator. Do you think it is as good as cleaning with a carbon then a copper remover in a situation where there apparently is a lot of carbon and copper that needs to be removed on a regular basis rather than more of a maintenance cleaning?

Thanks,
Steve

I use boretech eliminator only. The first few passes gets all of the carbon and then I work it a little more to get the copper. Still curious how long I will be able to go on just a quick carbon cleaning. I haven't shot it enough to see.

 

[Precision Underground]

PU,

What load are you using?

After you realized the copper was causing an issue, what is your cleaning regiment now? How often?

I read before I purchased my 300 Norma that some people with double based powders were experiencing the carbon issues. I use don't want to spend an hour cleaning after every 50 shots. If it is necessary would like to find a different cleaner. I have seen some people use the foam cleaner that you let sit in your bbl for a prescribed about of time and then remove. Anyone have experience with these?

Thanks,
Steve

Mine will go at least 100 using RL33. I haven't gone more than that because after I got everything back to normal and then finished developing a load I had a trip planned to the 2300 yd range. I didn't want to use that as a testing ground to see how long I could go without cleaning! I'll know more over the coming weeks. I'll shoot it until accuracy falls off, clean, repeat and see what pattern emerges.

 

[Stevo3556]

Thanks PU!

 

[pbatesaz]

Have you checked COAL ? Perhaps something happened to the seating die and you are now jamming bullets?

 

[pbatesaz]

Ah, just noticed that you had the problem with factory smmo too, disregard. A puzzle to be sure. I will be very interested to know what you learn from this.

 

[Bkultra]

I have a new AI 300NM barrel that I haven't had a chance to use yet. If you don't get anywhere with cleaning and want to test another barrel to help you trouble shoot the problem send me a PM and I'll send it your way for testing.

 

[Precision Underground]

Thanks PU!

No prob. It's no fun when a new rifle acts up. Mine shot great with 1/2" groups the first time out and then went to 1.2 MOA and had me all worried. It was the copper. I think my theory about long 300 norma bullets, lots of pressure and speed, and fouling makes sense. I've never had any issues with copper on other rifles.

 

[Yerman]

What are all your guys round counts with your 300NM?

 

[Precision Underground]

I’m at 400.

 

[Stevo3556]

Ah, just noticed that you had the problem with factory smmo too, disregard. A puzzle to be sure. I will be very interested to know what you learn from this.

I did check this after the high pressure issue and found that I was jumping .01. One of my thoughts as well until I shot the factory.

Thank you, appreciate the help.

Steve

 

[Stevo3556]

I have a new AI 300NM barrel that I haven't had a chance to use yet. If you don't get anywhere with cleaning and want to test another barrel to help you trouble shoot the problem send me a PM and I'll send it your way for testing.

WOW! This is the most gracious offer I have ever received on SH! Thank you very much! I could not do that though. Thank you. I would hope that AI might do something like this. I talked to Lance at the "home office" a month before I decided to buy the AXMC. He was very helpful, answered many questions and was not in a hurry with me. He actually helped me might my final decision on the 300 Norma as they have one that he said was out in the field and is having amazing results.

I have been calling the home office of AI since Dec 22 I believe and they have been closed, or it is at least rolling to voice mail. Mile High has also been unable to contact them since December 26 when they reopened from Christmas.

I talked to Adam at MH and I asked him to tell me how to adjust the firing pin travel, we moved it back half a turn. No difference. Just something else I had read that might make a difference.

Looks like a beautiful day in Houston area, will be reloading in a few mins and going to the sand pit to see if the cleaning did the trick. I have high hopes. I did get way more copper out of the bbl than I thought was there. I also cleaned with the Bore Tech carbon cleaner and possibly removed more carbon. Should know in a couple of hours...

Thank you,

Steve

 

[Stevo3556]

No prob. It's no fun when a new rifle acts up. Mine shot great with 1/2" groups the first time out and then went to 1.2 MOA and had me all worried. It was the copper. I think my theory about long 300 norma bullets, lots of pressure and speed, and fouling makes sense. I've never had any issues with copper on other rifles.

PU,
No it isn't! Especially when it costs this much.

Right now I am happy I listened to my wife didn't start selling my other rifles like I wanted to.

I shot my scope in and a group at 100. With the group I didn't measure, but all three shots were touching and the steel was calling me! I really wanted to get the AB program set up and corrected. I was hitting a 20"X18" steel target at 1,000 immediately. The next day out to 1200. It has been shooting great. I attributed my misses to me and the wind at 90 deg an d gusts. I never noted the accuracy going away, but since I didn't shoot at 100 for groups, it certainly could have! I might shoot at paper when I go back out to see.

Thank you,
Steve

 

[Stevo3556]

What are all your guys round counts with your 300NM?

Yerman,

I shot 50 a day for the first three days I had this rifle. then less than fifty trying to figure this out with Adam from Mile High.

Steve

 

[MOUNTIC]

I would give Mile High a call and they will get you squared away.

Edit. Noticed you just posted you were talking to Adam at mile high.

 

[Stevo3556]

I did as soon as they reopened from Christmas and Adam was back. They are working on it but have not been able to contact the AI home office either.

Thanks
Steve

 

[Barney88PDC]

I just use Eliminator. I haven't ever really tried a bunch of different cleaners. I just clean when I'm bored or if accuracy falls off. My 300 Norma probably only has about 200 rounds on it. My match guns (6.5x47L, 260Rem back in the day, 6Creedmoor) I run several hundred rounds between cleanings usually.

 

[Stevo3556]

Well it wasn't the fix or I don't know how to clean a rifle. Still high pressure with reloads and I shot another Norma factory round and it looks like the other two I shot previously, punched primers....

I hope the AI home office is open tomorrow so I can get this issue resolved and enjoy my new rifle!

Thanks everyone for the help!

Steve

 

[Precision Underground]

Well it wasn't the fix or I don't know how to clean a rifle. Still high pressure with reloads and I shot another Norma factory round and it looks like the other two I shot previously, punched primers....

I hope the AI home office is open tomorrow so I can get this issue resolved and enjoy my new rifle!

Thanks everyone for the help!

Steve

And you are positive there is no oil/moisture left in the chamber? That will skyrocket pressure. Once I am done cleaning I take a microfiber cloth and cut a few 3x3 squares and push them In from the center with an AR chamber brush. I spin the brush covered in the cloth all of the way in, bottom it out pretty hard( still spinning), and spin it back out. I always get a ton of “wet” out when I do that. Even on the second one. The third usually comes out pretty dry.

 

[Stevo3556]

Am am pretty sure. I am removing the bbl when I clean so I can see the chamber very easily. When I am done cleaning I use a .410 shotgun mop with a clean patch on it and do the same as you. Push it in whlie turning. The first one is wet and I continue until dry. If we want to be certain it is completely dry I could use some brake cleaner and it would leave it totally dry.

 

[Precision Underground]

Have you taken the barrel to clean every time? Even the first two before it went south?

 

[Stevo3556]

Taken it off every time because I didn't have a bore guide. Found it is easier to clean. Went over removal and installation with Adam at Mile High to ensure I was following procedure.

 

[texag0842]

Following.

Let me know if you get ahold of them today

 

[Stevo3556]

Talking to them now.

 

[Stevo3556]

I got ahold of the home office today. Great visit, learned much.

In summary, my load is over pressure. It was fine until the bbl sped up now with the increased pressure it is too much.
The round for the military is a 215 gr bullet at around 2900FPS. My load is 225 going around 3040 now, started just below 3,000. So I will pull the rest of my rounds, load some with less powder and clean the rifle very well again and head back to the range.

Would like to hear what you think of this.

Thanks again all for all the help!

Steve

 

[Precision Underground]

I got ahold of the home office today. Great visit, learned much.

In summary, my load is over pressure. It was fine until the bbl sped up now with the increased pressure it is too much.
The round for the military is a 215 gr bullet at around 2900FPS. My load is 225 going around 3040 now, started just below 3,000. So I will pull the rest of my rounds, load some with less powder and clean the rifle very well again and head back to the range.

Would like to hear what you think of this.

Thanks again all for all the help!

Steve

mmmm, I don't know about that. What about the factory ammo? All rifles are different but I shoot 230g at just under 3k with no pressure signs. That is a little faster than the norm I think but you should be able to send a 215 at 3k without big pressure indicators IMO. @bjay what do you think?

 

[Stevo3556]

PU,

I would be interested in BJay's answer as well. I THINK he was one of the people that was using this load with great results. I know it was not showing high pressure signs and was making good groups when I first started. Really liked the performance.

I referred to the factory ammo, was my "benchmark." Figured Norma could load ammo within spec and should be fine in any rifle. Apparently that is not their thinking. I don't have all the information that AI and others have at my disposal so I will just accept that fact.

I loaded up some 300NMs starting at 88grs and down I am seeing just under 2900FPS with the Hornady 225. No high pressure signs except for the small amount of primer flow around the firing pin. I think this is normal with AI unless you bush your bolts. Would like to hear from other AI 300NM shooters.

There is definitely a difference between the 92.6 and 88 gr of RL33. At 1200yrds I was at 8.5 mils, with the 88gr load I'm at 9.4 mils.

Steve

 

[Precision Underground]

PU,

I would be interested in BJay's answer as well. I THINK he was one of the people that was using this load with great results. I know it was not showing high pressure signs and was making good groups when I first started. Really liked the performance.

I referred to the factory ammo, was my "benchmark." Figured Norma could load ammo within spec and should be fine in any rifle. Apparently that is not their thinking. I don't have all the information that AI and others have at my disposal so I will just accept that fact.

I loaded up some 300NMs starting at 88grs and down I am seeing just under 2900FPS with the Hornady 225. No high pressure signs except for the small amount of primer flow around the firing pin. I think this is normal with AI unless you bush your bolts. Would like to hear from other AI 300NM shooters.

There is definitely a difference between the 92.6 and 88 gr of RL33. At 1200yrds I was at 8.5 mils, with the 88gr load I'm at 9.4 mils.

Steve

Yea I went up to 93 gr with 230 Berger’s with no pressure other than maybe a little flattened primer.

 

[Stevo3556]

PU,

What rifle are you shooting the 300NM in??

Wonder if the bearing surface is longer on the Hornadys?

My first 50 were 25 Hornady 225's and 25 Berger 230's. Again, no high pressure signs.

What MV are you seeing?

Steve

 

[Precision Underground]

I shot the Hornady 225's and Berger 230s. Its a Rem 700 Ultra Mag action with a Rock Creek barrel.

 

[Stevo3556]

Thanks PU.

 

[Precision Underground]

Thanks PU.

And you have stripped copper until NO copper is visible from the muzzle with no device on it right?

 

[Stevo3556]

Correct.

 

[Precision Underground]

Correct.

That's strange man. I can't imagine that much of a difference in pressure just from the barrel breaking in. I even jam mine at 92.5 grains and don't get pressure.

 

[Stevo3556]

I don't know what to say. I thought it was as well. I do know that AIs seem to need bushed bolts before others have issues.

What is you r MV?