.28 Nosler Pressure

[GoneHuntingOutfitter]

I have a .28 Nosler that during break in showed no real brass pressures with 195 grain VLD until I got to 86 grains of RL 33. I am now getting pressure signs clear down to 81 grains. Sticky bolt occasionally, flattened primers and extractor marks. Speeds are way above stated in book. Having to load near minimum loads and that is fine. I'm just confused as to the reason for this. Barrel is de-coppered and no carbon buildup. Have also cleaned chamber in case it had oil.

Any Ideas????

 

[Smokinyotes]

I have not shot a 28 nosler but have you taken a fired case and slipped a bullet into it. If it wont go you have too much neck tension and your throat is too tight or your brass too thick.

 

[GoneHuntingOutfitter]

I checked several fired brass and neck tension seems normal. Test barrel in my book was a 26 inch 1/9 twist. My barrel is a 27 inch 1/8 twist. This in theory could push up pressure.

The part I can't understand is that during break in I went significantly higher charge without pressure. Brass were new at that time so I even purchased more brass to see if that made a difference now. The new brass are also showing the pressure. Gun shoots good and has the higher speeds with lighter loads, gues I shouldn't worry about it, but it still bothers me why I cant approach a max load????? Stumped!!!

Thanks for input!

 

[SansSouci]

I have a .28 Nosler that during break in showed no real brass pressures with 195 grain VLD until I got to 86 grains of RL 33. I am now getting pressure signs clear down to 81 grains. Sticky bolt occasionally, flattened primers and extractor marks. Speeds are way above stated in book. Having to load near minimum loads and that is fine. I'm just confused as to the reason for this. Barrel is de-coppered and no carbon buildup. Have also cleaned chamber in case it had oil.

Any Ideas????

If it's a Nosler rifle, call Nosler. Nosler has excellent customer service.

 

[Darkker]

I have a .28 Nosler that during break in showed no real brass pressures with 195 grain VLD until I got to 86 grains of RL 33. I am now getting pressure signs clear down to 81 grains. Sticky bolt occasionally, flattened primers and extractor marks. Speeds are way above stated in book. .

Any Ideas????

Don't watch brass for "signs" it is at best, better than nothing, but absolutely no more accurate than that.
The fact that you are getting faster than book velocity, is a clue. Your powders burning rate is much faster than what was tested in the manual. They're is a very real reason why all powders warm to that lot variations can swing by 10%.

 

[WildRose]

You might want to read this thread.

http://www.longrangehunting.com/forums/f28/28-nosler-195-berger-re33-testing-159270/

88gr seems to be where many if not most are hitting a pressure wall and some below that depending on how long your throat is.

 

[Darkker]

What I got from that threads OP, is exactly why I posted my response.

88gr of RE 33 is a Max charge for a 175gr class bullet, yielding @ 3200 fps.
Moving up 20gr in bullet weight, increasing the bearing surface of the bullet, keeping the same charge, and getting the same velocity?! That isn't a mysterious pressure wall, that's a bloody bomb! Unless waiting for Jesus to appear in toast, the "signs" all say that is grossly over pressure. The fact that the brass forgot to tell them earlier, shouldn't be stunning to anyone.

Back to this threads OP:
Book data gets shot in SAAMI minimum spec equipment, a mass produced rifle will have looser tolerances; meaning at the same start pressures, lower velocity. Ergo, there are no "fast barrels" there is powder with quicker burning rates than what was tested, and people over-pressuring things.

Quite some time ago, some of the major members of SAAMI were all sent reference powder, loaded carefully. All reported back the CUP of the reference ammo. The results of the study showed that CUP is inaccurate when used above about 45,000psi; inaccurate to the tune of 20,000 psi swings!!
All this was covered by any gun rag of the day, and why the industry moved away from it. Since Olin in the 50's, no one publishes brass specs anymore either. However in the day, they were using Olin C260 alloy. That alloy was spec'd to be hardened to a tensile strength of @ 75-80,000 psi.
In another thread on this board a Lapua rep confirmed Creed brass
In that thread it was claimed Lapua tests to 130% of cartridge MAP, where domestics are only 125%.... There is your 75-80,000 psi number before you'd see brass stretched.....

Technically trained people using reference crushers, and reference lots of powder; know that system is inaccurate. A random handloader using, blended canister grade powder, with unknown brass, and different unknown alloy primers in a mass produced rifle? Well that person isn't magical going to be suddenly more accurate for pressures divination, by staring at his fired case.

Believe what your chronograph told you, you are over pressure.

 

[Deleted member 46119]

I've been shooting xx-Nosler longer than most though I don't shoot them often. Perhaps there are shooters with more shots down range with xx-Nosler than I have but none with the variety of projectiles and data. I have now sold my 28-Nosler to build a new one with a Proof Research barrel.

Pressure and velocity rise after "break-in".

By break-in, I assume you mean something along the lines of:
1 shot, clean
1 shot, clean
2 shots, clean
2 shots, clean
3 shots, clean
3 shots, clean
5 shots, clean
10 shots, clean

or similar.

Questions for you:
1) how many shots since your last cleaning now?
2) do you clean the chamber?
3) did you get a different can of RL-33 with a different lot number?

Clean your bore AND chamber.

Do you have any form of bore scope? If you do, have a really good look at the neck and throat area. If not have a gunsmith with a good bore scope look over your chamber, neck and throat.

I have suspicions but need more information.

 

[GoneHuntingOutfitter]

Shot a minimum load of 85 grains RL-33 today and still seeing signs of pressure. Averaged 3200 FPS @5400 feet elevation with the 168 Accubond with a max deviation of 30 FPS. Considering my barrel length of 27" shilen, this don't seem to far out of line. Book shows 3035 on a 26 inch barrel.

Flattened Primers with occasional sticky extraction point.

Bullets drop into fired brass ok so don't think its a tight neck.

Going to look for a Carbon build up, but I really don't think thats the issue either. Still can't get past the fact that during break in the first 75 rounds I did not see the same pressure signs with loads a grain or two above max. The pressure issues started showing up after about 100 rounds fired.

I clean every 30-50 rounds after break in and take out all copper. Possible I have a carbon build up I am not seeing. Will run some Modern Spartan Systems Carbon destroyer through it and might even run a little JB compound through it. Then try again with a slower powder either US 869 or H50BMG.

Thanks for all the replies. We will see what happens.

 

[GoneHuntingOutfitter]

Break in was something similar to what you mentioned. Cleaning every shot for first 10 or until it starts cleaning easily then every 3-5 until I hit 30+ rounds.

Barrel was last cleaned about 50 rounds ago before I shot today.

I cleaned it today both chamber area, lugs and bore. It cleaned easily and I did not remove every bit of copper as I was in a hurry.

I did not have any black after first 5 patches and was very little blue when I finished after 15 patches. Started with Hoppes and finished with Sweets.

Put some bore oil in and removed then cleaned the Chamber area to assure nothing got in that area with a mop and chamber lug cleaner.

I have only been using Nylon brushes, but I am going to run copper brush through tonight when get home. A carbon build up is about the only thing I can come up with. Don't expect that to be it though.

Placed a small amount of grease on back of lugs then went and shot. . See results in my other post above.

 

[coyotezapper]

What I got from that threads OP, is exactly why I posted my response.

88gr of RE 33 is a Max charge for a 175gr class bullet, yielding @ 3200 fps.
Moving up 20gr in bullet weight, increasing the bearing surface of the bullet, keeping the same charge, and getting the same velocity?! That isn't a mysterious pressure wall, that's a bloody bomb! Unless waiting for Jesus to appear in toast, the "signs" all say that is grossly over pressure. The fact that the brass forgot to tell them earlier, shouldn't be stunning to anyone.

Back to this threads OP:
Book data gets shot in SAAMI minimum spec equipment, a mass produced rifle will have looser tolerances; meaning at the same start pressures, lower velocity. Ergo, there are no "fast barrels" there is powder with quicker burning rates than what was tested, and people over-pressuring things.

Quite some time ago, some of the major members of SAAMI were all sent reference powder, loaded carefully. All reported back the CUP of the reference ammo. The results of the study showed that CUP is inaccurate when used above about 45,000psi; inaccurate to the tune of 20,000 psi swings!!
All this was covered by any gun rag of the day, and why the industry moved away from it. Since Olin in the 50's, no one publishes brass specs anymore either. However in the day, they were using Olin C260 alloy. That alloy was spec'd to be hardened to a tensile strength of @ 75-80,000 psi.
In another thread on this board a Lapua rep confirmed Creed brass
In that thread it was claimed Lapua tests to 130% of cartridge MAP, where domestics are only 125%.... There is your 75-80,000 psi number before you'd see brass stretched.....

Technically trained people using reference crushers, and reference lots of powder; know that system is inaccurate. A random handloader using, blended canister grade powder, with unknown brass, and different unknown alloy primers in a mass produced rifle? Well that person isn't magical going to be suddenly more accurate for pressures divination, by staring at his fired case.

Believe what your chronograph told you, you are over pressure.

+1. Read and use this info.

 

[coyotezapper]

I have a .28 Nosler that during break in showed no real brass pressures with 195 grain VLD until I got to 86 grains of RL 33. I am now getting pressure signs clear down to 81 grains. Sticky bolt occasionally, flattened primers and extractor marks. Speeds are way above stated in book. Having to load near minimum loads and that is fine. I'm just confused as to the reason for this. Barrel is de-coppered and no carbon buildup. Have also cleaned chamber in case it had oil.

Any Ideas????

What is your freebore??

 

[Oakcreek]

I also have a 28 nosler that showed pressure signs about 100 rounds after break in. I shoot the 195 Berger's with reloader 33 oal 3.730 so it is throated long. I shot a 3 shot group of .605 at 400 yards with 88.3 grains. Now I'm at 85 grains because of pressure. I would also like to know what caused the problem. I had to pull alot of bullets. I'm not sure what changed. I have never had this happen before on any of my other guns. The temperature did get colder when this started to happen. My problem sounds exactly like this first post.

 

[Oakcreek]

My rifle is a Remington 700 Krieger barrel if that makes a difference. New nosler brass. 195 berger bullets. CCI 250. reloader 33 powder.