.28 Nosler Pressure

[coyotezapper]

I was out this weekend with my new 28 nosler doing some load testing with the 195's. Temp was 34f 65% humidity 2000ft elevation DA 1400. I started at 83gr of rl 33 and worked up to 88. What I found was at 84.5gr I seen slight ejector marks and velocity was 3020. Keeping a close eye on case expansion and bolt lift I continued with my load testing. I found that case expansion bolt lift and the ejector marks did not change at all out to 88gr with a velocity of 3190. My best groups were around 87 87.5 and 88 with a ladder test at 300yards with a 1" group. I have a 27 1/4" benchmark on a trued 700 with greyboe stock trigger tech trigger. Coal is 3.745" that's .015" jump. So I'm not sure what to take on the pressure signs. I'm not sure if it's because of the soft nosler brass giving the pressure signs at such a low powder charge and not making any difference as I climb 5 grains in charge. Any thoughts?

Quickload shows the pressure to be around 75K with 88 grain loading. If I knew your case capacity I could get this prediction closer. 3000-3050 fps will give you everything you need and will not be over pressured and will be easier on your barrel life.

 

[HellsCanyon]

Bumping this one to the top. I had a similar experience with a customers 28 a few weeks back. It came back to crappy Nosler brass. Was able to run up to 82 grains of retumbo on virgin brass with no issues, then once brass got 3 firings on it I started popping primers, down to 79 grains. Not a humidity/powder related problem. Finally settled on 77 grains Retumbo with virgin brass, and 76 grains on 1X+ fired brass. Yielded 2980fps with an ES of <15fps between virgin and 1X fired brass, 1/3 MOA consistently. The virgin brass absorbs more energy to form to the chamber walls. Annealing after EVERY firing really helps here. The case necks are work hardening, and gripping the bullet harder even with a measured .002" neck tension. They work hardened to the point they would give WIDE inconsistent seating depths (.015"ish) measured from ogive. Started annealing and this problem went away, lower ES's came back, and pressure signs went away. This was with Fed magnum primers, Nosler brass, 195 Bergers and Retumbo on a finished 25" Rock Creek blank.


Going out to test some RE33 here shortly. Going to start at 84 grains and go up to 88 and see what nodes I find.

Mike

 

[coyotezapper]

Bumping this one to the top. I had a similar experience with a customers 28 a few weeks back. It came back to crappy Nosler brass. Was able to run up to 82 grains of retumbo on virgin brass with no issues, then once brass got 3 firings on it I started popping primers, down to 79 grains. Not a humidity/powder related problem. Finally settled on 77 grains Retumbo with virgin brass, and 76 grains on 1X+ fired brass. Yielded 2980fps with an ES of <15fps between virgin and 1X fired brass, 1/3 MOA consistently. The virgin brass absorbs more energy to form to the chamber walls. Annealing after EVERY firing really helps here. The case necks are work hardening, and gripping the bullet harder even with a measured .002" neck tension. They work hardened to the point they would give WIDE inconsistent seating depths (.015"ish) measured from ogive. Started annealing and this problem went away, lower ES's came back, and pressure signs went away. This was with Fed magnum primers, Nosler brass, 195 Bergers and Retumbo on a finished 25" Rock Creek blank.


Going out to test some RE33 here shortly. Going to start at 84 grains and go up to 88 and see what nodes I find.

Mike

This is the velocity I got - 2969 fps at 64.7K pressure using Retumbo. RL33 will give you a little more velocity. Retumbo was more accurate in the one rifle I tested.

 

[squeeeeze]

Tagging in, just got my build started.

 

[HellsCanyon]

This is the velocity I got - 2969 fps at 64.7K pressure using Retumbo. RL33 will give you a little more velocity. Retumbo was more accurate in the one rifle I tested.

RL33 yesterday tested really well for me. Going back to test today. 26.75" barrel was getting 3000-3080 fps from 86-88 grains. Punched a <.2 3 shot group at 87 grains. Going back to test 86.7, 86.9, 87.1 and 87.3 and find the limits of the node. 2.998" COAL measured from ogive (.020" off the lands).

I think if you have the barrel length, RL33 is the way to go, and don't push it too hard and chase too much speed. The Nosler brass doesn't like it. I've talked with two industry "names" whom I trust and they've had the same issues with brass after 3-5X firings.

Mike

 

[LongBomber]

I have seen the exact same thing in my 26 nosler, which makes the brass issue the likely cause. I ran a box of factory 140gr accubond load (88gr of us869), no pressure signs and easy case extraction. By the third loading with the factory load duplicated case extraction was very difficult and accuracy was way off. Wish I would have shot a few over a chrony to see what the speeds went to. Turned the case necks (more of a skim, just cleaned them up) and annealed. No pressure signs on the first loading accuracy was where it was, the second loading almost needed a hammer to extract the case.

I would like to try forming some from remington ultra-mag brass or maybe from some of the bertram edge brass I have. See if brass will make a difference.

 

[cgordon]

The guys that are getting pressure signs after 3-5 reloads are you full length resizing? I assume you are. I am on my 3rd reload now with my 28 and I haven't seen them getting harder to extract or anything. I'm running 85.7gr rl33 195's velocity is 3120fps from a 27 1/4" barrel. I do have and hve always had slight ejector marks but it didn't matter if I loaded 82 or 87 it had the same marks. I would be nice to see lapua or Norma make some of the Moslem stuff. I'm not sure if that can or will ever happen. I don't have a anealer machine and haven't anealed before. I'm worried if I just wing it with a drill socket and torch I'll mess my brass up.

 

[Kmccord]

The guys that are getting pressure signs after 3-5 reloads are you full length resizing? I assume you are. I am on my 3rd reload now with my 28 and I haven't seen them getting harder to extract or anything. I'm running 85.7gr rl33 195's velocity is 3120fps from a 27 1/4" barrel. I do have and hve always had slight ejector marks but it didn't matter if I loaded 82 or 87 it had the same marks. I would be nice to see lapua or Norma make some of the Moslem stuff. I'm not sure if that can or will ever happen. I don't have a anealer machine and haven't anealed before. I'm worried if I just wing it with a drill socket and torch I'll mess my brass up.

I have not annealed brass, but found this on YouTube search with a torch and water no drill or amachine, just using bare hands.

[ame]https://youtu.be/Url1QguVhHE[/ame]

 

[coyotezapper]

The guys that are getting pressure signs after 3-5 reloads are you full length resizing? I assume you are. I am on my 3rd reload now with my 28 and I haven't seen them getting harder to extract or anything. I'm running 85.7gr rl33 195's velocity is 3120fps from a 27 1/4" barrel. I do have and hve always had slight ejector marks but it didn't matter if I loaded 82 or 87 it had the same marks. I would be nice to see lapua or Norma make some of the Moslem stuff. I'm not sure if that can or will ever happen. I don't have a anealer machine and haven't anealed before. I'm worried if I just wing it with a drill socket and torch I'll mess my brass up.

Nosler brass is made by Norma.

This is interesting what is happening. I have used Nosler brass with both my 7STW and 7RUM and had zero issues. You all may be running them a little warm. I have learned that pressure indicators show long after you are over pressured. Its best to judge pressure by the velocity you are getting. I have learned all of this by using a Oehler 43PBL by measuring pressure and velocity at the same time.

 

[cgordon]

Would it be possible to make 28 brass from say a 7mm ultra using a 28 die and trimming to length and trim the neck thickness? Has anyone tried it?

 

[coyotezapper]

Would it be possible to make 28 brass from say a 7mm ultra using a 28 die and trimming to length and trim the neck thickness? Has anyone tried it?

What do you think you would gain?

 

[cgordon]

What do you think you would gain?

Harder brass. Nosler brass is soft

 

[coyotezapper]

Harder brass. Nosler brass is soft

R-P brass is a major step down IMO. In my 7STW R-P was ok but in 7RUM it was not good at all and very inconsistent. Maybe a bad lot but it was not good.

Like I stated above I think you are just running your loads a little warm. A deer or an elk is not going to care whether the load started out at 3000 fps or 3100 fps. Also if run loads near 70K your barrel life will be very short. My 7STW and 7RUM ran right at max pressures with no issues using Nosler brass.

 

[Coyote Dan]

I see others are having problems too, thought I was going nuts, love my 28 Nosler, till ran out of R-33 , new batch is way to hot, went from 85 to 81gr. Lost 3-4 moa elevation at a mile, found some new R-33 again its a little better not much, 82gr with 195s and 84grs with 180s, half a grain more and extractor marks again, finally got it to shoot again but have not had a chance to try long range yet. When I first got it she was idling 3000 with 195s and 3100 with 180s then it sped up after break in to 3125 with 195s same load till ran out of my first batch of powder. Now my cousins giving me crap cause hes pushing his 7 mag. right up close to my 28. Im nuts about keeping my guns clean. Don't know if I like nosler brass much, doesn't seem to last anywhere as long as Lapua brass on my other guns. Got a lot a money in this gun, very frustrating . Im no expert so its hard to understand whats going on , why lots of powder can be so different or even bullets , I have had lots of bullets be 5-25 thousands shorter in length , don't get that either , just to picky I guess.

Safe Shooting everyone,

Danny