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BoatTail
Well-Known Member
I did some load testing with RL-33 in the 28 Nosler. Honestly I was disappointed and a bit confused. The two loads I tested was 88 grs and 89 grs of RL-33 with 175 gr ABLR's. You will remember that I reported that Nosler is close to releasing their data and that they had indicated that 88 grs was the max with this powder and achieving a velocity near 3200 fps.
I'll list the data below but I did not reach Nosler's verbally shared velocity of close to 3200 fps. Instead achieving average velocities of 3086 and 3112 fps respectively. Perhaps I heard the Nosler Rep wrong. Still looking forward to Nosler's release of their load data for this round so I can validate what I'm seeing.
The Brass for both my loads show no ejector or extractor marks and the primers are still well round at the edge suggesting, at least in my rifle, the 88 gr load of RL-33 this is not the max. Group size was also a disappointment, 1.9375 and 1.4375 inches respectively.
The anomaly was that I also loaded test loads of 85, 86 and 87 grs just to work up to the the max load and make sure I did not blow my self up. Velocities were 2961, 3007 and 3048 fps. What was interesting was I shot these on to the same part of the target and these differently loaded rounds obtained a 3 shot group of 1/2 inch.
No, I can't explain it. I need the official Nosler Load data to decide on next steps. Unless, one of you have some great ideas.
I'll list the data below but I did not reach Nosler's verbally shared velocity of close to 3200 fps. Instead achieving average velocities of 3086 and 3112 fps respectively. Perhaps I heard the Nosler Rep wrong. Still looking forward to Nosler's release of their load data for this round so I can validate what I'm seeing.
The Brass for both my loads show no ejector or extractor marks and the primers are still well round at the edge suggesting, at least in my rifle, the 88 gr load of RL-33 this is not the max. Group size was also a disappointment, 1.9375 and 1.4375 inches respectively.
The anomaly was that I also loaded test loads of 85, 86 and 87 grs just to work up to the the max load and make sure I did not blow my self up. Velocities were 2961, 3007 and 3048 fps. What was interesting was I shot these on to the same part of the target and these differently loaded rounds obtained a 3 shot group of 1/2 inch.
No, I can't explain it. I need the official Nosler Load data to decide on next steps. Unless, one of you have some great ideas.
chuckhammer
Well-Known Member
Sounds like you have an accuracy node around 3k fps. Since that's around 7 Rem Mag ballistics for a 26-27" bbl, I bet there some more gas in your tank at 90+ grains to reach the next accuracy node.
Couple of questions:
1) What's your barrel length, contour, and twist?
2) How far off the riflings was your 175 ABLR load mentioned here?
3) 1x-fired or new brass? More than 1x-fired?
4) Neck sized only or FL resized?
5) Coated or uncoated bullets?
For a 28" bbl running a full-house charge of RL33 behind a 180 Berger Hybrid (for example) you should at least be able to match my 7mm Valkyrie (7-300WM improced wildcat) MV of 3250-3300 fps. And at a lower max pressure. Your case capacity is 7-9 grains more than mine.
Couple of questions:
1) What's your barrel length, contour, and twist?
2) How far off the riflings was your 175 ABLR load mentioned here?
3) 1x-fired or new brass? More than 1x-fired?
4) Neck sized only or FL resized?
5) Coated or uncoated bullets?
For a 28" bbl running a full-house charge of RL33 behind a 180 Berger Hybrid (for example) you should at least be able to match my 7mm Valkyrie (7-300WM improced wildcat) MV of 3250-3300 fps. And at a lower max pressure. Your case capacity is 7-9 grains more than mine.
BoatTail
Well-Known Member
Here are the details:
The barrel is attached to is a Borden Action, on a McMillan Graphite stock that I believe is pillar bedded. The barrel is free floating.
Based on what I'm seeing I may try taking the RL-33 load up another 2 - 3 grains to see what it does.
This was my assumption, that if the bullet is pushed at the similar speed out of a particular rifle with different powders, they will be similar in accuracy so long as the velocity spread of the load is similar.
That was not the case with earlier tests with the Retumbo and H1000. With Average velocities of 3173 and 3186 and Standard Deviations in velocity of 7.7 and 8.4 respectively the group sizes were 2.3 and 0.375 inches. This wasn't due to a flyer. On the Retumbo the shots were spread out. On the H1000 the were of course very tight shooting in similar spots on the target, with the same group size for both the 83 and 83.5 gr loads.
- The Barrel is a Hart #3 Contour, 25.5 inches long with a twist rate of 1 in 9.
- The 175 ABLR's are 50 thousands off the lands with a COAL of 3.51.
- The Brass is new 26 Nosler Brass with the neck opened up and then turned to a uniform 14 thousands thickness and then full length sized (I don't have a neck sizer) to ensure the bullets are held uniformly.
- The ABLR's are uncoated
The barrel is attached to is a Borden Action, on a McMillan Graphite stock that I believe is pillar bedded. The barrel is free floating.
Based on what I'm seeing I may try taking the RL-33 load up another 2 - 3 grains to see what it does.
This was my assumption, that if the bullet is pushed at the similar speed out of a particular rifle with different powders, they will be similar in accuracy so long as the velocity spread of the load is similar.
That was not the case with earlier tests with the Retumbo and H1000. With Average velocities of 3173 and 3186 and Standard Deviations in velocity of 7.7 and 8.4 respectively the group sizes were 2.3 and 0.375 inches. This wasn't due to a flyer. On the Retumbo the shots were spread out. On the H1000 the were of course very tight shooting in similar spots on the target, with the same group size for both the 83 and 83.5 gr loads.
chuckhammer
Well-Known Member
Okay, the 25.5" #3 contour explains the slightly lower speeds and the favoring of certain speed ranges. I agree with your observations on Retumbo vs. H1000 at nearly the same speeds. H1000 has been the single most preferred powder for this class of larger 7mms so I can't say I'm surprised by your barrel favoring it, although that is a huge difference in group size. Hard to attribute that to a change in burn rate alone. Jumping the ABLRs .050 doesn't sound bad to me since that bullet's ogive is not a long, 15-20 caliber secant VLD like a Berger or JLK. Coated vs. uncoated and throat length/bullet jump; I was digging for another explanation for the slower speeds. It appears that's more your barrel length, though. If you were shooting coated with a .100+ jump (Weatherby style), that would have been a culprit.
I'd say add powder in 1 grain increments until you find a true, hard max load. With a nearly straight-walled case like the 28 Nosler and a custom barrel like yours whose chamber is polished, you probably won't get sticky bolt lift until after your primers are fully flattened and cratered and you're also getting ejector marks on the case head. If that max load also shoots tiny groups I would be tempted to leave it alone, assuming the associated short case life (primer pockets lossening after maybe 3 firings) is acceptable to you. If not, back off until you're comfortable with the pressure signs and you find the most accurate speed for the harmonics of your #3 contour. 25.5" 28 Nosler shooting 175 ABLRs with a .050 jump in front of RL33.......I'd guess something like 3250-3300 is achievable as a hard max. Wish that case was in QuickLOAD so I could run it.
Does the .050 jump place the bullet shank-to-boat tail joint at or slightly above the bottom of the case neck?
BoatTail
Well-Known Member
Here is the picture of the 28 Nosler with the 175 gr ABLR load at 3.51 COAL for comparison. As you can see the junction reaches well below the neck giving full value of the shorter neck on this load.
I did shoot some test loads for the RL-33 and the data is shown below. As you can see I shot test loads of 90, 91 and 92 grs of RL-33. No ejector marks were seen on the 90 and 91 and only a slight mark was seen on the 92 gr load. Primers on all are still round on the edges.
The 90 gr load has just a little space with this cartridge configuration, the 91 is partially compressed or at least the case is full and no powder moves when shaken. The 92 gr version however is compressed. Unsure how much but did not cause a loading issue.
What was interesting was the group sizes did not tighten up with this configuration until I shot the 92 gr version. Then they came down to that 0.375 inch group size I also saw with the H1000 loads of 83 and 83.5. It appears my rifle likes maximum loads with this seating depth of the bullet.
Let me just state that the loads I list are well above what is likely going to be published as the max load for the 28 Nosler by Nosler. Nosler quoted over the phone that 88 grs was the max for RL-33 and I'm at 92 grs or 4 grs over, and for H1000, Nosler quoted 79 grs as max and I'm at 83 or 83.5 grs or 4 to 4.5 grs over.
As you can see velocity for the RL-33 at 92 grs averages 3262 fps as chuckhammer predicted. For the H1000 with loads of 83 and 83.5 grs the average velocities were 3162 and 3186 respectively.
What I was hoping to achieve a velocity somewhere between 3150 and 3200 fps and a group size of 1/2 inch or less at 100 yards with this rifle. Looks like I was able to reach that but at what appears to be max + loads of these powders that are well about what will likely be published.
What's next? I have two options: First, take those max + loads for RL-33 and H1000 and do one more set of load testing to verify the accuracy and go with one of them. Second, I could do load testing with the RL-33 at 90 and 91 grs and move the ABLR in and out to change the COAL to see if I can get the 0.375 inch group I got with the other max + loads. The advantage would be a load with 0 ejector marks. However, this will take some work as the next best grouping was the 90 gr load at 1.375 inches.
Maximum overall loaded length that Nosler published for the 28 Nosler is 3.340 inches. That's a jump in my rifle of 0.22 inches and just seems too far for good accuracy. Normally I load for a 15 thousands jump. I only went to 50 thousands because others loading ABLR's were finding the sweet spot for accuracy at about 50 thousands off the lands and I was trying to shorten my development time. But I may try it. Perhaps I will load some to the published COAL and some 15 Thousands off the lands and see what happens. Hope I don't burn my barrel out before I settle on a load!
I did shoot some test loads for the RL-33 and the data is shown below. As you can see I shot test loads of 90, 91 and 92 grs of RL-33. No ejector marks were seen on the 90 and 91 and only a slight mark was seen on the 92 gr load. Primers on all are still round on the edges.
The 90 gr load has just a little space with this cartridge configuration, the 91 is partially compressed or at least the case is full and no powder moves when shaken. The 92 gr version however is compressed. Unsure how much but did not cause a loading issue.
What was interesting was the group sizes did not tighten up with this configuration until I shot the 92 gr version. Then they came down to that 0.375 inch group size I also saw with the H1000 loads of 83 and 83.5. It appears my rifle likes maximum loads with this seating depth of the bullet.
Let me just state that the loads I list are well above what is likely going to be published as the max load for the 28 Nosler by Nosler. Nosler quoted over the phone that 88 grs was the max for RL-33 and I'm at 92 grs or 4 grs over, and for H1000, Nosler quoted 79 grs as max and I'm at 83 or 83.5 grs or 4 to 4.5 grs over.
As you can see velocity for the RL-33 at 92 grs averages 3262 fps as chuckhammer predicted. For the H1000 with loads of 83 and 83.5 grs the average velocities were 3162 and 3186 respectively.
What I was hoping to achieve a velocity somewhere between 3150 and 3200 fps and a group size of 1/2 inch or less at 100 yards with this rifle. Looks like I was able to reach that but at what appears to be max + loads of these powders that are well about what will likely be published.
What's next? I have two options: First, take those max + loads for RL-33 and H1000 and do one more set of load testing to verify the accuracy and go with one of them. Second, I could do load testing with the RL-33 at 90 and 91 grs and move the ABLR in and out to change the COAL to see if I can get the 0.375 inch group I got with the other max + loads. The advantage would be a load with 0 ejector marks. However, this will take some work as the next best grouping was the 90 gr load at 1.375 inches.
Maximum overall loaded length that Nosler published for the 28 Nosler is 3.340 inches. That's a jump in my rifle of 0.22 inches and just seems too far for good accuracy. Normally I load for a 15 thousands jump. I only went to 50 thousands because others loading ABLR's were finding the sweet spot for accuracy at about 50 thousands off the lands and I was trying to shorten my development time. But I may try it. Perhaps I will load some to the published COAL and some 15 Thousands off the lands and see what happens. Hope I don't burn my barrel out before I settle on a load!
Attachments
chuckhammer
Well-Known Member
You are getting some very consistent velocities with all three loads, 90, 91, and 92 grains. That's a testament to the quality of your barrel as well as your hand loading techniques. The ejector marks for the 92 grain load may disappear or fade somewhat if you move the COAL out to 3.540 or so. More room in the case but still not jammed into the riflings. If the groups hold you'll then have the best of all worlds. Running 3260 fps accurately with a 175 is quite admirable for a 25.5" sporter-weight barrel.
Nosler developing loads for this cartridge and bullet combination with a 3.340 COAL is pretty silly, in my opinion. SAAMI standards aside, do their rifles actually have a mag box that short?
Edited to correct 3.750 to 3.540 COAL.
Nosler developing loads for this cartridge and bullet combination with a 3.340 COAL is pretty silly, in my opinion. SAAMI standards aside, do their rifles actually have a mag box that short?
Edited to correct 3.750 to 3.540 COAL.
Last edited:
BoatTail
Well-Known Member
Well I thought I was done with load development however after sending 50 or so rounds down the barrel the velocity increased by 30 to 40 fps. My groups also opened up to 2 inches at 200 yards. I'm going to drop a grain or two and see if it comes back in to sub half minute it was before I started experimenting with other powders.
sheepaholic
Well-Known Member
Just reviving this thread to see what people settled on for powder and loaks and what velocities they're getting
I just got my old rem 700 7mm remember mag rechambered to 28 nosler so it only a 24" barrel I plan on rebareeling with a proof barrel but time will tell if I stay with the 24 or go to 26" I want to build a sporter weight rifle
I just got my old rem 700 7mm remember mag rechambered to 28 nosler so it only a 24" barrel I plan on rebareeling with a proof barrel but time will tell if I stay with the 24 or go to 26" I want to build a sporter weight rifle
D
Deleted member 46119
Guest
What bullet? COAL?
sheepaholic
Well-Known Member
I think I want to run the 175 eldx
mag box max length is 3.69
Eldx 175 grain max coal is 3.593 bullet to ching the lands
I have h1000 and retumbo powder to try
mag box max length is 3.69
Eldx 175 grain max coal is 3.593 bullet to ching the lands
I have h1000 and retumbo powder to try
D
Deleted member 46119
Guest
(bad joke warning) You would pick a bullet I don't have the specs on. How in considerate hahaha
I get all that. My testing for 175 Sierra GameKing (spbt) was with H1000 so it's just a bullet change except I don't have that bullet specs.
Can you measure some things for me?
Bullet length
Boat tail length
Boat tail diameter
