.... you are correct. I swear that last year when i was considering that bullet, Berger's official stance was 1:8 or faster.They actually recommend a minimum of 1-9 or faster.
Good to know. Thanks
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View thread Contact support.... you are correct. I swear that last year when i was considering that bullet, Berger's official stance was 1:8 or faster.They actually recommend a minimum of 1-9 or faster.
I think it was, but even their own stability calculator was showing 1/9 as sufficient. I'm sure this crowd is aware but Litz says faster twists aid stability and thus drag (especially entering transonic), which makes trajectories more predictable..... you are correct. I swear that last year when i was considering that bullet, Berger's official stance was 1:8 or faster.
Good to know. Thanks
i do have a spare barrel for it that is 1:8twist but dont anticipate needing it for a while.I think it was, but even their own stability calculator was showing 1/9 as sufficient. I'm sure this crowd is aware but Litz says faster twists aid stability and thus drag (especially entering transonic), which makes trajectories more predictable.
Have you tried truing the BC to match the actual MV and elevation you were using?I am not sure if this is something for a new thread or just keep it here...
As a refresher, i am shooting a 300PRC, 30" barrel, 1:9twist, Berger 230gr HOTM and my average MV is 2972. I previously used a LabRadar to get my MV and have since moved over to the Garmin Xero. My scope is a Vortex Razor Gen III 6-36x56.
I setup my scope with a mount that allows me to set a 800yd zero with enough elevation to reach out to 2200yards.
I was at the one-mile on Sunday and the gun performed well. However, the predicted elevation was 46MOA but the actual elevation as dialed in on the scope was about 43.5 MOA. I received my calculation for windage using a Kestrel, Vortex Fury HD AB, and an app on my phone and all provided similar predictions of 46MOA. When i calculated what the correction would be to true the MV, the difference was appx 70fps (initial MV was 2972 and calculated correction was 3042MV). I previously noticed a similar correction needed back in March on the same Rifle/Scope during my first ELR experience.
My question is whether or not this is normal. I am guessing that the need for a correction could be caused by a number of different factors including differences in how the scope measures and other factors.
In the end, what I am trying to understand is what could be the cause of the difference and whether or not to manually update my MV in my calculation.
are you running a G7, CDM or PDM?I am not sure if this is something for a new thread or just keep it here...
As a refresher, i am shooting a 300PRC, 30" barrel, 1:9twist, Berger 230gr HOTM and my average MV is 2972. I previously used a LabRadar to get my MV and have since moved over to the Garmin Xero. My scope is a Vortex Razor Gen III 6-36x56.
I setup my scope with a mount that allows me to set a 800yd zero with enough elevation to reach out to 2200yards.
I was at the one-mile on Sunday and the gun performed well. However, the predicted elevation was 46MOA but the actual elevation as dialed in on the scope was about 43.5 MOA. I received my calculation for windage using a Kestrel, Vortex Fury HD AB, and an app on my phone and all provided similar predictions of 46MOA. When i calculated what the correction would be to true the MV, the difference was appx 70fps (initial MV was 2972 and calculated correction was 3042MV). I previously noticed a similar correction needed back in March on the same Rifle/Scope during my first ELR experience.
My question is whether or not this is normal. I am guessing that the need for a correction could be caused by a number of different factors including differences in how the scope measures and other factors.
In the end, what I am trying to understand is what could be the cause of the difference and whether or not to manually update my MV in my calculation.
All I can say is those are incredible numbers. Berger's data shows they only got 2805fps with their max load of N565 (78.7, nearly a full grain more than your load). Yes, it was a 26" barrel vs yours at 30", but still that's a lot of difference. You're getting 167fps more than they did with 0.9gr less of the same powder, and truing a whopping 237fps higher at distance. Those numbers are higher than most 300 Normas are getting.I am not sure if this is something for a new thread or just keep it here...
As a refresher, i am shooting a 300PRC, 30" barrel, 1:9twist, Berger 230gr HOTM and my average MV is 2972. I previously used a LabRadar to get my MV and have since moved over to the Garmin Xero. My scope is a Vortex Razor Gen III 6-36x56.
I setup my scope with a mount that allows me to set a 800yd zero with enough elevation to reach out to 2200yards.
I was at the one-mile on Sunday and the gun performed well. However, the predicted elevation was 46MOA but the actual elevation as dialed in on the scope was about 43.5 MOA. I received my calculation for windage using a Kestrel, Vortex Fury HD AB, and an app on my phone and all provided similar predictions of 46MOA. When i calculated what the correction would be to true the MV, the difference was appx 70fps (initial MV was 2972 and calculated correction was 3042MV). I previously noticed a similar correction needed back in March on the same Rifle/Scope during my first ELR experience.
My question is whether or not this is normal. I am guessing that the need for a correction could be caused by a number of different factors including differences in how the scope measures and other factors.
In the end, what I am trying to understand is what could be the cause of the difference and whether or not to manually update my MV in my calculation.
I have never tried that. I will look into it.Have you tried truing the BC to match the actual MV and elevation you were using?
All I can say is those are incredible numbers. Berger's data shows they only got 2805fps with their max load of N565 (78.7, nearly a full grain more than your load). Yes, it was a 26" barrel vs yours at 30", but still that's a lot of difference. You're getting 167fps more than they did with 0.9gr less of the same powder, and truing a whopping 237fps higher at distance. Those numbers are higher than most 300 Normas are getting.
Custom drag model is the way to go but truing the BC for the distance your shooting is actually what the bullet is doing during flight vs making up a velocity number to coincide with your elevation adjustment.I have never tried that. I will look into it.
Is that the preferred approach over changing the MV?
All I can say is those are incredible numbers. Berger's data shows they only got 2805fps with their max load of N565 (78.7, nearly a full grain more than your load). Yes, it was a 26" barrel vs yours at 30", but still that's a lot of difference. You're getting 167fps more than they did with 0.9gr less of the same powder, and truing a whopping 237fps higher at distance. Those numbers are higher than most 300 Normas are getting.
300PRC one-mile at Clinton House SC | |||
# | Speed (FPS) | Δ AVG (FPS) | Time |
1 | 2996.8 | 23.9 | 11:06:16 AM |
2 | 2963.7 | -9.2 | 11:08:12 AM |
3 | 2961.6 | -11.4 | 11:10:46 AM |
4 | 2978.6 | 5.7 | 11:12:22 AM |
5 | 2974.2 | 1.3 | 11:13:57 AM |
6 | 2954.0 | -19.0 | 11:15:49 AM |
7 | 2961.6 | -11.4 | 11:24:44 AM |
8 | 2972.9 | 0.0 | 11:27:12 AM |
9 | 2979.9 | 7.0 | 11:28:59 AM |
10 | 2961.2 | -11.8 | 11:30:59 AM |
11 | 2991.5 | 18.6 | 11:33:08 AM |
12 | 2967.6 | -5.4 | 11:36:53 AM |
13 | 2984.6 | 11.7 | 11:40:33 AM |
AVERAGE SPEED | 2972.9 | ||
STD DEV | 12.4 | ||
SPREAD | 42.8 | ||
SESSION NOTE | 0.0 | ||
DATE | June 23, 2024 at 11:02 AM |
Before adjusting BC make sure your look angle and sight height is set correctly. Maybe do a tall target test to validate your scope!!
My preferred method is to put a cheap chrono behind the steel plate your shooting and at the distance you are shooting. I did this for my 6.5 CM and trued the BC to actual speeds. Now that I have the 300PRC new loads tested I might try the same thing at 1000yds next time I'm shooting.I have never tried that. I will look into it.
Is that the preferred approach over changing the MV?
Looks like they are jamming the lands. Lucky to get it out without powder spill into trigger area. What round and barrel/rifle?What’s your first thought on this factory ammo chambered and then ejected in a brand new barrel?
It looks like this all the way around and I can feel them with my fingernail.
It might be the lands easy way to see is seat a bullet deeper and retest to see but that honestly looks like a messed up throat300prc
I think he was looking for .....300prc
Factory barrel or custom barrel job?What’s your first thought on this factory ammo chambered and then ejected in a brand new barrel?
It looks like this all the way around and I can feel them with my fingernail.
2,761 fps average.I like 74.6 of N565
Max load 76.4 looks great, but depending on fps wants, I’d take accurate easy load that’s not pushing the limits of my gear.
What kind of speed you getting with this?
I didn't hit any pressure signs for any of those loads. the "max load" refers to what the manufacture websites recommend.Max load of 76.4 with Retumbo? I'm running 79.0gr with a 230 Berger and no pressure signs (they started around 80.0).
I was so excited when I saw that group. up until that point, I had shot about 100 rounds and the best groups were 0.7MOA. I began to think there might be something wrong with the barrel.Bottom Target G5 76.4
Yeah, but my point is that I don’t think that’s right. I have data sent straight from Berger for 230gr LRHT. With Retumbo their STARTING load isn’t much less than what you’re showing as “max”. For the 230, they start at 75.9 and go to a Max of 83.4. Obviously, your lighter 220gr bullet should allow the charges to be even higher. I started to bump into pressure at 80.0 with the 230, but you shouldn’t even be really in the ballpark at 76.4, especially with a 220.I didn't hit any pressure signs for any of those loads. the "max load" refers to what the manufacture websites recommend.
I used the data from Hodgon. Yes I have seen that table from Berger. Not sure who is correct so I used the lower ones.Yeah, but my point is that I don’t think that’s right. I have data sent straight from Berger for 230gr LRHT. With Retumbo their STARTING load isn’t much less than what you’re showing as “max”. For the 230, they start at 75.9 and go to a Max of 83.4. Obviously, your lighter 220gr bullet should allow the charges to be even higher. I started to bump into pressure at 80.0 with the 230, but you shouldn’t even be really in the ballpark at 76.4, especially with a 220.View attachment 8469117
I think I will pick that for my seating depth test. One question, is it necessary a bad thing to see the vertical strings in this group and the two next to it?I like 74.6 of N565
Max load 76.4 looks great, but depending on fps wants, I’d take accurate easy load that’s not pushing the limits of my gear.
What kind of speed you getting with this?
What ever you get from the good guys. It’s not crucialWhat’s the consensus on a barrels bore diameter for the 3PRC?