300 PRC update

Merovingian

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Originally RCC had my spec at 0.017" neck thickness. But brought down to 0.014". I don't plan to neck turn
17 would have been right at 342? Odd that they would want to run it that tight. I think you made the right decision.
 

Merovingian

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My neck thickness will be at .014 i will be using 230 A-Tip. Will tell you what happens later this week i will begin testing. Try different neck bushing put more pressure on it or try bumping powder up untill you reach max pressure. I find my node always right under max pressure. But again be careful, H1000 max is right about 80.6gr with 230 A tip and hornady brass and ES was under 10FPS. I’m at 1100 feet 40 F temp.
Thanks for the suggestion. Apparently wasn't out in left field turning to 14. May just still fighting the crappy Hndy brass. H1K peaked for me at 77.9/2890, backed it down to 77.6/2870 (27" 1:9 Suppressed). There's a CBTO change there too because shorter OAL's were running better. I've got 10 now at 77.3 that I'm pushing back up to .020 & .030 off to see what happens. Also rolled up a 215 BHT ladder. If I can't get 230's to calm down, and the 215's are too slow to make up the difference, I may have to join you at $0.90 a pop.
 

LakuNoc

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Thanks for the suggestion. Apparently wasn't out in left field turning to 14. May just still fighting the crappy Hndy brass. H1K peaked for me at 77.9/2890, backed it down to 77.6/2870 (27" 1:9 Suppressed). There's a CBTO change there too because shorter OAL's were running better. I've got 10 now at 77.3 that I'm pushing back up to .020 & .030 off to see what happens. Also rolled up a 215 BHT ladder. If I can't get 230's to calm down, and the 215's are too slow to make up the difference, I may have to join you at $0.90 a pop.
I think reason i can push 230 A-Tips faster and go up to 80.6 gr with H1000 untill i hit maximum pressure is because i coat them with Hex boron Nitride (hBN).
 

dukerugger25

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Got the 300PRC to the range finally for ladder testing. Used 225gr ELDM'S, RL-26 and 215m primers. Barrel is 26" and 9.5tw.

Found two nodes: 74.1gr - 2856fps, 76.0gr - 2937fps. Slight ejector swipe at 77gr (2974fps), primers were still round and no noticeable increase in bolt lift. Stopped there. I will load up some for seating at both nodes and test accuracy in a few weeks. Still have a late season archery tag to fill.

Factory 225 loads were shooting at 2880fps for comparison.
 

Rocketmandb

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Got the 300PRC to the range finally for ladder testing. Used 225gr ELDM'S, RL-26 and 215m primers. Barrel is 26" and 9.5tw.

Found two nodes: 74.1gr - 2856fps, 76.0gr - 2937fps. Slight ejector swipe at 77gr (2974fps), primers were still round and no noticeable increase in bolt lift. Stopped there. I will load up some for seating at both nodes and test accuracy in a few weeks. Still have a late season archery tag to fill.

Factory 225 loads were shooting at 2880fps for comparison.
What contour and manufacturer on the barrel?
 

waveslayer

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Got the 300PRC to the range finally for ladder testing. Used 225gr ELDM'S, RL-26 and 215m primers. Barrel is 26" and 9.5tw.

Found two nodes: 74.1gr - 2856fps, 76.0gr - 2937fps. Slight ejector swipe at 77gr (2974fps), primers were still round and no noticeable increase in bolt lift. Stopped there. I will load up some for seating at both nodes and test accuracy in a few weeks. Still have a late season archery tag to fill.

Factory 225 loads were shooting at 2880fps for comparison.
Where are you finding the RL 26 at, it is like a Unicorn...
 

pengilly

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If you want more MV why not just buy a longer barrel? We're getting ~3000 out of factory ammo.
Im getting 3000 FPS out of factory 225
The next thing i need to do is double check my chrony with another one
28" Bartlien 9:1. My 212 load is one ragged hole 3210 fps low SD I ran my load on QL with an H2O case capacity and it was just over SAAMI max @ 66,000 psi i can load it down but it shoots so good and im in a node.
 
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Dippy

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Im getting 3000 FPS out of factory 225
The next thing i need to do is double check my chrony with another one
28" Bartlien 9:1. My 212 load is one ragged hole 3210 fps low SD I ran my load on QL with an H2O case capacity and it was just over SAAMI max @ 66,000 psi i can load it down but it shoots so good and im in a node.
I’m looking forward to building the 300 PRC hunting rifle with the 28” bartlein 9 twist I have in order. Built for shooing 212 eld-x bullets.
 
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LakuNoc

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What Muzzle Brake are you guys running on your 300 PRC?
Thank you
 

NVScout

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#BRAKESAREFORBITCHES HAHAH ! Mine is 10.2 loaded and after about 20 rnds you definitely start to feel it. Still plan on shooting her bare until the ultra 7 gets out of jail.
 

b2lee

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I wanted to post this little tidbit of information on my reloading. Yesterday I got around to reloading 21 pieces of brass I shot the other day on a load work up. 1 piece was a retail round, so this would be the first loading. I resized and trimmed to 2.565". I then resized the other 20 pieces and went to trim....and nothing. I mic'd and found that I had zero growth on these 5x fired brass. Primer pockets were still very snug as well.

Even the piece marked at 80gr of N565 had zero growth and the primer pocket had the same snug feel on seating a new Federal GMM #210. Originally I trimmed 50 pieces of new brass, loaded and shot....and on the first reload I had about 8-10 thou of growth....but nothing since then.

Also, after the next firing...I will most likely have to anneal them. However, they still seem to have consistent neck tension.

And another thing. Zero'd the rifle using 230gr A-Tips and Vihtavuori N565 on a 70F day. This morning it was 18F. My shots were within an error factor that could just be me and the cold. MV averaged with 20fps difference than the 70F day with and SD of 8.
 

gnochi

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I wanted to post this little tidbit of information on my reloading. Yesterday I got around to reloading 21 pieces of brass I shot the other day on a load work up. 1 piece was a retail round, so this would be the first loading. I resized and trimmed to 2.565". I then resized the other 20 pieces and went to trim....and nothing. I mic'd and found that I had zero growth on these 5x fired brass. Primer pockets were still very snug as well.

Even the piece marked at 80gr of N565 had zero growth and the primer pocket had the same snug feel on seating a new Federal GMM #210. Originally I trimmed 50 pieces of new brass, loaded and shot....and on the first reload I had about 8-10 thou of growth....but nothing since then.

Also, after the next firing...I will most likely have to anneal them. However, they still seem to have consistent neck tension.

And another thing. Zero'd the rifle using 230gr A-Tips and Vihtavuori N565 on a 70F day. This morning it was 18F. My shots were within an error factor that could just be me and the cold. MV averaged with 20fps difference than the 70F day with and SD of 8.
Which brass did you end up using? Hornady? And that’s great to know about the N565.
 

b2lee

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This test was on the Hornady Brass I got back before I even had my rifle. I will be getting RCC and ADG Brass....well...RCC Soon...and ADG when it is released.

On the difference in MV...Those numbers are less than the 0.5fps per degree F I was accustomed to getting with other stable powders.... does that 'jive' with other peoples beliefs/data on what they get with their stable powders?

Also, on the 70F day the ammo set out and became 'room temp' but not in the sun for about 30mins...under a covered shooting bench. On the 18F shooting....it was in the trunk of the car at about half an hour at maybe 60F...and then under the same covered bench at 18F fairly shielded from the wind...for a good 30mins before I got to shooting. I've always wanted to do a test of putting some rounds in dry ice and then shooting...and putting some in my food dehydrator I use to dry out my brass....and take a temp reading at about 130F before shooting...and measuring the MV difference.
 

b2lee

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Another note.... N560 is not temp stable...and neither is N570....but N565 is and is marketed as very temp stable...which I have seen.

I do have a question that probably needs to be asked in a different thread...but what is the temp stability of something like a Magneto Speed V3? If more than I expect...how could I analyze the difference in MV and attribute it to powders/primers or to the measuring equipment.

But...if I am close enough in MV to actually have to ask that question...my load is probably good to go no mater what.

/end OCD Rabbit Hole
 
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gnochi

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Assuming the plastic that the magnetospeed sensors are mounted to is something along the lines of 30% glass filled Nylon 66 (I haven’t found pictures of mold markings on the part but that would be PA66GF30 if anyone has one disassembled):
  • Coefficient of linear thermal expansion ~50 microns per meter Kelvin (0.005% per degC, a hair under 0.0028% per degF)
  • 3000fps nominal
  • -20 to 130F ammo temps
There may end up being some differential signal lag, etc., but mechanically the worst you can end up with for a time-vs-distance measurement is 0.084 FPS per degree and an extreme spread of measurements of 13fps across those ranges, compared to 75fps for the powder assuming your numbers hold.

This is also consistent and can be corrected for in the magnetospeed itself (if they bothered) and your dope (which you need regardless for powder trueing), so I think it’s fair to assume that temperature variance of the magnetospeed itself can be ignored.
 

jasent

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I have measured h1000 at .21 fps per degree f
This was with a 338/375 ruger improved and 243 win and 338 lapua. Using a temp gun to check ammo temps and coolers both warm and cold. Jme
 

pengilly

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Of course, but most calibers for the exception of an extreme load will show a roundabout average.

bench
1200 -1500 is what I was told by a barrel manufacturer. That he told me a story of a test where a 338 Lapua achieved around 34-3500 round life by loading at 2400 fps. So your load and how you shoot have a huge effect on barrel life
 
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benchmstr

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Mine has eaten nothing but Hornady factory loads of 225eldm. I wasn't sure if I was going to like the caliber and didn't want to invest in any reloading equipment for the caliber...so i just went factory.

I will build my load with the new barrel though...

In all honesty, i just want to hit about 2900-2950 and retain the same accuracy, but more consistent velocity than the hornady.

bench
 

Dippy

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Bottom metal ordered for my 2nd 300 PRC hunting rifle. Accurate mag bottom metal 3.850 CID mag. Going to have Dave Tooley spin up a 28” finish 5R sendero profile fluted bartlein once it arrives. They told me 6 months, it’s been 3... upgrade maybe 300 win mag M700 deer gun.

Good thing I have my first 300 PRC Tooley Custom Rifle to keep me simmered down! Optics getting ordered got that one on black rifle Friday!
 

LakuNoc

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I finally got my RCC brass chambers in 300 PRC. Just to be clear i payed for my brass around $600 for 100 pieces. I took random 10 pieces of brass and did measurements.
As i stated before i will perform full review of RCC brass this is part 1 and part 2 will be coming after i do all testing on range.
I used Mitutoyo ball style Micrometer, and results were amazing.
Neck thickness of brass was within in 0.0005, 0.0005, 0.001, 0.0005, 0.001, 0.001, 0.0005, 0.001. 0.0005, 0.001. Better than Lapua brass that i use in my 6.5CM.

IMG-2359.jpg
After neck thickness i weighted 10 pieces of brass. Using Lab scale FX-120i.
Brass was very close in weight 288.46gr 288.44 288.35 287.43 288,41 288.33 287,89 288.46 287.95 288.40.
IMG-2362.jpg
Then i filled brass with H2O to measure internal case capacity and to see how consistent it was be using same scale. I think this is very important at least to me because i shoot long distance. This has big impact on Extreme Spread internal volume of brass is something that can be more than 10-20 GN that i witness in my 338Lapua brass which is consider one of best out there in my opinion.
Results came out again very consistent and close to each other.
Internal case H2O capacity: 90.98 90.91 90.81 89.90 90.80 90.91 90,82 90.99 90.98 90.95
So far I'm liking the results its very good.
IMG-2363.jpg
IMG-2364.jpg
Last in this part1 but not least i did perform Concentricity of brass i don't like to do this until i load ammo and do Concentricity of loaded ammo. Results were okay i can't say they were perfect because i like all my rounds to be within one thousands of and inch. I can't judge this part yet i want to fire brass at least once and load full ammo than do Concentricity on loaded ammo.
But results were okay no to write out all Measurements . Concentricity was 6 cases within in one thousands of and inch and 4 causes were 2 to 2.5 thousands of an Inch runout.
IMG-2361.jpg

Part 2 will be:
-Load development to see how low of and extreme spread and SD i can get using RCC brass, H1000, BR-2 primers and 230gr A-Tip
-How many firings primmer pocket will hold with 80gr of H1000
-Will load case to maximum to see what kind of pressure it will hold comparing to Hornady brass which now is maxed out at 80.6Gr of H1000.

This is my test I'm no expert but i love long distance/precision shooting and as i said i payed for all this stuff with my own $$$. Just want to give something back because i learned a lot on here about 300 PRC.
 
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Rocketmandb

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Part 2 will be:
-Load development to see how low of and extreme spread and SD i can get using RCC brass, H1000, BR-2 primers and 230gr A-Tip
-How many firings primmer pocket will hold with 80gr of H1000
-Will load case to maximum to see what kind of pressure it will hold comparing to Hornady brass which now is maxed out at 80.6Gr of H1000.

This is my test I'm no expert but i love long distance/precision shooting and as i said i payed for all this stuff with my own $$$. Just want to give something back because i learned a lot on here about 300 PRC.
I highly recommend starting with a much lower powder charge and working up. I think somewhere in this thread someone did an H20 measurement of Hornady brass, and I seem to remember it being a decent bit higher.
 

jwknutson17

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I had slight starting signs of pressure at 80gr of h1k with 215 bergers in hornady brass. For what it's worth.
 
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goinghunting

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I finally got my RCC brass chambers in 300 PRC. Just to be clear i payed for my brass around $600 for 100 pieces. I took random 10 pieces of brass and did measurements.
As i stated before i will perform full review of RCC brass this is part 1 and part 2 will be coming after i do all testing on range.
I used Mitutoyo ball style Micrometer, and results were amazing.
Neck thickness of brass was within in 0.0005, 0.0005, 0.001, 0.0005, 0.001, 0.001, 0.0005, 0.001. 0.0005, 0.001. Better than Lapua brass that i use in my 6.5CM.

View attachment 7183944
After neck thickness i weighted 10 pieces of brass. Using Lab scale FX-120i.
Brass was very close in weight 288.46gr 288.44 288.35 287.43 288,41 288.33 287,89 288.46 287.95 288.40.
View attachment 7183975
Then i filled brass with H2O to measure internal case capacity and to see how consistent it was be using same scale. I think this is very important at least to me because i shoot long distance. This has big impact on Extreme Spread internal volume of brass is something that can be more than 10-20 GN that i witness in my 338Lapua brass which is consider one of best out there in my opinion.
Results came out again very consistent and close to each other.
Internal case H2O capacity: 90.98 90.91 90.81 89.90 90.80 90.91 90,82 90.99 90.98 90.95
So far I'm liking the results its very good.
View attachment 7183988
View attachment 7183989
Last in this part1 but not least i did perform Concentricity of brass i don't like to do this until i load ammo and do Concentricity of loaded ammo. Results were okay i can't say they were perfect because i like all my rounds to be within one thousands of and inch. I can't judge this part yet i want to fire brass at least once and load full ammo than do Concentricity on loaded ammo.
But results were okay no to write out all Measurements . Concentricity was 6 cases within in one thousands of and inch and 4 causes were 2 to 2.5 thousands of an Inch runout.
View attachment 7183994

Part 2 will be:
-Load development to see how low of and extreme spread and SD i can get using RCC brass, H1000, BR-2 primers and 230gr A-Tip
-How many firings primmer pocket will hold with 80gr of H1000
-Will load case to maximum to see what kind of pressure it will hold comparing to Hornady brass which now is maxed out at 80.6Gr of H1000.

This is my test I'm no expert but i love long distance/precision shooting and as i said i payed for all this stuff with my own $$$. Just want to give something back because i learned a lot on here about 300 PRC.

What concentricity tool is that?
 

LakuNoc

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I highly recommend starting with a much lower powder charge and working up. I think somewhere in this thread someone did an H20 measurement of Hornady brass, and I seem to remember it being a decent bit higher.
Will do thank you
 

LakuNoc

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What concentricity tool is that?
Here is the link
 

JohnK454

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Your tray Looks like some I have from a medical lab - they originally held vials for blood. They work very well!
 
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Merovingian

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Anybody had a case separation yet? (See my previous post questioning pressure signs) Hit 4X on some Hornady last weekend, didn't notice till last night that I had 7 definitely ringed/toast, and about 15 others that are now very suspect which is close to a 30% failure rate on that lot and I'm not pushing them near what some of you guys are. Dropped the gun off this morning to have the chamber, bolt, chassis, looked over in detail. I/We would really would like to see pics from anyone of 2x, 3x fired Hndy brass bases if anyone has time. Thx.
 

jwknutson17

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Anybody had a case separation yet? (See my previous post questioning pressure signs) Hit 4X on some Hornady last weekend, didn't notice till last night that I had 7 definitely ringed/toast, and about 15 others that are now very suspect which is close to a 30% failure rate on that lot and I'm not pushing them near what some of you guys are. Dropped the gun off this morning to have the chamber, bolt, chassis, looked over in detail. I/We would really would like to see pics from anyone of 2x, 3x fired Hndy brass bases if anyone has time. Thx.
I can get you pics on Monday. I have about 20 pieces that the primer pockets are already toast from a hot load early on in the barrel. I've backed down since and have 7x on about 80 pieces of Hornady with still a decently stout load.
 

Rocketmandb

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Anybody had a case separation yet? (See my previous post questioning pressure signs) Hit 4X on some Hornady last weekend, didn't notice till last night that I had 7 definitely ringed/toast, and about 15 others that are now very suspect which is close to a 30% failure rate on that lot and I'm not pushing them near what some of you guys are. Dropped the gun off this morning to have the chamber, bolt, chassis, looked over in detail. I/We would really would like to see pics from anyone of 2x, 3x fired Hndy brass bases if anyone has time. Thx.
I've got a bunch of ~5x fired brass. No signs of case separation. My issue was always primer pockets giving out. This is why I moved to fire-formed 8x68S
 

Merovingian

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Thx guys for any pics. Much appreciated. Forgot to add: Nailed down two loads. 230 BHT's / .030 off / 77.4 H1K / 2860 - 21 ES / .496 @ 200 +++ 215 BHT's / .020 off / 79.6 H1K / 2898 - 17 ES / .31 vertical + 1.3 right horizontal string @ 200 (got rushed because some instructor showed up wanting to start a class and I strung em...yeah yeah...excuses are like aholes….but the bullet width vertical at 200 made my day. Best vert spread of 4 pills and 40 + combos.
 

b2lee

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I'm interested in what you guys are trimming at. I trim at 2.565" and I got zero growth on the last few reloadings. I know that is the Hornady spec but I've seen Hodgdon and others list 2.850" as trim length on their webapp and that is the Max case length.

I'll try and get out to the range and make some more empty brass...but dang do I hate the cold. I'll take pics of my brass for a 6x reload when I can.
 

waveslayer

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I'm interested in what you guys are trimming at. I trim at 2.565" and I got zero growth on the last few reloadings. I know that is the Hornady spec but I've seen Hodgdon and others list 2.850" as trim length on their webapp and that is the Max case length.

I'll try and get out to the range and make some more empty brass...but dang do I hate the cold. I'll take pics of my brass for a 6x reload when I can.
I just measured new Hornady brass at 2.577 and my once fired at 2.5785 with twice fired at 2.580