300 PRC update

Dippy

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Jan 19, 2019
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Why seat the bullets deeper if you don't have to? I wouldn't want the shorter reamer unless your limited to the action or rifle not taking CIP length mags. I personally would rather seat the pills further out as long as I have the mag length to do it.

If your switching from an existing 300 win mag, that only takes 3.715 magazines, the custom reamer is probably the best best. As your limited to COAL. At that point, yes you would have to reload.
I’m hoping Dave chimes in on this one as he’s the professional!
 

Dippy

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Jan 19, 2019
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I’m not a pro, just like shooting rifles but... From what have complied a shorter throat will minimize how much further out you have to seat the bullet to reach the lands.

Per Hornady load data H225 eld m 3.680” coal.

With a sammi thoat and H225 eld m,you would be at 3.730” coal touching the lands. .050” jump from 3.680”. You know to keep the lawyers happy due to factory ammo not always 3.680”...

Now if my notes are correct the 338 CIP mag has an internal length of 3.764”.

So if you seat at the lands with a sammi throat your left with about .034” room in the cip mag. Now as the throat erodes your going to be chasing the lands and encroaching more on the room you have left in the cip mag.

This cartridge was designed with the bullet seated out further in the case to achieve the velocity without higher pressures and seating a bullet way out in the neck like we do with our 300 WM loads to get the higher velocity.

So if Dave throats my chamber where the H225 bullet is touching the lands at 3.680” ill be able to reach the lands while maintaining the original design length of the cartridge and have plenty of room in my mag to chase the throat at it erodes.

Just my thoughts correct me if I’m wrong!
 
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jwknutson17

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I’m not a pro, just like shooting rifles but... From what have complied a shorter throat will minimize how much further out you have to seat the bullet to reach the lands.

Per Hornady load data H225 eld m 3.680” coal.

With a sammi thoat and H225 eld m,you would be at 3.730” coal touching the lands. .050” jump from 3.680”. You know to keep the lawyers happy due to factory ammo not always 3.680”...

Now if my notes are correct the 338 CIP mag has an internal length of 3.764”.

So if you seat at the lands with a sammi throat your left with about .034” room in the cip mag. Now as the throat erodes your going to be chasing the lands and encroaching more on the room you have left in the cip mag.

This cartridge was designed with the bullet seated out further in the case to achieve the velocity without higher pressures and seating a bullet way out in the neck like we do with our 300 WM loads to get the higher velocity.

So if Dave throats my chamber where the H225 bullet is touching the lands at 3.680” ill be able to reach the lands while maintaining the original design length of the cartridge and have plenty of room in my mag to chase the throat at it erodes.

Just my thoughts correct me if I’m wrong!
Your thinking is correct....

My Sammi cut chamber is at 3.700 with the 225 eld to the lands. 300 Win mag CIP mags can run a COAL of 3.750. Ill prob shoot out the barrel before I run out of mag length. If I am 20 thou off the lands making my COAL 3.680, I may never run out of mag length before the throat erodes enough to matter. We'll have to see with time. With the 215 bergers then maybe pending how you treat and shoot the rifle. If shooting the 212s you will never run out of mag length. Think it's a non issue unless your running them smoking hot and hard.
 
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Magoo124

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Dec 19, 2018
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This is my 300 PRC that we assembled last weekend. Started life as a Remington 700 300 win. Green mountain barrel 1in 8 twist, KRG Bravo stock, Vortex Viper HS LR. She was easily ringing steel at 832 yards. Was shooting factory 225 eld Hornady. It was 5 moa flatter than my buddies 338 LM with 300 grain federal ammo. Love the cartridge so far.
 

Rocketmandb

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Nov 2, 2018
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I went to a private range today for some load development. Good and bad on this front.

Bad:
I am having serious consistency issues on full length resizing. I've never had this before and am not sure what's causing it. Lengths are varying by as much as 6 thousandths. As such, I was only able to have 15 rounds that were consistent. I did 5 3-round groups at 75.5, 76, 76.5, 77 and 77.5 gr of H1000 with the 225 gr ELD.

Good:
It was 70 degrees today, not a cloud in the sky (ok, a few whispy ones), and I was in the hills by myself popping off rounds (after LD and also with my 6mm CM) at 600 and 850 yard steel targets. The operators also said there are places where they think I can get out to a mile after things dry out a bit.

Anyway... here's what data I could collect. All groups shot at 200 yards.

77.5 gr - Group Size: 1.32
2858 fps
2873 fps
2879 fps

77 gr - Group Size: 1.25
2873
2862
2871

76.5 gr - Group Size: 1.09
2834
2845
2835

76 gr - Group Size: See attached pic
2826
2807
2842

75.5 - Group Size: 1.41
2781
2814
2791

I'm loving the spread on 76.5 and 77 grain loads, and am surprised at the group on 76 with the spread it has. I'll probably do another load development day (hopefully I can get my consistency issue figured out) going from 76 to 77 at .2 gr increments. This range seems to yield the best spread, and groups were likely impacted by consistency, even after sorting.
 

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nick338

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Feb 21, 2013
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Looking like the 245 EOL has been scrapped completely or put on the back burner of a stove that isn't even in the kitchen. Not listed in 2019 catalog and someone posted an email from Berger about the 329 gr EOL that basically stated neither one is a priority right now. Well that sucks.
 
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b2lee

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Dec 30, 2018
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Could you guys PLEASE stop hording brass....so I can start hording brass :) Finding components is starting to get stupid for 300PRC.
 

b2lee

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Dec 30, 2018
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I guess I have to. I just got a reply from Peterson that they aren't looking at producing 300 PRC brass at this time. BOO!!!!!
 
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Supersubes

Snafu
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Based on Hornady’s past practices, I don’t think there’s gonna be too much issue with finding stuff. Save your clams, and go big when the sales hit. Then tend to do that early in a products cycle.
 

doctordoctor

El Doctor
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Apr 30, 2011
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So I got to try out my 300 PRC. It's always a joy to shoot but I had a sticky bolt no matter the charge weight.

I loaded 1x fired brass from D. Tubbs that I bought. FL resized with the hornady match diet set.

225 eld pills7045263
COL = 3.66"
Cci 250 primers

Top row is Retumbo bottom is H1000.

OCW ranged for Retumbo 76.9 to 79.4
H1000 74.8gr to 78.2gr

What say you? OCW charge and why the sticky bolts. I had to mallet every round out!
 
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Rocketmandb

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Nov 2, 2018
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Well that's good to know. The one being built for me is a 28" Bartlein #9 1-9 with a Lil B too.
I don't know how big you are or how well you are able to absorb recoil, but for me, this rifle feels perfect. Just enough thump to let me know I'm letting loose something substantial, but not so much that I'm not able to keep the target in the scope and watch the impact. I can fire this thing all day long with no ill effects. When the rifle was chambered in 300 WM with no brake, I had a very difficult time controlling the recoil. If it was just barely off center of mass, it would bounce all over the place. I was good for maybe 35 shots before I had to pull out my 6mm. Now I'm like, "crap, I'm out of ammo. Time to pull out the 6mm."

Not that the 6mm isn't fun to shoot, it's just not as fun as this. Now if Lapua will just make some brass...
 

b2lee

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Dec 30, 2018
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well... 5'6" 185lbs...but generally shoot prone and with good technique loading the bipod. Recoil doesn't bother me. Never had an issue with anticipating recoil and affecting my shots. I heard people complain about not wanting to shoot their K98's with steel buttplates more than a few rounds...or their 91/30's...same deal....never had a problem with either. On a modern chassis with a muzzle brake...I don't think there will be an issue.
 

nick338

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Feb 21, 2013
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I'm not sure what doctor's barrel length is. Mine is 28" Bartlein #9 1-9 with a Lil Bastard brake.
Good to know the Lil B gets the job done, I was considering the Fat B for mine but it sounds like maybe it isn't necessary.
 

Rocketmandb

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Nov 2, 2018
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After shooting 60+ rounds I wish I had a bigger brake. I'm 6' 200lbs. But I'm sore now.
I've heard that bigger people tend to try to absorb recoil rather than rolling with the punch. I'm a couple inches taller and weigh in at a little more than you... well... yeah, just a little more. And I don't roll so well. But it's all muscle!

Anyway, there is a good post on Precision Rifle blog doing a brake comparison here: https://precisionrifleblog.com/2015/08/21/muzzle-brake-summary-of-field-test-results/

Ability to stay on target comparison: https://precisionrifleblog.com/2015/07/25/muzzle-brakes-ability-to-stay-on-target/

Finally, recoil reduction comparison: https://precisionrifleblog.com/2015/07/17/muzzle-brake-recoil-reduction/

I really like the last one as it gives percentage recoil reduction. The Little B comes in third at 43% reduction in recoil, trailing its big brother and the Alamo Four Star by only 3%. I also heartily agree with the overall comparison that the APA brakes are loud. I double up on hearing protection with ear plugs and electronic muffs. On my 6mm (yes, I have the same brake on both), the cheek riser sometimes causes my ear muffs' seal to just barely break. My hearing is still a little wonky in that ear from Saturday... I just ordered some better plugs.

The main thing on the APA brakes that I like is that they are very easy to install and level with their reverse nut mounting mechanism. So simple, yet so effective.
 

carpooler

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Jul 7, 2014
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If anyone here has a few fired cases that they'll part with, e-mail me with details. I have made two wildcats on the 375 Ruger case. My 8mm x 66mm Mag. is a real bear to case form, from 375 R Brass. This 308 cal. may make it possible to do it with only one or two strokes on my old RCBS rockchucker press. FYI, these 66mm Ruger cases were made to work through standard length actions. Adding another 0.3" inch for streamlined bullets kind of defeats it's avowed purposes. I also have a take off SS REmington 300 Winnie Mag barrel, which I had my G.S. run a neck throat reamer into it's chamber, and now I make an improved case with a 3.14 inch long neck, out of 300 Wea. Pull Downs. The 300 Win. Mags are the max capacity in .30 which Hodgdon lists H- 4895 Reduced loadings for. I'm loading down, not up, and have some pretty close to the old 308 Win.'s power levels. I also had to buy a loaded RCBS sizing die for the 300 Win. Mag. to F. L. size these long necked cases. I doubt that these new Hornady bullets will seat properly, even in a long necked 300 Win. Mag. case.
 

Kickin45

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Oct 7, 2018
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So is there a concensus on best twist rate?
I’m having a barrel spun up here and I’m reading 1-8, 1-8.5, 1-9.
I’ll only be shooting the 225’s and anything larger once they are available in factory loads.
 

Hollywood 6mm

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Dec 9, 2013
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Flori-duh.
So is there a concensus on best twist rate?
I’m having a barrel spun up here and I’m reading 1-8, 1-8.5, 1-9.
I’ll only be shooting the 225’s and anything larger once they are available in factory loads.
I talked to Ken at GAP yesterday, and based on what he said it sounds like 8 or 9 twist is going to be the way to go for heavies, especially the 225. Playing with the numbers on the 225 with a reasonable hand load (2900-3000FPS) is what made me decide that I want a 300PRC for an ELR rig.
 

b2lee

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Dec 30, 2018
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That would be a pretty good poll. Ask why people started their journey down the 300PRC road. For me, I found a bullet I wanted to push at a certain speed. After looking at specs of different calibers I decided on 300PRC. At the time I had no idea about any military applications or other hype.
 

Rocketmandb

Private
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Nov 2, 2018
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That would be a pretty good poll. Ask why people started their journey down the 300PRC road. For me, I found a bullet I wanted to push at a certain speed. After looking at specs of different calibers I decided on 300PRC. At the time I had no idea about any military applications or other hype.
My decision-making steps were:

  1. I had stock work done and had a new Decelerator pad put on. Superior overall stock, but not as forgiving as my last recoil pad.
  2. I need a brake, but my barrel isn't threaded.
  3. Spend time and money to thread a partially worn factory barrel? Difference is basically just the cost of the barrel, so no.
  4. Get a new barrel - do it in 300 WM?
  5. Well, I've heard about this new 300 PRC, how about looking at that?
  6. Looks like a superior round in just about every respect.
  7. What about the brass? Hornady only? Now I'm not sure...
  8. It's based on 375 Ruger - Nosler makes a 375 Ruger case, I can neck it down. Brass problem solved.
  9. OK - let's go for new barrel in 300 PRC
  10. Crap, Nosler discontinued 375 Ruger. So, what about the brass?
  11. Deal with it until someone comes out with something better.
Long story short: I set out to modify the stock, ended up with a whole new rifle (except the action).
 

Dippy

Private
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Jan 19, 2019
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I just talked to Hodgdon powder tech and he said they are currently testing powders in the 300 PRC.

Also I talked to Hornady and they said they are running production on the 300 PRC brass, should be back in stock around mid April.
 

Rocketmandb

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Nov 2, 2018
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More data from another day at the range.

Temp: 68 F
Range: 200 yds
Bullet: Hornady 225 ELD
Powder: H1000
Loads tested: 76 - 77 gr, .2 gr increments
# of shots/group: 4

77gr - group size: 1.258" - ES: 17 fps
2883 fps
2887 fps
2893 fps
2876 fps

76.8 gr - group size: 1.073" - ES: 16 fps
2876 fps
2887 fps
2889 fps
2873 fps

76.6 gr - group size: 1.115" - ES: 26 fps
2875 fps
2863 fps
2879 fps
2853 fps

76.4 gr - group size: 1.008" - ES: 28 fps
2864 fps
2875 fps
2847 fps
2859 fps

76.2 gr - group size: 1.038" - ES: 15 fps
2866 fps
2867 fps
2869 fps
2881 fps

76 gr - group size: 1.481" - ES: 15 fps
2862 fps
2860 fps
2859 fps
2874 fps

Notes:
- Muzzle velocity is up over last visit.
- 76.2 gr looks like a good place to play, 76.8 is similar
- Not sure why my 76.2 gr loads have a higher average than 76.4...
- Still having some consistency issues on full length resizing. Called Hornady, they are at a loss too. Going to try a few things.

EDIT: Also dropped 3 out of 4 in about a 4" group on steel at 750 using 76.5 gr. 4th took group to about 7"
Also also, was shooting steel to test my new portable steel hanging setup - worked like a champ. Unfortunately I didn't take any pics. Will set it up in my yard and take a few. Boy do these 225s move the plate and sound the gong.
 

azbiker

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Mar 1, 2013
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I would like to get a 300 PRC barrel for my AXMC. Has anyone here had a barrel for your AXMC made? If so, what length, twist rate, and contour did you go with? Additionally, who made your barrel? I appreciate any help with this as I'm ready to add a 300 PRC barrel to my 300 win mag AXMC.
 

Dschapp44

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Oct 15, 2018
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has anyone gotten a reamer or chamber done with Sherman's 300 PRC S.I.?
Just ordered my dies from Rich (told me they should ship near the beginning of May) and will have the rest of my stuff in hand by Friday. I went with the build listed below

-Tl3 long action. I’m going to get the feed ramp adjusted to fit a CIP mag
- manners PRS2 CIP since it was in stock and weighs in the same as the TA’s I use in my other hunting rifle.
- proof 26 inch 1-9 twist barrel
- leopuld VX-6 3-18x50. First gen
- spuhrs new hunting mount.

I have a 280AI with the same components and it weighs in at 10 pounds. I think that not a bad weigh considering the cartridge.
 
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LakuNoc

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Jun 13, 2018
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Just ordered my dies from Rich (told me they should ship near the beginning of May) and will have the rest of my stuff in hand by Friday. I went with the build listed below

-Tl3 long action. I’m going to get the feed ramp adjusted to fit a CIP mag
- manners PRS2 since it was in stock and weighs in the same as the TA’s I use in my other hunting rifle.
- proof 26 inch 1-9 twist barrel
- leopuld VX-6 3-18x50. First gen
- spuhrs new hunting mount.
very nice setup.
where did you get barrel from? Are you installing barrel your self or?
 

Dschapp44

Sergeant of the Hide
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Oct 15, 2018
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very nice setup.
where did you get barrel from? Are you installing barrel your self or?
I ordered the barrel thru stockys. Still no sales tax so it was $750 to my door and I’ve got a local guy that does great work and can turn them around in 4 weeks so should be about perfect timing for my dies to get here. I have a 375 ruger already but the BC on the bullets isn’t great when compared to a 215 Berger or 240 SMK. I’m holding off on brass since rich is working with ADG to get it made with the right headstamp. OCD I know but worse case I can size some of my 375 brass since the PRC brass is harder to find than a unicorn.
 
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b2lee

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Dec 30, 2018
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I found a unicorn...he was out on a quest looking for 300PRC brass....he lowered his head...and said, 'No Joy'...poor Uni.
 
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