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300 PRC update

I just got off the phone with Jeff at RCC Brass. This is related to my earlier cryptic post about doing something that by many standards would be considered somewhere up on the stupidity scale.

For those of you who don't know RCC, they machine brass in all sorts of wonky (and not so wonky) calibers - he told me they're making shells for the 75mm gun of a Sherman... This is not stamped brass, it's machined out of solid brass rod, and done so to very tight tolerances. Anyway, I asked Jeff if he could make 300 PRC brass, since it's not on their web site, and he said that since it's got a SAAMI spec, they can make it for $5.65 a case. That's a lot per case, but then the brass isn't worked much during forming, so it lasts longer. Even if it only lasts 50% longer, you're getting it for the equivalent of just over $3.75/case. Still a lot, but then you're also getting cases that measure out at +/- .1 gr of water per case, according to Jeff, so very consistent.

I ordered 100 cases. I'm going to run extensive tests after I receive them. Unfortunately they are a little backed up and I have to wait about 8 weeks. As always, I'll post the results. I'm looking forward to tinkering with them...

It’s funny that you mention them. I ran across this for the first time when I saw the 375 terminator. Honestly it is a lot but the thought behind it is solid and the quality is supposed to be outstanding. If we did a group buy do you think the price would go down? If not I’d still be in.

I don’t know if you’ve thought about it but once the 300 Sherman magnum has a steeper shoulder would there be an issue fireforming?
 
It’s funny that you mention them. I ran across this for the first time when I saw the 375 terminator. Honestly it is a lot but the thought behind it is solid and the quality is supposed to be outstanding. If we did a group buy do you think the price would go down? If not I’d still be in.

I don’t know if you’ve thought about it but once the 300 Sherman magnum has a steeper shoulder would there be an issue fireforming?

I don't know where the shoulder starts on the 300 Sherman. From the pic on their web site, it looks like it's about the same. If so, and it's just a longer neck, then it's an easy one step to fire form. If the shoulder is sits longer, I'd think an annealing and FL resize with the PRC die would do the trick. I looked for the dimensions and did not see them.
 
I don't know where the shoulder starts on the 300 Sherman. From the pic on their web site, it looks like it's about the same. If so, and it's just a longer neck, then it's an easy one step to fire form. If the shoulder is sits longer, I'd think an annealing and FL resize with the PRC die would do the trick. I looked for the dimensions and did not see them.
Typically Sherman's have an improved shoulder and less body taper
 
I talked to rich again today and mentioned to him that I’m hoping the 300 PRC spurs better brass for the 375 ruger parent case. His response was you won’t have to hop your breath long. It should come out sooner rather than later.
 
I talked to rich again today and mentioned to him that I’m hoping the 300 PRC spurs better brass for the 375 ruger parent case. His response was you won’t have to hop your breath long. It should come out sooner rather than later.
ADG would be the assumption then?
 
Typically Sherman's have an improved shoulder and less body taper

RCC has 30/375 ruger as well which is what this cartridge started out as before he made some tweaks after the 300 PRC launch
 
im shooting a 338/375 ruger xl. Love it. I ran my reamer .025” deeper so I can use Norma or RWS 8x68 s brass and fire form with out trimming. Gained about 4% capacity. Shooting a 250 gr Berger at 3025 fps from a 30”

what is the angle of the shoulder after firing the RWS brass?
 
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what is the angle of the shoulder after firing the RWS brass?
88F1962C-9C49-4F99-9626-3841917B4B61.jpeg

Left to right
375 ruger hornady brass, fire formed 1x 8x68 s Norma, ready to fire form 8x68s brass. I don’t have any pics of the RWS

The head is .020” smaller on the 8x68 brass but I’ve had zero extraction issues
Shoulder is still 30° But my case walls are .025” longer. And case length is 2.605” after fire forming. Reamer design was just a straight neck down of 375 ruger to 338 but I didn’t want to have to trim brass to fire form and liked the extra capacity. So I ran the reamer in an extra .025”. I simply neck up the 8x68 to 375 with a fl 375 ruger die. Then neck down to 338 using 338 rcm die adjusted Appropriately to form a false shoulder that’s slightly crush fit in the chamber to hold the brass still to fire form. 100% success with zero kulls.

My Hornady brass it 103.4. Norma is 98.8gr H2o
 

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I'm really thinking about getting mine done as a 300 PRC-SI. Sherman has pics targets on longrangehunting.com of factory 300PRC fired in his improved chamber to form and it's deadnutz accurate.
 
First you guys bought all the brass, now the loaded ammo is starting to sell out. I see the Match Grade dies sell out and then replenished....next the bullets will go.

Do you guys feel the following holds?

1. New Cartridge design released
2. We all drink the cool aid and start spec'ing out our rifles
3. We buy up all the components and dies while waiting on the months long waiting list of good smiths.
4. Everyone sells out of components and we start panic buying retail ammo at any cost.
5. We complain that there aren't enough options and beg for help from the industry.
6. We finally get our rifles and we have enough ammo to last 10 years before the first shot is taken.
7. The manufactures finally get full production runs and flood the market at 1/3rd the price we panic bought at.
8. We buy some just because of a good price but we already have more than we need.
9. We are fat, dumb and happy with our new rifle and tell everyone what a hammer it is.
10.The next big thing is announced and we go to step 1.

I'm already to Step 5! for this rifle anyway :)
 
First you guys bought all the brass, now the loaded ammo is starting to sell out. I see the Match Grade dies sell out and then replenished....next the bullets will go.

Do you guys feel the following holds?

1. New Cartridge design released
2. We all drink the cool aid and start spec'ing out our rifles
3. We buy up all the components and dies while waiting on the months long waiting list of good smiths.
4. Everyone sells out of components and we start panic buying retail ammo at any cost.
5. We complain that there aren't enough options and beg for help from the industry.
6. We finally get our rifles and we have enough ammo to last 10 years before the first shot is taken.
7. The manufactures finally get full production runs and flood the market at 1/3rd the price we panic bought at.
8. We buy some just because of a good price but we already have more than we need.
9. We are fat, dumb and happy with our new rifle and tell everyone what a hammer it is.
10.The next big thing is announced and we go to step 1.

I'm already to Step 5! for this rifle anyway :)

I mean yea... the same thing happened with 6.5 creedmoor. The good thing though is it was actually worth it all. There are plenty of fad cartrages that come and go becuase they arent proven and really dont contribute to the market. For example, the 300 norma, i see that round on the down slide becuae for its cartrage class.... it really doesnt offer much to gained by other cartridges, it will just eat your barrel.

The biggest competitor for the 300 prc is the 300 win mag. The 300 prc is better becuase of its ability to seat longer heavier bullets that we all adore, and its non belted. I think that will be cause for it to stick around. And for that reason im lurking in the shaddows till i can fund my build lol. 26” barrel, 230gr sierra, supper sonic to 2000 yards. Yes please!
 
Pretty much. I still haven't built a 6.5 Creedmoor and that has been the goal for a couple years now, but here I am reading about the 300 PRC.
 
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[/QUOTE]
I just got off the phone with Jeff at RCC Brass. This is related to my earlier cryptic post about doing something that by many standards would be considered somewhere up on the stupidity scale.

For those of you who don't know RCC, they machine brass in all sorts of wonky (and not so wonky) calibers - he told me they're making shells for the 75mm gun of a Sherman... This is not stamped brass, it's machined out of solid brass rod, and done so to very tight tolerances. Anyway, I asked Jeff if he could make 300 PRC brass, since it's not on their web site, and he said that since it's got a SAAMI spec, they can make it for $5.65 a case. That's a lot per case, but then the brass isn't worked much during forming, so it lasts longer. Even if it only lasts 50% longer, you're getting it for the equivalent of just over $3.75/case. Still a lot, but then you're also getting cases that measure out at +/- .1 gr of water per case, according to Jeff, so very consistent.

I ordered 100 cases. I'm going to run extensive tests after I receive them. Unfortunately they are a little backed up and I have to wait about 8 weeks. As always, I'll post the results. I'm looking forward to tinkering with them...

Interested... Following... Interested in test results and maybe even group buy
 
Pretty much. I still haven't built a 6.5 Creedmoor and that has been the goal for a couple years now, but here I am reading about the 300 PRC.

Could do 6.5 prc... And kinda get both? Haha
 
Just for reference: Left to right: 270WIN, 338 WIN MAG, 300 PRC with 225gr ELD-M, 8mm Mauser with 170gr Interlocks, 308 WIN with 168gr Everglades Match, 5.56 with 60gr 22lr to .224 corbin die swaged, and the 300blk with 150gr plated.
7051055
 
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For those of you running the 230gr Sierra MatchKings....which seem to be in stock everywhere at the moment....are you using a tipping die and/or meplat trimmer on these? From the geometry it seems I can use the same tipping punch that I currently use on the 175gr SMKs. Guess I'll order some 230's and try it out.
 
I'm still having some small consistency issues on FL resizing. It can vary as much as a few thousandths for me - about 1 out of 6 falls outside +/- .0005. On the plus side, I found a couple pounds of Retumbo (bought them out of their last 2), so I'm heading out to the range tomorrow to run through 6 loads and see how it does.
 
There is another thread here that flat out says the dies are WAY off. I can't wait to try new brass. Retumbo looked much more promising for me than h1000
 
There is another thread here that flat out says the dies are WAY off. I can't wait to try new brass. Retumbo looked much more promising for me than h1000

I'm considering getting a custom die made. I've never experienced this level of variation on FL resizing. I measure every case coming out of the die right now, which is annoying.
 
I'm considering getting a custom die made. I've never experienced this level of variation on FL resizing. I measure every case coming out of the die right now, which is annoying.


I believe a call to hornady is warranted. We are having issues. Is there anyone else out there with issues?
 
I believe a call to hornady is warranted. We are having issues. Is there anyone else out there with issues?

I did call Hornady.

Notes from call then my steps:

- The guy was perplexed as to why this was occurring.
- I use a turreted press (Redding T-7) and I used a Lee turreted before that. He said movement in the turret could be to blame. I told him I'd give them that on the Lee, but the Redding is rock solid and there is absolutely no play. I'm an ex-Space Shuttle engineer, and I know a little bit about structural mechanics and dynamics. The press isn't the issue, especially because I don't have this problem on other case types.
- He mentioned to try camming over the die more, and I told him I'd try that.

My steps:
- Adjusted the die to provide more cam-over, and used a varying-height holder set to adjust case length.
- The variation tightened up significantly, but still exists.
- Using the Hornady head spacer gauge to measure, my ideal case should measure out at 2.1925". I got 9 that ranged from 2.189" (just one, a few at 2.190") on the low side to 2.1935" on the high side. About 1/3 of the cases that were in the acceptable range measured 2.192", the remainder were 2.1925"
- Even re-pressing the high side cases, I could not force them into compliance. I even told them, "you have fifteen seconds to comply," but that did no good either.

I'm not too worried about 1/2 a thousandth (2.192 vs 2.1925), but I don't at all like spitting out a case that's 3 thousandths too short.

EDIT: Before I did the cam-over adjustment, I was getting as much as 6 thousandths short on the low side. Also, cleaned and recleaned the die to make sure there was no grease or debris inside.
 
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is any using the redding dies having these problems?

If someone can show me where to find one, I'll purchase and do a comparison just to satisfy my curiosity. I looked a couple days ago and couldn't find one available.
 
Ok gang I just got back from my 9 day vacation to Kauai! It was great. 9 days without the kids. It was hard to return until I saw the kids.

Anyhow I was trying to do some load development and ran into ejection issues. No matter the charge I had to pound the bolt back to extract.

Chambering was not difficult. A little tight but nothing that spooked me.

I was using the 1x fired brass from Mr Tubbs that I purchased.

Anyhow @Rocketmandb was kind enough to send me 10 brand new pieces of brass.

I just tried Chambering and ejecting the new brass. I had ZERO issues Chambering or extracting.

However when I try the samething with the now 2x fired brass.... It's hard to close the bolt and hard as hell to extract.

I checked the brass and all looks well except for this carbon ring.

People have said it is the used brass. But I am FL resizing. So maybe it is the brass or is it the die? Chamber bad? I need help.

Accuracy was great. I have not had a chance to fire the new brass yet.
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PRC Update from the Range:

I went up to the 750 yard range today and a great time - again, 70 and bright blue skies. There was about a 10 mph coming in at about 30 degrees front right. My purpose(s) of the trip:

1) Load test Retumbo
2) Test my rifle's new trigger
3) Put my new attempt at a portable steel target holder to the test - one that can take being on a hill and absorb a 225 gr bullet hitting it at 2000 fps.

Load Test Retumbo
I started the ladder at 77.5 gr, which I thought would get me close to the equivalent of 76 or so of H1000. I was wrong. The muzzle velocity of the first load averaged 2891 fps, with an ES of 14 and a SD of 5.9 - nice! The group? Not so nice. It was all over the place. Okay, so not a good (or even decent) group, move up to the next load. It was worse than the first. The best group I got was 1.7" at 200 yards = ouch. It was so bad that I thought my scope might be loose, or that mucking with the trigger screwed up the joining of the action to the stock. I stopped my development and switched ammo over to my 76.2 gr H1000 load. I averaged 2853 fps and shot a .73" (.365 MOA) 5-shot group. I'm not ready to give up on Retumbo, but clearly the upper end of the spectrum isn't working for me.

New Trigger
Works great - very happy.

Portable Steel Target Holder
Another not so great result. It sets up easy, - put it up at 750 yards - but cant' take the beating from the PRC shooting 225s. I got four rounds into it before it fell most of the way over. Then it took about another 6-8 before it went all the way down. Back to the drawing board here. Below is a video of the first shot - it's not the greatest quality because I had my phone set up incorrectly, but it's cool because you can see the bullet flying in.



I ended up switching over to the range's steel (also at 750). Look at what the 225s do to steel that's not AR500 - and not just the edge shot. It put gouges in the middle :)

7052661


My target stand didn't hold up, but at least my steel did :)
 
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Try reloader33. I think youll b happy
 
Never seen a carbon mark like that

It does look kind of odd. If doctor hadn't said it was a carbon mark, I would have said that something is wrong with the brass. If you look closely at the edges of carbon marks, they tend to be diffuse, as they are made by gas. These marks have very defined edges - I don't see how the finger-like markings in the first image could have been made by gas. I would suggest sending a picture to Hornady and asking them how these marks could have been made.
 
It does look kind of odd. If doctor hadn't said it was a carbon mark, I would have said that something is wrong with the brass. If you look closely at the edges of carbon marks, they tend to be diffuse, as they are made by gas. These marks have very defined edges - I don't see how the finger-like markings in the first image could have been made by gas. I would suggest sending a picture to Hornady and asking them how these marks could have been made.
The gas marks are consistent on every fired brass that I have out of my gun. Something is wrong.
 
The gas marks are consistent on every fired brass that I have out of my gun. Something is wrong.

For a gas to make hard edges like that, the unmarked portion has to be completely sealed. Conceivably, the brass could be expanding and sealing against the chamber before the round exits, but I wouldn't think you'd get those sort of irregularly shaped lines. Do any two pieces of brass have the same or similar patterns?
 
For a gas to make hard edges like that, the unmarked portion has to be completely sealed. Conceivably, the brass could be expanding and sealing against the chamber before the round exits, but I wouldn't think you'd get those sort of irregularly shaped lines. Do any two pieces of brass have the same or similar patterns?
All the brass has those findings. I should and will check concentricity. I'm guessing something is off with the chamber
 
I would index 4 rounds with a witness mark, single round feed with said mark into the position of 12, 3, 6 & 9 O'clock.

When fired does the carbon mark always end up in the same spot relative to the chamber? Or does it follow the
concentricity of the brass?

On my larger caliber rifles I anneal after each firing. It will not hurt your brass if done properly and it keeps
the neck/shoulder area flexible allowing the case to expand during the firing cycle which helps with several
issues.....neck tension, sealing the chamber etc. Although this is not a cure if the neck of the loaded round is way too
small vs. chamber neck size.

I hope this makes sense? It did when my little brain typed it out :(

Respectfully submitted,

Chet
 
So what's my options? Just deal with it and move on?
I recommend to my customers to always start with new brass. The reason is 99.9% of the time, if there is a problem it's traced to the brass that's been fired in a different chamber. Not all reamers are the same size, close but there are -0.000" + tolerances. Then the chamber. Not everyone cuts the same size chamber even using the same reamer.
 
Earlier someone posted they were having trouble finding RL25. I found some at Bass Pro shops in Auburn Hills, MI. Bought one but they have a couple left.
 
Powder Valley is showing 14 5lb jugs and 21 llb bottles in stock at the moment. Yesterday their rebates started. Buy over 4lbs of Alliant and get $2 a pound rebate...up to $20.