300 PRC update

[yej0001]

What would be a correct 300PRC set-up in an AI AXMC? A 300WM bolt, a 300PRC barrel, and a 338LM magazine?

 

[MOUNTIC]

What would be a correct 300PRC set-up in an AI AXMC? A 300WM bolt, a 300PRC barrel, and a 338LM magazine?

300 Win mag bolt and magazine. 300 PRC barrel. The 300 PRC ammo is way to loose in the 338 mag on the AXMC.

 

[pengilly]

I don't know what if any brass prep you did but one thing I always do with Hornady brass is straighten the necks and chamfer in and out. The way Hornady trims the brass to length it rolls out a lip on the case mouth. I've seen it cause a slight interference fit in some chambers. That could well be the reason for your two out liars. Neck tension alone would not cause that much increase in velocity. It's in our head that neck tension causes major issues but it's been my experience that it's over rated. The act of seating the bullet acts like an expander mandrel and pretty much makes all the neck tension the same. Brass hardness affects it more. That's why I don't anneal. They're all the same.

That is a fact....I just recieved 100 new Hornady 300 PRC cases and the first thing I noticed was a lip on the case mouth opening.

 

[MOUNTIC]

That is a fact....I just recieved 100 new Hornady 300 PRC cases and the first thing I noticed was a lip on the case mouth opening.

That's what all mine looked like. Spent hours yesterday prepping 100 new Hornady 300 PRC brass. Hoping ADG starts making it for the 300 PRC soon. Talk about frustrating times having to prep this Hornady stuff. Good thing it's -2 here and I didn't have much else to do.

 

[Hawaiian SRS-A1]

What dies are you guys using for 300PRC? I could only find Hornady, unless I go with custom made ones from Whidden. I have never used Hornady dies and was wondering what you guys use/prefer. Mostly all my dies are Forster dies but I don’t think they came out with 300PRC yet. Sorry if this question was asked before.

 

[doctordoctor]

What dies are you guys using for 300PRC? I could only find Hornady, unless I go with custom made ones from Whidden. I have never used Hornady dies and was wondering what you guys use/prefer. Mostly all my dies are Forster dies but I don’t think they came out with 300PRC yet. Sorry if this question was asked before.

The hornady match dies are what I plan on using. They have been fine for my creedmoor

 

[Supersubes]

What dies are you guys using for 300PRC? I could only find Hornady, unless I go with custom made ones from Whidden. I have never used Hornady dies and was wondering what you guys use/prefer. Mostly all my dies are Forster dies but I don’t think they came out with 300PRC yet. Sorry if this question was asked before.

I’ve had great results with Hornady. While I haven’t used my 300 PRC dies yet, they have the same nice finish as my other Hornady match dies. I find they’re dimensioned perfectly to hornady’s cartridges. I’m a rabid Redding hater.

 

[MOUNTIC]

I'm using the Hornady match die set. Using the 336 neck bushing. Seem to work well for the Hornady Brass. I use redding for everything else so I had some reservations with the Hornady Die set, but its working well so far.

 

[DAVETOOLEY]

That is a fact....I just recieved 100 new Hornady 300 PRC cases and the first thing I noticed was a lip on the case mouth opening.

Yep I've bitched for 20 years but it is what it is. Actually not a bad thing as it makes us do basic prep work which we should do with any brass. It doesn't take long if you can run the tools under power.

 

[b2lee]

Someone pick apart my build preferences for the 300PRC

Defiance Deviant Action
Bartlein Barrel 28" 1-9 twist fluted
APA Little B Muzzle Brake
J Allen JAE-700 stock
TriggerTech Diamond Trigger
Spuhr Mount
Vortex Razor GenII HD with Horus Tremor

I started the journey today with a purchase of....Hornady Match Die set.

 

[pengilly]

Yep I've bitched for 20 years but it is what it is. Actually not a bad thing as it makes us do basic prep work which we should do with any brass. It doesn't take long if you can run the tools under power.

I really dont mind doing that kind of work and someday we will hopefully have more choices on brass.
Jeff

 

[Rocketmandb]

Someone pick apart my build preferences for the 300PRC

Bartlein Barrel 28" 1-9 twist fluted
APA Little B Muzzle Brake

I have a 28" Bartlein 1-9 (#9 contour) with the Little B on the front end.

Notes:

• The rifle is frikkin heavy with that big barrel, but I'm not hunting with it, so it's all good.
• I feel that the combination of weight and brake makes this rifle just about perfect for me from a recoil standpoint. There's enough there that I know I'm shooting something big, but my shoulder doesn't feel it after 30-40 shots like it did on my 300 WM with no brake.
• I really like the Little B, but the blast is playing hell with my Lab Radar (see next post).

I only know the rest of your parts by reputation (good), so I won't comment on those.

 

[Rocketmandb]

Update from day 2 at the range:

Good news and bad news here - fortunately the bad news is more about data collection than anything going on with the build.

Bad news first:
My Lab Radar was failing to pick up a fair number of shots. I'm pretty sure the blast from the Little Bastard brake is knocking it around. I love the Lab Radar unit, but my biggest issue is that they have crappy solutions for mounting it, especially for use with larger caliber rifles with brakes that blow backward. I think I'm going to have to craft something that clamps it in and allows sand bags to weight it down (current thinking is just getting a drill press vise, and mounting it to piece of plywood).

The main issue with this is that of my nine neck-turned, annealed rounds, only three registered, so there's just not a big enough sample size to gauge the difference vs. other.

Here are the muzzle velocities I was able to capture (working backward):

2956
2928
2950
2933
2945
2935
2950
2943
2932
2934
2943
2945
2931
2924
2945
2954
2925
2932
2924
2930

The three neck-turned/annealed rounds I was able to capture
2936
2953
2930

There's still a big ES, but the numbers tightened up considerably. If I had already done load development and was getting the spread I'm getting here, I'd not be happy, but this isn't bad considering.

More notes:

Versus first set, average velocity ticked up slightly from 2935 to 2938 (roughly .1%), and standard deviation went down to 9.9.

Group size decreased. Best was .34 MOA, with most hovering near half MOA. I expect these to go down with load development. I will also probably

No signs of overpressure on any brass.

Load: 78.5 gr H1000, 225 gr ELD-X, Federal 215M primers.

 

[b2lee]

I was trying to compare your numbers to the published PDF from Hornady and then noticed they are pushing their test loads out of a 24" 1/8 twist. I see their lawyers say don't go above 77.5gr of H1000 for 2825ft/sec in that barrel. Later on when I finally build out my rifle I was going to test up some 225-ELD-M's with RL25, RL26, H1000 and Retumbo...but I imagine by the time I'm done...Hogdon will have out a new powder just for 300PRC the way things are going.

On the Labradar...have you tried mounting it above the barrel and sight line? It really works well for me.

 

[Rocketmandb]

On the Labradar...have you tried mounting it above the barrel and sight line? It really works well for me.

Do you just raise it on a tripod (I'm using that now)? How high?

 

[Rocketmandb]

but I imagine by the time I'm done...Hogdon will have out a new powder just for 300PRC the way things are going.

And then it will never be in stock.

 

[b2lee]

I've seen people with little tri-pods and such...but I thought those put the labradar too high above the barrel. So I simply took a 2x4 and cut it into three sections and put together like a U.....like a little bookshelf....the legs have the underside of the cross piece about 1/2" above the top of my scope.

Where I do my testing is a small 100 and 200 yard range and it is very flat and shooting from a bench. I put some L brackets on the legs on all 4 sides of each leg...but I can't screw them down to a bench I don't own...but I can place sand bags on the outside edge of it. Works pretty good and the gases go out to the side when I shoot and the labradar doesn't even wiggle...the labradar base plate is screwed to the 2x4 cross section.

 

[Rocketmandb]

I was trying to compare your numbers to the published PDF from Hornady and then noticed they are pushing their test loads out of a 24" 1/8 twist.

For reference, I have a 28" 1:9

 

[b2lee]

I've noticed while checking around online retailers for 300PRC that most things are OUT OF STOCK/BACK ORDER OK. I'm sure some of that may be place holders for stuff coming...like maybe the Redding 3 die set. However, I've seen things in stock with '6 left' and then a refresh of the page and they are gone.

To me this looks like much more of a demand than I would have thought from reading forums like this here and other places. I'm sure Hornady can pump out dies/bullets/brass like there is no tomorrow if there is a demand....just reminds me of years ago when I was reading the 6.5 Creedmore nay sayers but I couldn't find stuff to buy in stock.

 

[j741]

Anyone need a Hornday 300PRC custom grade die set? It's their non-match set. I didn't realize I had it and I bought a match die set. Just found it when arranging supplies this weekend. still shrink wrapped - $40 shippped to your door.

 

[doctordoctor]

I've seen people with little tri-pods and such...but I thought those put the labradar too high above the barrel. So I simply took a 2x4 and cut it into three sections and put together like a U.....like a little bookshelf....the legs have the underside of the cross piece about 1/2" above the top of my scope.

Where I do my testing is a small 100 and 200 yard range and it is very flat and shooting from a bench. I put some L brackets on the legs on all 4 sides of each leg...but I can't screw them down to a bench I don't own...but I can place sand bags on the outside edge of it. Works pretty good and the gases go out to the side when I shoot and the labradar doesn't even wiggle...the labradar base plate is screwed to the 2x4 cross section.

Could you post or send me some pictures. I'd like to see your setup. Thanks

 

[C3P003]

What would be a correct 300PRC set-up in an AI AXMC? A 300WM bolt, a 300PRC barrel, and a 338LM magazine?

Here's a link to a CIP length 300 Win Mag AICS magazine:
https://www.brownells.com/magazines...-sku100012488-71760-120056.aspx?sku=100012488

 

[MOUNTIC]

Here's a link to a CIP length 300 Win Mag AICS magazine:
https://www.brownells.com/magazines...-sku100012488-71760-120056.aspx?sku=100012488

That would not be the correct magazine for the AXMC. Different magazines. The AXMC doesn't use AICS mags.

 

[C3P003]

That would not be the correct magazine for the AXMC. Different magazines. The AXMC doesn't use AICS mags.

My mistake. Are AXMC magazines double stack only?

 

[Ledzep]

I think so. Are there 300 win mag AXMC magazines? That would be the better choice. The 300PRC seems to feed well out of most 300wm mags I've seen, provided the COAL allowance is long enough.

 

[W54/XM-388]

The .300WM AXMC magazines would work well, they are going to let you load the rounds pretty much as long as you want them to be, as the .300WM magazines are the same overall length as the .338LM magazines.

 

[C3P003]

I think so. Are there 300 win mag AXMC magazines? That would be the better choice. The 300PRC seems to feed well out of most 300wm mags I've seen, provided the COAL allowance is long enough.

https://www.milehighshooting.com/ac...i-6867-axmc-300-win-mag-doublestack-12-round/

 

[18Echo]

Is there any particular reason to go CIP length DBM vs a Wyatt's extended box for a BDL set up, or is it just personal choice. If I prefer a Wyatt's BDL set up should I look at 300 RUM instead?

 

[DAVETOOLEY]

Personal choice. I run a standard Rem box w/o issues with 300 PRC.

 

[b2lee]

What kinda total weight sans ammo are you guys getting on your 300 PRC builds? Out of my list of parts I'm getting 20 1/4lbs....hopefully chambering takes a little weight off the advertised barrel weight...plus fluting the barrel and bolt...I can get below 20lbs...but not by much.

I better edit and add that weight is with a Spuhr mount and a heavy Vortex Razor Gen II

 

[j741]

My Mausingfield hunter + LRI sendero-like 24” + KRG Bravo is just under 10lbs. with M10 rings+ATACR+bipod should be easily under 15.

 

[MOUNTIC]

Anyone make a 3 round AICS CIP magazine that's shorter in height?

Found that MDT makes a 3 round but shows the dimensions are the same.

 

[doctordoctor]

Barrel is in! Got some brass. All I need is some bullets!

 

[b6graham]

Barrel is in! Got some brass. All I need is some bullets! View attachment 7037655View attachment 7037656

well that's an um interesting contour

 

[doctordoctor]

well that's an um interesting contour

It's for my DT.

 

[b6graham]

It's for my DT.

ahh. never seen one before. makes sense.

 

[doctordoctor]

But yes it is "different". What's the leftist way to say it.... "special"

 

[motofrog]

Anyone make a 3 round AICS CIP magazine that's shorter in height?

Found that MDT makes a 3 round but shows the dimensions are the same.

Accurate Mag has one it’s listed as 2.93” high vs 4.01” for the 5-rounder

 

[MOUNTIC]

Accurate Mag has one it’s listed as 2.93” high vs 4.01” for the 5-rounder

Perfect. Thank you. I must have missed it. Want the option when hunting to have a slightly shorter mag. Helps not snag on gear.

 

[Polizei45]

Just so I have right. If I want to use a AI AICS AX chassis for the 300 PRC I need to use the the AICS AX CIP 338 Lapua chassis and use the Accurate Mag Win Mag 3.850 magazine. The 300 Win Mag chassis won't work because of the magazine length.

 

[doctordoctor]

Gun is ready. If only I had bullets and dies.

 

[j741]

Just so I have right. If I want to use a AI AICS AX chassis for the 300 PRC I need to use the the AICS AX CIP 338 Lapua chassis and use the Accurate Mag Win Mag 3.850 magazine. The 300 Win Mag chassis won't work because of the magazine length.

Correct, you want CIP length

 

[Blaster7Romeo]

Forgive me if I missed it somewhere but..

Has anyone seen how fast they can push a 230 gr Berger?

 

[Dooby]

Any issues using BR2 primers with H1000? Also have WLR primers and CCI #34 NATO spec primers.

 

[NewsShooter]

Do you just raise it on a tripod (I'm using that now)? How high?

I'd make up a plate like photographers use for remotes and big lenses. Steel or aluminum plate, drill holes in each corner for thumbscrews to level it and one in the middle for a small head to mount the labradar. You could buy one for lots of money or make one for a few bucks. Like this one, https://farm1.staticflickr.com/496/19548243501_d8965185e3_b.jpg

 

[rfurman24]

Anyone shooting H1000 with 215 Bergers? I was hoping to shoot factory ammo but my rifle hates both.

 

[doctordoctor]

Forgive me if I missed it somewhere but..

Has anyone seen how fast they can push a 230 gr Berger?

Not yet. I was going to try some.

 

[wade2big]

I have read where Tikka isnt a good action for the .300 win mag if you want to load heavy bullets. Would the 300 PRC work better in a Tikka action or would I still be giving up something?

 

[b6graham]

I have read where Tikka isnt a good action for the .300 win mag if you want to load heavy bullets. Would the 300 PRC work better in a Tikka action or would I still be giving up something?

it's not long enough. that's the issue

 

[wade2big]

it's not long enough. that's the issue

I understand that. Would it be long enough for the 300 PRC?