300 PRC update

jmornoinf

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On my lapua brass I'm using a redding .335 bushing in my FL die. Then .3075 expander mandrel. Getting very consistent seating pressure of 40 psi +/-2 psi on my 21st centry arbor press.
Thanks for the intel. I am probably going to do the same. I have have great luck using a smallish size bushing on 6.5 Creedmoor(.288) then using a mandrel to get .001-.002 neck tension.
 
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338LM

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Your chamber is a bit small (~.002") which is causing higher pressures than normal. Mine comes in at .003" under.

As @DellaDog mentioned, there are some small reamers out there.
Got my barrel maker to open my chamber up with the correct size reamer. They did get some of the out of spec (undersize) 300 PRC reamers when they originally chambered my barrel.
No more sticky bolt anymore with 76.0 grains of Retumbo or H1000. The barrel is still drilling 5 shots into the same hole at 100 yards. Now I can proceed in increasing my powder charges to see how much more velocity/accuracy I can get out of it.
 

screaminweasil

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Got my barrel maker to open my chamber up with the correct size reamer. They did get some of the out of spec (undersize) 300 PRC reamers when they originally chambered my barrel.
No more sticky bolt anymore with 76.0 grains of Retumbo or H1000. The barrel is still drilling 5 shots into the same hole at 100 yards. Now I can proceed in increasing my powder charges to see how much more velocity/accuracy I can get out of it.
What size is your brass at the web now? You went from .530" to what?????

My Bergara Premier Approach in 300 PRC shows .532" after firing but I haven't sized or shot anything other than virgin to know if I'm going to run into "issues" in the future.
 

338LM

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What size is your brass at the web now? You went from .530" to what?????

My Bergara Premier Approach in 300 PRC shows .532" after firing but I haven't sized or shot anything other than virgin to know if I'm going to run into "issues" in the future.
When I measure with my micrometer (versus calipers), the original undersize chamber fired brass was .5295. The brass now is measuring only .001 larger (.5305). This is with Hornady brass and not real hot loads. The main thing is that the bolt is not sticking at all. Before, the bolt was pretty hard to open. I did not ask how much the chamber got opened up.
 

LongRangeAggie

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Got my barrel maker to open my chamber up with the correct size reamer. They did get some of the out of spec (undersize) 300 PRC reamers when they originally chambered my barrel.
No more sticky bolt anymore with 76.0 grains of Retumbo or H1000. The barrel is still drilling 5 shots into the same hole at 100 yards. Now I can proceed in increasing my powder charges to see how much more velocity/accuracy I can get out of it.
Same problem I was having with my Christensen, my GS is opening it up right now and hope that fixes the issue. Glad to hear it did for you.
 

jmm68

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Hi,
I was testing my hotest load using 80 gn of N565 with 230 a-tips and I noticed a curious phenomenon, the cases are completely cold and almost 100% clean after shooting (adg virgin brass), a 79 gn load with same bullet an virgin brass comes hot and dirty out of the action.
Could this mean that the 80 gn load is expanding the brass in a way that seals much better and no gases go into the chamber?
There are no bolt stickiness nor ejector marks with this load and primers have reasonably round edges.
 

Emerson0311

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Hi,
I was testing my hotest load using 80 gn of N565 with 230 a-tips and I noticed a curious phenomenon, the cases are completely cold and almost 100% clean after shooting (adg virgin brass), a 79 gn load with same bullet an virgin brass comes hot and dirty out of the action.
Could this mean that the 80 gn load is expanding the brass in a way that seals much better and no gases go into the chamber?
There are no bolt stickiness nor ejector marks with this load and primers have reasonably round edges.
The same thing happened to me with a 375 H&H AI. A bit more pressure cleaned them right up.
 

96C

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230gr A-Tips in ADG brass. 2850fps. Have been happy with these. Sitting at 0.135" off.
 

Bandit320

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How do you like your ADG brass? I’ve been on back order for Lapua brass since January and I’m getting tired of waiting. Thanks.
 

96C

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How do you like your ADG brass? I’ve been on back order for Lapua brass since January and I’m getting tired of waiting. Thanks.
It's nice, this is the first ADG I have used, difficult to get in Australia until recently.

The packaging is excellent, everything comes extremely clean and straight.
 
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JB.IC

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Proof prefit 26” 1:8T carbon. 👍
I’m always stunned how shorter barrels compared to my 29” are pushing nice speeds. I used RL26 or n565. Have some h1000 and n570 to test at some point.
 
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JB.IC

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Isn't that slow for 300 prc? I don't know though just asking. I do don't have or never shot one. Just curious
It depends on a lot of things. Brass, powder, bullet, bore tightness, action, barrel thickness around the combustion area. That’s why everyone repeats the same old phrases about starting low and working up.
 
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Schw15

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    It depends on a lot of things. Brass, powder, bullet, bore tightness, action, barrel thickness around the combustion area. That’s why everyone repeats the same old phrases about starting low and working up.
    I was thinking the 300 prc pushes the 230 like 2950 to 3000. But yes everything plays a factor in all of it.
     

    JB.IC

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    I was thinking the 300 prc pushes the 230 like 2950 to 3000. But yes everything plays a factor in all of it.
    From what I can tell amongst all the various combinations of things, 2800 is a pretty safe bet for a 230 bullet with a 26” barrel. 2900 fps if we’re talking close to pressure. But I’ve seen people shooting 250s near in 2800-2900fps with 26-28” barrels and I just scratch my head when I see that.

    What I consider a safe load is when pressure occurs from say a heavy bolt lift, backing off that by 100 FPS. Idk how many people follow a rule like mine but I suspect some are pushing it closer to the edge than they want to admit.
     

    Schw15

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    From what I can tell amongst all the various combinations of things, 2800 is a pretty safe bet for a 230 bullet with a 26” barrel. 2900 fps if we’re talking close to pressure. But I’ve seen people shooting 250s near in 2800-2900fps with 26-28” barrels and I just scratch my head when I see that.

    What I consider a safe load is when pressure occurs from say a heavy bolt lift, backing off that by 100 FPS. Idk how many people follow a rule like mine but I suspect some are pushing it closer to the edge than they want to admit.
    I tend to not run at top pressure I always back off a grain or two and run with it. I had a 300 win mag throated long 28 inch barrel 225 eldm at 2929 and 245 berger 2800. That's why I was asking. Seeing the difference maybe coming back to 30 cal.
     
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    Bandit320

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    I tend to not run at top pressure I always back off a grain or two and run with it. I had a 300 win mag throated long 28 inch barrel 225 eldm at 2929 and 245 berger 2800. That's why I was asking. Seeing the difference maybe coming back to 30 cal.

    For reference, I have a 26” 300WM that I run 225 ELDMs at 2900. My 24” Howa PRC does about the same with 225 ELDMs / 230 A-Tips. It gets around 2830 with 250 A-Tips. It’s a factory barrel that seems slow to me. It’s about to become a 28”.
     
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    Schw15

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    For reference, I have a 26” 300WM that I run 225 ELDMs at 2900. My 24” Howa PRC does about the same with 225 ELDMs / 230 A-Tips. It gets around 2830 with 250 A-Tips. It’s a factory barrel that seems slow to me. It’s about to become a 28”.
    Seems like the old 300 win mag keeps up well with the 300 prc
     
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    Schw15

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    Have any of you guys had any issues with the 230 a-tip or 250 a-tip blowing up? I know some of the eldms and 190 a-tip has
     

    96C

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    It’s definitely not FAST, but I’m not trying to kill the barrel either.

    This is 78 grains of ADI AR2225 (our version of Retumbo / Reloader 25). There isn’t heaps of room left in the case.

    I’d rather be fairly conservative and have an accurate load, for the distances I’m generally shooting (800-1300m) this is plenty of rifle.

    What charge loads are you guys sitting around?
     

    Bandit320

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    Seems like the old 300 win mag keeps up well with the 300 prc

    It does well. Of course, I seat them quite long ( a bit over 3.6”) and have to single feed them. If I’d bought an 8 twist barrel instead of a 10 twist for my WM I wouldn’t be messing with the PRC.
     

    Schw15

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    It does well. Of course, I seat them quite long ( a bit over 3.6”) and have to single feed them. If I’d bought an 8 twist barrel instead of a 10 twist for my WM I wouldn’t be messing with the PRC.
    My win mag with the 225 eldm was loaded at 3.777 I run long action cup mags load alot longer in them. But got rid of it for other things. But 30 cals are fun might be getting another
     
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    newageroman

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    Any thoughts on Structured Barrell with a +1 twist for copper solids? Would the faster spin rate be better for turned copper solids. I'm thinking more spin would be better through the transonic zone will help stabilize it no? nice info thread , I'm about to read/catch up on it.
     

    parshal

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    I just tested 250 a-tips in the yard for pressure before I test for accuracy. Velocity was with the Magnetospeed. 29" barrel has exactly 100 rounds down it before these shots. Action is an Atlas Tactical. At 88 degrees, with Lapua brass and 215M's I got the following:

    N565
    72 - 2660 fps
    76 - 2845 fps; no bolt lift and a very small smear

    N570
    75 - 2702 fps
    76 - 2790 fps; began feeling powder when seating bullet with Wilson arbor die
    78 - 2829 fps; zero pressure signs; could still hear powder when shaking case
     
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    nealm66

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    I just tested 250 a-tips in the yard for pressure before I test for accuracy. Velocity was with the Magnetospeed. 29" barrel has exactly 100 rounds down it before these shots. Action is an Atlas Tactical. At 88 degrees, with Lapua brass and 215M's I got the following:

    N565
    72 - 2660 fps
    76 - 2845 fps; no bolt lift and a very small smear

    N570
    75 - 2702 fps
    76 - 2790 fps; began feeling powder when seating bullet with Wilson arbor die
    78 - 2829 fps; zero pressure signs; could still hear powder when shaking case
    Coal?
     

    newageroman

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    Used rifle on the way. Hint - no structured barrel. I will need a brake(Cortina Tuner Brake?) and some powder, I think I have everything else. Will be digging on the recipes and new profiles for strelock.
     

    nealm66

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    COAL was roughly 3.700".
    Man, that’s bitter sweet. I fricking love/hate n570. Not sure your groups but I bought a tmb tuner and was able to keep coal and charge with the 245’s @2940 and punching one big hole at 200 yards. Hoping to test out to distance this Saturday = 4.5 hour drive
     
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    b2lee

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    I know I can get it faster but I also want to keep the recoil down so I can better spot my shots in ELR events.

    In ELR events...we are running our COAL a lot longer than 3.7.....by about 100 thou or more. I don't even go down to 3.70 when magazine feeding.
     

    parshal

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    The seater was set to the depth I'm using on the 225 ELD-M's. Since I was just looking for pressure I just left the depth where it was. I hit my velocity goal before any real pressure at that depth. I'll be starting at max length for the CIP magazine when I start testing for accuracy.
     

    nealm66

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    Might have been better to seat out as far as will cycle to check pressure. Then seating in to get groups.
     

    b2lee

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    Anybody fiddled with N568 yet? I'll be trying it soon with 215 and 245s.

    I'll play with it after the ELR season....don't have the time to do new load development when all I do is work all week...and travel on the weekends to shoot. This Winter...I'll put some effort into it...but I can almost guarantee you that I'll run 76.0 grains and tune a seating depth in about 10 shots and call it a day....with the 245's
     
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    b2lee

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    Today...about an hour ago actually....

    300PRC
    29.5" barrel
    245gr EOL's
    76.0gr of RL-26
    2887 fps no pressure signs ******* caveat ******
    Lapua Brass
    Elevation 954ft

    So....the reason my speeds are slower than the were...and no pressure signs are the following:

    I didn't clean my brass...I brushed out the necks with a 30cal nylon brush just to get the big carbon out.
    I annealed with Aztec Code 168 on an Amp Annealer *** on neck turned brass at 13.5Thou ***
    I full length resized with a LE WIlson bushing die...and I forget exactly which bushing...but very little neck sizing.
    I Mandrel each one back out to 2 thou below bullet size.
    I Coat my bullets with HBN

    This coupled with my seating depth...I've reduced pressure for the sake of consistency. If I skip one of these steps and go same powder load...it will show pressure signs....The HBN really slicks up the bullets and drops your MV...but it makes verticals at ELR ranges really nice.

    So....when you read loads on the Internet...even if they are true and real...there are a lot more things going on that you need to be aware of.

    Signed,

    B2
     

    Bandit320

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    b2lee

    I was looking at AB Mobile for the 245 EOLs and it was showing a higher G7 BC than the Berger published number (.438 vs Berger’s .413). From your usage does this seem correct? Also, what’s your opinion on the quality and consistency compared to the A-Tips. I had planned on starting out using the 250s since I can find them, occasionally. Thanks.

    Mike
     

    b2lee

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    b2lee

    I was looking at AB Mobile for the 245 EOLs and it was showing a higher G7 BC than the Berger published number (.438 vs Berger’s .413). From your usage does this seem correct? Also, what’s your opinion on the quality and consistency compared to the A-Tips. I had planned on starting out using the 250s since I can find them, occasionally. Thanks.

    Mike

    I do believe that Berger is conservative with their numbers....and hence why they tried to educate people with the No BS BC series. The .413 is at a certain condition at a certain range.....with a certain barrel...and a certain velocity. Me using a 29.5" barrel and getting a little more giddy up behind the bullets....increases the BC. Now....I also tip my bullets and HBN coat them...I'm currently at around a .455 G7.

    I've shot a lot of 230 A-Tips...and many hundred 250's. While I really like the A-Tips...they have a tendency to explodicate at the absolute worst time. If I'm shooting an ELR match and one explodes and I miss....probably not that big a deal since my odds of hitting that 2000+ yard steel aren't certain....but when you shoot 1 mile paper...and 1 miss is a DQ....then it just pisses you off.

    I originally started shooting the 245 EOLs because they were $50/100 or so...while the A-Tips where like $80/100.....the price difference was large enough for me to give them a try. Then I found I shot consistent with the Bergers and while I was going to tip them...thus more work....I really liked them. It seems a 1-9tw likes the 245 Berger more than the 250 A-Tip...

    I still have hundreds of A-Tips...but I have a lot of 245 EOL's I will shoot first.....until the new 245-ish Berger comes out soon...then I'll test them out. I was hoping the Bergers were 'close enough' for me not to fret over when shooting ELR....and they've exceeded my expectations.....I've had matches where I shoot a sub 2" vertical at a mile...but blow my wind calls....and last week I shot 3 groups with 2" horizontals....but had something going wonky with the rear bag and my vertical dispersion was too much to keep all 5 on paper. One day I'll get both at the same time and it will be magical.

    So...the A-Tip is one sexy looking bullet. They are great....it's just that the low probability of one flying apart...seems to catch me and others at exactly the wrong time. Not much Hornady can do about that....it is what it is. The bergers have been consistently great for me....I'll measure the snot out of stuff...and they are great from lot to lot.

    Both are great bullets....but like I said...I originally shot the A-Tips...and wanted to convert to something not so price heavy...and ended up finding something I like more.
     
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