300 Rum Load development help needed.

[Chippewa]

I've been reloading for a 300RUM C.Arms Ridgeline for awhile now. And to say after all the reading up on here, LRO, and other resources, I'll just share my boiled down set-up and routine.
So I fully Devcon bed the factory stock and my optics rail, shot/clean broke in the carbon barrel, mounted NXS 5.5-22x56, and running 212eldx @ 3050fps.

Recipe: mag length 3.69"oal to tip in Norma fire formed brass, 90g H1000, 215M primers pockets just brushed. Following the shoulder bump an neck tension resize back .003" routine of Jeff Brozovitch You Tube vids. Also "vld" bevel insides of neck and use Hornady Unique lube on shoulders then on bullet base before seating but after powder added. Brass is really holding up nicely. On 5th reload so far. Recently have been wet polishing brass then, length trim if needed, then anneal with homemade drill socket stand an started that before third resize. The wet method may harden brass but it does clean inside so capacity stays the same.
I fought ES issues as well an really saw number drops once lubing bullets and annealing. Also I switched to Boretech Eliminator an clean after each session. Also, Also, try an watch heating effects. As your cooling between shots bring a don't put next round in chamber to soak heat....

Good Luck. Keep shootin

 

[Mt rummy]

I've been reloading for a 300RUM C.Arms Ridgeline for awhile now. And to say after all the reading up on here, LRO, and other resources, I'll just share my boiled down set-up and routine.
So I fully Devcon bed the factory stock and my optics rail, shot/clean broke in the carbon barrel, mounted NXS 5.5-22x56, and running 212eldx @ 3050fps.

Recipe: mag length 3.69"oal to tip in Norma fire formed brass, 90g H1000, 215M primers pockets just brushed. Following the shoulder bump an neck tension resize back .003" routine of Jeff Brozovitch You Tube vids. Also "vld" bevel insides of neck and use Hornady Unique lube on shoulders then on bullet base before seating but after powder added. Brass is really holding up nicely. On 5th reload so far. Recently have been wet polishing brass then, length trim if needed, then anneal with homemade drill socket stand an started that before third resize. The wet method may harden brass but it does clean inside so capacity stays the same.
I fought ES issues as well an really saw number drops once lubing bullets and annealing. Also I switched to Boretech Eliminator an clean after each session. Also, Also, try an watch heating effects. As your cooling between shots bring a don't put next round in chamber to soak heat....

Good Luck. Keep shootin

 

[Mt rummy]

The heat soaking is spot on. So are shells laying out flat and others in the box. Especially when your near the top of your pressures.

For what it's worth. Pay close attention in your follow through. I find that when that barrel starts flipping right and not carrying through on the axis, you loose consistency. Especially with the 210 and longer.

 

[Dell]

ok Thanks for the input ballistics guy...prob overthinking the numbers, but it's gotten me this far! I guess it's worth a try to take that 92-92.5 out to 1000 and see if it'll hold together but always heard that SD's should be single digit if you want consistency at 1000. And it has held true for me up to this point. I guess for a hunting round .5 moa that percentage error can be acceptable at higher spreads from what I'm reading. Last year with the h1000/NLRAB nosler brass the ladder work was straight forward with low ES being the best groups. ES/SD went Up and down in the corresponding accuracy nodes. Pretty straight forward. Now this year the opposite is true. Still scratching my head wondering why? I guess barrel harmonics are what they are. Will shoot some longer strings to confirm ES #'s but again I'm having a hard time finding more retumbo which makes me wanna ration it out. Any one know where some is? I'm on a few websites email notify list, but from what I'm hearing it's been picked up by the military and it'll be out for awhile. Last year I had zero luck with h1000 and 210 vlds but maybe because it was still breaking in under 50 rnds. Hard to go back to h1000 now that I've seen this retumbo/vld combo produce such good results. Btw can you guys tell me your brass prep preferences in your 300 RUM? Neck size, partial neck and body, or F/L size? Neck turn or anneal? 1,2,3 thou neck tension? So much to learn from you guys. I don't have nearly any local resources for long range shooting info. You guys are it. Thank you.

Tried any IMR 7828 SC in that 300 RUM? I am a big Retumbo fan as well.When it was impossible to find a couple years ago I started experimenting for a friend I was reloading for (in 300 RUM, custom build, Rem. 700 action, Sendaro contour Schneider barrel). Actually, the 7828 was suggested by a Hodgdon tech guy when I called them about the Retumbo shortage. Went thru the load development process with the 190 VLD's and wow was I pleasantly surprised. Shot several 5 shot groups in the half MOA range with SD's in the single digit's every time. I have watched this friend kill elk with one shot drops out to 750 with this rifle and load and consistently ring steel at 1000 with it. Anyway, I was pleasantly surprised with the 7828 results and for my buds 300 RUM and the 190 Berger it's his powder of choice.
Brass was once fired, trimmed to length, primer pockets uniformed, bushing bump neck sized, shoulders bumped back .003, neck tension at .002, Fed. GM 215 M primers. Bullet jump at .015. Anyway, that's the set up that worked for that rifle.

 

[JDMAC]

I would recommend at least 5 shots to come up with any type of reliable statistical data as one of the other guys mentioned. Attached is my load development for new Nosler brass, no additional prep as they are trimmed, chamfered, PP deburred, and weight sorted (I think that is what they advertise). Powder charge accuracy is +/-0.02 grains, seating depth is measured to within +/-0.001 on each round (not sure this is necessary with hybrids); I have full length resized this brass, bumping the shoulder 0.002 with similar results. The rifle is nothing special, as it is a 1998 (or so) stock Win M70 SS composite stock sporter barrel; the only thing I did was put a Timmeny trigger and a muzzle brake on it.

 

[BIGBASS78]

So I'm totally new here and could really use some help here in analyzing this load development data. I have an amazing custom rifle from GA precision with Defiance action, 26" proof barrel, T3 Terminator muzzle brake, Manners T5 elite swamp, topped with a 7-35 56 NF Atacr. I finally got this thing after waiting over a year in July of last year and found a great 1/2 MOA load within 100 rnds in nosler brass with H1000 and 210 NLRAB. Fast forward to this season, when I have more time for load development and I decide to try retumbo and 210 VLD's with the new Gunwerks brass. Here's my first load ladder.
Bottom 2 right groups are my old h1000 load in 4th fired neck sized brass, and old h1000 load in new Gunwerks brass. Unnaceptable. Rifle was totally clean and then fouled with old load prior to retumbo ladder. 1st group in ladder at 90 gr is 3 shots in one ragged hole. All loads are .015 off lands. Poi is way low so I adjusted up for the remainder of the ladder. As you can see the high ES/SD groups are one hole. Lowest ES/SD are the worst groups. H1000 old load ES/SD was 5/2.5! But well over 1MOA in the new brass (how does that make sense?). 91 gr has been a consistent 1/2moa on a few ladders now but not good ES/SD. I haven't had a chance to take anything out to yardage but I'm having a hard time deciding what to do next. Anyone else seen this happen where the good groups are the highest ES/SD and lowest ES/SD were the worst?! What load should I pick? I shot the next ladder at 300 but with neck sized only 1st fired brass and the 91gr load was the only charge to stay under 1/2 moa. Hoping to run this ladder again with F/L resize and then tune seating depth from there but not sure what to make of this...

 

[BIGBASS78]

I really like the 210 NLRAB's, but worked my load with RL25. The first season it was great at 90gr, but now im getting a sticky bolt and the Nosler brass primer pocket are getting lose. my gun smith told to JB bore clean it and it was probably copper fouled. I was curious what your recipe was for the 210 NLRAB and the H1000. Powder charge? Bullet seating depth?

 

[Wachsmann]

Its interesting ballistic guy had said shoot for under 20 on the ES. That's been my take as well with the 300 RUM. I would love to get to some single digits, but I think I just always ran my loads at the extreme right before showing pressure to squeak out the most FPS out of them. I have always taken the best group size but a lot of times my ES has been very close to 20 or sometime around 22 to 23 fps for 10 shots. With these loads I have been able to ring steal at 1000yrds with decent results. I tried the loads out close to a mile and it was a whole different ball game. They were at best along with bad wind calls printing about the size of a house door. So like 4 feet by 4 feet from what I could tell through my scope. My best load printed 1/2 to .75 inch at 200yrds. I generally try to shoot at 200 for initial load development and try to get 1/2 MOA or better at 200yrds. A few years back I had my longest kill shot at 761 yards. A little further back in the rib cage but I got all excited when the shot presented itself and I completely forgot my wind hold. Still one shot and dirt nap on a Utah buck. No tags this year so I'm going to work on some load development for some 225 ELDX. I don't think they will work at mag length but that were I'm going to try and start. The 220ELDX worked at mag length and worked well.

 

[Mt rummy]

I run 3.660 on those 220 eld-x on my 22 lb platform for giggles and was very impressed. Shoved some in my meat gun and was even more impressed. The 220 was the only one out of this line that worked for me.Go figure. Now we will see if it dispatches as quick as a Berger.

 

[Wachsmann]

I was also running the 220 eldx but the BC thing bit me in the *** last week and I got weak in the wallet and bought the 225. The deer that I took at 761 yards was with the 220 eldx. Now that I have the 225's I will have to start tinkering again with a new bullet.

 

[Mt rummy]

I'd be very interested in feed back on the issue of dispatch on large game within the envelop of 600 to a 1000 yards. I've been on a Berger diet for more years than I can count and will be first time jumping ship.

 

[BoatTail]

This is helping me with my other thread on the 300 PRC Sherman improved versus the 300 Remington Ultra Mag . I'm tagging me in.

 

[Wachsmann]

I had found the RL26 gave me the most speed with the 220ELDX. I think I was running them with 89.4grains which was right at the pressure limit. I forget the actual FPS but it was above 3100 but not a lot. This is out of a stock sendero barrel. The thing that was a little off is the next year I took out the same loads I had loaded the year before and the group had opened up. So I dont know if i got lucky or the last 5 or 8 peices of brass had something different with them or what. But I'm starting over this year with some 225 ELD match and new brass.

 

[freebird63]

My 300 RUM loves 91.5gr of N570 at 3180fps.