load workup for 300 RUM...

[venom600]

BTW, last time I was there I was shooting Cutting Edge 180's sub .5 MOA @ 3470 with 99.5 gr of Retumbo.

Still liking the Cutting Edge 180s?

After spending the last 2 months doing load development, hell bent on finding the perfect 200g bullet load, I've spent some time over the last couple of days punching numbers into the ballistics calculator (better late than never). Current higher end bullet offerings in .308 seem to yield the best BC at around the 180g weight (i.e. the cutting edge and GS custom).

According to the numbers, a faster, higher BC 180g bullet kicks the crap outta the 200g offerings on the market right now.....at every range.

Had decent results at the range last night (found another sub-MOA load w/ Barnes LRX @ 200 yds). So, I think I'm going to finish testing my current 'golden load' (200g LRX, 97g Ramshot Magnum) and get a turret built for my scope with it. Then, round 2 of load development will be dedicated to the 180g super bullets I've found recently (the GS and the Cutting Edge).

--Ben

 

[venom600]

Spent some time at the range Thurs night and today. Got a bunch of shooting done and tried some new loads.

Here's the new loads I've tried (all with the 200g Barnes LRX):
88.0g Retumbo, 3.62 OAL, Rem 9 1/2M : 2999FPS avg, OK accuracy (1.5" @ 100, 2.0" @ 200)
88.6g Retumbo, 3.62 OAL, Rem 9 1/2M : 2969FPS avg, Poor accuracy (2.5" @ 100, 3.2" @ 200)
89.0g Retumbo, 3.62 OAL, Rem 9 1/2M : 3026FPS avg, OK accuracy (1.2" @ 100, 2.3" @ 200)

Was able to confirm my confidence in my current golden load. With it today I put 6 shots into 3.25" @ 435 yds. Felt pretty good. Here's it's load data (again with 200g Barnes LRX):
97.0g Magnum, 3.62 OAL, Rem 9 1/2M : 3200FPS avg, shoots sub-MOA consistently

I had one slightly stiff bolt with it today. Might back off a half grain and run it at 96.5. Should put MV right around 3185, which is pretty good w/ a 200g projectile.

--Ben

 

[trebark]

Like venom600, got out to the range today to test a few loads. Here's my data...

Bullet: 208grain Amax
Powder: Retumbo
Primer: F215M

Powder Charge: 90.5
Average Velocity: 3128
ES = 33
Accuracy = .395moa at 200 yards

Powder Charge: 91.0
Average Velocity: 3138
ES = 13
Accuracy: .299moa at 200 yards

Shooting from http://www.longrangehunting.com/forums/f53/my-300rum-mcr-70809/#post494570

 

[MontanaRifleman]

Still liking the Cutting Edge 180s?

After spending the last 2 months doing load development, hell bent on finding the perfect 200g bullet load, I've spent some time over the last couple of days punching numbers into the ballistics calculator (better late than never). Current higher end bullet offerings in .308 seem to yield the best BC at around the 180g weight (i.e. the cutting edge and GS custom).

According to the numbers, a faster, higher BC 180g bullet kicks the crap outta the 200g offerings on the market right now.....at every range.

Had decent results at the range last night (found another sub-MOA load w/ Barnes LRX @ 200 yds). So, I think I'm going to finish testing my current 'golden load' (200g LRX, 97g Ramshot Magnum) and get a turret built for my scope with it. Then, round 2 of load development will be dedicated to the 180g super bullets I've found recently (the GS and the Cutting Edge).

--Ben

Hey Ben,

Unfortunately, it's that time of year when I get busy. Haven't done anymore CE or GS testing since the last post and it doesn't look like I'll be doing anymore shooting until late summer and early fall. FWIW, I just got Litz's second book and he tested the CE 180's @ an average G1 BC of .478 between 1500 - 3000 fps which is about .1 less than the CE testers observed. This is almost identical to Bryan's BC for the 180 AB, which is almost identical to the 180 E-Tip and when I lay a CE 180 next to an E-Tip their form is almost identical except hte CE has a longer boattail. . I talked with Dan (from CE) a couple of months ago and asked why all three versions of the 180's tested .6 and he said that's the way they tested in the field. That being said Bryan tested the standard 180's and the MAX's are slightly better in form and the MAX AGG's are slightly better yet. I have to assume their BC's are better. The CE stnd 180's are right in line with almost all the other "higher BC' 180 offerings from the other manufacturers like Hornady, Nosler and Scenar. The Barnes 180 tested
@ .447. I offered to send Bryan some GS 177's to test and he agreed.

The CE bullets are getting me slightly better velocities (about 50 fps) than other bullets and the GS bullets are getting me about 100-150 fps better velocity. The CE bullets give me the best accuracy of all and the GS bullets need to be seated to the lands for accuracy which is impossible for me because their nose is so long I would be unable to seat 2 or 3 driving bands into the neck of my long throated Sendero. If you have a long throat, don't waste your time with the GS bullets. If you want to meet up someday, I'll show what I'm talking about.

If I was you, I would give the 180 MAX's and MAX AGG's a go and see how they do. Follow the reloading online instructions well and seat them about .0202-030 off the lands. The seal tight band and driving band both come into play here. Call Dan and talk to him.

Good shooting and keep us posted.

Mark

 

[venom600]

So, I've settled in on my golden load w/ the LRX. After shooting this weekend, all the way out to 1000yds in Townsend.

200g Barnes LRX
96.5g Ramshot Magnum
Remington 9 1/2M primer
COAL 3.62
Avg. MV: 3207

It's pretty odd to me that the average velocity of this load is higher than the loads I'd prepared w/ 97g Magnum (only slightly faster....but still). That tells me that I'm probably near the top end from a pressure perspective. I didn't have any pressure signs with the 96.5 load, but I would occasionally get a stiff bolt w/ the 97g load.

The 96.5g load has averaged .96 MOA accuracy over ranges from 200-550 yds. I didn't shoot groups with them further than that, but had some success putting a 1 shot kill shot on a cardboard antelope at ~760 yds yesterday. Groups at 550 yds were bouncing around between 4-6". Grouping at about 1.8" at 200.

I think (after yesterday) that I've confirmed that the published BC of the 200g LRX is low. All calculated drops (using Huskemaw BC calc, Shooter on my Android and Strelok on my iPad) using the factory published BC of .546 were a little over a full MOA high at both 550 and 760 yds. I haven't tried to back into the 'real world BC' based on my data yet, but I'll publish that when I figure it out.

Now....on to the 180 grainers :
I just ordered a batch of CE 180 LD HPBT-STD to start playing with. I don't even want to start playing w/ the MAX or MAX AGG, since they're not going to fit in my mag box at recommended seating depths. This is a hunting rifle, after all..... . I guess I could trying seating them deeper than recommended to fit in my mag box if the bullets do actually have a better BC. But, putting that 'Seal Tite Band' below the neck of the case seems scary to me for some reason. We'll see how the STD does for now. I've also toyed w/ the idea of having a Wyatt's extended box fitted into my Sendero (since it's got such a long throat), but that's a future project for sure.

Next bullet for testing after the CE is going to be either the Swift Scirocco II or the E-tip.

--Ben

 

[venom600]

Well....looky what the UPS guy brought to my front door yesterday!

Gonna load some of these up this weekend based on some load data that CE sent to me. Starting w/ 95g Retumbo and working up from there. Hope to get these moving at 3400fps if I can do so safely.

--Ben

 

[venom600]

Well....either my gun hates Retumbo (I've yet to find a load using Retumbo that was accurate in my Sendero), or it hates Cutting Edge bullets......or I was having a crappy day at the range.

I tested 8 different loads w/ the Cutting Edge 180g STD (MTH C48) bullets. I started at 95.0g of Retumbo and worked my way upwards in .5g increments until I hit 99.0g. The best group I could manage (at 200 yds) was 1 MOA @ 3387 FPS. That load was a bit hot....slightly stiff bolt on 2 of 3 shots. So, realistically my gun maxes out with this bullet at 98.5g of Retumbo, which produced 3325 FPS and a crappy 2.8 MOA group.

I'll try this again, using a few Retumbo variations and some Magnum (which my gun *loves*) loads and report back. But, so far, I'm not impressed. All loads were 3.62" COAL, using Remington 9 1/2M primers, with F/L sized brass.

--Ben

 

[trebark]

All loads were 3.62" COAL, using Remington 9 1/2M primers, with F/L sized brass.

Try Fed215M primers and I bet you get better results.

On your COAL, are you jumping or jamming?

 

[venom600]

Try Fed215M primers and I bet you get better results.

On your COAL, are you jumping or jamming?

I haven't found any Fed 215M primers available for sale for quite some time. Do you know where to find them?! Do you really think they'll make that big of a difference, though?

I'm definitely jumping. The Max COAL on my (long throated) Sendero is 3.83, but 3.62 is as big as I can load them and still fit in the mag box.

--Ben

 

[trebark]

I haven't found any Fed 215M primers available for sale for quite some time. Do you know where to find them?! Do you really think they'll make that big of a difference, though?

I'm definitely jumping. The Max COAL on my (long throated) Sendero is 3.83, but 3.62 is as big as I can load them and still fit in the mag box.

--Ben

Primers can make a ton of difference. Third Generation has Fed215M in stock...

FED LARGE RIFLE MAGNUM MATCH 1000 PRIMERS

You're jumping your bullets .020. That's a pretty long way. Do you really have to fit in the mag? Generally when longrange hunting, single loading is not a problem. I find that .010 or .005 generally works better.

 

[trebark]

The Rem 9 1/2 primer is a decent primer, but the match primers like the F215M and and even the Winchester primers are more consistant.

WIN LARGE RIFLE MAGNUM 1000 PRIMERS

Remember that if you go the route of changing your primer, you have to start you load development all over. I was amazed in the difference velocities in my 300RUM when I changed from F215M (match) and their F215 (not match) primer.

 

[venom600]

You're jumping your bullets .020. That's a pretty long way. Do you really have to fit in the mag? Generally when longrange hunting, single loading is not a problem. I find that .010 or .005 generally works better.

I'm actually jumping them .210, and you're right, that is a long way typically. Maybe it matters for these cutting edge bullets, but it definitely hasn't mattered for the Barnes LRXs that I've been shooting at the same COAL.

I guess it's worth trying to push them out farther, but ideally that means a different bullet all together with the CE bullets, since they suggest putting their "seal tite band" right at the case mouth.

I'd really like to be able to use my mag box, if possible, but I realize that's not an absolute requirement. If long bullets become my new reality, I could always have a Wyatt's extended box fitted.

--Ben

 

[Emm 300 RUM]

I'm using a Caldwell lead sled rest too so my hold is fairly steady

 

[MikeL88]

I, too, am working up a load for my new .300 RUM Sendero.

Spent last weekend at the range trying various loads and found that my gun really likes the Tipped TSX. I had a couple of different loads (with RL-25 and Retumbo) that were pushing the 200g TTSX at 2950fps. I loaded up some more with additional RL-25 and 3 different loads with Ramshot Magnum. I'll be shooting those over the course of the next 2 weeks and let you know how they do and provide load data. They should be pushing up over 3100 FPS.

I had several loads with (200g) Accubonds last weekend too, and they weren't grouping well at all (2-2.5" groups @ 100). I haven't given up on them yet, and I've put together a few more test loads with them as well. But, group sizes w/ the TTSX were half the size of the Accubond groups at similar velocities and same powders. I loaded some Accubonds with Magnum too, for testing, and will let you know what I find.

--Ben