Rmr 75gr bthp over rl15

[Big-bore-bob]

Hi all,
So I'm diving in to reloading rifle cartridges for the first time. I just bought a radian model 1, 18in ar15. I've just ordered some rem 7 1/2 primers and sourced 5lbs of rl15. I plan on using once fired lake city brass. I would like to use rmr 75gr bthp bullets because of the incredible price. Does anyone have experience with this component combo? I'm looking for sub moa accuracy for coyote and target work. I have manuals that list this powder with a 75gr bullet so I don't need load data, just curious about personal experience with this bullet and/or powder. Thanks in advance for any replies! Happy shooting.

 

[LiveLife]

I have plans to do range testing with RMR 75 gr BTHP with BL-C(2) and Staball Match due to lack of powder availability locally after the rainy season.

FWIW, Johnny's Reloading Bench tested Hornady 75 gr BTHP with 24 gr of RL15 and got 1.22" group with 2708 fps (24 gr of Varget produced 1.21" group with 2622 fps) at 16:15 minute of video in this 19 powder comparison:

.223 Rem - 75gr Hornady BTHP with 19 powders

I'm trying every powder and load that was mentioned in the comments section of last week's video.We're shooting the 75gr Hornady BTHP with Cannelure and this...

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And OAL range testing using Hornady 75 gr BTHP from 2.233" to 2.260" which I plan on repeating with RMR 75 gr BTHP (Quite a bit of variation in group size from 0.56" to 1.19")

223 Rem - 75gr Hornady BTHP with AR-Comp

I'm testing the 75gr Hornady BTHP with Cannelure using AR-Comp. We've got a known-good charge, so I want to test seating depth in this video.I also make a cu...

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[Big-bore-bob]

FWIW, Johnny's Reloading Bench tested Hornady 75 gr BTHP with 24 gr of RL15 and got 1.22" group with 2708 fps (24 gr of Varget produced 1.21" group with 2622 fps)

Thanks for the reply! I watched this video during my reloading research phase. The rl15 wasn't the best powder tested for sure but it was the cheapest/best/available powder i could get locally, however my rifle will shoot 1.2in groups with bulk winchester 55gr m193, so I was being optimistic with my sub moa goal I suppose. I was considering a 1000 bullet order. Should I buy less for testing purposes? My goal would be a mk262 ish clone. Also I was looking for a powder that would meter well in my bench powder dropper.

 

[LiveLife]

My goal would be a mk262 ish clone.

BTW his Mk262 clone testing with 77 gr Sierra BTHP and RL15 at 23.7/23.9/24.1/24.3/24.5 gr steps at 15:40 minute of video

Cloning Mk262 - pt 10 - H4895 and Reloder 15

The quest continues to duplicate the Black Hills 77gr OTM factory ammunition, also known as Mk 262 Mod 1. Today's test powders are Hodgdon H4895 and Alliant...

www.youtube.com

 

[LiveLife]

Another thing to consider is adjusting OAL/bullet seating depth.

When Johnny's Reloading Bench ran OAL testing using Hornady 75 gr BTHP from 2.233" to 2.260" (which I plan on repeating with RMR 75 gr BTHP), he saw quite a bit of difference in group size from 0.56" (2.251") to 1.19" (2.236").

 

[Big-bore-bob]

When Johnny's Reloading Bench ran OAL testing using Hornady 75 gr BTHP from 2.233" to 2.260" (which I plan on repeating with RMR 75 gr BTHP), he saw quite a bit of difference in group size from 0.56" (2.251") to 1.19" (2.236").

Just rewatched the video, rl15 did pretty good. Is 2650fps sufficient for long range target and coyote work? It's about 100 fps short of mk262, though i havent chronographed mk262 in my rifle. As you've pointed out the longer loaded rounds seem to group better. I have a 223 wylde chamber and I'm not sure how that factors in to coal choice and magazine length restrictions. Also I have a 1-8 twist barrel.

 

[bullseye308]

RL15 is a top mentioned powder for heavy 223/556 loads on a few boards and lots have had great success with that combo. The determining factor will be if your rifle likes it. A Wylde chamber is the best option in my mind, allowing you to shoot 223 or 556 pressured rounds in it, and your twist should do well with that combo.

When I order bullets that have great reviews or a good track record for what I’m after, I get at least 1000 so they are from the same lot and should all shoot the same. My next RMR order will be a few thousand of those and probably 5k of the 124 Nukes. Love RMR bullets and I’m going for the same goals you are, sub moa groups but with a different powder.

 

[bullseye308]

Your magazine will limit your OAL unless you single load them. I’d expect 2650 to be sufficient with a 77 bthp to drop a yote, bullet placement obviously is key, but it should, I’d expect, do the job nicely.

 

[Show Me]

Open sights. Blast away, won't matter. Target rifle with scope. I never buy more than a lb to test.

 

[conan32120]

Might I ask what's the twist rate on your ar barrel? 77gr might need a 1-7" to show good performance and as stated earlier mag length also tends to be a factor

 

[Laphroaig]

I've been loading the 75 Hornady version, mag length, over Rl15 w/ various brass, IMI currently. It's a great combination for 300 yd. service rifle competition. My barrel is 1:8.

I've never tried the RMR's but I think that you will do fine from everything that I have read about them.

 

[Larry in wyoming]

I recently started loading the 75gr rmr in an 8 twist 18" barrel over varget. 3 shot groups are sub MOA

 

[Big-bore-bob]

Might I ask what's the twist rate on your ar barrel?

It's 1-8.

 

[conan32120]

I asked because my 9 twist struggles over 69gr

 

[Larry in wyoming]

I asked because my 9 twist struggles over 69gr

How fast are you pushing them?

 

[Big-bore-bob]

If usps ever manages to deliver my new dies I'll be able to work up my ladder test and have a range report this weekend. I just finished swaging 650 lake city 5.56 cases and ordered 1000 rmr 75gr bthp, they should show up today. Components are ready to go.

 

[Larry in wyoming]

I shot this yesterday 75 gr rmr over 22.5gr mp540 these bullets are all I am going to shoot in this rifle I think.

 

[Laphroaig]

mp540

Tell us more about that powder. Ball or extruded? Where did you get it? Any chrono data with that load?

 

[Larry in wyoming]

Tell us more about that powder. Ball or extruded? Where did you get it? Any chrono data with that load?

Extruded. Americanreloading.com. No chrono data yet. Burn rate appears to be around 8208xbr or N135 according to these guys http://natoreloading.com/MP540/

 

[Random 8]

I have done fairly well with R15 and the 75 Hornady HPBT and the 75 Hornady ELD-M in a RRA 20" 1:8 service rifle.

That said, it is NOT my favorite powder here. It runs dirty, and my groups are slightly larger with the R15 loads vs Varget or AA2495. My long line load, with the 75 Eld-M loaded long (do not attempt mag length here) is a different matter. This load is used to 600 yards in Service rifle competition, and was tested at distance vs several other powders and came out on top, so R15 certainly has potential. It is certainly not a bad choice in your application, and should do well. If you really want to squeeze down your groups, I would give a few other powders a try along the way. AA2495 and N140 should be on your short list.

 

[Big-bore-bob]

My long line load, with the 75 Eld-M loaded long (do not attempt mag length here) is a different matter.

Eld-m can't be loaded to mag length? Longer bullet? I haven't researched all the bullet offerings for 5.56/223 quite yet.

 

[JEBruns]

Eld-m can't be loaded to mag length? Longer bullet? I haven't researched all the bullet offerings for 5.56/223 quite yet.

The 75gr version can't be. The lighter ELD-M's do not have to be loaded longer than mag length.

 

[AJC1]

The 75gr version can't be. The lighter ELD-M's do not have to be loaded longer than mag length.

I believe you have that reversed. The eldm 75 will not load mag length, but the 75bthp will without issue. I wasn't wowed by the bthp.

 

[Random 8]

Eld-m can't be loaded to mag length? Longer bullet? I haven't researched all the bullet offerings for 5.56/223 quite yet.

Correct in the 75 grain weights, due to bullet length. It is designed specifically for single loading for long range shooting in the 5.56, and has some utility in other calibers. Your RMRs, the Hornady HPBT, Sierra and Nosler 77 HPBT CAN all be loaded to mag length in the 5.56 NATO. As far as I know, these are the heaviest bullets that may be safely loaded to magazine length in a 5.56 AR. They do make some lighter weights of ELD-M that can be loaded to mag length, but there is not much gain in BC vs more conventional offerings with these.

 

[Big-bore-bob]

Well I assembled my ladder test for the weekend. Rmr 75gr bthp 3gh, lake city once fired brass, rem 7 1/2 primer, rl15 powder, assembled with a dillon 3 die set. I decided to start the charge weights in the upper middle of the hornady .223 data (22.5gr) and work up in .5gr increments to 24.5gr (24.9 max per hornady for 5.56 nato). I figured I could locate the nodes and dial in around them in my second round of testing. Rounds are mag length ( about 1/32in gap from touching the tips on the magazine, 2.2515). The crimp was an eighth turn down from case mouth contact ( about 1 thou crimp as best as I could measure it. Sanity check please!? Any tips anyone is willing to share are greatly appreciated!