LR primers in place of LRM

Dented

WKR
Joined
Jan 4, 2021
Messages
383
I'll be loading 257 Weatherby and I haven't got any LRM primers. Can anybody offer some insight on using LR primers in their place? Thoughts, suggestions, anything to look it for?
Thanks!
 

Odd1out

FNG
Joined
Sep 6, 2023
Messages
97
I looked up powder capacity on 257. Its on the line between 60 to 70grs were usually people go to magnum primers. I would suggest you watch a video by the real gunsmith on utube called primers. Its 20mins but its packed with info and real world experience.

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Joined
Mar 16, 2023
Messages
19
With that size powder charge, you might get incomplete or inconsistent powder burn, leading to velocity swings and inaccuracy. It might be ok depending on what powder you're using, or it might not. I know, that's super helpful...
 

ckleeves

WKR
Joined
Feb 25, 2012
Messages
1,540
Location
Montrose,Colorado
It wouldn’t phase me to load LR primers in a .257 bee (although somewhat powder dependent). At this point I have loaded and shot thousands of rounds of 300 wm, 300 wsm, SAUM’s and even 300 prc with standard LR if they gave me better numbers and have yet to have a hangfire or a single problem.

Try it and see. If your worried about hangfires freeze a few rounds and try them.
 

Andouille

Lil-Rokslider
Joined
Oct 5, 2021
Messages
221
Location
AK
I can provide some anecdotal information based on my similar powder charge and LR primers for 300 WSM. I've had excellent results with powder charges of up to 73.5gr Superformance and 67.5 gr Staball 6.5 and H4832SC. Standard deviations generally less than 15 and as low as 8 fps, so clearly no issues igniting the powder. I shot 10 rounds with mag primers and had lower velocities and larger SD/ES with Superformance, so I only run LR primers now.
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
833
From my research on 300prc, plenty of people using LRP instead of magnums and getting great results. I'm testing that hypothesis out tomorrow. I hope it works because I can't find magnum primers anywhere.
 
OP
D

Dented

WKR
Joined
Jan 4, 2021
Messages
383
Great input, thank you! I'll be watching the SD numbers.
 

Odd1out

FNG
Joined
Sep 6, 2023
Messages
97
From my research on 300prc, plenty of people using LRP instead of magnums and getting great results. I'm testing that hypothesis out tomorrow. I hope it works because I can't find magnum primers anywhere.
Let us know your results

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SloppyJ

WKR
Joined
Feb 24, 2023
Messages
833
Well I went out today and had some interesting results. I ran a ladder test for 215 Bergers, 200 ELD X, and 180 TTSXs. I tried H1000, Retumbo, and Staball HD.

I had a lot of variation in the Staball HD specifically. This was new brass and I used my digital Frankford scale. This was also the first 40 shots on the barrel and my first time with my garmin chrono. I have no data to compare it to but I need to tighten this up a bunch. I'm going to start by running subsequent ladders weighing charges with my beam for consistency. I imagine that there has to be more consistency with brass that's better formed to my chamber as well.

With this data I can't say that it's the primers but I certainly can't rule it out. Take it with a grain of salt.

I'm concerned with the 0.5gr jumps in powder charge and velocity going down. To me, that means there is significant deviation in these loads. Easiest thing to me is to rule out my scale first. I'll report back when I get out again.

Staball HD 215 Berger
82gr - 2807.7
82.4 - 2776.1?
82.6 - 2794.7

Staball HD 200 ELD X
81.5gr - 2829.8
82 - 2884.6
82.5 - 2887.2
83 - 2864.1 ?
83.5 - 2917.9

Staball HD 180 Barnes TTSX
83gr - 2920.4
83.5 - 2895.8
84 - 3016.0
84.5 - 2992.5

H1000 180 Barnes TTSX
83.5gr - 3037.6
84 - 3102.3


H1000 Ladder 215 Berger
78gr - 2688.1
79 - 2716.4
79.5 - 2760.5
80 - 2791.0
80.2 - 2808.0
80.4 - 2780.1 ?
80.6 - 2805.0

Retumbo Ladder 215 Berger
79gr - 2716.2
79.3 - 2746.7
79.5 - 2759.7
80 - update prompt missed shot
80.3 - 2808.3
 
Joined
Aug 23, 2023
Messages
15
Location
Central Pennsylvania
There's only one way to find out for sure. Load up a few and try them. You'll know fairly quickly if it's a viable option. I've had instances where they worked better and vice versa. Like someone mentioned above, lots of guys have had success with LR primers in a 300 prc. I'd say that it's worth a try.
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
833
There's only one way to find out for sure. Load up a few and try them. You'll know fairly quickly if it's a viable option. I've had instances where they worked better and vice versa. Like someone mentioned above, lots of guys have had success with LR primers in a 300 prc. I'd say that it's worth a try.
Well that's the problem. I cannot find them. I'll have to start tracking them down now. I'll run some of the same loads and see how they compare.
 

eric1115

WKR
Joined
Jun 26, 2018
Messages
591
I used BR2's in my 7mm RM with 65 hr H1000 with no issues ever. Very consistent, no ignition problems even in cold temps.
 
OP
D

Dented

WKR
Joined
Jan 4, 2021
Messages
383
I haven't found LRM anywhere. I figure it'll be another case of watch until they're released by the manufacturer and buy a brick. And the price will be exorbitant...🤦🏻‍♂️
 
Joined
Jul 18, 2019
Messages
2,076
I shot a few hundred 7RM with LRPs (BR2s) when magnums were nowhere to be found.

My experience was 50 fps slower and higher SD, but still great accuracy.

Testing with Retumbo, H100, 4831sc, and IMR 4350. 168 VLDs and 180 ELDMs.
 

tdhanses

WKR
Joined
Sep 26, 2018
Messages
5,744
It wouldn’t phase me to load LR primers in a .257 bee (although somewhat powder dependent). At this point I have loaded and shot thousands of rounds of 300 wm, 300 wsm, SAUM’s and even 300 prc with standard LR if they gave me better numbers and have yet to have a hangfire or a single problem.

Try it and see. If your worried about hangfires freeze a few rounds and try them.
Same here.
 

tdhanses

WKR
Joined
Sep 26, 2018
Messages
5,744
Well I went out today and had some interesting results. I ran a ladder test for 215 Bergers, 200 ELD X, and 180 TTSXs. I tried H1000, Retumbo, and Staball HD.

I had a lot of variation in the Staball HD specifically. This was new brass and I used my digital Frankford scale. This was also the first 40 shots on the barrel and my first time with my garmin chrono. I have no data to compare it to but I need to tighten this up a bunch. I'm going to start by running subsequent ladders weighing charges with my beam for consistency. I imagine that there has to be more consistency with brass that's better formed to my chamber as well.

With this data I can't say that it's the primers but I certainly can't rule it out. Take it with a grain of salt.

I'm concerned with the 0.5gr jumps in powder charge and velocity going down. To me, that means there is significant deviation in these loads. Easiest thing to me is to rule out my scale first. I'll report back when I get out again.

Staball HD 215 Berger
82gr - 2807.7
82.4 - 2776.1?
82.6 - 2794.7

Staball HD 200 ELD X
81.5gr - 2829.8
82 - 2884.6
82.5 - 2887.2
83 - 2864.1 ?
83.5 - 2917.9

Staball HD 180 Barnes TTSX
83gr - 2920.4
83.5 - 2895.8
84 - 3016.0
84.5 - 2992.5

H1000 180 Barnes TTSX
83.5gr - 3037.6
84 - 3102.3


H1000 Ladder 215 Berger
78gr - 2688.1
79 - 2716.4
79.5 - 2760.5
80 - 2791.0
80.2 - 2808.0
80.4 - 2780.1 ?
80.6 - 2805.0

Retumbo Ladder 215 Berger
79gr - 2716.2
79.3 - 2746.7
79.5 - 2759.7
80 - update prompt missed shot
80.3 - 2808.3
Just as a comparison I’m getting 2,963ft/s with the 215’s out of a 300wsm. I use LR primers and RL26. I would of expected over 3000ft/s with a 300prc pretty easy with the 215’s.
 
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