brn2hnt
WKR
Really like the live-hunt style threads, and thought I would go along with a live load development thread to chronicle load workup for my new 300 win mag by Hells Canyon Armory.
I am looking to built an accurate, precise load, but lack many tools commonly used by top reloaders (namely annealers and bushing dies) in the hopes that it might help someone searching for the same. Outside of the powder scale, virtually all of my equipment was a budget purchase, and so I think represents a pretty good “entry level” setup. I’ll lay out the objective, context, and what I have to work with, as if you don’t know where you’re headed, it is impossible to make an informed decision, and the context and givens help shed light on WHY certain decisions are made, your needs may be different, and thus would necessitate a different decision, but the logic behind why the decision was made would still be applicable.
Objective:
Accurate, reliable, and consistent hunting round that will deliver over 2,000 ft/lbs KE past 6” wind drift (4mph) range at 6,000 ft elevation.
Context:
Recently received my custom build 300 WM from Mike at Hells Canyon Armory, and want to document the load workup. Rifle is throated for 215 bergers, 26” barrel, 1 in 9.5” twist, with 4 port MBM brake. Primary functions will be elk, mule deer, and black bear. Roughly 50% elk, 40% deer, 10% other. Hunting elevations ranging from 5,000’ to 10,000’. Must perform well from 0-800 yds on game, as shots in typical terrain are usually under 200 or over 450.
Givens:
Brass prep:
I had a bunch of fired 300wm brass from a pair of existing rifles, so I tumbled to clean, and full length re-sized to space off the belt to make sure they would fit, not knowing the dimensions of this new chamber. Trimmed all cases to within SAAMI spec and to square off the necks, the chamfered inside and out. Cleaned all primer pockets, then tumbled one last time for good measure.
After the final tumbling, I primed with Federal 215M primers, as there’s tons of recipes that use them, and I have nearly 1,000 of them.
For a starting load workup, I scoured the interwebs, finding lots of preferred loads from 74-77 grains of H1000 and the 215 bergers. I started with 73.5 grains, working up to 77.5 grains in .5gr increments. This was nine charges with 5 rounds each simply because I figured I would run into pressure by 77.5 grains and because I only had one 50 round case and 45 pieces of brass ready. Additionally, many other reloaders pointing to “typical” preferred charges being under 77.5 grains, I saw no need to work up higher.
Went to the range yesterday to test out all 9 charges. (100 yd range, shooting off cheapo harris bipod and rear bag) Fired one round from each charge to test for pressure signs first, however, even at 77.5 grains I never saw any signs of pressure. This is likely due to the extremely long COAL increasing case volume thus decreasing pressure. Needless to say, always work up from well below max loads.
After verifying safe pressures, I shot 9 4 shot groups and recorded velocities from my chronograph and measured group sizes. I got 2 great (for me) groups out of the 9 charges, One at ⅜” and one a ½”.
I will be testing these further, as the velocity data throughout the shooting session has seriously shattered any faith I have in the chrony. WIthin the 4 shots of the ½” group, my ES was over 250!
So, going forward, the plan is to test 6 new charges, the tight group charges an .2gr+/- for each of them. Shoot for groups again, even with the chrony’s questionable results, then shoot at much longer distance to verify true velocity.
I am looking to built an accurate, precise load, but lack many tools commonly used by top reloaders (namely annealers and bushing dies) in the hopes that it might help someone searching for the same. Outside of the powder scale, virtually all of my equipment was a budget purchase, and so I think represents a pretty good “entry level” setup. I’ll lay out the objective, context, and what I have to work with, as if you don’t know where you’re headed, it is impossible to make an informed decision, and the context and givens help shed light on WHY certain decisions are made, your needs may be different, and thus would necessitate a different decision, but the logic behind why the decision was made would still be applicable.
Objective:
Accurate, reliable, and consistent hunting round that will deliver over 2,000 ft/lbs KE past 6” wind drift (4mph) range at 6,000 ft elevation.
Context:
Recently received my custom build 300 WM from Mike at Hells Canyon Armory, and want to document the load workup. Rifle is throated for 215 bergers, 26” barrel, 1 in 9.5” twist, with 4 port MBM brake. Primary functions will be elk, mule deer, and black bear. Roughly 50% elk, 40% deer, 10% other. Hunting elevations ranging from 5,000’ to 10,000’. Must perform well from 0-800 yds on game, as shots in typical terrain are usually under 200 or over 450.
Givens:
- Chargemaster Scale
- Lyman tumbler (corn cob)
- RCBS single stage press
- RCBS FL 300 WM Dies
- Hornady Comparator adapter for calipers
- Universal Decapping Die
- Cheap Primer pocket cleaner
- Cheap Case trimmer
- RCBS Case lube and pad
- RCBS Hand Priming tool
- Chrony Alpha Chronograph
- Federal Brass* (not required, but do have ~100 cases existing)
- Federal 215M Primers
- H1000 powder
Brass prep:
I had a bunch of fired 300wm brass from a pair of existing rifles, so I tumbled to clean, and full length re-sized to space off the belt to make sure they would fit, not knowing the dimensions of this new chamber. Trimmed all cases to within SAAMI spec and to square off the necks, the chamfered inside and out. Cleaned all primer pockets, then tumbled one last time for good measure.
After the final tumbling, I primed with Federal 215M primers, as there’s tons of recipes that use them, and I have nearly 1,000 of them.
For a starting load workup, I scoured the interwebs, finding lots of preferred loads from 74-77 grains of H1000 and the 215 bergers. I started with 73.5 grains, working up to 77.5 grains in .5gr increments. This was nine charges with 5 rounds each simply because I figured I would run into pressure by 77.5 grains and because I only had one 50 round case and 45 pieces of brass ready. Additionally, many other reloaders pointing to “typical” preferred charges being under 77.5 grains, I saw no need to work up higher.
Went to the range yesterday to test out all 9 charges. (100 yd range, shooting off cheapo harris bipod and rear bag) Fired one round from each charge to test for pressure signs first, however, even at 77.5 grains I never saw any signs of pressure. This is likely due to the extremely long COAL increasing case volume thus decreasing pressure. Needless to say, always work up from well below max loads.
After verifying safe pressures, I shot 9 4 shot groups and recorded velocities from my chronograph and measured group sizes. I got 2 great (for me) groups out of the 9 charges, One at ⅜” and one a ½”.
I will be testing these further, as the velocity data throughout the shooting session has seriously shattered any faith I have in the chrony. WIthin the 4 shots of the ½” group, my ES was over 250!
So, going forward, the plan is to test 6 new charges, the tight group charges an .2gr+/- for each of them. Shoot for groups again, even with the chrony’s questionable results, then shoot at much longer distance to verify true velocity.
