.243 Win H380 75gr V-Max question

[7kings]

Question - looking for a good starting load for a Model 11 .243 Win for precision paper punching at 300 yards.

With a 1:9.25 twist rate (which I believe is correct for the Model 11 .243), I'm thinking this:

42gr of H380 (maybe not the best powder, but it's what I have)
75gr H V-Max
COAL: 2.700" ***

Hodgdon lists a COAL of 2.640" for the 75gr HDY HP, but 2.600" COAL for the 58gr and 65gr V-Max (they don't have a 75gr V-Max listed in their data for the .243)

I was basing the 2.700" COAL on some research I've done across the interwebs, but I'm wondering if I should try the 2.600" COAL listed for the lighter weight V-Max that Hodgdon lists instead?

Thoughts?

[7kings]

Also - I'm not married to the 75gr V-Max - I've just heard a ton of good things about it in the .243.

If you have alternate suggestions, please let me know.

[243winxb]

Hornady 75 gr -i have 2.640" & 2.675" OAL in my notes. The H380 i used in a different cartridge. It needs a magnum primer. More so with low pressure starting loads. At near maximum pressure, a standard primer may be ok?

Good all purpose load- 243 win- Sierra 85 gr hpbt #1530 bullet. IMR 4350- 42 to 43 grs. Work up. Cci Br2. Win or Rem brass.

H4350 will work also, just takes a tiny bit more powder.

[7kings]

Hornady 75 gr -i have 2.640" & 2.675" OAL in my notes. The H380 i used in a different cartridge. It needs a magnum primer. More so with low pressure starting loads. At near maximum pressure, a standard primer may be ok?

Good all purpose load- 243 win- Sierra 85 gr hpbt #1530 bullet. IMR 4350- 42 to 43 grs. Work up. Cci Br2. Win or Rem brass.

H4350 will work also, just takes a tiny bit more powder.

Thanks for the feedback. That's weird that you needed a magnum primer - Hodgdon calls for regular LRP in their reload data for this powder / caliber. I guess I'll need to keep it in mind when I'm trying out my starting loads in case I get any strange behavior in the ignition.

[243winxb]

The longer bullets need 3000 fps to stabilize in a 10 twist barrel.https://www.thehighroad.org/index.php?media/243-bullets.3917/full

[Dave Hoback]

Brian, I’d stick to MAX bullet length of the 75gr Vmax & 85gr HPBT with your stock 1:10 barrel. If down the road you decide to build this into a serious contender, you can slap on a 26-28” barrel with 1:8 twist. That way you’ll be able to stabilize the longest, heaviest, highest BC pills out there. Bullets like the 108gr ELD @ .536BC, the 109gr Bergers @ .568BC or the 110SMK at a blistering .617BC!

Oh... and you’ll be fine with regular primers.

[7kings]

Brian, I’d stick to MAX bullet length of the 75gr Vmax & 85gr HPBT with your stock 1:10 barrel. If down the road you decide to build this into a serious contender, you can slap on a 26-28” barrel with 1:8 twist. That way you’ll be able to stabilize the longest, heaviest, highest BC pills out there. Bullets like the 108gr ELD @ .536BC, the 109gr Bergers @ .568BC or the 110SMK at a blistering .617BC!

Oh... and you’ll be fine with regular primers.

Thanks Dave. Sounds like a plan.

[243winxb]

Not saying a standard primer will not work. Just be aware of possible issues. :smile-new:


Ball powders do better with a magnum primer. More so in cold weather. H450 (discontinued) & H380 use coatings to control burn rate. The H450 is slower then H380. Using a CCI Mag primer, i had H450 start to burn in a 22-250 , then it just stopped. When the misfired bullets were pulled, there were clumps of powder burnt together. The rest of the powder in tne case, looked normal. The bullets never moved.

Powders- https://www.firearmsid.com/Feature%20Articles/McCord_gunpowder/ primers- https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

At this link, photos of all different powder. http://www.ilrc.ucf.edu/powders/sample_detail.php?powder_id=257

If you want to know what chemicals are in a powder, go to Hodgdon or Alliants websites a look for the SDS or safety data sheet. Some othere haVE a MSDS.

[7kings]

Not saying a standard primer will not work. Just be aware of possible issues. :smile-new:


Ball powders do better with a magnum primer. More so in cold weather. H450 (discontinued) & H380 use coatings to control burn rate. The H450 is slower then H380. Using a CCI Mag primer, i had H450 start to burn in a 22-250 , then it just stopped. When the misfired bullets were pulled, there were clumps of powder burnt together. The rest of the powder in tne case, looked normal. The bullets never moved.

Powders- https://www.firearmsid.com/Feature%20Articles/McCord_gunpowder/ primers- https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

At this link, photos of all different powder. http://www.ilrc.ucf.edu/powders/sample_detail.php?powder_id=257

If you want to know what chemicals are in a powder, go to Hodgdon or Alliants websites a look for the SDS or safety data sheet. Some othere haVE a MSDS.

Understood. Thanks - lots of good information!

[charlie b]

Which is why a lot of people like the Winchester primers. They are 'advertised' as being suited for the ball powders that Win sells.

I have not seen evidence but some have determined that std Win primers have a bit more output than other mfg primers, kinda like a +P primer.

[Dave Hoback]

This ain’t a bad thing to have also. https://www.natchezss.com/hornady-lock-n-load-o-a-l-gauge-overall-length-straight.html Can just make one, like I did if you have some basic machining/fabrication skills.

It’s best to know exactly where the lands will meet each bullet ogive. Shouldn’t go with what others load. You want to know YOUR chamber’s exact OAL, so you can play with bullet jump.

[charlie b]

I always just use an empty case slightly neck sized to hold the bullet I am using. Then chamber it to determine where the lands are.

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