I can't be the only one...

[Liveforhuntin]

I acquired a box of Lehigh Defense 194 grain controlled expansion, and loaded them up for (God forbid) a time I would NEED them. For practice, I am developing a load with SMK 190grain projectiles. I figure they are so close in weight, the POA would be very close. Anybody else using the 190s?

And I must have missed it, but why is 220 the most common, favorite, etc weight for subs? There must be some sort of scientific or technical reason?

[BlogSarge]

I don't reload, so my 194 MEs are factory. I find that the Gem-Tech 187 subsonics are very close in POI out of my gun to 100yds, which is as far as I've shot them. Mostly I stay within 50yds with the subs.

You can probably load cheaper loads, but this shows that you should be able to match the 194 ballistics close enough for practice.

[dellet]

I used the Sierra 190's when working up the initial load.

Then have switched to Nosler 190's for practice since they are much cheaper in bulk and at times can be found as blems for even less.

[tallburnedmidget]

I acquired a box of Lehigh Defense 194 grain controlled expansion, and loaded them up for (God forbid) a time I would NEED them. For practice, I am developing a load with SMK 190grain projectiles. I figure they are so close in weight, the POA would be very close. Anybody else using the 190s?

And I must have missed it, but why is 220 the most common, favorite, etc weight for subs? There must be some sort of scientific or technical reason?

You have the right idea but you will probably want to try and keep the same amount of bullet in case with the 190SMK as you would have for the lehigh defense bullet so you can get close on the subsonic velocity you are trying to obtain. Once you have that done then you won't have to throw away as many 190ME's to get dialed in for both speed and accuracy.

[Table Rock Arms]

I can't say for sure but seems like I remember that initially the idea behind going with 220gr was that the are heavy enough to cycle in any gun that meets 300 blackout specs. I assume there was a specific set of criteria and that they needed an acceptable margin of error so they are clearly over the weight at which the guns will cycle to account for that. Could be wrong however.

[orbitup]

I can't say for sure but seems like I remember that initially the idea behind going with 220gr was that the are heavy enough to cycle in any gun that meets 300 blackout specs. I assume there was a specific set of criteria and that they needed an acceptable margin of error so they are clearly over the weight at which the guns will cycle to account for that. Could be wrong however.

That and heavier bullets are easier to keep at consistent velocities.

[Whole Bunches]

It takes a bit more pressure to move the heavier bullets, thus giving a stronger gas push exiting the bbl at the gas port which is more likely to cycle the gun.

[colt933]

And given the context of a subsonic load, where velocity is limited, all things being equal, a higher mass moving at the same speed will have more inertia/energy.

Physics, yo.

[rebel]

I know the bullets are expensive.... but when I worked up a load with these a stuck with the bullet. It has it's own idiosyncrasies that another bullet will not reproduce. I'm happy with what they will do and do not regret putting the $$ downrange.

[Disregarded9-Side]

Just an opinion based on experience (though none with the Lehighs), FWIW;

the SMKs will likely have a POI shift worth taking into account when compared to the Lehighs. You'll be dealing with very different pressures (I'm assuming) because of the difference in the OAL of each projectile (assuming the lead-free Lehigh is much longer than the SMK), and that will throw it off. The difference the lengths of the bullets will also change the way they move through your barrel.
The different projectiles will also have drastically different ballistic coefficients based on their respective designs, which given that you're likely not going to be shooting these loads over extreme ranges shouldn't matter as much as it would in a precision rifle-type situation, but it will certainly still make a difference.

It is not at all uncommon for me to see POI shifts worth accounting for between two projectiles of the same weight, and even within the same brand (SP vs Ballistic Tip, for instance), especially when ranges are extended.

If you have a 300BLK setup with co-wittnessed irons and an Eotech or similar, you can zero the irons for the Lehighs and then change the Eotech to match the POI of the other loads you're shooting at the time. It's easy to then record the POI change for each load you shoot in terms of how many windage and elevation clicks you need to adjust to align POA and POI; after you've got it mapped out written down once, you can zero your rifle to any load easily before changing cartridges and know you'll be on target. Then when you're done you can just look down the sights and put the reticle back on top of the irons' zero. This works much better precision-wise with a 1 MOA dot like an Eotech as opposed to a 4-6 MOA dot of the Aimpoints or similar, but the idea is the same

I'm totally with you that I like to "practice what I preach" when it comes to loads that I'm hunting with or hoping I never have to use to defend myself. Frankly, for this reason I don't shoot $2 projectiles. If money were no object at all the Lehighs would be the only subs I would load up. When loading ammo for hunting/SD I find cost effective projectiles that are also effective on target and stick with them for lots of shooting and familiarization. I have no doubt at all that the Lehighs are extremely devastating on target... but if you find a two-legged nocturnal varmint in your home at 1:30am and shoot it within 25 yards with a Blackout, then stand over them and ask "Hey, did that feel like a 194gr Lehigh non-toxic or a 245gr cast bullet to you?", I doubt you'll get a coherent, correct answer--even if the exit wound will indeed tell the whole story.

Good luck man,
D