Hornady 75gr BTHP for XCR-L/AR's?
- Thread starter ccwcanada
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gushulak
CGN frequent flyer
I use a 14.5" Sabre Defence and put alot of the 5.56mm TAP 75gr. BTHP's through mine. Accuracy has been good and feeding and ejection not a problem. Using a 1/7barrel with M4 feedramps. Any 5.56mm ammo runs like a charm in my AR.
I have an Armalite 1:8 twist barrel that stabilizes the 75 hpbt just fine...but then I shoot out to, and on occasion past 500m.
The primary reason to shoot heavier bullets is to take advantage of their increased ballistic coefficient, and reduced dope at distance. With that in mind, the real question should be, do you need to shoot these bullets? The Hornady 68 hpbt and Sierra 69 SMK do better at shorter distances (out to 300m), can be driven faster, and cost less. The 69s will definately stabilize in a 1:9.
Common misconception is that it is the weight of the bullet that matters, when in fact it is the length, and bearing surface of the bullet and the velocity that makes or breaks a bullet from stabilizing.
The Hornady 75gr. HPBT is slightly longer overall than the 77 SMK, (by .01") but both have similar bearing lengths.
It is possible to load longer 'VLD' type bullets that have a shorter bearing length than either of those bullets, but then you are looking at single-load, near the lands, gheyness that is part in parcel with alot of belly gun shooting - black guns shouldn't go there!
The primary reason to shoot heavier bullets is to take advantage of their increased ballistic coefficient, and reduced dope at distance. With that in mind, the real question should be, do you need to shoot these bullets? The Hornady 68 hpbt and Sierra 69 SMK do better at shorter distances (out to 300m), can be driven faster, and cost less. The 69s will definately stabilize in a 1:9.
Common misconception is that it is the weight of the bullet that matters, when in fact it is the length, and bearing surface of the bullet and the velocity that makes or breaks a bullet from stabilizing.
The Hornady 75gr. HPBT is slightly longer overall than the 77 SMK, (by .01") but both have similar bearing lengths.
It is possible to load longer 'VLD' type bullets that have a shorter bearing length than either of those bullets, but then you are looking at single-load, near the lands, gheyness that is part in parcel with alot of belly gun shooting - black guns shouldn't go there!
Are you refering to Overall Length? - the loaded round length is the same at or around 2.250" oal for magazine fitment.
running crappy mags or tilting followers can cause mis-feeds in any ammo, be it double nickel or 77gr. otm rounds.
Another common misconception is that you need these things to be going as fast as they can...it's false, and in fact, sometimes it pays in accuracy to tone down the speed a touch. Sure, you'll need more elevation, but windage isn't affected that much.
A 16" barrelled AR will handle lighter loads with 77gr. SMK no problem out to 500m and then some.
Shelldrake
CGN frequent flyer
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I tried a whack of 75 gr Amax bullets in my DPMS Barreled 1:8 twist 20" tube. Shot really well, but here's the rub....
If you are using/loading to magazine tolerant lengths, we are in trouble. I discovered that the long and skinny/tapered ogive shape of the bullet is nice to be a wind cheater, but when you load it to magazine length, the ogive is so tapered / tight that the neck cannot grip the bullet properly and the bullet slides back into the case. Now you have feeding problems.
So I (experiment: don't do this to your magazines ) cut out the front of an old 5/20 rounder that I could sacrifice. Then I seated the bullet to load into the magazine, just extending the bullet tip beyond the front wall of the magazine, almost contacting the magazine well. Is this reliable?
Yes it fed really nicely, but that dremel hacksaw cut sure looked awful. I still have that magazine and I use it for local range work when testing loads.
In short, I just keep the 75 gr. Amax bullets for my .223 or .22-250 sniper rig(s). They work well out to 800m at Connaught's NSCC matches.
Life is good. I hope this helps your project fun.
Cheers,
Barney
If you are using/loading to magazine tolerant lengths, we are in trouble. I discovered that the long and skinny/tapered ogive shape of the bullet is nice to be a wind cheater, but when you load it to magazine length, the ogive is so tapered / tight that the neck cannot grip the bullet properly and the bullet slides back into the case.
Now you have feeding problems.So I (experiment: don't do this to your magazines
) cut out the front of an old 5/20 rounder that I could sacrifice. Then I seated the bullet to load into the magazine, just extending the bullet tip beyond the front wall of the magazine, almost contacting the magazine well. Is this reliable?Yes it fed
really nicely, but that dremel hacksaw cut sure looked awful. I still have that magazine and I use it for local range work when testing loads. In short, I just keep the 75 gr. Amax bullets for my .223 or .22-250 sniper rig(s). They work well out to 800m at Connaught's NSCC matches.
Life is good. I hope this helps your project fun.
Cheers,
Barney
Thanks Hungry, (and everyone else)
Well, the Hornady manual says the BTHP's can be loaded to standard COL and magazine fit, i.e., 2.25". It does also say that their AMAX will NOT do this reliably, and is best for single shot shooting. So...will have to see on the HP.
They also specify that they shot a Colt AR-15, 1:9" twist, 20" length barrel, in their tests and had excellent results. Which is pretty close to what I got.
It seems every other person has a different opinion...however, given that there generally IS the recommendation for a faster twist, likely a good thing to do just to stop worrying about it.
Been looking at getting a Lilja 20" barrel @ 1:7 twist put on my XCR, but first waiting to hear a range report from Alberta Tactical Rifle on weather it's worth the cost...they're doing a job on someone else's XCR. XCR action and tolerances might not allow for much more accuracy anyway?? Can always just keep using and loading cheapo 55gr FMJ's if it doesn't make a difference.
But I already bought 400 of the 75gr BTHP's!!!! I just really like the idea of a heavy HP round for the XCR if tshtf...
Well, the Hornady manual says the BTHP's can be loaded to standard COL and magazine fit, i.e., 2.25". It does also say that their AMAX will NOT do this reliably, and is best for single shot shooting. So...will have to see on the HP.
They also specify that they shot a Colt AR-15, 1:9" twist, 20" length barrel, in their tests and had excellent results. Which is pretty close to what I got.
It seems every other person has a different opinion...however, given that there generally IS the recommendation for a faster twist, likely a good thing to do just to stop worrying about it.
Been looking at getting a Lilja 20" barrel @ 1:7 twist put on my XCR, but first waiting to hear a range report from Alberta Tactical Rifle on weather it's worth the cost...they're doing a job on someone else's XCR. XCR action and tolerances might not allow for much more accuracy anyway?? Can always just keep using and loading cheapo 55gr FMJ's if it doesn't make a difference.
But I already bought 400 of the 75gr BTHP's!!!! I just really like the idea of a heavy HP round for the XCR if tshtf...
