I’m in the process of building a 7.5 in 556 7 twist pistol to keep in my truck just in case the libtards go crazier someday. Question is I am not sure which ammo would be best 50g vmax or something similar or say 75 or 77g or maybe something like a 64g gold dot which would you use?
Engagement distance can only be speculative but assume 5 to 50 yds.
I think the vmax or any varmint load would be terrible - they don’t penetrate enough, especially through intermediate barriers. Heavy OTM rounds are a good choice like MK318 and the gold dot is great too. Check out the terminal ballistics section, lots of info for you there and that’s typically where questions like this will get more responses.
I’d recommend 10.5" minimum for 5.56.
Shorter than that, strongly consider an alternative caliber like 300 BLK, 277 WLV or 6.8SPC
ETA:
The 64gr Gold Dot should be a good choice.
https://www.m4carbine.net/showthread.php?120445-Your-thoughts-of-223-64-gr-SPEER-GDSP
^ I second that too.
I understand the no shorter than 10.5 reasoning, I have an 11inch and 12.5 inch 556 uppers to go on my 2 300blk which are 8.5 and 10.5 inch. I am just trying to build something as short, and light as possible to keep in my vehicle which could if nessesary be deployed out the window relatively quick.
Or possible be placed in a get home bag. Thank you all for the responses thus far
Speer’s 64 gr. GD is in my “truck gun”- 10.5" “pistol”.
Effective and accurate round.
I’ve used it deer hunting with success. Terminal performance was impressive- and encouraging.
I have watched a few youtube videos on the 64g gold dots they do look impressive, I also noticed PSA has them on sale quite often for 9.99 and free shipping if you buy 10, I might just have to order a few and see how well they do. Thank you gentlemen
Agreed. Less than 10 or so is useless.
Reliability and function issues aside - will the 64 gr gold dot even reach its expansion threshold for velocity from a 7.5" barrel? I don’t recall what the velocity threshold figure is. If the gold dot won’t expand at the low end of velocity, nothing will and you’d just be ice-picking a would be assailant.
I think one thing is for sure nobody likes my 7.5 in 556 short, lite, truck gun idea perhaps I’ll rethink my planned purpose and just build another 8 in 300 blk, the one I currently have is way to nice to be a truck gun.
Are you stuck on the AR platform? If not, have you thought about the Micro Draco. It is only ~15" OAL.
7.62x39 works right in the range you are desiring.
I am stuck with the ar platform I guess, been messing with them since the early 80’s and I know absolutely nothing about ak platform. I have 7 ar’s in various calibers and enough parts to build at least 3 more. Guns are my obsession in life.
I spend all my money on guns, beer and women the rest I just waste.
Those above linked threads showed the expansion threshold of 1800 fps.
Looks like a muzzle velocity of somewhere between 1900-2000fps from a 7.5" barrel.
This gives an expansion range between 35 and 65 yards, sufficient for stated purposes.
Some other germane threads.
https://www.m4carbine.net/showthread.php?107703-7-5-quot-AR-amp-Speer-Gold-Dot-ammo
https://www.m4carbine.net/showthread.php?73955-Federal-XM223SP1-62gr-Bonded/page2
You should…even touching off 556 out of SBR lengths inside a vehicle without ear pro will feel like getting flashbanged. Id hate to imagine what a pistol length AR would feel like.
I have a 7.75 inch that runs well but it is a PWS Diablo. I really like it and I have no issues running it.
I do use a Dead Air Sandman on it for long periods of shooting.
Maybe something like the basic 55gr Hornady JSP would be ok? I recall the 55gr Hornady JSP came up just a bit short in gel from a 16" barrel, so maybe the lower velocity would help it retain more weight and fragment less and penetrate more?
If I absolutely had to use a 7.5" barrel it would be a 9x19 or .300blk.
I thought about the 55g sp, and you are probably correct . Slower velocity might work for that bullet.
I guess my original thought on the 7.5 inch is that I would rather have a short, ar pistol than a hand gun in a shtf like riots ect. I have watched to many people get dragged out of there vehicle and nearly beaten to death I can assure you it won’t be happening to me. It will be say hello to my little friend
If you’re committed to the 7.5" barrel, and a top contender appears to be the 64gr Gold Dot, why not consider the 55gr? In the grand scheme of things it’s a very capable round. Mission drives the gear, right? For this “truck gun” the worst case scenario is getting hemmed up by some BLM or social justice terrorists. The goal is to have enough firepower to get the ef’ out of there.
So, we’re talking engagements likely within 25 yards; but probably more like 25 feet. As Cliff stated, the 64 should be fine up to around 50 yards. Honestly, most defensive loads we discuss would provide you with the means to get out. Still, it won’t hurt to have a little more velocity at the muzzle; which the 55 would provide.
I’m sure a round loses some juice going through a windshield or door. How much? I have no clue. Regardless, the higher the starting point above that 1800-ish fps threshold, the better.
If I were restricted to your barrel length, caliber, and setup I’d likely look to something in the 55gr range. Beyond the GD, I do think a sp would be a worthy consideration. The 50gr TSX would be another.
Ready for my wildcard…
…How about the DRT offerings? I may get reamed for this, but their threshold is claimed to be in the 1400-1500 range. Yes, it fragments, rather than expands. However, it appears to handle barriers quite well. Add the lower velocity threshold, and you now have heavier options to choose from. It’s thought of as a gimmicky round; and it very well might be. But, there is a good amount of testing and user reports that show it’s effective on small to medium game.
Before anyone goes too crazy over the above, it’s not what I’m recommending as a top choice. It’s more of a “just for fun” thought. I simply wonder if those who’d never consider it for normal defensive use might be willing to entertain the idea within the OPs variable constraints and theoretical defensive scenario.
I have considered the 55g gold dot, I have purchased 1200 rds of the 64g gold dots from psa but they never seem to have a sale on the 55 or 75 or for that matter have them in stock. If they do become available I will purchased a case, to keep on hand.
Ultimately, the 64s should be fine. Right now, it does look like they have the 55s on sale for $10.99/box and are showing in stock.