Shorter, lighter bullets in the 7mm PRC?

NYDAN

Handloader
Sep 17, 2013
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I am intrigued by the 7mm PRC and really like the cartridge case design. I have a left-handed M70 in 7mm RM and plan to replace the barrel on it in 2023. I am considering going with the 7mm PRC instead. The only issue is that I wasn't planning to use it for long range shooting over 500 yards. Instead, I want to load 150 grain BT's and 160 grain AB's rather than the 175 gr. ELD-X. Hornady has load data for the Hornady bullets down to 139 gr. However, the C.O.A.L.s for everything less than the 175 gr. ELD-X are quite short indicating a lot of bullet jump.

I have two questions:
  1. Does anyone know if a 150 gr. BT loaded to near the lands will be long enough to have the shank of the bullet in the neck of the cartridge case?
  2. Other than possibly short C.O.A.L.s is there any other downsides to using this cartridge with these lighter and shorter bullets or in an action designed for the 7mm RM?
Thank you for your thoughts. Dan
 
I'd just scrap the whole idea and sell the rifle to me ;)

in all seriousness, Hornady did release a new 160gr bullet just for the 7 PRC release. It was their new CX, but still. Jim on Backfire TV used 145gr LRX in his with success. I doubt you'd have too much of an issue.
 
I don't have a .284 150 grain BT in hand, but according to JBM's bullet list that bullet measures 1.300 in length. If that is true, then seated to the base of the neck the overall length would be 3.293.

The 7mm PRC uses a standard long action length action with a max overall cartridge length of 3.340. So based on that if your rifle is not chambered for a long throat, you would be right there with that bullet.
 
Guy, I look forward to your results. The chamber drawings show a long free bore. If you have a chance, I would love to know what the C.O.A.L. is for a Nosler BT or AB bullet to touch the lands.
 
So far, from what I am reading, the advantage of the 7 PRC is the faster twist for the longer, higher BC bullets.
If sticking to the average bullet weights, there really isn't any advantage to going to the PRC.
The 7mm Rem Mag is still a great cartridge that will be around for a long time to come. If it has performed for you, why fix it? It ain't broke. While at 60 years old, it might not be as sexy as the new cartridge on the block, but it is a solid, consistent performer.
 
If you are barreling the rifle, just have the smith set the chamber/lead up for whatever bullet you want. A shorter throat than a SAMMI reamer has may be something to consider.
I agree with Charlie. Personally, I would focus on the 160 gr AB and BT's. You would have the BT for target and deer and the AB for everything.

JD338
 
If you are barreling the rifle, just have the smith set the chamber/lead up for whatever bullet you want. A shorter throat than a SAMMI reamer has may be something to consider.
THIS!
Give your smith the bullets you plan to use and he can come up with a compromise throat that will work well with all of them.

Yes, I have throated a chambering for a specific bullet more than one time... I am not recommending this here.
 
Looking at this from a different perspective when I had my 35 Whelen AI chambered I had to have JES give it some free bore to accommodate the longer bullets. the free bore never hurt the accuracy and helped with the pressure my reloads were generating just like the Weatherby free bore chambers. I would stick with the Saami specifications.
 
Thanks to everyone for the replies. I am not rushing into anything yet, but I will let you know when I come to a decision. Dan
 
Sounds great Guy. Fingers crossed that you can do the late season cow elk hunt.
What bullet(s) are you considering to use?

JD338
 
Now that the two hour snow shovel workout is over, I'll be setting up my press with 7 PRC dies... :)

Results will be published in a couple of weeks and if everything is looking good that rifle may get used on a late season cow elk hunt.

Guy
Guy, good luck with the reloading. I will be looking forward to reading about it. Also, I hope you get to hunt the late season with it and get to post your results.
 
Dan, here is my thoughts on your idea. You have a M70 that can easily be swapped over to a 3.6" magazine box so unless you're just dying to have the PRC and shoot PRC ammo, you'd really do everything that the PRC can do. Overall, the Rem Mag holds more powder than a PRC. The rub is when you start seating long, heavy, sleek bullet way down in the case you start to lose powder space, whereas Hornady tailored the case for their 175-180 ELD's. If you want to shoot more normal bullets like you mentioned, I'd stick with the Rem Mag, here's my reason, Rem Mag brass is everywhere and made by alot of great companies and is relatively available and priced right, it'll be some years before the big dogs like Lapua, ADG, etc start making their excellent brass.

I think a 7 Rem Mag with a 3.6" mag box on your 70, throated for a 160 AB to touch around 3.575 or so would really give you a more well rounded hunting rig you're asking about.

Saying all that, I'd bet and Guy's shooting (with the 7 PRC) will tell me if I am full of crap or not, but the tight, just over bullet diameter throat might handle the lighter, shorter bullets just fine as is. I'd definitely wait to see what kinda data Guy puts out.

I think the 7 PRC is a factory wonder. Well designed case, excellent ballistics and minimizes all of the gunsmith work us guys have been doing for years opening up 7 Rem Mags, adding 8 twist barrels and trying to figure out proper throats. It really doesn't get much easier, but if you're never planning on running the long, high BC bullets, I'd spec my gun more suited to what I wanted to use. There's my 2 cents... Probably worth 1/2 as much by the time you read this.
 
Scotty, I really appreciate your comments. I don't think I would want to shoot 1,000 yards at game. I really won't want to wound an animal because I don't know how to read the wind correctly or because I forgot to factor in the difference between trajectories at 1,200 feet above sea level and 8,000 feet above sea level. At a motel in Montana, I met a guy who shot and hit a 6 x 6 bull with a 300 PRC at 1,100 yards. He only wounded the bull and chased it for miles before finally dispatching it. He ended up on private property, was caught by the lessee of property, and was tagged by the conservation officer for leaving meat behind, etc. That is not for me.

So, I probably don't need the long sleek bullets like the 175 grain ELD-X. Since I already have the 300 Win. Mag, and have a 300 WSM build in progress, I don't think I need another "dedicated" elk rifle. So, then I am talking about a deer and antelope rifle. Most likely the 140 gr. AB, the 150 gr. BT, or the 160 gr. AB will do everything that I would like from the rifle for shooting at game out to 500 yards. If I could get a 150 gr. AB or a 168 gr. ABLR to shoot from a 7mm RM then I would have a one load rifle for everything less than elk.

Yeah, I probably don't need the 7mm PRC. It just looks so cool. To be practical I should stay with the 7mm RM. But I will wait to see Guy's results, before I make any decisions. If he shows there is no downside to using the shorter, lighter bullets in the 7mm PRC I may go that route.

Again, thanks to everyone for your responses. Dan.
 
One thing to mention is BC helps from the muzzle out to any distance Dan. Not saying to lock on any high BC bullet just sheerly because of BC but added BC doesn't hurt on the windy days in Wyoming, Idaho, Montana, etc. A good blend of terminal performance is out there and it's for sale daily, you just have to see what you want as it touches down. The 168 ABLR you mentioned is a great one, as is the 175 version. Having a couple inches less wind drift at your stated 500 yard max range is very nice. Run the numbers from a 175 PT at 3000 and a 175 ELD at 3000, while it won't be feet, it'll be enough to assist you, the shooter a little margin of error.

The great thing about a good gunsmith is they can set up your chamber any which way you want. If/when you get some PRC case, and some Rem Mag cases (which I think you have), start seating some bullets you wanna use in them. I typically set my chamber up for the shortest to Ogive bullet of the bunch I want to use. Meaning, when I set my last Mashburn up, I seated the 180 Berger, 175 ELD, 175 Nosler and 180 Scenar to 3.575 (3.6") magazine. Then I measured them all to the ogive. The 175 Hornady ELD was the shortest, so that is where I set the throat. I knew, without a doubt that I could touch and work from the lands AND function through my magazine with any of those bullets at that point.

Do the same thing with your Rem Mag. Do a bit of studying....

I think the PRC is going to be a good one. Offers great performance without blazing so much you'll need to wear a sandbag on your had to shoot it and you'd likely always be able to pick up a box or two of ammo soon enough to get out hunting if you ran into a problem on the loading bench. Plus, it is only a matter of time before other ammo companies start loading for it.

A well thought out analysis, Scotty. I think you have a good handle on this.
Jeeze, I try Mike. I have been messing with these 7 mags for a long time and here Hornady comes and makes a cartridge that does 95% of what my Mashburn Super does and then sells box ammunition to boot. The nerve of them is amazing.
 
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