7mm Rem Mag F-class?


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jwrowland77
September 4, 2013, 05:51 AM
Is/can a 7mm RM be used in f-class prone competitions?

I was just wondering. I have a 7mm RM that I use for hunting and have a load that shoots 5 shot groups the size of a dime, and I'm thinking I could accomplish the same thing with a match grade bullet like SMK or Berger or something of the sort. Mine has a 1:9 twist and the 7mm RM has a flatter trajectory than .308 with more velocity.

I've been thinking about this since I started my research into f-class comp.

Thoughts....

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USSR
September 4, 2013, 09:58 AM
Sure, it can be used in F Class Unlimited Class, where all the cartridges other than .223 and .308 compete. But, not a good choice.

Don

jwrowland77
September 4, 2013, 10:00 AM
Why's that, other than the mule kick it has? Just trying to learn.

Jim Watson
September 4, 2013, 10:40 AM
It is not a common choice, there is some interest in more "modern" 7mms like WSM and SAUM and wildcats. But if it will shoot accurately (the F target ten ring is 1 MOA, the X is 1/2 MOA) then the part about "I have a 7mm RM" is what counts.

No reason not to attend some matches and see if you like the sport.
Then you can get a dedicated match rifle.

627PCFan
September 4, 2013, 10:56 AM
If you just want to shoot what you brung, theres not a thing wrong with it if you can take the recoil. I built one in 6.5x55, but the flavor at the time was 6.5x284. Shootings shootin, and its always fun :)

Trent
September 4, 2013, 11:01 AM
7mm mag will be fine in F-Open

Heck, I use 300 Win Mag and do really well.

Only problem you're going to run in to is heat, same as me. Magnums make barrels get hot, and damn fast. Those 20 shot strings are not fun with a magnum.

jwrowland77
September 4, 2013, 11:21 AM
True, I have noticed though that I am able to shoot more reloads than I can factory loads. I was actually surprised one day when I was able to go through 60 reloads in one day, with my 7mm RM and my shoulder wasn't falling off.

Hmmm, decisions. I just like to shoot. I might have to try it out one time and see what happens.

USSR
September 4, 2013, 12:11 PM
Magnums make barrels get hot, and damn fast. Those 20 shot strings are not fun with a magnum.

+1. Also, you will be firing from the prone position. Recoil in the area of your collar bone gets noticeable REAL quick!:eek:

Don

BullfrogKen
September 4, 2013, 12:50 PM
Yeah, as long as there's no muzzle brake or other such thing. That's not nice to the people to your left and right on the line.


But you will be pretty bruised up at the end of a 3x600 match. Hey, go try it. Don't let it stop you.

jwrowland77
September 4, 2013, 01:01 PM
I actually like shooting it more from the prone than I do from a bench.

Definitely no muzzle brake on it, I wouldn't want to scare the people in the next county. LOL.

Only one way to find out I reckon. :D

Jim Watson
September 4, 2013, 04:50 PM
Moot point. Muzzle brakes are not allowed in F class.

Either a strap on shoulder pad, padded shooter's jacket or vest, or the ugly but cushiony Shooters Friend slip-on pad will help a lot.

Go try it out.
You might have an order in for a Barnard the next day or you might go back to hunting.

BullfrogKen
September 4, 2013, 04:55 PM
Jim,

Our local club will allow them - muzzle brakes - on the line, but they shoot "out of competition". The program does it for the few tactical people in the club who want to compete with their tactical rifles. They usually don't shoot much, but if they do we put them on one end, and if we can, separate them by a point or two from the others on the relay.

stubbicatt
September 4, 2013, 09:59 PM
I think the F Open World Champion this year shot a standard 284 Winchester. The 7mm Berger 185 (maybe it's a 180?) grain bullet seems to be the one to beat this year. I don't know why a 7mm Mag wouldn't be competitive, assuming one can build ammo that will perform. I can only imagine that one would want every ounce of the 10kg one is allowed.

Jim Watson
September 4, 2013, 10:39 PM
Ken,

I guess I should have said NRA F class.

I saw some of the last silenced rifles shot before NRA equated suppressors to brakes.
Obviously soft shooters. Not quiet enough for naked ears though. Interesting to hear the whistle as the can bled off pressure after the shot.

25cschaefer
September 4, 2013, 11:26 PM
The biggest reason it is probably not more popular is because it head spaces off the belt and not the neck. Belted magnums do not have the perception of being accurate. The common thought is that the bullet may not be aligned with the bore as the chamber is a little larger than the case. This "problem" can be eliminated by neck sizing which will allow the round to be "headspaced/centered" by the shoulder like beltless cartridges.

CountGlockulla
September 5, 2013, 12:23 AM
I think it could be competative.

I'm in the process of building another .284 caliber gun for use in competition as well. It's hard to ignore the awesome bullet selection and lower recoil available in this general caliber class.

Right now it is looking like a .280 or 7mm-06 semi-wildcat for me.

jwrowland77
September 5, 2013, 07:20 AM
I had thought about neck sizing, just have experimented with it as of yet. I finally got through my first lot of once fired brass in my 7mm RM, and the load actually surprised me quite a bit considering its a hunting round. I plan to take this lot and neck size only since the brass is now fire formed to my chamber, and see how that affects the accuracy.

This is my hunting load at 100yds (5-shot group):
http://img.tapatalk.com/d/13/09/05/y4a9u5e2.jpg

I'm hoping I can somewhat better this with neck sizing and also by using match grade bullets. The picture above was FL sizing, hand weighing every charge and weighing bullets to put in groups of .2. The above I believe is 138.8-138.9 Hornady BTSP. Maybe with some SMK I can get one ragged hole.

taliv
September 5, 2013, 08:15 AM
that's good shooting

BullfrogKen
September 5, 2013, 08:21 AM
Yeah, that is.

jwrowland77
September 5, 2013, 08:22 AM
that's good shooting

Thank you. I think it's more rifle than me. It's always been a fairly accurate rifle with factory ammo, and then when I started reloading, the accuracy really came out in the rifle. That's why I've been thinking about coming up with a match load for it and trying it out.

rule303
September 5, 2013, 09:41 AM
Looks like the rifle is plenty capable. If you can make it through the match without the recoil beating you up, you should certainly be a contender.

Jim Watson
September 5, 2013, 10:50 AM
I'm hoping I can somewhat better this with neck sizing and also by using match grade bullets. The picture above was FL sizing, hand weighing every charge and weighing bullets to put in groups of .2. The above I believe is 138.8-138.9 Hornady BTSP. Maybe with some SMK I can get one ragged hole.

My inclination would be to take that load and run with it.
You can wear out a high velocity barrel looking for that just slightly better load.

You need to know the muzzle velocity so you can calculate comeups for the various ranges.

F class is "belly benchrest."
Practice shooting prone over a rest like you will do in a match.
It is not the same thing as hunkering down over a bench. You must develop a stable position with the least strain on your body. You may have to adjust your scope location to stay in the eyebox while prone.

jwrowland77
September 5, 2013, 11:07 AM
My inclination would be to take that load and run with it.
You can wear out a high velocity barrel looking for that just slightly better load.

You need to know the muzzle velocity so you can calculate comeups for the various ranges.


So I should just run with the hunting load I have come up with using hunting bullets?

Most tell me I should run it faster, but like I say, it's kind of hard to argue with the accuracy results of it. I'd rather be accurate then fast and not accurate any day of the week.

This load runs about 2900 fps which isn't real fast, but it gets the job done.

Trent
September 5, 2013, 11:19 AM
So I should just run with the hunting load I have come up with using hunting bullets?

Most tell me I should run it faster, but like I say, it's kind of hard to argue with the accuracy results of it. I'd rather be accurate then fast and not accurate any day of the week.

This load runs about 2900 fps which isn't real fast, but it gets the job done.

As long as it stays well above supersonic to the range you are shooting at, it doesn't matter. With a 7mm mag, that's not going to be an issue for a long way downrange. Run it too soft you might get close subsonic (maybe) by 1000 yards (I doubt it though). Have to run the numbers, but I remember 7mm mag staying supersonic out further than my 300 WM. Affected more by wind, but that sleek 7mm projectile stays faster, longer. 300 Win leaves the gate harder hitting, but past 700 yards it crosses over, ballistically, and the 7mm hits harder than my 300 WM.

I'd had serious thoughts of getting rechambered in 7mm mag (or 7mm STW) when I rebarreled my action a few years ago because the long range ballistics were better. But I'd have to retool all of my reloading stuff, etc.. would have been too costly.

Now, as far as what load to use; depends on your rifle. Most rifles are most accurate around the low end or high end of the powder spectrum. Given that you're shooting multiple 15 or 20 round strings in F-Class... I'd go on the low side, due to heat and recoil, *IF* you can find a load that groups good on that end. Less hostile to shooter and barrel.

Fortunately our magnum cartridges, don't have to be stressed hard to handle long ranges. Some of the F-TR shooters shooting 308 really have to push the envelope of what's safe, to stay supersonic out to 1,000 or 1,200 yards. Even then, on the latter, it's not reliably supersonic.

Jim Watson
September 5, 2013, 11:30 AM
What range will you be shooting at to start with?
Midrange up to 600 yards would be good. I started at 1000 and it was really jumping in at the deep end of the pool.

That is a pretty mild load, but still flatter and closer to the wind than a .308 175 SMK.
I think it good enough for a first trial, especially if you can get out at midrange of 200-600 yards.
But a serious 7mm shooter would be loading something like the 175 gr SMK at the maximum attainable velocity, well over 2800 fps even with book loads.

jwrowland77
September 5, 2013, 11:30 AM
Yeah, in my 7mm load, I'm using 57gr of IMR4350 which is about smack in the middle of the Hornady manual. I went clear up to 63, but the accuracy on those just couldn't beat the group I got at 57gr. The load with 57gr actually feels a lot nicer than any factory load I've shot.

My last visit to the range, I went through 80 rounds of it just shooting I enjoyed it so much. I do have a nice slip-on recoil pad that I bought for like $15 at Cabelas and it worked tremendously at reducing the recoil of it. I think all I need to do now is get me a bipod to put on it and take it and try it out.

The barrel does get extremely hot. I had worried about that 5 shot group walking on me, but it didn't, and I shot all 5 one after the other with no cool off period.

jwrowland77
September 5, 2013, 11:34 AM
What range will you be shooting at to start with?
Midrange up to 600 yards would be good. I started at 1000 and it was really jumping in at the deep end of the pool.

That is a pretty mild load, but still flatter and closer to the wind than a .308 175 SMK.
I think it good enough for a first trial, especially if you can get out at midrange of 200-600 yards.
But a serious 7mm shooter would be loading something like the 175 gr SMK at the maximum attainable velocity, well over 2800 fps even with book loads.

I'll be starting at the 600yd mark. I figured I'd do that for a couple of years before attempting the 1000yd mark.

I have been looking at the SMK 175gr's but wasn't sure if my twist would/could stabilize it. I saw on PV that it required a 1:8.5 mines a 1:9.25 from what I've read and seen. It's the Rem 700 BDL 26" barrel.

Jim Watson
September 5, 2013, 11:35 AM
Have at it.
Note: You will be shooting in F Open and not limited to a bipod like F-T/R.
Put your bench rest on the ground... or on a board on the ground, put a sandbag under the butt, and get a solid position.

If you don't have enough twist for a 175 gr SMK, there are other bullets with good BC. A 168 gr Berger, for one.

jwrowland77
September 5, 2013, 11:39 AM
I wonder if like a golfer has certain clubs they use when windy as compared to a calm day, a shooter does the same as in, if windy, using the 7mm since trajectory is flatter and using a .308 when it's calmer.

I'll just have to try them both out and see which one I like better.

jwrowland77
September 5, 2013, 11:41 AM
Is the Berger good? I have no idea about them. I've only used Hornady, Sierra and Nosler up to now.

How's the bullet to bullet weight? Pretty consistent?

Jim Watson
September 5, 2013, 11:47 AM
Bergers are excellent.
I have shot mostly SMK 175s and Lapua 155 Scenars in .308.
A friend took Hornady A-Max to the National and World F class championships just the past couple of weeks.

Berger and JLK and Hornady A-max have shot accurately in .223. (A fast twist .223 is a fine midrange rifle, but it lacks a bit at 1000 even though the tables say it could be made to shoot like a .308.

jwrowland77
September 5, 2013, 11:53 AM
What grain of .223 would you suggest for mid-range 600yd?

I'm actually looking at getting my oldest daughter started in it next year, but need to get her a rifle with a faster twist. Right now hers is 1:12 and the max I load for her is a 60gr Nosler Partition.

I've looked at the Bergers and Scenars as well. I'll have to order some boxes and just try them out and see what I like.

Would you look at a slow powder like IMR7828 for the bigger pill or stick with the IMR4350 that I've used?

BullfrogKen
September 5, 2013, 11:59 AM
What grain of .223 would you suggest for mid-range 600yd?

The 80 grain is what most of us service rifle shooters use at 600 yards. You'll need a new barrel for that one, though.

jwrowland77
September 5, 2013, 12:11 PM
The 80 grain is what most of us service rifle shooters use at 600 yards. You'll need a new barrel for that one, though.

Thank you Ken. That'll give me something to look at for her birthday present this year for next year competing with dear old dad.

Trent
September 6, 2013, 10:13 AM
Thank you Ken. That'll give me something to look at for her birthday present this year for next year competing with dear old dad.

If you're building it off an AR platform, look for a 223 Wylde chamber and a 1:7 or 1:7.5 twist (1:8 might work for 80 grain, but it's iffy). That chambering has a longer throat so you can load those 80 grain bullets properly. You have to single feed them in an AR. It will absolutely shoot lighter / shorter bullets, but it won't be optimal due to bullet skip before hitting the lands; velocity will string out badly on normal factory AR ammo, and accuracy will suffer.

If you're doing a bolt rifle in 223, watch the twist rate on those too. You need a fast twist for 80 grain bullets. And... Expect it to shoot lighter bullets (55gr) poorly. Most bolt actions are not set up for fast twist, so you'll need to pay attention to specs closely before buying. Since 80 grain bullets must be loaded very long, also pay attention to throating, you need extra space for that bullet to sit in the tube without cramming it in to the rifling.

jwrowland77
September 6, 2013, 10:37 AM
I had planned to go the bolt action with my daughter, she has a fairly quick trigger finger and isn't afraid to use it. We've gotten told several times at the range to slow down, and every time, she was the one shooting my Ruger 10/22. LOL. It's worth it every now and then though to see her smile. She's 8 getting ready to be 9 and loves shooting with me.

Yeah, I'll have to start doing some research and find one with a nice fast twist rate to it, with a long throat. I wonder if Savage has one with a fast twist in .223? I know my Savage .308 sure does have a long throat. I checked the OAL on that when I started loading, and the bullet kept falling out of the modified case it was so far out.

Jim Watson
September 6, 2013, 12:47 PM
I think Savage has some (not all) models of .223 with 7 twist barrels.
The Tikka T3 can be had with an 8 twist which Berger says is adequate for their 82 gr bullet. The ballistician there said he would not go with maximum bullet weight in .223, he favored the 75 gr at higher velocity.

You could get her an AR and a Bob Sled single loader. That's what I use. No magazine or rapid fire involved. As said, slow fire .223s are commonly loaded over magazine length anyhow.

jwrowland77
September 6, 2013, 12:57 PM
I bet she would love an AR. She would probably be the only girl in her age/grade to have one too. :D. Just trying to raise her right. LOL

Trent
September 6, 2013, 07:18 PM
She'll slow down if the AR bolt locks back every time she fires. As Mr. Watson said, there's followers for AR magazines that are designed for single loading that do this.

Heck, for that matter you could get a solid front sight block and not even have a gas system, do it the way the brits do, yank the handle to charge it... :)

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