Is 7mm ? accurate enough for 600m to 1000m

P

Phill Smyth

Guest
Ga’day, Guys of Knowledge, need some advise I wish to build a long range Benchrest and on occasion long range feral animal controller up to Wild Donkeys and Camels. I will have two stocks one for bench and the other with tripod. I do not think it needs to be more than a single shot for feral animals out at that distance. The reason I ask about 7mm cal is that I am very happy with the two rifles I shoot Centrefire Silhouette. I have 125gr 145gr 168gr & 178gr projectiles, Redding dies to these two and comp seater, plus all the other reloading accessories and the cleaning gear ect .
This gun is not going to be used more than 6 to 12 times per year if that. I just like as close to perfection and competitive when pulling the trigger.
The spec’ on the two existing are:
a. Remington 700 custom built - 7mm Br 1:8 twist - at Rams 500m with Sierra 175Gr match kings or Finn Ram kings - max MV-2,485 fps- the best 5 shot group has been 24mm.
b. Off the shelf black Plastic Remington 700 - 7mm-08 I floated the barrel and using 168Gr match kings. Shoots 75mm - 3" groups I have not checked MV. I was given the load and spec's tried it, it worked so stayed with it.
SO now the Question: is 7mm Cal in Rem Mag or another spec Competitive in 500m to 1000m Benchrest competition, and will it have the impact and kill power out at long range to cull feral animals -large and small - larger Deer, Kangaroo’s, foxes, goats, pigs and on occasion Donkey or Camel.

Advise on Spec's would be appreciated for - Actions, make and model, - was thinking, I would most probably do a right bolt left port and maybe drop port Barrels - length , dia and twist and Stocks . looking forward to your knowledgeable advise. Regards Phill
 
Short answer is yes.

Never did blieve in magic components, except maybe bullets (& they're not magic, just "well designed for the task at hand," & especially "well made").

In Oz, you're somewhat limited to bullets, I believe. If you're going to be shooting against Jeff Rogers from Canberra, you'll not only need your A game, but a lot of luck & maybe a .30, with the greater bullet choice. If your 7mm can shoot 5-shot, 3.XXX inch groups at 1K, you're in the hunt.

Why not check with Jeff, & maybe Stuart & Annie Elliot, too. If I recall correctly, Annie has a new small .30 that shoots awfully well.
 
7mm

So 7mm rem mag or other 7mm configerations would not be competitive with up to 175 Gr projectiles, compared to 30 cal Projectiles having a wider range of heavier projectiles. What are competitive or the winning combinations - cal, barrel and twist in 600m to 1000m bench rest target Comp.
 
Is a 7 mm accurate enough for 600 and 100 yard competition. Well read this and see what you think.
http://www.accurateshooter.com/guns-of-week/gunweek071/

You ask, "What are competitive or the winning combinations - cal, barrel and twist in 600m to 1000m bench rest target Comp."
Look at the NBRSA and IBS records, and match reports, most are doing will with varients of the 6BR, the 6 Dasher seems to be the hot deal right now.
 
Phil, I think you'll find the limiting factor to be bullets, specifically bullet jackets. It's sometimes hard to find GOOD 7MM bullets.

IMO you'll be better served with a 30 for this reason. A 300WSM would be hard to beat :)

al
 
In the article link above 175gr Sierra Match kings were used and that is what I use on rams @ 500m in the 7mmBR rem br primers 30.2 gr of ADI 2208 and they group fantastic. The best 5 shot group, when doing load development for max MV and group was 24.6mm. The set up is a worked / trued Remington 700, 24” True-flight NZ - fluted 1:8 Twist, Pesco trigger in HS pres t/h silhouette stock. Smithed by Keith Hills Canberra now in Cowra NSW Australia, I need to talk to keith after the Holiday brake and get his advise also. ( I would highly recommend Keith, he is a great guy and a excellent knowledgeable tradesman who competes at the highest level and knows his stuff)
 
People are talking about different things here. BR, hunting, f-class, silhouettes. All completely different animals (pun intended).

You want a hunting rifle for long-range big game and a BR winning ticket in one; those are far removed from one another.

If you want to shoot 600/1000y BR, which means fast strings, then cartridges like the 6BR, 6Dasher, 6x47 etc is what you are after: light recoil, medium ballistics but very accurate rounds. This however, does not stroke with having enough energy down range to bring down a camel.

F-Class is different shooting than BR where you will need a high BC bullet to dodge the wind changes that happen in euro-style F shooting where it can take over a minute and a half before it's your next shot (having two other shooters rotating). US style string shooting still has the target coming down after each shot to mark and score it, so this is a bit faster, but still slow enough for wind to change dramatically. Hence the big calibers in F-Open. One of these calibers would be more of a match with your hunting rifle double-role. 7mm-270WSM is the norm in F-Class, shooting either Sierra 175/180 or 180 Bergers at 3050-3150fps. Not many .30's there are you need a huge case to match ballistics of the 7mm, giving equally massive recoil; the 300WSM will not cut it in those terms, think 300 Lapua Magnum (ouch) firing the 230-240 class of bullets and still not gaining much, if anything, over the 7 mils.
 
Thanks again for the input. The long range big animals Trip would only be once or twice a year. So that was why I was thinking of one set up with two stocks in 7mm something, to use existing components and tools. I will have to do some more thinking , may be one action, possibly two bolts, two stocks and two different barrels. I have done this before and worked out well. I used to have to many rifles so I re-evaluated to have light caliber bolt action hunting rifle in 223 Ack imp 1;8 twist to cover up to 90 grain projectiles, & 204, for larger game I have the Rem 700 in 7mm08.
For Benchest, I have Brno & Winchester 52's in 22LR for Hunter, Custom, BR-30, RBA 25 - a Hall 6mmPPC for centrefire and Fienwerkbau P70 for Air BR and Silhouette. Anschutz 54 Small bore, 1710 hunter silhouette Model 1 Brno for Bunnys and feild rifle. Cowboy lever action silhouette Marlin 39A's 22lr and Rossi357 and lastly 12g Rizzini u&o for clays. Many thanksto you all. I have more to think about and homework required.
 
phill

just a suggestion, have you considered a trip to the majura and mcintosh ranges in canberra to discuss your needs.

you will find the members most willing to share their knowledge in relation to specific calibres/loads etc for 500m fly, f class and 1000yd BR.

cheers
goodi
 
Thanks for the reply, I have to go down to Canberra for the Pre Australia day Silhouette shoot and will talk to some of the benchrester after that abd besfore the Australia Day shoot. I was just throwning out a questions to a wider group of knowledable people and it has been great I have had a number of other responses through PM. I have done Rimfire BR and a smiggon of Centerfire with the Hall I bought of The Brumwells. My late Brother in law Garry Crane moved to Tamworth and became friends with Nashy and Co and wanted to start BR so I sold / gave him the Hall. I stopped CF BR and most shooting barr a few Silhouette comps and club days, Most of time when shoots were on my son Travis had Golf tournements, so shooting was shelved. Travis has developed into one of Australia's top junior golfers with a hanicap of + 2.5 and is in regional and state teams. We have been told by some that he has seeds of greatness and could be something very special and that he could have a big future if he puts the effort and dedication require into his future. He is now 18 and licensed, and now travels to all his commitments and does not want his parents tagging along, all he need me for is money and encouragement. So, I now may have time to start shooting again if I can afford it, LOL.
I was thinking out loud and have had great responce, that I thank you all for. regards Phill
goodi said:
phill

just a suggestion, have you considered a trip to the majura and mcintosh ranges in canberra to discuss your needs.

you will find the members most willing to share their knowledge in relation to specific calibres/loads etc for 500m fly, f class and 1000yd BR.

cheers
goodi
Click to expand...
 
Hello Phill:

The hunting objectives you stipulate appear to be compatible with your preferred 7BR with one noteable exception: camels. I offer the following comments:

For the purposes of the following discussion, I have assumed that donkeys weigh on the order of 500 lbs, camels on the order of 1200 pounds, and kangaroos on the order of 150 pounds. I have also assumed a legitimate hunting bullet is used, such as a 175 grain Sierra Game King. With your stated muzzle velocity of 2485 fps, the following are estimated maximum ranges for the previously stipulated animals:

donkey: 250 yds
kangaroo: 1000 + yds
camel: NA

If you were to use a 7mm mag with a MV of 2900 fps, the following are estimated maximum ranges for the previously stipulated animals:

donkey: 500 yds
kangaroo: 1000 + yds
camel: NA

In my view, no 7mm or 30 cal is "satisfactory" for taking a camel. "Satisfactory" means taking the animal with only 1 shot, with the animal dropping within 100 yds almost all of the time. There are undoubtedly many folks who will forcefully say "balderdash" to that opinion. Fair enough. I have read books by John Taylor, Elmer Keith, and Kevin Robertson, and these gentlemen would likely be of the same opinion (particularly Robertson). I stand with them. A hot 338 with a minimum of a 250 grain premium bullet (e.g. 340 Wthby shooting a 250 grain Nosler Partition @ 2900 fps) would be the absolute minimum I would use. Even at that, the shot would be at less than 200 yds.

Sounds like your 7BR is a peach. With the 2485 fps MV, you would still be supersonic @ 1000 yds. However, wind drift will be more with your 7BR than with one of the hot 6's, a 6.5x284, or any of the 30's. Because of the wind drift handicap, you may want to consider limiting your 7BR to 600 yd competition. A move up in case capacity to drive a 175 grn bullet at greater velocity would be prudent if you wanted to competitively shoot at 1000 yds. My friend, Jim Hardy, (a former shooter on the US Palma team) has had excellent success with a 284 case, rather than a belted magnum case, driving these wind cheater bullets.

You don't say at what distance your 24 mm group was shot. To be competitve in 1000 yd benchrest competition, I would suggest looking for a system that is capable of 5 shot groups on the order of 1/2 inch at 200 yds. For whatever reason, most US competitors shoot 6mm, 6.5mm, and 30 cal. in 1000 yd benchrest. If vendors in Australia resemble vendors in the US, there could be more bullet choices available in these calibers than 7mm. More bullet choices means a better chance of finding a bullet that your system "likes".

I hope these comments have helped you sort things out. Good luck to you.

Scott
 
You must log in or register to reply here.
Back
Top