Thread: Keeping the 7mm ahead of the 30 cal?

you know what i mean!

Originally Posted by Terminator

A 7mm rum should give you 3000-3100 depending on barrel length
The 7mm lapua imp 3200-3300 but dont expect the barrel to last to long.

I second that on the barrel life, I ran my RUM at 3471fps with the 180 Bergers in a 30 inch tube with a Gabe Zigliani suppressor and barrel life was woeful, I used a short throat and after 100 rounds of hunting and target shooting my OAL grew to keep a just touch. 200 rounds down the tube and I had to start slowing it down to 3400fps to keep accuracy, then to 3330 to keep it accurate, then the accuracy just went.

I pushed the RUM hard as I wanted something for 1500 to 2000yrd practise.I'd say the barrel would still be alright if I had been more conservative.
All the practise confirmed one thing, a first round lethal hit on a deer past 1450yrds in a no wind situation is unlikely for me with a 7mm projectile.
A VERY stiff load in the saum pushes the 180 berger at 3000fps, I dont know what it would push the 195 at.
As a hunting projectile im not sure if the 195 would be an improvement over the A-max in a saum.
Hard to knock the 162 a-max off its perch for a hunting projectile when comparing like with like at saum speeds.

And KiwiGreg has 5 very valid points here....
"IF they get the BC they are looking for & they will stand up to the twist rate required without the jackets getting to thick, they will be good for hunting.

But in a Rum etc they will only be a whisker in front of a .338 300 Hybrid that will have 3-5 times the barrel life & the 300 will be miles easier to keep accurate over its life & will kill better"

Very hard to stay with the 7mm when shooting out past 1000-1500yrds........

Originally Posted by 7mmsaum

I second that on the barrel life, I ran my RUM at 3471fps with the 180 Bergers in a 30 inch tube with a Gabe Zigliani suppressor and barrel life was woeful, I used a short throat and after 100 rounds of hunting and target shooting my OAL grew to keep a just touch. 200 rounds down the tube and I had to start slowing it down to 3400fps to keep accuracy, then to 3330 to keep it accurate, then the accuracy just went.

I pushed the RUM hard as I wanted something for 1500 to 2000yrd practise.I'd say the barrel would still be alright if I had been more conservative.
All the practise confirmed one thing, a first round lethal hit on a deer past 1450yrds in a no wind situation is unlikely for me with a 7mm projectile.
A VERY stiff load in the saum pushes the 180 berger at 3000fps, I dont know what it would push the 195 at.
As a hunting projectile im not sure if the 195 would be an improvement over the A-max in a saum.
Hard to knock the 162 a-max off its perch for a hunting projectile when comparing like with like at saum speeds.

And KiwiGreg has 5 very valid points here....
"IF they get the BC they are looking for & they will stand up to the twist rate required without the jackets getting to thick, they will be good for hunting.

But in a Rum etc they will only be a whisker in front of a .338 300 Hybrid that will have 3-5 times the barrel life & the 300 will be miles easier to keep accurate over its life & will kill better"

Very hard to stay with the 7mm when shooting out past 1000-1500yrds........

that seams stupidly hot? for that speed?

what do you run in the rum now?

anyone know when they are coming out? tho i still use the a-max over the 168 an 180 bergers now anyway but mite be worth a try

Originally Posted by tui_man2

that seams stupidly hot? for that speed?

what do you run in the rum now?

anyone know when they are coming out? tho i still use the a-max over the 168 an 180 bergers now anyway but mite be worth a try

I just necked the RUM up to 338 and put a 300g Gen 2 Hybrid in it. Same velocity as Burtonators one. Far better killing power.

Steve tried to talk sense into me years ago about the Edge but I wouldnt listen, and I should have.

To think the Yanks never liked 7mm that much, just look at them now. Seems silly not to go to 338 really.

Yes of course ,what was I thinking.No one wants to use a medium capacity 7mm and shoot less than a mile.
Im glad some of you buggers dont work as bullet designers, they only option we would have is a 300gr 338.

The big question of terminal performance and useful case size will be limited by the jacket thickness that berger ends up having to use to get them working well in a 1-8 twist only time will tell. But I would say this will probably limit the case size that they will be useful in to the bigger 7mms. The big 7mms should do well but like any extreme over bore case barrel life and keeping them turned through out there short barrel life have to be considered. Where I can really see them doing well is target shooting in windy conditions where they will be hard to beat.
Would I choose the 195gr and a big 7mm probably not the 162 Amax at 3000-3100fps dose all I would need up to 650 yards very well so would a 195gr beat a 300gr berger for the longer stuff ? I know recoil has been a worry for some with the 338s in the past but new muzzle brakes now available here in NZ I'm sure will change this in the future.

Andrew, you cannot get 3471 fps with a 180gn Berger out of 30 inch barrels RUM without out blowing cases. Either your chronograph is inaccurate, or you're talking BS. The Nosler RUM brass you were using won't take anymore than 65,000 psi without popping primers. A 30" RUM at just under primer popping pressure will push a 180gn at 3400fps max. We built your rifle, and many like it, and have strain gauges on enough of them to know exactly what they will do. Do not try and reach Andrew's claimed velocity or you will end up with molten brass in your eye at the very least!
Also, the only 180gn Berger that will stand 3400fps with accuracy is the Hybrid. Don't waist your time with the VLD's.
As Kiwi Greg and Don say, it depends on what you're trying to achieve. If you want the absolute best long range performance in the wind, with minimal recoil, in the lightest possible walkabout hunting rifle, then this new bullet with a projected .400 plus G7 BC may well be superb in our biggest fast twist 7mm's. The barrel life will be reasonably short in the likes of our 7mmSF or Kirby's 7mm AM, but as a specialist long range lightweight hunting rifle, who cares! If you can handle more rifle weight and recoil, then the biggest 338's will beat it in barrel life and killing performance for sure, but it will need to be a big, long barreled 338 to beat it ballistically for drop and windage. At the very least a 338/416 imp like our 338 Thor, or a 338 Cheytac imp like our 338 Lunatic. An Edge, Lapua, or Lapua AI won't touch it. The 375 Cheytac imp, if the new bullets/twists all work out, certainly will beat it and the big 338's. But in a lightweight hunting rifle, I shot and killed a lot of deer with the 7mm 200gn Wildcat bullet (until Richard sold the business), and know exactly what a really big 7mm can do! Bring it on!

Greg

Originally Posted by Greg Duley

Andrew, you cannot get 3471 fps with a 180gn Berger out of 30 inch barrels RUM without out blowing cases. Either your chronograph is inaccurate, or you're talking BS. The Nosler RUM brass you were using won't take anymore than 65,000 psi without popping primers. A 30" RUM at just under primer popping pressure will push a 180gn at 3400fps max. We built your rifle, and many like it, and have strain gauges on enough of them to know exactly what they will do. Do not try and reach Andrew's claimed velocity or you will end up with molten brass in your eye at the very least!
Also, the only 180gn Berger that will stand 3400fps with accuracy is the Hybrid. Don't waist your time with the VLD's.
As Kiwi Greg and Don say, it depends on what you're trying to achieve. If you want the absolute best long range performance in the wind, with minimal recoil, in the lightest possible walkabout hunting rifle, then this new bullet with a projected .400 plus G7 BC may well be superb in our biggest fast twist 7mm's. The barrel life will be reasonably short in the likes of our 7mmSF or Kirby's 7mm AM, but as a specialist long range lightweight hunting rifle, who cares! If you can handle more rifle weight and recoil, then the biggest 338's will beat it in barrel life and killing performance for sure, but it will need to be a big, long barreled 338 to beat it ballistically for drop and windage. At the very least a 338/416 imp like our 338 Thor, or a 338 Cheytac imp like our 338 Lunatic. An Edge, Lapua, or Lapua AI won't touch it. The 375 Cheytac imp, if the new bullets/twists all work out, certainly will beat it and the big 338's. But in a lightweight hunting rifle, I shot and killed a lot of deer with the 7mm 200gn Wildcat bullet (until Richard sold the business), and know exactly what a really big 7mm can do! Bring it on!

Greg

The trouble with any extreme over bore case like the very big 7mms when you talk about barrel life isn't just that its short its that they are sometimes very hard to keep tuned with the best BC bullet on offer for the entire short life of the barrel. Often you have to go to another lower BC bullet to keep it shooting after just half of the short barrel life, yes the barrel is still shooting but the best BC bullet can no longer be used so greatly changing the great ballistics it once had. Kerby had this happen to his 7mm Allen mag having to change from the 200gr wildcat to the 160gr AB, I am in no way saying that the Berger 195gr want be a great bullet but you may have trouble keeping it shooting in the big 7mms, now the target guys who don't need to push it hard to get expansion at long range will be very interested in this bullet in a medium case as a great windy day bullet.

Don,
That may have been the case with the thin jacketed VLD's in some barrels, but it depends more on how hard pressure and velocity wise you are driving them. I have had the old thin moly coated 180 VLD's shoot in a Kreiger barrel for well over 1000 rounds before it started to destroy them. This was at 64,000 psi and 3200 fps. Kirby ran a lot of rounds through that barrel doing testing for his customers, at some pretty serious pressures and velocities. You can get away with this due to the high quality brass they're based on. Someone else on this forum has a habit of doing the same thing occasionally, eh Kiwi Greg?

I have run many more rounds through one of our 7mm SF's than Kirby has through his own personal 7mmAM you're talking about, without any deterioration in accuracy, but we run the Lapua brass at 65,000psi, not the 70,000 plus some others run.
Anyway, this certainly isn't the case with the Hybrids and other similar ogive and jacket thickness bullets. That's the advantage of them, they are very throat tolerant. If used as a lightweight hunting rifle/load combination, the barrel life even with the biggest 7mm's or any other overbore cartridge will last for years. If you want to bust lots of rounds at gongs etc, then don't pick a big 7mm or any other largest case in any calibre, whether it be 22 cal on up. Build a 338 Edge and bang away to your hearts content, but do realise there are other cartridges that are better in the wind if a high round count is not important to you.
Horses for courses!
Greg

The 195gr will be a hunting bullet so should have a hunting jacket? not like the 180gr target hybrid with a thick jacket that even you admit will only expand up to a modest distance.

Don,
The 180gn 7mm and 300gn 338 Hybrid's I have lots of experience with expand just fine out to 1000 yards no problem. Not sure what you mean by modest distances? They are no different to SMK's, in fact expand better in my opinion. We have no issues with them terminally at all, and their superior ballistics makes them go to's for us. Sure, 180gn and 300gn A-Max's would be even better, but that's not likely any time soon by the sound of it. In the small and medium 7mm's out to 800 yards the 162gn A-Max is superb, but it ain't as good in the wind as the Hybrid, and that's a fact. I'll take hitting them in the right place first over a small terminal advantage any time! Do you think the CE's you've got for your 375 build are going to expand any better? Not in my experience they won't. I can show your footage of a Bull tahr hit smack in the middle of the shoulder with the 252gn CE doing 3550fps at 600 yards that takes off like he wasn't even hit. But we found him 100 yards away dead, hit exactly right in a very strong wind. There's no such thing as the perfect bullet yet, but they're working on it. When Smitty from CE puts his new alloy tips into his long range bullets, then we'll be almost there I reckon!
Anyway, the Red stag Willie shot at 720 yards on Monday night while we were in a "big country" headwater with a 180gn Hybrid out of the 7mm Fatmax just rolled over dead. Point of the shoulder, DOA!!
Greg

Firstly I haven't had alot of experience with the 180gr hybrid but was quoting you from another post saying you had shot alot of them and they only expanded okay up to 850 yards in your big 7mms? and we all know that the 7mm SMKs don't always expand well at long range ie 1000 yards. Now the cutting edge is in testing so I have no experience with it yet but quoting one long range shot dosen't mean anything I've seen plenty of deer run of hit well with the old thin jacket 180gr VLD then full dead at long range, a 400grs 375gr will have alot more energy than a 252gr to start of with before you add in the bullet expanding anyway, also being very long 2.2100 inches long tumble may also help? Now back to what we were talking about will a hunting jacket 195gr stay tuned in a 7mm SF when the throat starts to look like a gravel pit???

Don,
I expect the 195's will stay tuned as good as any other of the new Bergers etc. I presume they'll be better at this than the old VLD's, but we'll have to wait and see won't we!
Greg

Originally Posted by Greg Duley

Don,
I expect the 195's will stay tuned as good as any other of the new Bergers etc. I presume they'll be better at this than the old VLD's, but we'll have to wait and see won't we!
Greg

I expect it will be sometime before we see them, especially on this side of the world

By then they may well be obsolete except possibly for a niche market to the LR F class boys & shooters with blinkers on that are extremely reluctant to embrace change.

I say this because of improved muzzle brake designs that make even the biggest 338s etc far more manageable in light weight hunting rifles.

Also the 375 has taken over the higher ground in the LR performance stakes making even the biggest 338 look fairly average.

The bigger bore size means a quantum leap forward in barrel life, especially when coupled with much less powder burnt to achieve better ballistics.