7mm RUM vs other mags

[J E Custom]

Thats why I want to get the barrels off these rifles and cut them in half with an angle grinder, so I can substantiate what has been seen through bore scopes - with macro photos.

I don't have much choice over how cool the barrel stays during shoots as the rifle is often used by my hunting clients. Its not uncommon for clients to fire 3 shots in quick succession. The long range rifle is available week in, week out as we don't have set hunting seasons here.

The other problem as stated earlier, is that I have to practice a lot to understand how the wind changes from valley to valley here. Last night, I was shooting at 735 yards, down the length of a valley with a 15mph left to right crosswind. I dialed for 15mph but missed the target. I set the scope for zero wind and hit the target. When I went down to the target, a massive right to left draught was coming down a side valley (evening cooling etc). The big steep valleys here are always a challenge like this. I tend to avoid using the cheaper .308 for LR practice as it ends up several yards off target, I can't see the bullet strike and am left wondering what the heck is going on. Hence why I would rather practice with the rifle that is going to be used for the long shots anyway.

In a slightly different situation three weeks ago, I had a client here for a pig hunt. He spied a pig at 350 yards and being of an age where his joints would not allow him to climb down the ridge and get closer, he took the shot- and hit it in the backside. The poor pig took off at a hundred mile an hour, down the valley. I had three choices, either leave the clients behind and take off with the dog after the pig, take the clients back to the hut, then come back, go to the landrover and get the RUM.

The pig re-appeared again, way down the valley, still trotting along, the client had given up and was looking quite dejected. I went to the Land Rover, grabbed the gun, ammo, put the drop chart in my mouth. Ran back to the ridge edge, lay down, range 604 yards, angle must be 15-20 degrees-I better leave off a click and be sure not to aim above the center line, wind is about 5mph, ohh, better avoid the front roasts otherwise the client will have no meat left at all, aim, fire- job done.

Thats when all the practice pays off for me, being able to get a shot off quick on a non stationary target at long range, no mucking about.

Hope that explains my situation a bit better.

I am getting close to 400 rounds with this rifle which is a testament to the custom barrel. Whether it makes it to 600 rounds, who knows.

If you have the time to let the barrel cool between shots and only fire a handful of shots per year, thats great. You are still under the 600 round mark so it will be interesting to see how it lasts. The Bore snake idea sounds very useful.

I know the rules are different "Down Under" and understand perfectly where you are coming
from. But it sounds like you need a bigger bullet that will buck the wind better (Like a 338).

Wind gives EVERYONE fits that shoots long range especially in valleys and mountains where
you can have it blowing in all different directions at different distances.

I love the performance of the big 7mm But I use a 338 RUM for this type of shooting because
like most, the wind is the one thing that is unpredictable and I rely on the big bullets to help
minimize my error.

Sounds like you have and use a lot of tools to get the job done and the dedication to make
a good shot every time at long distance so That is why I would recomend the 338s It may
take a few more clicks up to get it done but the wind sounds like it is the culprit and the
338 may have the cure.

Its kind of like the professional hunters in Africa, They carry rifles that will end a bad situation
fast, even though it is larger than needed to take the game it is the right tool for the job and
the circumstances.

We are fortunate to be able to have as many rifles as we need or can afford so I try to match
the rifle to the task and hope conditions dont change to much and have to make to many
adjustments.

Hear in Texas the terrain is mostly flat with some hills and the wind is easier to read because
of the brush and grass. for this I like the flat and fast 7s and 30s but when I go to Colorado
where conditions are more like yours I go with the big stuff for my primary weapon and a
light carry rifle for back up and short distance.

Some day I hope to hunt down under and I will bring my 338 if they will allow it.

My all time favorite rifle is a custom 7/08 and it is responsible for the downfall of lots
of game animals at 500+yards but it does not buck the wind well enough for "ME" to use it
under certain conditions.

If barrel life is bad but it is the best choice for the job then I use it with the understanding that
I will have to replace it more often than others.

If I could live any where else it would New Zealand !!!

It is great being able to hear from you guys half way arround the world and share with experances
with each other.good luck and good hunting.

J E CUSTOM

 

[Kiwi Nate]

I have studied the .338 in the field here as part of our ballistics research for our business. Its great with certain bullets and on tough animals but we have a lot of lean game here and the SMK, which is the only suitable bullet for long range work, zips through vitals without opening up. Time after time, I have had animals run off- to the point that I thought I had either missed or gut shot them. Thank goodness for the dog, able to track down the animals to where they eventually expired.

If Berger bring out a .338 VLD, the .338 will be better suited to smaller, lean animals at long range. Even so, I still wouldn't adopt the .338 as my LR rifle.
I don't like the big recoil yet- muzzle brakes are no good here either. There is often no enough time to put ear plugs in if a snap shot has to be taken, other times the client will take a shot before I get earplugs in.

I had a brake on the 7mmRUM- I lost my hearing for two days after one shot from the 7mmRUM when I took a snap shot without earplugs in. I have to admit something here and it is really sad, my poor old dog, sitting a little ways behind me, endured about 6 shots over the course of a few weeks. He is now permanently deaf. Its the most horrible situation to see the old boy in this state and know that I am the cause of it.

I am very keen to try the 7mm-.300 Win mag this year. It might be a small step down in velocity with the 180VLD but I will get plenty of practice with it without the same level of wear. Recoil will be light from the intended platform and clients will be able to use it with ease. A .300 magnum would also be effective but I want to study this wildcat.

JE- if you come to NZ at any stage, you will be able to bring your .338- no worries. Would be nice if Berger would hurry up and get the new .338 VLD's into production.

 

[Kiwi Nate]

Here are some pics regarding the hunt I was talking about re- taking a quick shot at 600 yards.

A second client took this pic, I am just about to fire (on the left), pig has climbed onto the track across the valley and is making its way along the track as it is the easiest escape with such a large wound. Note the dog in his usual position.

The pig is a good size for roasting. Some clients want eating size pigs, others will stay a while longer and look for a trophy boar. The body weights tend to vary widely. In this pic you can see how the first shot struck the rear ham (frontal shot from above, POI between shoulder blades). The bullet grazed pelvis, exited down by tail)- the rifle suffered a shift in POI due to a very soft plastic stock. The second meat saver shot is mine from the 7mmRUM.

Exit wound from RUM. 180 grain VLD

Client left the rifle with me for accurising. Just finished today. The rifle is a Mossberg ATR100 .270. Yesterday, when I went to load the first round in it, the extractor fell to pieces. Spent the rest of the afternoon fabricating a new extractor. Atleast the rest of the bolt didn't fall to pieces! I shot the group below with the Speer 150gr BTSP which is always good for testing potential accuracy. A friend reackoned that the group looked good, then asked when I was going to go back to 100 yards and try it- smart%&#.

 

[fmajor]

This is such a great topic!!!

KiwiNate - I really like the pics BTW - it's puts 'flesh-n-bone' realism to the discussions RE: bullet/cartridge selection.

As many have mentioned, if you're really into the cartridge go for it, but as J E Custom mentioned, there's no free lunch. There is usually correlation/compromise between velocity and throat erosion. The 7RUM is a really hot loading - what awesome tragectory and energy!!! It sure would be great to get 2-3,000 rounds through a barrel with it, but that seems like quite a challenge.

For my preferences, i'm realizing a 2-gun battery is in order b/c one loading can't do it all (with equal performance at the ranges i'm interested in). For me and "nearer" LRH, the old 7mmRM is the best balance btw performance and barrel life. Not near so hot as the 7RUM, but doesn't give up too much to the 7STW or 7Roy either.

For honest LRH (especially for larger game), the hot 338's seem to be the way to go (longer barrel life, plently of punch, good bullet selection).

 

[Ridge Runner]

well I shoot 2 rifles for LRH
1 is the 7mm Allen, running a 160 accubond at 3575 fps
2 is a 6.5 gibbs runs a 140 berger at 3320 fps
both sighted dead on at 300 they are within 1 MOA to beyond 800 yards, the Gibbs is based on a 270 win. case and should last 2K rounds, ( I think it was dave from idaho) had one that lasted 2500 before he rebarreled.
I built the gibbs so I could shoot more.
RR

 

[Fiftydriver]

I always giggle a bit reading these posts hammering away on what have been labeled "Over Bore", "Hyper Velocity" small and medium bore chamberings. Most want to throw every caliber in the book and compare then head to head and this is simply silly. Its like comparing a Toyota Tundra to my 600HP, 1000 ft/lb torque GMC Duramax as far as towing performance...... SILLY and totally impossible to compare head to head.

With all due respect to the vast amount of knowledge on this board, I feel rather comfortable in saying i have likely burned out far more 7mm barrels then most others on this board combined. That is not bragging, its simply a fact because of the load development and testing I have done with my 7mm Allen Magnum which is on the top of the pile for performance in the 7mm bore family.

I have posted many many times that there are things that can be done to extend barrel life and I will do it again:

1. Use ball powders.
2. Do not overheat your barrel, never more then three shot strings
3. No high volume shooting
4. Use a barrel designed to offer longer barrel life
5. Use a bullet that has some jacket integrity
6. Use the rifle for its specialize design purpose and not for all around shooting

Let me explain these things even more.

1. Ball powders have been PROVEN to be less abrasive to the throat area of a barrel Then any stick powder. They have also been proven to burn at lower temps then stick powders. Ball powders ARE NOT the most stable over wide temp changed or dramatic elevation changes but when used in known conditions, every bit as good as any stick powder and they do increase barrel life noticably.

2. Never shoot 5 shot strings, EVER. THe damange caused by the last two shots is far more then cause by the first three, never do it, no need anyway with this type of weapon. Those that believe they can not deterime the accuracy potential of their rifle without 5 or 10 shot groups, We are not BR shooting, we are hunting and if you can not do the job in three shots, you need more practice to be honest.

3. If you want to take your 7mm RUM or 7mm AM to the prairie dog down, expect to change your barrel every year. Thats not its design purpose. Do not use these rifles for high volume shooting and they will last a long time

4. There are barrels that are known to offer longer barrel life out there. I use Lilja 1-9, 4 groove barrels for nearly all of my 7mm AM rifles because they will take the punishment and last long enough to cover most hunters careers inspite of what some would have you believe. You can get fancy rifling designs but none have proven better then the standard Lilja 4 groove barrels and I have burned up every 5R barrel made as well as many others.

5. The Berger bullets have a very thin jacket, even their new "thicker" jacketed hunting bullets. Use a bullet that will handle a bit of barrel wear. The two that come to mind are the 160 gr Accubond and 175 gr SMK. The 160 gr Accubond can take any velocity you want to drive it to. I have shot them to well over 3600 fps but will not pass on that load data. I will say, case life remained excellent in my 7mm AM. The 175 gr SMK is a great choice if you want better long range ballistics. Its true BC is more like 0.680 which compared very well with the Berger and it can be driven to well over 3500 fps in the 7mm AM depending on barrel length compared to the 180 gr Berger that is limited to around 3300 fps because its jacket will not handle much more then that.

6. A 7mm RUM or 7mm AM is designed for one thing, long range, dedicated medium game hunting, nothing more, nothing less. USe it for that purpose and take care of the barrels and it will last longer then most of our hunting careers.

I get a kick out of these guys putting numbers on barrel life and saying your barrel will be a paper weight after 450 to 600 rounds down the barrel..... Let me tell you about my current 7mm AM rifle, "Lil Green". Simple rifle, Rem 700 receiver, Lilja 1-9, 6 groove barrel, HS sporter stock, HS DM system, NF 20 moa rail base, Leupold Mk4 FFP 3.5-10x 40mm.

I built this rifle 6 years ago, used it for three seasons, figured it was ready to have a new barrel installed but decided to take it out and range test it before doing that on the summer between its 2nd and 3rd season. I had put just over 300 rounds down this barrel in load development and ballistic testing as well as hunting. Took her out and She put first shot within 1/2 moa of point of aim from 300 to 900 yards so I left it as it was. I was shooting the 200 gr ULD at 3250 fps at that time.

Took several big game critters that season at ranges from 450 to 800 yards.

Between season 3 and 4 I noticed that the 200 gr ULD RBBT was not shooting as well as I wanted it to, around 1.5 moa accuracy at longer ranges. I then switched to the 160 gr Accubond loaded to 3500 fps. Accuracy was easily within 1 moa out to 900 yards although the wind drift was noticably more which limited the conditions I allowed myself to shoot in. Still, that season I took another three big game animals from 500 to 750 yards with great one shot kill performance.

Between season 4 and 5 I repeated the range test and again, the rifle performed well enough to leave the old barrel on. Took three more big game animals at ranges from 400 to 850 yards.

Between seasons 5 and this season, I decided to try the relatively new 175 gr SMK and developed loads for that bullet which averaged 3450 fps as well. The ballistic performance came back. This bullet has a much lower BC then the 200 gr ULD but had a dramatic velocity advantage as well so out to 1/2 mile they were basically identical. Starting the 2009 big game season, this barrel, the original barrel, never set back or anything, had 645 rounds down the barrel and would still hold first shot impacts within 1/2 moa of point of aim if I read the wind conditions correctly.

This season I took a 16" pronghorn at 785 yards and a 5x5 mule deer at just under 700 yards and felt totally confident using this old, "worn out" barrel.

What most of you will not believe, I have only fireformed one box of Lapua brass for this rifle since the first day I started barrel break in for this rifle.

I have switched bullets three times. Had I started with the 175 gr SMK I would have never changed bullets once. I have never chased the lands although the lands are certainly eroded to some degree but not enough to eliminate consistant accuracy for big game hunting.

Let me also say I use 338 magnums ALOT. I Have burned out as many 338 barrels as 7mm barrels and certainly, a 338 magnum in the same capacity class will offer a longer barrel life. Will the 338 magnum be more consistant, that has been hard to prove to me. If you measure consistancy by single digit extreme spreads in velocity, then yes, the 338 has an edge. IF you base consistancy on never shifting more then 20 fps in velocity over 60 degrees of temp change or 5000 ft elevation change then yes the 338s have an edge in consistancy.

BUT, if you mean being able to put the bullet into and through the vitals of a big game animal at any range the shooter and rifle are capable of and the shooters knows his rifle as he should, I would like to see someone prove the 338s are more consistant for killing medium big game.

Ballistically, the 338s are good for sure but to be honest, they are flat out spanked by the big 7mms as far as bullet drop but more importantly wind drift.

Now if you want to hunt game in the 500 to 1000 lb range, DO NOT go with any 7mm as your go to gun, get a 30 caliber and if you want to do this at 1000 yards or beyond, get a 338.

There is no way to fairly compare a big fast 7mm to a big 338, two different beasts that are to different to compare head to head. I use them both, I love them both, in their specific uses, each are far superior to the other and its our job to educate outself and realize what those design purposes are.

Not looking to start any fights, I respect most of the posters on here tremendously, especially the ones that have been around a long time and I know well, you know who you are, just offering my solid experience in the field of 7mm barrel life.

Nuff said by me.

 

[Kiwi Nate]

Yes, thats defininitely my problem here, high volume shooting. I need both flat shooting and high volume so I won't go much bigger than the 7mm Rem mag or .300 Win mag next time around.

I am on a contract to shoot a minimum 20 goats for dog food per week, let alone the client usage and my personal hunts. I try to use the .308 where possible on the goats but as the shots get long, out comes the big gun. I have taken over 180 goats with the 175gr SMK since last November and over 100 head with the 180 grain VLD (I used the accubond and SST bullets a lot in my previous RUM barrel). On top of this is the fact that I simply enjoy long range shooting and as previously stated, need to keep on top of my game for clients- which means pleanty of practice and not practice with a secondary rifle/cartridge.

During one hunt that lasted two days a few weeks back, protecting crops, I used the .308 while a couple of guys backed me up with a 7RM and .300Win, we took 140 goats out of there over two evenings. I could barely touch the barrel of the .308, the other guys took the longer shots past 350 yards. I could have used the .308 past 350 but its a lot of mucking around trying to dial up on constantly moving game. Like I said, I try to use the .308 as much as possible.

The other problem is the lack of available ball powders here in NZ. RidgeRunner also mentioned that he was using ball powders and still engaging the lands with the same COAL at 400 shots. Pity these powders aren't so freely available here.

It would be good to have a sticky post on the subject of prolonging barrel life with the Ultra velocity magnums, drawing from 50drivers experience. Kirby, I noticed that you have put over 2500 posts on this forum so I can imagine it gets tiresome going over the same points.

 

[Iron Worker]

Life isn't fair . I'm gonna go to my iron worker job site and your gonna shoot goats for dog food. What a life !

 

[Forrest Ebert]

You could get the 180 VLD to what you want but you will loose a lot more in cases and barrel life ! I have a load in my RUM with a 189grn. Cauterucio VLD that I chronoed at 3150 and gave excellent accuracy but I wouldn't want to shoot it except for hunting purposes as it will wear everything out quickly and I have found that 88.5 grains of Retumbo with a 168 Berger VLD is a Real killer both in accuracy and on animals ! The 7mm,300 & 375 Ultra mag. cases are all the same with the .338 being the different one of the bunch !

 

[RockyMtnMT]

You could get the 180 VLD to what you want but you will loose a lot more in cases and barrel life ! I have a load in my RUM with a 189grn. Cauterucio VLD that I chronoed at 3150 and gave excellent accuracy but I wouldn't want to shoot it except for hunting purposes as it will wear everything out quickly and I have found that 88.5 grains of Retumbo with a 168 Berger VLD is a Real killer both in accuracy and on animals ! The 7mm,300 & 375 Ultra mag. cases are all the same with the .338 being the different one of the bunch !

Just curious, how many shots per year do you take hunting? I know that if I shot a rifle (any cal) just for hunting it would last for generations. I hear this barrel life thing a lot in respect to hunting rifles. Even the worst of the barrel burners would last 8 to 10 years if fired 100 times per year. Hear in MT I shoot about 6 animals per year. I realize there are some professional hunters that shoot hundreds of animals per year, but I don't think this is representative of the average hunter.

My opinion is get the hot rod cal of your choosing run it up hot and use it for what it was designed for. If you want to shoot 7 mag velocities out of a 7 RUM because you are afraid to burn up the barrel, then you should have a 7 mag.

Steve

PS. I am not aiming at Forrest here just commenting in general.

 

[Forrest Ebert]

Steve ,
I understand what you are saying and in fact agree with you but there are a lot of guy's that only can afford a gun or two and if you only have that type of gun you wouldn't be shooting it all the time and then you have to take into consideration practicing you end up with short barrel life. That is my point as I'm fortunate enough to be able to shoot from .223 -. 416 so I don't have to worry about burning a barrel out just have the problem of keeping powder & primers on hand to load with not mentioning bullets that appear and disappear !

 

[AZShooter]

I don't see how someone who has one of those magnum mashum flat type rifles cannot verify that the load shoots at long range and then switch to another rifle for the practice. If one was fanatical you could make an identical rig in a package with less recoil and longer barrel life to get the hands on experience.

 

[RockyMtnMT]

I'm sure there are a lot of guys that buy overbore mags not knowing that a barrel can be burnt out. It wasn't too many years ago that I had no idea that a rifle could be worn out. Never thought about it. I also only shot a 30-06 and bought two boxes of shells per year. Never shot past 300 yrds. I also thought there was no need for anything bigger than a 30-06. In that world, I was correct.

You guys are right on. There is no reason to burn up a big overbore rifle. JMHO. I am sure I couldn't be more wrong in some eyes.

Steve

 

[Kiwi Nate]

I don't see how someone who has one of those magnum mashum flat type rifles cannot verify that the load shoots at long range and then switch to another rifle for the practice. If one was fanatical you could make an identical rig in a package with less recoil and longer barrel life to get the hands on experience.

Its a valid point but I would rather practice/cull at long range using the rifle that was built for long range. When I step down to a smaller powered 7mm, I will still have to accept the fact that the barrel won't last as long as it could- the way I use it.

In hind sight, the .30-06 would have been a better choice rather than the .308 as my primary culling rifle. The little .308 suffers too much drift beyond 400 yards in our valleys, the short barrel limiting its performance with long, high BC bullets.